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Sample records for palladium coated iron

  1. Porous palladium coated conducting polymer nanoparticles for ultrasensitive hydrogen sensors

    Science.gov (United States)

    Lee, Jun Seop; Kim, Sung Gun; Cho, Sunghun; Jang, Jyongsik

    2015-12-01

    Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm) and stability toward hydrogen gas at room temperature due to the palladium sensing layer.Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm

  2. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers

    OpenAIRE

    Lushi Kong; Guanchun Rui; Guangyu Wang; Rundong Huang; Ran Li; Jiajie Yu; Shengli Qi; Dezhen Wu

    2017-01-01

    A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI) nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for u...

  3. Palladium coated fibre Bragg grating based hydrogen sensor

    International Nuclear Information System (INIS)

    Kasinathan, M.; Sosamma, S.; Kishore, S.; Elumalai, V.; Krishnan, R.; Babu Rao, C.; Dash, Sitaram; Murali, N.; Jayakumar, T.

    2011-01-01

    Detection of steam generator leaks in fast nuclear reactors is carried out by monitoring hydrogen in argon cover-gas. Hydrogen released during sodium cleaning of fast reactor components is required to be monitored. Hydrogen sensors with good sensitivity, stability and response time are required for all the above applications. We report a new type of hydrogen sensor with a Fibre Bragg Grating (FBG) coated with palladium thin film which is used to detect the leak of hydrogen gas in the Steam Generator (SG) module of the Fast Breeder Reactor (FBR). If water leaks into sodium, it results in sodium-water reaction. In this reaction hydrogen and sodium hydroxide are formed. Due to the explosive risk of hydrogen system, hydrogen sensors are of great interest in this case. It is known that hydrogen forms an explosive mixture with air once its concentration exceeds beyond the explosion limit of four percent. The advantages of FBG based hydrogen sensor over the other hydrogen sensors are its inherent property of safety from sparking, immunity to ambient electromagnetic interference. The sensing mechanism in this device is based on mechanical strain that is induced in the palladium coating when it absorbs hydrogen. This process physically stretches the grating and causes the grating period and grating's refractive index, to change. The Bragg wavelength shift is directly proportional to the strain induced and can be directly related to the percentage of hydrogen exposure. The online monitoring of palladium thin film coating on FBG is carried out and recorded the wavelength change and strain induced on the FBG. A hydrogen sensor set up have been fabricated which consists of SS vessel of capacity 10 litres, provided with pressure gauge, Argon filling line with a valve, Hydrogen injection line with flange, a vent line with valve and Hydrogen sensor fixing point. The Palladium coated FBG based Hydrogen sensor is tested in this experimental facility in the exposure of hydrogen in

  4. Superparamagnetic bimetallic iron-palladium nanoalloy: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Nazir, Rabia; Mazhar, Muhammad [Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Akhtar, M Javed; Nadeem, M; Siddique, Muhammad [Physics Division, PINSTECH, PO Nilore, Islamabad 44000 (Pakistan); Shah, M Raza [HEJ Research Institute of Chemistry, University of Karachi, Karachi 75270 (Pakistan); Khan, Nawazish A [Material Science Laboratory, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Mehmood, Mazhar [National Centre for Nanotechnology, PIEAS, Islamabad 45650 (Pakistan); Butt, N M [Pakistan Science Foundation, Islamabad 44000 (Pakistan)], E-mail: mazhar42pk@yahoo.com

    2008-05-07

    Iron-palladium nanoalloy in the particle size range of 15-30 nm is synthesized by the relatively low temperature thermal decomposition of coprecipitated [Fe(Bipy){sub 3}]Cl{sub 2} and [Pd(Bipy){sub 3}]Cl{sub 2} in an inert ambient of dry argon gas. The silvery black Fe-Pd alloy nanoparticles are air-stable and have been characterized by EDX-RF, XRD, AFM, TEM, magnetometry, {sup 57}Fe Moessbauer and impedance spectroscopy. This Fe-Pd nanoalloy is in single phase and contains iron sites having up to 11 nearest-neighboring atoms. It is superparamagnetic in nature with high magnetic susceptibility, low coercivity and hyperfine field.

  5. Behavior of palladium and its impact on intermetallic growth in palladium-coated Cu wire bonding

    International Nuclear Information System (INIS)

    Xu Hui; Qin, Ivy; Clauberg, Horst; Chylak, Bob; Acoff, Viola L.

    2013-01-01

    This paper describes the behavior of palladium in palladium-coated Cu (PdCu) wire bonding and its impact on bond reliability by utilizing transmission electron microscopy (TEM). A Pd layer approximately 80 nm thick, which is coated on the surface of Cu wire, dissolves into the Cu matrix during ball formation (under N 2 gas protection) when the wire tip is melted to form a ball. As a result of dissolving the very thin Pd layer into the ball, Pd is almost undetectable along the entire bond interface between the ball and the Al pad. The behavior of Pd during thermal aging in air, however, is different for central and peripheral interfaces. At the central interface, less than 5 at.% Pd is present after 168 h aging at 175 °C. At the periphery, however, Pd diffuses back and congregates, reaching a level of ∼12 at.% after 24 h, and a Pd-rich (Cu,Pd) 9 Al 4 layer (>40 at.% Pd) forms after 168 h. Pd acts substitutionally in Cu 9 Al 4 but cannot penetrate into the CuAl 2 or CuAl. By comparison of intermetallic thickness and interfacial morphology between PdCu and bare Cu wire bonds, it is concluded that the presence of Pd reduces intermetallic growth rate, and is associated with numerous nanovoids in PdCu bonds.

  6. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers.

    Science.gov (United States)

    Kong, Lushi; Rui, Guanchun; Wang, Guangyu; Huang, Rundong; Li, Ran; Yu, Jiajie; Qi, Shengli; Wu, Dezhen

    2017-11-02

    A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI) nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for use as highly efficient catalysts. The approach developed here is applicable for coating various noble metals on a wide range of polymer matrices, and can be used for obtaining polyimide nanotubes with metal loaded on both the inner and outer surface.

  7. Preparation of Palladium/Silver-Coated Polyimide Nanotubes: Flexible, Electrically Conductive Fibers

    Directory of Open Access Journals (Sweden)

    Lushi Kong

    2017-11-01

    Full Text Available A simple and practical method for coating palladium/silver nanoparticles on polyimide (PI nanotubes is developed. The key steps involved in the process are silver ion exchange/reduction and displacement reactions between silver and palladium ions. With the addition of silver, the conductivity of the PI nanotubes is greatly enhanced. Further, the polyimide nanotubes with a dense, homogeneous coating of palladium nanoparticles remain flexible after heat treatment and show the possibility for use as highly efficient catalysts. The approach developed here is applicable for coating various noble metals on a wide range of polymer matrices, and can be used for obtaining polyimide nanotubes with metal loaded on both the inner and outer surface.

  8. Novel Base Metal-Palladium Catalytic Diesel Filter Coating with NO2 Reducing Properties

    DEFF Research Database (Denmark)

    Johansen, K.; Dahl, S.; Mogensen, G.

    2007-01-01

    A novel alternative base metal/palladium coat has been developed that has limited NO2 formation and which even removes NO2 in a wide temperature range.Soot combustion, HC conversion and CO conversion properties are comparable to current platinum based solutions but the coating has a more attracti...... solutions. Furthermore, durability results from base metal/Pd coated DPFs installed on operating taxis and related tests cycle data is given....

  9. Study of electroplated silver-palladium biofouling inhibiting coating

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Schroll, Casper

    2008-01-01

    Biofouling can cause many undesirable effects in industrial and medical settings. In this study, a new biofouling inhibiting Ag-Pd surface was designed to form an inhibiting effect by itself. This design was based on silver combined with nobler palladium, both with catalytic properties. Owing to ...

  10. Electrochemical permeation tests on the kinetics of the hydrogen absorption of palladium and iron

    International Nuclear Information System (INIS)

    Dafft, E.G.

    1977-01-01

    Electrochemical permeation tests were performed to investigate the kinetics of the hydrogen development and hydrogen absorption. The cathode side of the samples was galvanostatically cathodically polarized in different electrolyte solutions with and without additions. THe hydrogen atoms diffusing out of the opposite side for iron and α-palladium were oxidized with potentiostatic, sufficiently anodic polarization. The thus registered stationary current is proportional to the hydrogen activity on the cathode side. Test apparatus and conditions are described. The measurements on iron are discussed. (orig./HPOE) [de

  11. Oxygen kinetics and mechanism at electrocatalysts on the base of palladium-iron system

    International Nuclear Information System (INIS)

    Tarasevich, M.R.; Zhutaeva, G.V.; Bogdanovskaya, V.A.; Radina, M.V.; Ehrenburg, M.R.; Chalykh, A.E.

    2007-01-01

    Binary nanodispersed carbon XC72 supported PdFe catalysts with different atomic palladium-to-iron ratios are synthesized and studied in oxygen reduction reaction in acid solution at 60 o C. The Pd:Fe ratio was well controlled by the initial concentrations of Pd and Fe in the precursor solutions. The nanoparticles were characterized by transmission electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The optimum Pd:Fe ratio for this reaction was determined to be 3:1. The comparison of activities of the catalysts with component ratios equaled 3:1 and 10:1 is shown that the activities are differed from each other by 10-15 times in advantage of catalyst with lesser content of palladium. This phenomenon can be related to the different particle size of both catalysts and different distribution of particles by size discovered by TEM method. The achievement of maximum activity near the ratio of Pd:Fe = 3:1 is due to as effect of alloy-forming and the influence of binary system component ratio and synthesis conditions on dispersity degree of metallic phase nanoparticles. Under optimal conditions of precursor mixture high-temperature pyrolysis, iron produces the stabilizing effect palladium. It gives rise to obtaining the uniform and finely divided (7-8 nm) metallic particles

  12. Site preference of rare earth doping in palladium-iron-arsenide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Stuerzer, Christine; Schulz, Anne; Johrendt, Dirk [Department Chemie, Ludwig-Maximilians-Universitaet Muenchen (Germany)

    2014-12-15

    The solid solutions (Ca{sub 1-y}RE{sub y}Fe{sub 1-x}Pd{sub x}As){sub 10}Pd{sub z}As{sub 8} with RE = La, Ce, and Pr were synthesized by solid state methods and characterized by X-ray powder diffraction with subsequent Rietveld refinements [(CaFeAs){sub 10}Pt{sub 3}As{sub 8}-type structure (''1038 type''), P anti 1, Z = 1]. Substitution levels (Ca/RE, Fe/Pd, and Pd/□) obtained from Rietveld refinements coincide well with the nominal values according to EDS and the linear courses of the lattice parameters as expected from the ionic radii. The RE atoms favor the one out of five calcium sites, which is eightfold coordinated by arsenic. This leads to significant stabilization of the structure, and especially prevents palladium over-doping in the iron-arsenide layers as observed in the pristine compound (CaFe{sub 1-x}Pd{sub x}As){sub 10}Pd{sub z}As{sub 8}. While the stabilization energy is estimated to about 40 kJ.mol{sup -1} by electronic structure calculations, the reason for the diminished Fe/Pd substitution through RE doping is still not yet understood. We suggest that the electrons transferred from RE{sup 3+} to the (Fe{sub 1-x}Pd{sub x})As layer makes higher palladium concentrations unfavorable. Anyway the reduced palladium doping enables superconductivity with critical temperatures up to 20 K (onset) in the RE doped Pd1038 samples, which could not be obtained earlier due to palladium over-doping in the active iron-arsenide layers. (Copyright copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Titanium tritide radioisotope heat source development: palladium-coated titanium hydriding kinetics and tritium loading tests

    International Nuclear Information System (INIS)

    Van Blarigan, Peter; Shugard, Andrew D.; Walters, R. Tom

    2012-01-01

    We have found that a 180 nm palladium coating enables titanium to be loaded with hydrogen isotopes without the typical 400-500 C vacuum activation step. The hydriding kinetics of Pd coated Ti can be described by the Mintz-Bloch adherent film model, where the rate of hydrogen absorption is controlled by diffusion through an adherent metal-hydride layer. Hydriding rate constants of Pd coated and vacuum activated Ti were found to be very similar. In addition, deuterium/tritium loading experiments were done on stacks of Pd coated Ti foil in a representative-size radioisotope heat source vessel. The experiments demonstrated that such a vessel could be loaded completely, at temperatures below 300 C, in less than 10 hours, using existing department-of-energy tritium handling infrastructure.

  14. Morphology of one-time coated palladium-alumina composite membrane prepared by sol-gel process and electroless plating technique

    Science.gov (United States)

    Sari, R.; Dewi, R.; Pardi; Hakim, L.; Diana, S.

    2018-03-01

    Palladium coated porous alumina ceramic membrane tube was obtained using a combination of sol-gel process and electroless plating technique. The thickness, structure and composition of palladium-alumina composite membrane were analyzed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and atomic force microscopy (AFM). Palladium particle size was 6.18 to 7.64 nm. Palladium membrane with thickness of approximately 301.5 to 815.1 nm was formed at the outer surface of the alumina layer. EDX data confirmed the formation of palladium-alumina membrane containing 45% of palladium. From this research it shows the combination of sol-gel process and electroless plating technique with one-time coating can produce a homogeneous and smoother palladium nano layer film on alumina substrate.

  15. A Palladium free method to create a Nickel coated electrode for electrochemical application

    Science.gov (United States)

    Tran, Thien Khanh; Vu, Thanh, Vi; Vo, Minh Xuan

    2018-04-01

    For many generations, the coating of metals provides many applications in the industry: decoration, functional, electroforming. Electroless plating of Nickel with the supports of Palladium/Tin is famous for its properties and effects. In this study, we provide another catalysis solution for the electroless plating process of Nickel. With plastic Polyvinyl Chloride substrate controlled in thickness (2 mm) and scale (200x400 mm), the efficiency of the coating process was carried out under simple lab scale condition. The result of the process is a thin film layer of Nickel coated on the surface of the substrate with exceptional adhesion and strong physical properties also. The product sample then was tested by many methods such as SEM, XRD, EDS, and FTIR to clarify its properties. According to our observation and the result we obtained, we believe there is still more room for improvement to this method, and a further investigation on its application as well can be carried on in the future.

  16. Effects of palladium coatings on oxygen sensors of titanium dioxide thin films

    International Nuclear Information System (INIS)

    Castaneda, L.

    2007-01-01

    Titanium dioxide (TiO 2 -anatase phase) thin films were deposited by the ultrasonic spray pyrolysis technique employing titanium (IV) oxide acetylacetonate (TiO(acac) 2 ) dissolved in pure methanol as a source material. In order to prepare oxygen sensors, TiO 2 thin films were deposited on interdigitated gold electrodes with contacted alumina substrates. Palladium (Pd) coatings were carried out by vacuum thermal evaporation through a metallic mask. The effect of the surface additive (Pd) on the response of the thin film TiO 2 oxygen sensors was monitored in a mixture with zero-grade air. The electrical characterization (monitoring of the electrical surface resistance with the operation temperature) of the sensors in an atmosphere of oxygen (diluted in zero-grade air) was performed in a vacuum chamber (10 -6 Torr), where the gas pressure can be controlled. The films sensitivity was estimated by the following relation: s=R gas -R 0 /R 0 . The response time of the sensor is defined to be the time needed to reach a 0.9R 0 value when the oxygen excess is removed. The gas-sensing properties of TiO 2 sensors in an atmosphere of 10 4 ppm of oxygen were measured between 100 and 450 deg. C. Experimental results obtained using palladium as a surface additive show that the sensitivity reaches a stationary value of 1.18 for O 2 concentration of 100ppm in zero-grade air at 300 deg. C, which is as high as those reported for oxygen sensors prepared with more expensive and complex techniques. The role and activity of palladium coatings incorporated on solid-state oxygen sensors are determined by their chemical state, aggregation form and interaction with the metal-oxide semiconductor

  17. Repair welding of cast iron coated electrodes

    Science.gov (United States)

    Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.

    2017-08-01

    Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.

  18. Direct Iron Coating onto Nd-Fe-B Powder by Thermal Decomposition of Iron Pentacarbonyl

    International Nuclear Information System (INIS)

    Yamamuro, S; Okano, M; Tanaka, T; Sumiyama, K; Nozawa, N; Nishiuchi, T; Hirosawa, S; Ohkubo, T

    2011-01-01

    Iron-coated Nd-Fe-B composite powder was prepared by thermal decomposition of iron pentacarbonyl in an inert organic solvent in the presence of alkylamine. Though this method is based on a modified solution-phase process to synthesize highly size-controlled iron nanoparticles, it is in turn featured by a suppressed formation of iron nanoparticles to achieve an efficient iron coating solely onto the surfaces of rare-earth magnet powder. The Nd-Fe-B magnetic powder was successfully coated by iron shells whose thicknesses were of the order of submicrometer to micrometer, being tuneable by the amount of initially loaded iron pentacarbonyl in a reaction flask. The amount of the coated iron reached to more than 10 wt.% of the initial Nd-Fe-B magnetic powder, which is practically sufficient to fabricate Nd-Fe-B/α-Fe nanocomposite permanent magnets.

  19. Improving Gas Sensing Properties of Tin Oxide Nanowires Palladium-Coated Using a Low Cost Technique

    Directory of Open Access Journals (Sweden)

    M. Barzegar

    2012-12-01

    Full Text Available Thin films of SnO2 nanowires were successfully prepared by using chemical vapor deposition (CVD process on quartz substrates. Afterwards, a thin  layer of palladium (Pd as a catalyst was coated on top of nanowires. For the deposition of Pd, a simple and low cost technique of spray pyrolysis was employed, which caused an intensive enhancement on the sensing response of fabricated sensors. Prepared sensor devices were exposed to liquid petroleum gas (LPG and vapor of ethanol (C2H5OH. Results indicate that SnO2 nanowires sensors coated with Pd as a catalyst show decreasing in response time (~40s to 1000ppm of LPG at a relatively low operating temperature (200o C. SnO2 /Pd nanowire devices show gas sensing response time and recovery time as short as 50s and 10s respectively with a high sensitivity value of ~120 for C2H5OH, that is remarkable in comparison with other reports.

  20. 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.

  1. Characteristics of Iron-Palladium alloy thin films deposited by magnetron sputtering

    Science.gov (United States)

    Chiu, Y.-J.; Shen, C.-Y.; Chang, H.-W.; Jian, S.-R.

    2018-06-01

    The microstructural features, magnetic, nanomechanical properties and wettability behaviors of Iron-Palladium (FePd) alloy thin films are investigated by using X-ray diffraction (XRD), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), nanoindentation and water contact angle (CA) techniques, respectively. The FePd alloy thin films were deposited on glass substrates using a magnetron sputtering system. The post-annealing processes of FePd alloy thin films were carried out at 400 °C and 750 °C and resulted in a significant increase of both the average grain size and surface roughness. The XRD analysis showed that FePd alloy thin films exhibited a predominant (1 1 1) orientation. The magnetic field dependence of magnetization of all FePd thin films are measured at room temperature showed the ferromagnetic characteristics. The nanoindentation with continuous stiffness measurement (CSM) is used to measure the hardness and Young's modulus of present films. The contact angle (θCA) increased with increasing surface roughness. The maximum θCA of 75° was achieved for the FePd alloy thin film after annealing at 750 °C and a surface roughness of 4.2 nm.

  2. Polypyrrole-palladium nanocomposite coating of micrometer-sized polymer particles toward a recyclable catalyst.

    Science.gov (United States)

    Fujii, Syuji; Matsuzawa, Soichiro; Hamasaki, Hiroyuki; Nakamura, Yoshinobu; Bouleghlimat, Azzedine; Buurma, Niklaas J

    2012-02-07

    A range of near-monodisperse, multimicrometer-sized polymer particles has been coated with ultrathin overlayers of polypyrrole-palladium (PPy-Pd) nanocomposite by chemical oxidative polymerization of pyrrole using PdCl(2) as an oxidant in aqueous media. Good control over the targeted PPy-Pd nanocomposite loading is achieved for 5.2 μm diameter polystyrene (PS) particles, and PS particles of up to 84 μm diameter can also be efficiently coated with the PPy-Pd nanocomposite. The seed polymer particles and resulting composite particles were extensively characterized with respect to particle size and size distribution, morphology, surface/bulk chemical compositions, and conductivity. Laser diffraction studies of dilute aqueous suspensions indicate that the polymer particles disperse stably before and after nanocoating with the PPy-Pd nanocomposite. The Fourier transform infrared (FT-IR) spectrum of the PS particles coated with the PPy-Pd nanocomposite overlayer is dominated by the underlying particle, since this is the major component (>96% by mass). Thermogravimetric and elemental analysis indicated that PPy-Pd nanocomposite loadings were below 6 wt %. The conductivity of pressed pellets prepared with the nanocomposite-coated particles increased with a decrease of particle diameter because of higher PPy-Pd nanocomposite loading. "Flattened ball" morphologies were observed by scanning/transmission electron microscopy after extraction of the PS component from the composite particles, which confirmed a PS core and a PPy-Pd nanocomposite shell morphology. X-ray diffraction confirmed the production of elemental Pd and X-ray photoelectron spectroscopy studies indicated the existence of elemental Pd on the surface of the composite particles. Transmission electron microscopy confirmed that nanometer-sized Pd particles were distributed in the shell. Near-monodisperse poly(methyl methacrylate) particles with diameters ranging between 10 and 19 μm have been also successfully

  3. Structural characterization and comparison of iridium, platinum and gold/palladium ultra-thin film coatings for STM of biomolecules

    Energy Technology Data Exchange (ETDEWEB)

    Sebring, R.; Arendt, P.; Imai, B.; Bradbury, E.M.; Gatewood, J. [Los Alamos National Lab., NM (United States); Panitz, J. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy; Yau, P. [Univ. of California, Davis, CA (United States)

    1997-10-30

    Scanning tunneling microscopy (STM) is capable of atomic resolution and is ideally suited for imaging surfaces with uniform work function. A biological sample on a conducting substrate in air does not meet this criteria and requires a conductive coating for stable and reproducible STM imaging. In this paper, the authors describe the STM and transmission electron microscopy (TEM) characterization of ultra-thin ion-beam sputtered films of iridium and cathode sputtered gold/palladium and platinum films on highly ordered pyrolytic graphite (HOPG) which were developed for use as biomolecule coatings. The goals were the development of metal coatings sufficiently thin and fine grained that 15--20 {angstrom} features of biological molecules could be resolved using STM, and the development of a substrate/coating system which would allow complementary TEM information to be obtained for films and biological molecules. The authors demonstrate in this paper that ion-beam sputtered iridium on highly ordered pyrolytic graphite (HOPG) has met both these goals. The ion-beam sputtered iridium produced a very fine grained (< 10 {angstrom}) continuous film at 5--6 {angstrom} thickness suitable for stable air STM imaging. In comparison, cathode sputtered platinum produced 16 {angstrom} grains with the thinnest continuous film at 15 {angstrom} thickness, and the sputtered gold/palladium produced 25 {angstrom} grains with the thinnest continuous film at 18 {angstrom} thickness.

  4. A study of DLC coatings for ironing of stainless steel

    DEFF Research Database (Denmark)

    Sulaiman, Mohd Hafis Bin; Christiansen, Peter; Bay, Niels Oluf

    2017-01-01

    severe lubrication conditions by adopting strip reduction testing to replicate industrial ironing production of deep drawn, stainless steel cans. Three DLC coatings are investigated; multi-layer, double layer and single layer. Experiments revealed that the double layer coating worked successful, i...

  5. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Energy Technology Data Exchange (ETDEWEB)

    Asit Biswas Andrew J. Sherman

    2006-09-25

    This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.

  6. Surface oxidation phenomena of boride coatings grown on iron

    International Nuclear Information System (INIS)

    Carbucicchio, M.; Palombarini, G.; Sambogna, G.

    1992-01-01

    Very hard boride coatings are grown on various metals using thermochemical as well as chemical vapour deposition techniques. In this way many surface properties, and in particular the wear resistance, can be considerably improved. Usually, also the corrosion behaviour of the treated components is important. In particular, oxidizing atmospheres are involved in many applications where, therefore, coating-environment interactions can play a relevant role. In a previous work, the early stages of the oxidation of iron borides were studied by treating single phase compacted powders in flowing oxygen at low temperatures (300-450deg C). In the present paper, the attention is addressed to the oxidation of both single phase and polyphase boride coatings thermochemically grown on iron. The single phase boride coatings were constituted by Fe 2 B, while the polyphase coatings were constituted by an inner Fe 2 B layer and an outer FeB-base layer. All the boride layers displayed strong (002) preferred crystallographic orientations. (orig.)

  7. Enhancement of Degradation and Dechlorination of Trichloroethylene via Supporting Palladium/Iron Bimetallic Nanoparticles onto Mesoporous Silica

    Directory of Open Access Journals (Sweden)

    Jianjun Wei

    2016-07-01

    Full Text Available This study is aimed to prevent the agglomeration of Pd/Fe bimetallic nanoparticles and thus improve the efficiency toward degradation and dechlorination of chlorinated organic contaminants. A mesoporous silica with a primary pore diameter of 8.3 nm and a specific surface area of 688 m2/g was prepared and used as the host of Pd/Fe nanoparticles. The Pd/Fe nanoparticles were deposited onto or into the mesoporous silica by reduction of ferrous ion and hexachloropalladate ion in aqueous phase. Batch degradation and dechlorination reactions of trichloroethylene were conducted with initial trichloroethylene concentration of 23.7 mg/L, iron loading of 203 or 1.91 × 103 mg/L and silica loading of 8.10 g/L at 25 °C. Concentration of trichloroethylene occurs on the supported Pd/Fe nanoparticles, with trichloroethylene degrading to 56% and 59% in 30 min on the supported Pd/Fe nanoparticles with weight percentage of palladium to iron at 0.075% and 0.10% respectively. The supported Pd/Fe nanoparticles exhibit better dechlorination activity. When the supported Pd/Fe nanoparticles with a weight percentage of palladium to iron of 0.10% were loaded much less than the bare counterpart, the yield of ethylene plus ethane in 10 h on them was comparable, i.e., 19% vs. 21%. This study offers a future approach to efficiently combine the reactivity of supported Pd/Fe nanoparticles and the adsorption ability of mesoporous silica.

  8. Preparation and chemical stability of iron-nitride-coated iron microparticles

    International Nuclear Information System (INIS)

    Luo Xin; Liu Shixiong

    2007-01-01

    Iron-nitride-coated iron microparticles were prepared by nitridation of the surface of iron microparticles with ammonia gas at a temperature of 510 deg. C. The phases, composition, morphology, magnetic properties, and chemical stability of the particles were studied. The phases were α-Fe, ε-Fe 3 N, and γ-Fe 4 N. The composition varied from the core to the surface, with 99.8 wt% Fe in the core, and 93.8 wt% Fe and 6 wt% N in the iron-nitride coating. The thickness of the iron-nitride coating was about 0.28 μm. The chemical stability of the microparticles was greatly improved, especially the corrosion resistance in corrosive aqueous media. The saturation magnetization and the coercive force were 17.1x10 3 and 68 kA/m, respectively. It can be concluded that iron-nitride-coated iron microparticles will be very useful in many fields, such as water-based magnetorheological fluids and polishing fluids

  9. Low-cost method for fabricating palladium and palladium-alloy thin films on porous supports

    Science.gov (United States)

    Lee, Tae H; Park, Chan Young; Lu, Yunxiang; Dorris, Stephen E; Balachandran, Uthamalingham

    2013-11-19

    A process for forming a palladium or palladium alloy membrane on a ceramic surface by forming a pre-colloid mixture comprising a powder palladium source, carrier fluid, dispersant and a pore former and a binder. Ultrasonically agitating the precolloid mixture and applying to a substrate with an ultrasonic nozzle and heat curing the coating form a palladium-based membrane.

  10. Method of coating an iron-based article

    Science.gov (United States)

    Magdefrau, Neal; Beals, James T.; Sun, Ellen Y.; Yamanis, Jean

    2016-11-29

    A method of coating an iron-based article includes a first heating step of heating a substrate that includes an iron-based material in the presence of an aluminum source material and halide diffusion activator. The heating is conducted in a substantially non-oxidizing environment, to cause the formation of an aluminum-rich layer in the iron-based material. In a second heating step, the substrate that has the aluminum-rich layer is heated in an oxidizing environment to oxidize the aluminum in the aluminum-rich layer.

  11. Model of the Alphinising Coating Crystallisation on Iron Alloys

    Directory of Open Access Journals (Sweden)

    S. Pietrowski

    2007-07-01

    Full Text Available The study presents a hypothetical model of crystallisation of the alphinising coating produced on iron alloys by immersion in the bath of silumin. Basing on a wide-range of experiments and investigations, the effect of the type of inserted material (“armco” iron, C45 steel, grey cast iron and nodular graphite cast iron and of the technological regime of the alphinising process (chemical composition of silumin bath, its temperature, the time of holding an insert in the bath, and the insert surface roughness height “Rz” on the coating structure was determined. The type of the coating structure was established by metallographic examinations carried out by optical microscopy, electron transmission microsopy and scanning electron microscopy, using additionally an X-ray microanalyser and X-ray diffraction patterns. The results of these investigations were described in [1÷7]. Basing on the obtained results, a probable model of the crystallisation of an alphi-nising coating on iron alloys, produced by immersion in the alphinising bath, was developed. It has been stated that, most probably, the alphinising process begins when the insert reaches its contact temperature “ts”.. Since that moment, due to the wetting process and convec-tion movement of bath around the insert surface, an intense process of the dissolution starts. A reactive diffusion of the atoms of Fe and Si from the insert to the bath and of the atoms of Al and Si from the bath to the insert takes place. An intermetallic Al3Fe phase is crystallis-ing on the steel, while on the cast iron, a silicon carbide Fe4CSi is growing, probably due to carbon diffusion from graphite. Then, on the steel, as an effect of the peritectic reaction, are successively crystallising the phases of Al12Fe3Si2 and Al9Fe3Si2. The Al3Fe phase probably crystallises on the cast iron to be transformed later, due to peritectic reaction, into an Al12Fe3Si2 phase on which the Al9Fe3Si2 phase will be growing

  12. A study of DLC coatings for ironing of stainless steel

    Science.gov (United States)

    Sulaiman, M. H.; Christiansen, P.; Bay, N.

    2017-09-01

    Stamping of sheet metal components without lubrication or using minimum amount of hazard free lubricant is a possible solution to diminish health hazards to personnel and environmental impact and to reduce production costs. This paper studies the application of diamond-like coating (DLC) under severe lubrication conditions by adopting strip reduction testing to replicate industrial ironing production of deep drawn, stainless steel cans. Three DLC coatings are investigated; multi-layer, double layer and single layer. Experiments revealed that the double layer coating worked successful, i.e. with no sign of galling using no lubrication even at elevated tool temperature, while the other two coatings peeled off and resulted in severe galling unless lubrication was applied.

  13. Manganese and Iron Catalysts in Alkyd Paints and Coatings

    Directory of Open Access Journals (Sweden)

    Ronald Hage

    2016-04-01

    Full Text Available Many paint, ink and coating formulations contain alkyd-based resins which cure via autoxidation mechanisms. Whilst cobalt-soaps have been used for many decades, there is a continuing and accelerating desire by paint companies to develop alternatives for the cobalt soaps, due to likely classification as carcinogens under the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals legislation. Alternative driers, for example manganese and iron soaps, have been applied for this purpose. However, relatively poor curing capabilities make it necessary to increase the level of metal salts to such a level that often coloring of the paint formulation occurs. More recent developments include the application of manganese and iron complexes with a variety of organic ligands. This review will discuss the chemistry of alkyd resin curing, the applications and reactions of cobalt-soaps as curing agents, and, subsequently, the paint drying aspects and mechanisms of (model alkyd curing using manganese and iron catalysts.

  14. Iron binary and ternary coatings with molybdenum and tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Yar-Mukhamedova, Gulmira, E-mail: gulmira-alma-ata@mail.ru [Institute Experimental and Theoretical Physics Al-Farabi Kazakh National University, 050038, Al-Farabi av., 71, Almaty (Kazakhstan); Ved, Maryna; Sakhnenko, Nikolay; Karakurkchi, Anna; Yermolenko, Iryna [National Technical University “Kharkov Polytechnic Institute”, Kharkov (Ukraine)

    2016-10-15

    Highlights: • High quality coatings of double Fe-Mo and ternary Fe-Mo-W electrolytic alloys can be produced both in a dc and a pulsed mode. • Application of unipolar pulsed current allows receiving an increased content of the alloying components and their more uniform distribution over the surface. • It is established that Fe-Mo and Fe-Mo-W coatings have an amorphous structure and exhibit improved corrosion resistance and microhardness as compared with the steel substrate due to the inclusion molybdenum and tungsten. - Abstract: Electrodeposition of Fe-Mo-W and Fe-Mo layers from a citrate solution containing iron(III) on steel and iron substrates is compared. The utilization of iron(III) compounds significantly improved the electrolyte stability eliminating side anodic redox reactions. The influence of concentration ratios and electrodeposition mode on quality, chemical composition, and functional properties of the alloys is determined. It has been found that alloys deposited in pulse mode have more uniform surface morphology and chemical composition and contain less impurities. Improvement in physical and mechanical properties as well as corrosion resistance of Fe-Mo and Fe-Mo-W deposits when compared with main alloy forming metals is driven by alloying components chemical passivity as well as by alloys amorphous structure. Indicated deposits can be considered promising materials in surface hardening technologies and repair of worn out items.

  15. The role of palladium in iron based Fischer-Tropsch catalysts prepared by flame spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minnermann, M.; Zielasek, V.; Baeumer, M. [Bremen Univ. (DE). Inst. of Applied and Physical Chemistry (IAPC); Pokhrei, S.; Maedler, L. [Bremen Univ. (DE). Foundation Inst. of Materials Science (IWT); Thiel, K. [Fraunhofer Institute for Manufactoring Technology and Applied Materials Research, Bremen (Germany)

    2011-07-01

    Flame spray pyrolysis (FSP) is a novel technique for the fabrication of nanostructured catalysts with far-reaching options to control structure and composition even in cases where complex composites need to be prepared. In this study, we took advantage of this technique to synthesize highly dispersed pure and Pd-doped iron oxide nanoparticles and investigated them as Fischer-Tropsch (FT) catalysts. By systematically varying the Pd content over a large range from 0.1 wt % to 10 wt %, we were able to directly analyze the influence of the Pd content on activity and selectivity. In addition to catalytic measurements, the structure and composition of the particles were characterized before and after these measurements, using transmission electron microscopy, adsorption measurements, X-ray diffraction and EXAFS. The comparison revealed, on the one hand, that small Pd clusters (diameter: 1-2 nm) evolve from initially homogeneously distributed Pd and, on the other hand, that the iron oxide transforms into iron carbides depending on the Pd content. The presence of Pd influences the particle size in the pristine samples (8 - 11 nm), resulting in specific surface areas that increase as the Pd content increases. However, after activation and reaction the specific surface areas become similar due to partial agglomeration and sintering. In a fixed bed FT reaction test, enhanced FT activity was observed with increasing Pd content while the selectivity shifts to longer chain hydrocarbons, mainly paraffins. (orig.)

  16. Preparation and microwave shielding property of silver-coated carbonyl iron powder

    International Nuclear Information System (INIS)

    Cao, Xiao Guo; Ren, Hao; Zhang, Hai Yan

    2015-01-01

    Highlights: • The silver-coated carbonyl iron powder is prepared by the electroless plating process. • The silver-coated carbonyl iron powder is a new kind of conductive filler. • The reflection and absorption dominate the shielding mechanism of the prepared powder. • Increasing the thickness of electroconductive adhesive will increase the SE. - Abstract: Electroless silver coating of carbonyl iron powder is demonstrated in the present investigation. The carbonyl iron powders are characterized by scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD) before and after the coating process. The relatively uniform and continuous silver coating is obtained under the given coating conditions. In this paper, the electromagnetic interference (EMI) shielding mechanism of the silver-coated carbonyl iron powder is suggested. The reflection of silver coating and absorption of carbonyl iron powder dominate the shielding mechanism of the silver-coated carbonyl iron powder. The silver-coated carbonyl iron powders are used as conductive filler in electroconductive adhesive for electromagnetic interference shielding applications. The effect of the thickness of electroconductive adhesive on the shielding effectiveness (SE) is investigated. The results indicate that the SE increases obviously with the increase of the thickness of electroconductive adhesive. The SE of the electroconductive adhesive with 0.35 mm thickness is above 38 dB across the tested frequency range

  17. Adsorption of Radioactive Chromium onto Iron Oxide Coated Sand

    International Nuclear Information System (INIS)

    Tadros, N.

    2008-01-01

    Iron oxide coated sand (IOCS) has been prepared and used as granular sorbent for 51 Cr radionuclide at different and specified concentration Ievels in aqueous solutions of constant ph value. Effect of different parameters such as: ph variation, contact time, 51 Cr ion concentration and variation of temperature on the adsorption of the radionuclide onto IOCS material have been discussed. At high ph value about 9()% of 51 Cr is adsorbed onto IOCS from the aqueous solution, The sorption capability of 51 Cr and the effect of ion concentration on the adsorbitivity have been discussed. Adsorption isotherms of Langmuir and Freundlich were expressed and their adsorption isotherm parameters are tabulated

  18. Hydrogen permeation through sol-gel-coated iron during galvanostatic charging

    International Nuclear Information System (INIS)

    Zakorchemna, I.; Carmona, N.; Zakroczymski, T.

    2008-01-01

    One-layer sol-gel silica-zirconia and two-layer silica-zirconia and zirconia coatings were deposited on one side of iron membranes by spin-coating, densified in air and annealed up to 800 deg. C in vacuum. Hydrogen permeation through the membranes, coated and uncoated, polarised cathodically under galvanostatic control in 0.1 M NaOH solution was studied using the electrochemical permeation technique. During the initial period, the effect of the sol-gel coatings was insignificant. However, the coatings quite efficiently prevented the iron surface become more active to hydrogen entry during a long-lasting cathodic polarisation. In addition, the electrochemical-corrosion behaviour of the coated iron and the effect of the sol-gel coatings on the effective diffusivity of hydrogen in the coated membranes were studied. On the basis of the polarisation curves and the hydrogen permeation data it was proved that the sol-gel coatings blocked the iron surface for the hydrogen evolution reaction and, consequently, for the hydrogen entry into iron. The effective coating coverage was determined by comparison of the hydrogen fluxes permeating the coated and uncoated membranes. Finally the real concentration of hydrogen beneath the uncoated iron sites and the amount of hydrogen stored in a membrane were evaluated

  19. Gentamicin coated iron oxide nanoparticles as novel antibacterial agents

    Science.gov (United States)

    Bhattacharya, Proma; Neogi, Sudarsan

    2017-09-01

    Applications of different types of magnetic nanoparticles for biomedical purposes started a long time back. The concept of surface functionalization of the iron oxide nanoparticles with antibiotics is a novel technique which paves the path for further application of these nanoparticles by virtue of their property of superparamagnetism. In this paper, we have synthesized novel iron oxide nanoparticles surface functionalized with Gentamicin. The average size of the particles, concluded from the HR-TEM images, came to be around 14 nm and 10 nm for unmodified and modified nanoparticles, respectively. The magnetization curve M(H) obtained for these nanoparticles are typical of superparamagnetic nature and having almost zero values of coercivity and remanance. The release properties of the drug coated nanoparticles were studied; obtaining an S shaped profile, indicating the initial burst effect followed by gradual sustained release. In vitro investigations against various gram positive and gram negative strains viz Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis indicated significant antibacterial efficiency of the drug-nanoparticle conjugate. The MIC values indicated that a small amount like 0.2 mg ml-1 of drug capped particles induce about 98% bacterial death. The novelty of the work lies in the drug capping of the nanoparticles, which retains the superparamagnetic nature of the iron oxide nanoparticles and the medical properties of the drug simultaneously, which is found to extremely blood compatible.

  20. Enhanced dechlorination of trichloroethylene using electrospun polymer nanofibrous mats immobilized with iron/palladium bimetallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hui [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Shi, Xiangyang, E-mail: xshi@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); CQM - Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal (Portugal)

    2012-04-15

    Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.

  1. Enhanced dechlorination of trichloroethylene using electrospun polymer nanofibrous mats immobilized with iron/palladium bimetallic nanoparticles

    International Nuclear Information System (INIS)

    Ma, Hui; Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan; Shi, Xiangyang

    2012-01-01

    Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.

  2. Structure and properties of composite iron-based coatings obtained by the electromechanical technique

    Science.gov (United States)

    Dubinskii, N. A.

    2007-09-01

    The influence of the electrolyte temperature and current density on the content of inclusions of powder particles in composite coatings obtained by the electrochemical technique has been investigated. It has been found that the wear resistance of iron coatings with inclusions of powder particles of aluminum, kaolin, and calcium silicate increases from 5 to 10 times compared to coating without inclusions of disperse particles, and the friction coefficient therewith decreases from 0.097 to 0.026. It has been shown that the mechanical properties of iron obtained by the method of electrochemical deposition depend on their fine structure. The regimes of deposition of iron-based coatings have been optimized.

  3. Gold-coated iron nanoparticles in transparent Si3N4 matrix thin films

    Science.gov (United States)

    Sánchez-Marcos, J.; Céspedes, E.; Jiménez-Villacorta, F.; Muñoz-Martín, A.; Prieto, C.

    2013-06-01

    A new method to prepare thin films containing gold-coated iron nanoparticles is presented. The ternary Fe-Au-Si3N4 system prepared by sequential sputtering has revealed a progressive variation of microstructures from Au/Fe/Au/Si3N4 multilayers to iron nanoparticles. Microstructural characterization by transmission electron microscopy, analysis of the magnetic properties and probing of the iron short-range order by X-ray absorption spectroscopy confirm the existence of a gold-coated iron nanoparticles of 1-2 nm typical size for a specific range of iron and gold contents per layer in the transparent silicon nitride ceramic matrix.

  4. Ultra-low power hydrogen sensing based on a palladium-coated nanomechanical beam resonator

    DEFF Research Database (Denmark)

    Henriksson, Jonas; Villanueva Torrijo, Luis Guillermo; Brugger, Juergen

    2012-01-01

    Hydrogen sensing is essential to ensure safety in near-future zero-emission fuel cell powered vehicles. Here, we present a novel hydrogen sensor based on the resonant frequency change of a nanoelectromechanical clamped-clamped beam. The beam is coated with a Pd layer, which expands in the presence...... of H 2, therefore generating a stress build-up that causes the frequency of the device to drop. The devices are able to detect H2 concentrations below 0.5% within 1 s of the onset of the exposure using only a few hundreds of pW of power, matching the industry requirements for H 2 safety sensors......, whereby the responsivity of the sensors is fully restored and the chemo-mechanical process is accelerated, significantly decreasing response times. The sensors are fabricated using standard processes, facilitating their eventual mass-production. © 2012 The Royal Society of Chemistry....

  5. Reductive dechlorination of 3,3',4,4'-tetrachlorobiphenyl (PCB77) using palladium or palladium/iron nanoparticles and assessment of the reduction in toxic potency in vascular endothelial cells

    International Nuclear Information System (INIS)

    Venkatachalam, Karthik; Arzuaga, Xabier; Chopra, Nitin; Gavalas, Vasilis G.; Xu, Jian; Bhattacharyya, Dibakar; Hennig, Bernhard; Bachas, Leonidas G.

    2008-01-01

    Palladium-based nanoparticles immobilized in polymeric matrices were applied to the reductive dechlorination of 3,3',4,4'-tetrachlorobiphenyl (PCB77) at room temperature. Two different dechlorination platforms were evaluated using (1) Pd nanoparticles within conductive polypyrrole films; or (2) immobilized Fe/Pd nanoparticles within polyvinylidene fluoride microfiltration membranes. For the first approach, the polypyrrole film was electrochemically formed in the presence of perchlorate ions that were incorporated into the film to counter-balance the positive charges of the polypyrrole chain. The film was then incubated in a solution containing tetrachloropalladate ions, which were exchanged with the perchlorate ions within the film. During this exchange, reduction of tetrachloropalladate by polypyrrole occurred, which led to the formation of palladium nanoparticles within the film. For the second approach, the membrane-supported Fe/Pd nanoparticles were prepared in three steps: polymerization of acrylic acid in polyvinylidene fluoride microfiltration membrane pores was followed by ion exchange of Fe 2+ , and then chemical reduction of the ferrous ions bound to the carboxylate groups. The membrane-supported iron nanoparticles were then soaked in a solution of tetrachloropalladate resulting in the deposition of Pd on the Fe surface. The nanoparticles prepared by both approaches were employed in the dechlorination of PCB77. The presence of hydrogen was required when the monometallic Pd nanoparticles were employed. The results indicate the removal of chlorine atoms from PCB77, which led to the formation of lower chlorinated intermediates and ultimately biphenyl. Toxicity associated with vascular dysfunction by PCB77 and biphenyl was compared using cultured endothelial cells. The data strongly suggest that the dechlorination system used in this study markedly reduced the proinflammatory activity of PCB77, a persistent organic pollutant

  6. Iron coated pottery granules for arsenic removal from drinking water.

    Science.gov (United States)

    Dong, Liangjie; Zinin, Pavel V; Cowen, James P; Ming, Li Chung

    2009-09-15

    A new media, iron coated pottery granules (ICPG) has been developed for As removal from drinking water. ICPG is a solid phase media that produces a stable Fe-Si surface complex for arsenic adsorption. Scanning electron microscopy (SEM) was used to document the physical attributes (grain size, pore size and distribution, surface roughness) of the ICPG media. Several advantages of the ICPG media such as (a) its granular structure, (b) its ability to absorb As via the F(0) coating on the granules' surface; (c) the inexpensive preparation process for the media from clay material make ICPG media a highly effective media for removing arsenic at normal pH. A column filtration test demonstrated that within the stability region (flow rate lower than 15L/h, EBCT >3 min), the concentration of As in the influent was always lower than 50 microg/L. The 2-week system ability test showed that the media consistently removed arsenic from test water to below the 5 microg/L level. The average removal efficiencies for total arsenic, As(III), and As(V) for a 2-week test period were 98%, 97%, and 99%, respectively, at an average flow rate of 4.1L/h and normal pH. Measurements of the Freundlich and Langmuir isotherms at normal pH show that the Freundlich constants of the ICPG are very close to those of ferric hydroxide, nanoscale zero-valent iron and much higher than those of nanocrystalline titanium dioxide. The parameter 1/n is smaller than 0.55 indicating a favorable adsorption process [K. Hristovski, A. Baumgardner, P. Westerhoff, Selecting metal oxide nanomaterials for arsenic removal in fixed bed columns: from nanopowders to aggregated nanoparticle media, J. Hazard. Mater. 147 (2007) 265-274]. The maximum adsorption capacity (q(e)) of the ICPG from the Langmuir isotherm is very close to that of nanoscale zero-valent indicating that zero-valent iron is involved in the process of the As removal from the water. The results of the toxicity characteristic leaching procedure (TCLP

  7. Iron coated pottery granules for arsenic removal from drinking water

    International Nuclear Information System (INIS)

    Dong Liangjie; Zinin, Pavel V.; Cowen, James P.; Ming, Li Chung

    2009-01-01

    A new media, iron coated pottery granules (ICPG) has been developed for As removal from drinking water. ICPG is a solid phase media that produces a stable Fe-Si surface complex for arsenic adsorption. Scanning electron microscopy (SEM) was used to document the physical attributes (grain size, pore size and distribution, surface roughness) of the ICPG media. Several advantages of the ICPG media such as (a) its granular structure, (b) its ability to absorb As via the F(0) coating on the granules' surface; (c) the inexpensive preparation process for the media from clay material make ICPG media a highly effective media for removing arsenic at normal pH. A column filtration test demonstrated that within the stability region (flow rate lower than 15 L/h, EBCT >3 min), the concentration of As in the influent was always lower than 50 μg/L. The 2-week system ability test showed that the media consistently removed arsenic from test water to below the 5 μg/L level. The average removal efficiencies for total arsenic, As(III), and As(V) for a 2-week test period were 98%, 97%, and 99%, respectively, at an average flow rate of 4.1 L/h and normal pH. Measurements of the Freundlich and Langmuir isotherms at normal pH show that the Freundlich constants of the ICPG are very close to those of ferric hydroxide, nanoscale zero-valent iron and much higher than those of nanocrystalline titanium dioxide. The parameter 1/n is smaller than 0.55 indicating a favorable adsorption process [K. Hristovski, A. Baumgardner, P. Westerhoff, Selecting metal oxide nanomaterials for arsenic removal in fixed bed columns: from nanopowders to aggregated nanoparticle media, J. Hazard. Mater. 147 (2007) 265-274]. The maximum adsorption capacity (q e ) of the ICPG from the Langmuir isotherm is very close to that of nanoscale zero-valent indicating that zero-valent iron is involved in the process of the As removal from the water. The results of the toxicity characteristic leaching procedure (TCLP) analysis

  8. Arsenic removal from water using iron-coated seaweeds.

    Science.gov (United States)

    Vieira, Bárbara R C; Pintor, Ariana M A; Boaventura, Rui A R; Botelho, Cidália M S; Santos, Sílvia C R

    2017-05-01

    Arsenic is a semi-metal element that can enter in water bodies and drinking water supplies from natural deposits and from mining, industrial and agricultural practices. The aim of the present work was to propose an alternative process for removing As from water, based on adsorption on a brown seaweed (Sargassum muticum), after a simple and inexpensive treatment: coating with iron-oxy (hydroxides). Adsorption equilibrium and kinetics were studied and modeled in terms of As oxidation state (III and V), pH and initial adsorbate concentration. Maximum adsorption capacities of 4.2 mg/g and 7.3 mg/g were obtained at pH 7 and 20 °C for arsenite and arsenate, respectively. When arsenite was used as adsorbate, experimental evidences pointed to the occurrence of redox reactions involving As(III) oxidation to As(V) and Fe(III) reduction to Fe(II), with As(V) uptake by the adsorbent. The proposed adsorption mechanism was then based on the assumption that arsenate was the adsorbed arsenic species. The most relevant drawback found in the present work was the considerable leaching of iron to the solution. Arsenite removal from a mining-influenced water by adsorption plus precipitation was studied and compared to a traditional process of coagulation/flocculation. Both kinds of treatment provided practically 100% of arsenite removal from the contaminated water, leading at best in 12.9 μg/L As after the adsorption and precipitation assays and 14.2 μg/L after the coagulation/flocculation process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Structure and Corrosion Behavior of Arc-Sprayed Zn-Al Coatings on Ductile Iron Substrate

    Science.gov (United States)

    Bonabi, Salar Fatoureh; Ashrafizadeh, Fakhreddin; Sanati, Alireza; Nahvi, Saied Mehran

    2018-02-01

    In this research, four coatings including pure zinc, pure aluminum, a double-layered coating of zinc and aluminum, and a coating produced by simultaneous deposition of zinc and aluminum were deposited on a cast iron substrate using electric arc-spraying technique. The coatings were characterized by XRD, SEM and EDS map and spot analyses. Adhesion strength of the coatings was evaluated by three-point bending tests, where double-layered coating indicated the lowest bending angle among the specimens, with detection of cracks at the coating-substrate interface. Coatings produced by simultaneous deposition of zinc and aluminum possessed a relatively uniform distribution of both metals. In order to evaluate the corrosion behavior of the coatings, cyclic polarization and salt spray tests were conducted. Accordingly, pure aluminum coating showed susceptibility to pitting corrosion and other coatings underwent uniform corrosion. For double-layered coating, SEM micrographs revealed zinc corrosion products as flaky particles in the pores formed by pitting on the surface, an indication of penetration of corrosion products from the lower layer (zinc) to the top layer (aluminum). All coatings experienced higher negative corrosion potentials than the iron substrate, indicative of their sacrificial behavior.

  10. The convenient preparation of stable aryl-coated zerovalent iron nanoparticles

    Directory of Open Access Journals (Sweden)

    Olga A. Guselnikova

    2015-05-01

    Full Text Available A novel approach for the in situ synthesis of zerovalent aryl-coated iron nanoparticles (NPs based on diazonium salt chemistry is proposed. Surface-modified zerovalent iron NPs (ZVI NPs were prepared by simple chemical reduction of iron(III chloride aqueous solution followed by in situ modification using water soluble arenediazonium tosylate. The resulting NPs, with average iron core diameter of 21 nm, were coated with a 10 nm thick organic layer to provide long-term protection in air for the highly reactive zerovalent iron core up to 180 °C. The surface-modified iron NPs possess a high grafting density of the aryl group on the NPs surface of 1.23 mmol/g. FTIR spectroscopy, XRD, HRTEM, TGA/DTA, and elemental analysis were performed in order to characterize the resulting material.

  11. The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2012-12-01

    Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showeda heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived.Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

  12. The Effect of Ductile Cast Iron Matrix on Zinc Coating During Hot Dip Galvanising of Castings

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2012-12-01

    Full Text Available The growth kinetics of the zinc coating formed on the surface of casting made from ductile iron grade EN-GJS-500-3 was investigated. To produce homogenous metal matrix in test samples, the normalising and ferritising annealing was carried out. Studies showed a heterogeneous structure of cast iron with varying content of the phases formed. This was followed by hot dip galvanising treatment at 450°C to capture the growth kinetics of the zinc coating (the time of the treatment ranged from 60 to 600 seconds. Nonlinear estimation of the determined growth kinetics of the alloyed layer of a zinc coating was made and an equation of the zinc coating growth was derived. Based on the results of the investigations it was concluded that thickness of the zinc coating formed on the surface of casting with a 100% pearlitic matrix makes 55% of the thickness of coating formed on the surface in 100% ferritic.

  13. Fabrication of Nitrogen-Doped Mesoporous-Carbon-Coated Palladium Nanoparticles: An Intriguing Electrocatalyst for Methanol and Formic Acid Oxidation.

    Science.gov (United States)

    Ray, Chaiti; Dutta, Soumen; Sahoo, Ramkrishna; Roy, Anindita; Negishi, Yuichi; Pal, Tarasankar

    2016-05-20

    Inspired by the attractive catalytic properties of palladium and the inert nature of carbon supports in catalysis, a concise and simple methodology for in situ nitrogen-doped mesoporous-carbon-supported palladium nanoparticles (Pd/N-C) has been developed by carbonizing a palladium dimethylglyoximate complex. The as-synthesized Pd/N-C has been exfoliated as a fuel cell catalyst by studying the electro-oxidation of methanol and formic acid. The material synthesized at 400 °C,namely, Pd/N-C-400,exhibitssuperior mass activity and stability among catalysts synthesized under different carbonization temperaturesbetween300 and 500 °C. The unique 1D porous structure in Pd/N-C-400 helps better electron transport at the electrode surface, which eventually leads to about five times better catalytic activity and about two times higher stability than that of commercial Pd/C. Thus, our designed sacrificial metal-organic templatedirected pathway becomes a promising technique for Pd/N-C synthesis with superior catalytic performances. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Study of corrosion using long period fiber gratings coated with iron exposed to salty water

    Science.gov (United States)

    Coelho, L.; Santos, J. L.; Jorge, P. A. S.; de Almeida, J. M. M.

    2017-04-01

    A study of long period fiber gratings (LPFG) over coated with iron (Fe) and subjected to oxidation in water with different sodium chloride (NaCl) concentrations is presented. The formation of iron oxides and hydroxides was monitored in real time by following the features of the LPFG attenuation band. Preliminary results show that Fe coated LPFGs can be used as sensors for early warning of corrosion in offshore and in coastal projects where metal structures made of iron alloys are in contact with sea or brackish water.

  15. Accumulation of magnetic iron oxide nanoparticles coated with variably sized polyethylene glycol in murine tumors

    DEFF Research Database (Denmark)

    Larsen, Esben Kjær Unmack; Nielsen, Thomas; Wittenborn, Thomas

    2012-01-01

    Iron oxide nanoparticles have found widespread applications in different areas including cell separation, drug delivery and as contrast agents. Due to water insolubility and stability issues, nanoparticles utilized for biological applications require coatings such as the commonly employed...... polyethylene glycol (PEG). Despite its frequent use, the influence of PEG coatings on the physicochemical and biological properties of iron nanoparticles has hitherto not been studied in detail. To address this, we studied the effect of 333–20 000 Da PEG coatings that resulted in larger hydrodynamic size...

  16. Enhanced antioxidation and microwave absorbing properties of SiO2-coated flaky carbonyl iron particles

    Science.gov (United States)

    Zhou, Yingying; Xie, Hui; Zhou, Wancheng; Ren, Zhaowen

    2018-01-01

    SiO2 was successfully coated on the surface of flaky carbonyl iron particles using a chemical bath deposition method in the presence of 3-aminopropyl triethoxysilane (APTES). The morphologies, composition, valence states of elements, as well as antioxidation and electromagnetic properties of the samples were characterized by scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and microwave network analyzer. TG curve shows the obvious weight gain of carbonyl iron was deferred to 360 °C after SiO2-coated, which can be ascribed to the exits of SiO2 overlayer. Compared with the raw carbonyl iron, SiO2-coated sample shows good wave absorption performance due to its impedance matching. The electromagnetic properties of raw and SiO2-coated carbonyl iron particles were characterized in X band before and after heat treatment at 250 °C for 10 h. It was established that SiO2-coated carbonyl iron demonstrate good thermal stability, indicating SiO2-coating is useful in the usage of microwave absorbers operating at temperature up to 250 °C.

  17. Influence of iron and beryllium additions on heat resistance of silicide coatings on TsMB-30 molybdenum alloy

    International Nuclear Information System (INIS)

    Zajtseva, A.L.; Fedorchuk, N.M.; Lazarev, Eh.M.; Korotkov, N.A.

    1985-01-01

    Alloying of titanium modified silicide coatings on TsMB-30 molybdenum alloy with iron or beryllium is stated to improve their protective properties. Coatings with low content of alloying elements have the best protective properties. Service life of coatings is determined by the formed oxide film and phase transformations taking place in the coating

  18. The detection of HBV DNA with gold-coated iron oxide nanoparticle gene probes

    International Nuclear Information System (INIS)

    Xi Dong; Luo Xiaoping; Lu Qianghua; Yao Kailun; Liu Zuli; Ning Qin

    2008-01-01

    Gold-coated iron oxide nanoparticle Hepatitis B virus (HBV) DNA probes were prepared, and their application for HBV DNA measurement was studied. Gold-coated iron oxide nanoparticles were prepared by the citrate reduction of tetra-chloroauric acid in the presence of iron oxide nanoparticles which were added as seeds. With a fluorescence-based method, the maximal surface coverage of hexaethiol 30-mer oligonucleotides and the maximal percentage of hybridization strands on gold-coated iron oxide nanoparticles were (120 ± 8) oligonucleotides per nanoparticle, and (14 ± 2%), respectively, which were comparable with those of (132 ± 10) and (22 ± 3%) in Au nanoparticle groups. Large network aggregates were formed when gold-coated iron oxide nanoparticle HBV DNA gene probe was applied to detect HBV DNA molecules as evidenced by transmission electron microscopy and the high specificity was verified by blot hybridization. Our results further suggested that detecting DNA with iron oxide nanoparticles and magnetic separator was feasible and might be an alternative effective method

  19. Generation of drugs coated iron nanoparticles through high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Radhika Devi, A.; Murty, B. S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Chelvane, J. A. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Prabhakar, P. K.; Padma Priya, P. V.; Doble, Mukesh [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)

    2014-03-28

    The iron nanoparticles coated with oleic acid and drugs such as folic acid/Amoxicillin were synthesized by high energy ball milling and characterized by X-ray diffraction, Transmission electron microscope, zeta potential, dynamic light scattering, Fourier Transform Infra red (FT-IR) measurements, and thermo gravimetric analysis (TGA). FT-IR and TGA measurements show good adsorption of drugs on oleic acid coated nanoparticles. Magnetic measurements indicate that saturation magnetization is larger for amoxicillin coated particles compared to folic acid coated particles. The biocompatibility of the magnetic nanoparticles prepared was evaluated by in vitro cytotoxicity assay using L929 cells as model cells.

  20. Chemical vapor deposition of aluminide coatings on iron, nickel and superalloys

    International Nuclear Information System (INIS)

    John, John T.; De, P.K.; Dubey, Vivekanand; Srinivasa, Raman

    2009-08-01

    Aluminide coatings are a class of intermetallic coatings applied on nickel and cobalt base superalloys and steels to protect them from different forms of environmental degradation at high temperatures. In this report a CVD system that can produce the aluminide coatings on iron, nickel and nickel base alloys has been described and the result of chemical vapor deposition of aluminide coatings on iron specimens, their characterization, and property evaluation have been presented. The CVD system consists of an AlCl 3 bath, a stainless steel retort as a hot-wall reacto, cold traps and vacuum system. Aluminium chloride vapor was carried in a stream of hydrogen gas at a flow rate of 150 SCCM (standard cubic centimeter per minute) into the CVD reactor maintained in the temperature range of 1173 - 1373 K and at a pressure of 1.33 kPa (10 Torr). Aluminum deposition takes place from aluminium subchlorides produced by reaction between AlCl 3 and pure aluminum kept in the CVD reactor. The aluminum diffuses into the iron samples and iron aluminide phases are formed at the surface. The coatings were shining bright and showed good adherence to the substrate. The coatings consisted of FeAl phase over a wide range of experimental conditions. The growth kinetics of the coating followed a parabolic rate law and the mean activation energy was 212 ±16 kJ/mol. Optical microscopic studies on the transverse section of the coating showed that the aluminide coating on iron consisted of two layers. The top layer had a thickness in the range of 20-50 μm, and the under layer had thickness ranging from 35 to 250 μm depending on coating temperature in two hours. The thickness of the aluminide layer increased with coating duration and temperature. Electron microprobe studies (EPMA) showed that the aluminum concentration decreased steadily as distance from the surface increased. TEM studies showed that the outer most layer had a B2 order (of the FeAl phase), which extended even into the under

  1. Corrosion monitoring of iron, protected by an organic coating, with the aid of impedance measurements

    International Nuclear Information System (INIS)

    Hubrecht, J.; Piens, M.; Vereecken, J.

    1984-01-01

    The ac impedance measurement has proved to be a useful electrochemical technique for mainly qualitative studies of electrochemical and corrosion systems. Even for complicated systems such as coated metals in corrosive environments this technique has been used with success. The system chosen for the present study is an ARMCO iron plate, coated with a SrCrO 4 -pigmented styrene acrylic polymer, and immersed for several weeks in an aqueous NaCl solution. Impedance measurements analyze a system under test into its constituting phenomena. The dependence of system parameters on coating layer thickness, NaCl concentration, and pigmentation of the coating during the immersion time provides insight into the corrosion and protection mechanisms at the coating/metal interface, besides the behavior of the coating itself

  2. Annealing effects on magnetic properties of silicone-coated iron-based soft magnetic composites

    Science.gov (United States)

    Wu, Shen; Sun, Aizhi; Zhai, Fuqiang; Wang, Jin; Zhang, Qian; Xu, Wenhuan; Logan, Philip; Volinsky, Alex A.

    2012-03-01

    This paper focuses on novel iron-based soft magnetic composites synthesis utilizing high thermal stability silicone resin to coat iron powder. The effect of an annealing treatment on the magnetic properties of synthesized magnets was investigated. The coated silicone insulating layer was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Silicone uniformly coated the powder surface, resulting in a reduction of the imaginary part of the permeability, thereby increasing the electrical resistivity and the operating frequency of the synthesized magnets. The annealing treatment increased the initial permeability, the maximum permeability, and the magnetic induction, and decreased the coercivity. Annealing at 580 °C increased the maximum permeability by 72.5%. The result of annealing at 580 °C shows that the ferromagnetic resonance frequency increased from 2 kHz for conventional epoxy resin coated samples to 80 kHz for the silicone resin insulated composites.

  3. Size-Dependent Accumulation of PEGylated Silane-Coated Magnetic Iron Oxide Nanoparticles in Murine Tumors

    DEFF Research Database (Denmark)

    Larsen, Esben Kjær Unmack; Nielsen, T.; Wittenborn, T.

    2009-01-01

    following intravenous injection. Biocompatible iron oxide MNPs coated with PEG were prepared by replacing oleic acid with a biocompatible and commercially available silane-PEG to provide an easy and effective method for chemical coating. The colloidal stable PEGylated MNPs were magnetically separated...... into two distinct size subpopulations of 20 and 40 nm mean diameters with increased phagocytic uptake observed for the 40 nm size range in vitro. MRI detection revealed greater iron accumulation in murine tumors for 40 nm nanoparticles after intravenous injection. The enhanced MRI contrast of the larger...

  4. Doxorubicin loaded PVA coated iron oxide nanoparticles for targeted drug delivery

    International Nuclear Information System (INIS)

    Kayal, S.; Ramanujan, R.V.

    2010-01-01

    Magnetic drug targeting is a drug delivery system that can be used in locoregional cancer treatment. Coated magnetic particles, called carriers, are very useful for delivering chemotherapeutic drugs. Magnetic carriers were synthesized by coprecipitation of iron oxide followed by coating with polyvinyl alcohol (PVA). Characterization was carried out using X-ray diffraction, TEM, TGA, FTIR and VSM techniques. The magnetic core of the carriers was magnetite (Fe 3 O 4 ), with average size of 10 nm. The room temperature VSM measurements showed that magnetic particles were superparamagnetic. The amount of PVA bound to the iron oxide nanoparticles were estimated by thermogravimetric analysis (TGA) and the attachment of PVA to the iron oxide nanoparticles was confirmed by FTIR analysis. Doxorubicin (DOX) drug loading and release profiles of PVA coated iron oxide nanoparticles showed that up to 45% of adsorbed drug was released in 80 h, the drug release followed the Fickian diffusion-controlled process. The binding of DOX to the PVA was confirmed by FTIR analysis. The present findings show that DOX loaded PVA coated iron oxide nanoparticles are promising for magnetically targeted drug delivery.

  5. Effect of a weak magnetic field on the Mizoroki–Heck coupling reaction in the presence of wicker-like palladium-poly(N-vinylpyrrolidone)-iron nanocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee, Ezzat, E-mail: ezzat_rafiee@yahoo.com [Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah 67149 (Iran, Islamic Republic of); Institute of Nano Science and Nano Technology, Razi University, Kermanshah 67149 (Iran, Islamic Republic of); Joshaghani, Mohammad [Department of Inorganic Chemistry, Faculty of Chemistry, Razi University, Kermanshah 67149 (Iran, Islamic Republic of); Institute of Nano Science and Nano Technology, Razi University, Kermanshah 67149 (Iran, Islamic Republic of); Abadi, Parvaneh Ghaderi-Shekhi [Institute of Nano Science and Nano Technology, Razi University, Kermanshah 67149 (Iran, Islamic Republic of)

    2016-06-15

    The wicker-like Pd-PVP-Fe (palladium-poly(N-vinylpyrrolidone)-iron) was synthesized by the external magnetic field (EMF). The Pd-based catalyst with nano and the face-centered cubic (fcc) structure was obtained at room temperature without using any additive. The resulting composite was characterized. The results show that EMF has a great influence on morphology, particle size, and crystalline structure of the Pd-PVP-Fe composite. The resulting composite (Pd-PVP-Fe), was found to be an effective catalyst for the Mizoroki–Heck reaction while is exposed to EMF with the intensity at 486 µT. The reused catalyst for at least five repeating cycles, shows excellent activity. - Highlights: • The wicker-like Pd-PVP-Fe nanocatalyst was synthesized via external magnetic field. • The resulting catalyst composite was characterized. • The C–C coupling reaction was carried out at magnetic field and room temperature. • Magnetic field affects on the morphology and size of the catalyst. • The catalyst could be reused without significant degradation in activity.

  6. Enhancement in the Tribological and Mechanical Properties of Electroless Nickel-Nanodiamond Coatings Plated on Iron

    Directory of Open Access Journals (Sweden)

    Z. Karaguiozova

    2017-12-01

    Full Text Available A technology to improve the tribological and mechanical surface properties of iron alloys is developed based on the electroless nickel plating. The technology combines sol-gel and electroless deposition technique. Novel nanocomposite coatings are obtained consisting of Nickel-phosphorus-nanodiamond (Ni-P-ND. The ND sol is added directly to the electroless Ni-P solution. A suitable surfactant is added to achieve well-dispersed ND particles in the electroless solution to facilitate their embodiment and equal distribution in the coating. Substrates of steel 17CrNiMo6 and spheroidal graphite cast irons are used for the manufacture of the iron alloys specimens. The surface morphology and microstructure observation performed by scanning electron microscopy (SEM and optical metallography confirms the influence of ND particles on the coating structure. The structural phase investigation by X Ray analysis indicates a transformation of the amorphous phase to a crystalline one such as Ni, Ni3P after coatings' heat treatment. The microhardness investigation by Knoop Method and wear resistance measurement in accordance with the Polish Standard PN-83/H-04302 of Ni-P and Ni-P-ND composite coatings are evaluated and compared with each other. The increase in the value of hardness and wear resistance of Ni-P composite coatings in the presence of ND particles and after heat treatment is obtained.

  7. Identifying the optimal HVOF spray parameters to attain minimum porosity and maximum hardness in iron based amorphous metallic coatings

    Directory of Open Access Journals (Sweden)

    S. Vignesh

    2017-04-01

    Full Text Available Flow based Erosion – corrosion problems are very common in fluid handling equipments such as propellers, impellers, pumps in warships, submarine. Though there are many coating materials available to combat erosion–corrosion damage in the above components, iron based amorphous coatings are considered to be more effective to combat erosion–corrosion problems. High velocity oxy-fuel (HVOF spray process is considered to be a better process to coat the iron based amorphous powders. In this investigation, iron based amorphous metallic coating was developed on 316 stainless steel substrate using HVOF spray technique. Empirical relationships were developed to predict the porosity and micro hardness of iron based amorphous coating incorporating HVOF spray parameters such as oxygen flow rate, fuel flow rate, powder feed rate, carrier gas flow rate, and spray distance. Response surface methodology (RSM was used to identify the optimal HVOF spray parameters to attain coating with minimum porosity and maximum hardness.

  8. The kinetics of zinc coating growth on hyper-sandelin steels and ductile cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2007-12-01

    Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent E = (Si+2.5P.103, and coating thickness dependences were obtained.

  9. The shaping of zinc coating on surface steels and ductile iron casting

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2010-01-01

    Full Text Available The studies aimed at an analysis of the formation and growth kinetics of zinc coating on reactive silicon-killed steels in a zinc bath. The growth kinetics of the produced zinc coatings was evaluated basing on the power-law growth equation. As regards galvanizing of the surface of products, investigation was done for various steel grades and ductile iron (DI taking into account the quality and thickness of coating. It has been proved that the chemical constitution of basis significantly influences the kinetics of growth of the individual phases in a zinc coating. This relationship was evaluated basing on the, so called, silicon and phosphorus equivalent ESi,P and coating thickness dependences were obtained.

  10. A Study on DLC Tool Coating for Deep Drawing and Ironing of Stainless Steel

    DEFF Research Database (Denmark)

    Üstünyagiz, Esmeray; Hafis Sulaiman, Mohd; Christiansen, Peter

    2018-01-01

    ) to replicate industrial ironing of deep drawn, stainless steel parts. Non-hazardous tribo-systems in form of a double layer Diamond-like coated tool applied under dry condition or with an environmentally friendly lubricant were investigated via emulating industrial process conditions in laboratory tests...

  11. Iron nanoparticles from blood coated with collagen as a matrix for ...

    Indian Academy of Sciences (India)

    A simple wet precipitation technique was used to prepare nanobiocomposite containing iron nanoparticles coated with collagen. This nanobiocomposite was used as matrix for the synthesis of nanohydroxyapatite. The physicochemical characteristic studies of the nanohydroxyapatite thus formed were carried out using ...

  12. Microwave electromagnetic properties of carbonyl iron particles and Si/C/N nano-powder filled epoxy-silicone coating

    International Nuclear Information System (INIS)

    Qing Yuchang; Zhou Wancheng; Luo Fa; Zhu Dongmei

    2010-01-01

    The electromagnetic characteristics of carbonyl iron particles and Si/C/N nano-powder filled epoxy-silicone coatings were studied. The reflection loss of the coatings exceeds -10 dB at 8-18 GHz and -9 dB at 2-18 GHz when the coating thickness is 1 and 3 mm, respectively. The dielectric and magnetic absorbers filled coatings possess excellent microwave absorption, which could be attributed to the proper incorporate of the multi-polarization mechanisms as well as strong natural resonance. It is feasible to develop the thin and wideband microwave absorbing coatings using carbonyl iron particles and Si/C/N nano-powder.

  13. Microwave electromagnetic properties of carbonyl iron particles and Si/C/N nano-powder filled epoxy-silicone coating

    Science.gov (United States)

    Qing, Yuchang; Zhou, Wancheng; Luo, Fa; Zhu, Dongmei

    2010-02-01

    The electromagnetic characteristics of carbonyl iron particles and Si/C/N nano-powder filled epoxy-silicone coatings were studied. The reflection loss of the coatings exceeds -10 dB at 8-18 GHz and -9 dB at 2-18 GHz when the coating thickness is 1 and 3 mm, respectively. The dielectric and magnetic absorbers filled coatings possess excellent microwave absorption, which could be attributed to the proper incorporate of the multi-polarization mechanisms as well as strong natural resonance. It is feasible to develop the thin and wideband microwave absorbing coatings using carbonyl iron particles and Si/C/N nano-powder.

  14. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Xianjun, E-mail: xjxie@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Wang, Yanxin, E-mail: yx.wang@cug.edu.cn [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pi, Kunfu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Liu, Chongxuan [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu [State Key Laboratory of Biogeology and Environmental Geology, School of Environmental Studies, China University of Geosciences, 430074 Wuhan (China)

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO{sub 4} and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na{sub 2}HAsO{sub 4}) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles

  15. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study

    International Nuclear Information System (INIS)

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-01-01

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO 4 and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na 2 HAsO 4 ) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles. - Highlights:

  16. In situ functionalization and PEO coating of iron oxide nanocrystals using seeded emulsion polymerization.

    Science.gov (United States)

    Kloust, Hauke; Schmidtke, Christian; Feld, Artur; Schotten, Theo; Eggers, Robin; Fittschen, Ursula E A; Schulz, Florian; Pöselt, Elmar; Ostermann, Johannes; Bastús, Neus G; Weller, Horst

    2013-04-16

    Herein we demonstrate that seeded emulsion polymerization is a powerful tool to produce multiply functionalized PEO coated iron oxide nanocrystals. Advantageously, by simple addition of functional surfactants, functional monomers, or functional polymerizable linkers-solely or in combinations thereof-during the seeded emulsion polymerization process, a broad range of in situ functionalized polymer-coated iron oxide nanocrystals were obtained. This was demonstrated by purposeful modulation of the zeta potential of encapsulated iron oxide nanocrystals and conjugation of a dyestuff. Successful functionalization was unequivocally proven by TXRF. Furthermore, the spatial position of the functional groups can be controlled by choosing the appropriate spacers. In conclusion, this methodology is highly amenable for combinatorial strategies and will spur rapid expedited synthesis and purposeful optimization of a broad scope of nanocrystals.

  17. Conducting polymer-coated, palladium-functionalized multi-walled carbon nanotubes for the electrochemical sensing of hydroxylamine

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunhee; Ahmed, Mohammad Shamsuddin; You, Jung-Min; Kim, Seul Ki; Jeon, Seungwon, E-mail: swjeon@chonnam.ac.kr

    2012-08-31

    Electrochemical sensors of hydroxylamine were fabricated on glassy carbon electrodes (GCEs) by the electropolymerization of 3,4-ethylenedioxypyrrole (EDOP) and 3,4-ethylenedioxythiophene (EDOT) on palladium (Pd) nanoparticles attached to thiolated multi-walled carbon nanotubes (MWCNTs), denoted as PEDOP/MWCNT-Pd/GCE and PEDOT/MWCNT-Pd/GCE. The sensors were characterized by field emission scanning electron microscopy and electrochemical impedance spectroscopy. They showed strong catalytic activity toward the oxidation of hydroxylamine. Cyclic voltammetry and amperometry were used to characterize the sensors' performances. The detection limits of hydroxylamine by PEDOP/MWCNT-Pd/GCE and PEDOT/MWCNT-Pd/GCE were 0.22 and 0.24 {mu}M (S/N = 3), respectively. The sensors' sensitivity, selectivity, and stability were also investigated. - Highlights: Black-Right-Pointing-Pointer Multi-wall carbon nanotubes-Pd nanoparticles (MWCNT-Pd) based electrodes. Black-Right-Pointing-Pointer Electropolymerized electrodes by poly3,4-ethylenedioxythiophene(PEDOT). Black-Right-Pointing-Pointer PEDOT/MWCNT-Pd has a low detection limit of 0.24 Micro-Sign M for hydroxylamine. Black-Right-Pointing-Pointer PEDOT/MWCNT-Pd exhibits a wide linear range from 1 Micro-Sign M to 6 mM hydroxylamine. Black-Right-Pointing-Pointer The resulting sensor shows fast response and good stability.

  18. Biocompatibility of chitosan-coated iron oxide nanoparticles with osteoblast cells

    Directory of Open Access Journals (Sweden)

    Shi S

    2012-10-01

    Full Text Available Si-Feng Shi,1 Jing-Fu Jia,2 Xiao-Kui Guo,3 Ya-Ping Zhao,2 De-Sheng Chen,1 Yong-Yuan Guo,1 Tao Cheng,1 Xian-Long Zhang11Department of Orthopedic Surgery, Shanghai Sixth People’s Hospital, School of Medicine, 2School of Chemistry and Chemical Technology, 3Department of Medical Microbiology and Parasitology, School of Medicine, Shanghai Jiao Tong University Shanghai, ChinaBackground: Bone disorders (including osteoporosis, loosening of a prosthesis, and bone infections are of great concern to the medical community and are difficult to cure. Therapies are available to treat such diseases, but all have drawbacks and are not specifically targeted to the site of disease. Chitosan is widely used in the biomedical community, including for orthopedic applications. The aim of the present study was to coat chitosan onto iron oxide nanoparticles and to determine its effect on the proliferation and differentiation of osteoblasts.Methods: Nanoparticles were characterized using transmission electron microscopy, dynamic light scattering, x-ray diffraction, zeta potential, and vibrating sample magnetometry. Uptake of nanoparticles by osteoblasts was studied by transmission electron microscopy and Prussian blue staining. Viability and proliferation of osteoblasts were measured in the presence of uncoated iron oxide magnetic nanoparticles or those coated with chitosan. Lactate dehydrogenase, alkaline phosphatase, total protein synthesis, and extracellular calcium deposition was studied in the presence of the nanoparticles.Results: Chitosan-coated iron oxide nanoparticles enhanced osteoblast proliferation, decreased cell membrane damage, and promoted cell differentiation, as indicated by an increase in alkaline phosphatase and extracellular calcium deposition. Chitosan-coated iron oxide nanoparticles showed good compatibility with osteoblasts.Conclusion: Further research is necessary to optimize magnetic nanoparticles for the treatment of bone disease

  19. A study of DLC coatings for ironing of stainless steel

    DEFF Research Database (Denmark)

    Sulaiman, Mohd Hafis Bin; Christiansen, Peter; Bay, Niels Oluf

    2017-01-01

    Stamping of sheet metal components without lubrication or using minimum amount of hazard free lubricant is a possible solution to diminish health hazards to personnel and environmental impact and to reduce production costs. This paper studies the application of diamond-like coating (DLC) under...

  20. Laboratory Investigation of Complex Conductivity and Magnetic Susceptibility on Natural Iron Oxide Coated Sand

    Science.gov (United States)

    Wang, C.; Slater, L. D.; Day-Lewis, F. D.; Briggs, M. A.

    2017-12-01

    Redox reactions occurring at the oxic/anoxic interface where groundwater discharges to surface water commonly result in iron oxide deposition that coats sediment grains. With relatively large total surface area, these iron oxide coated sediments serve as a sink for sorption of dissolved contaminants, although this sink may be temporary if redox conditions fluctuate with varied flow conditions. Characterization of the distribution of iron oxides in streambed sediments could provide valuable understanding of biogeochemical reactions and the ability of a natural system to sorb contaminants. Towards developing a field methodology, we conducted laboratory spectral induced polarization (SIP) and magnetic susceptibility (MS) measurements on natural iron oxide coated sand (Fe-sand) with grain sizes ranging from 0.3 to 2.0 mm in order to assess the sensitivity of these measurements to iron oxides in sediments. The Fe-sand was also sorted by sieving into various grain sizes to study the impact of grain size on the polarization mechanisms. The unsorted Fe-sand saturated with 0.01 S/m NaCl solution exhibited a distinct phase response ( > 4 mrad) in the frequency range from 0.001 to 100 Hz whereas regular silica sand was characterized by a phase response less than 1 mrad under the same conditions. The presence of iron oxide substantially increased MS (3.08×10-3 SI) over that of regular sand ( Laboratory results demonstrated that SIP and MS may be well suited to mapping the distribution of iron oxides in streambed sediments associated with anoxic groundwater discharge.

  1. Annealing effects on magnetic properties of silicone-coated iron-based soft magnetic composites

    International Nuclear Information System (INIS)

    Wu Shen; Sun Aizhi; Zhai Fuqiang; Wang Jin; Zhang Qian; Xu Wenhuan; Logan, Philip; Volinsky, Alex A.

    2012-01-01

    This paper focuses on novel iron-based soft magnetic composites synthesis utilizing high thermal stability silicone resin to coat iron powder. The effect of an annealing treatment on the magnetic properties of synthesized magnets was investigated. The coated silicone insulating layer was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. Silicone uniformly coated the powder surface, resulting in a reduction of the imaginary part of the permeability, thereby increasing the electrical resistivity and the operating frequency of the synthesized magnets. The annealing treatment increased the initial permeability, the maximum permeability, and the magnetic induction, and decreased the coercivity. Annealing at 580 °C increased the maximum permeability by 72.5%. The result of annealing at 580 °C shows that the ferromagnetic resonance frequency increased from 2 kHz for conventional epoxy resin coated samples to 80 kHz for the silicone resin insulated composites. - Highlights: ► Silicone uniformly coated the powder, increased the operating frequency of SMCs. ► The annealing treatment increased the DC properties of SMCs. ► Annealing at 580 °C increased the maximum permeability by 72.5%. ► Compared with epoxy coated, the SMCs had higher resistivity annealing at 580 °C.

  2. Microwave-assisted combustion synthesis of nano iron oxide/iron-coated activated carbon, anthracite, cellulose fiber, and silica, with arsenic adsorption studies

    Science.gov (United States)

    Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was com...

  3. Cell tagging with clinically approved iron oxides: feasibility and effect of lipofection, particle size, and surface coating on labeling efficiency.

    Science.gov (United States)

    Matuszewski, Lars; Persigehl, Thorsten; Wall, Alexander; Schwindt, Wolfram; Tombach, Bernd; Fobker, Manfred; Poremba, Christopher; Ebert, Wolfgang; Heindel, Walter; Bremer, Christoph

    2005-04-01

    To evaluate the effect of lipofection, particle size, and surface coating on labeling efficiency of mammalian cells with superparamagnetic iron oxides (SPIOs). Institutional Review Board approval was not required. Different human cell lines (lung and breast cancer, fibrosarcoma, leukocytes) were tagged by using carboxydextran-coated SPIOs of various hydrodynamic diameters (17-65 nm) and a dextran-coated iron oxide (150 nm). Cells were incubated with increasing concentrations of iron (0.01-1.00 mg of iron [Fe] per milliliter), including or excluding a transfection medium (TM). Cellular iron uptake was analyzed qualitatively at light and electron microscopy and was quantified at atomic emission spectroscopy. Cell visibility was assessed with gradient- and spin-echo magnetic resonance (MR) imaging. Effects of iron concentration in the medium and of lipofection on cellular SPIO uptake were analyzed with analysis of variance and two-tailed Student t test, respectively. Iron oxide uptake increased in a dose-dependent manner with higher iron concentrations in the medium. The TM significantly increased the iron load of cells (up to 2.6-fold, P .05). As few as 10 000 cells could be detected with clinically available MR techniques by using this approach. Lipofection-based cell tagging is a simple method for efficient cell labeling with clinically approved iron oxide-based contrast agents. Large particle size and carboxydextran coating are preferable for cell tagging with endocytosis- and lipofection-based methods. (c) RSNA, 2005.

  4. MONTANA PALLADIUM RESEARCH INITIATIVE

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John; McCloskey, Jay; Douglas, Trevor; Young, Mark; Snyder, Stuart; Gurney, Brian

    2012-05-09

    Project Objective: The overarching objective of the Montana Palladium Research Initiative is to perform scientific research on the properties and uses of palladium in the context of the U.S. Department of Energy's Hydrogen, Fuel Cells and Infrastructure Technologies Program. The purpose of the research will be to explore possible palladium as an alternative to platinum in hydrogen-economy applications. To achieve this objective, the Initiatives activities will focus on several cutting-edge research approaches across a range of disciplines, including metallurgy, biomimetics, instrumentation development, and systems analysis. Background: Platinum-group elements (PGEs) play significant roles in processing hydrogen, an element that shows high potential to address this need in the U.S. and the world for inexpensive, reliable, clean energy. Platinum, however, is a very expensive component of current and planned systems, so less-expensive alternatives that have similar physical properties are being sought. To this end, several tasks have been defined under the rubric of the Montana Palladium Research Iniative. This broad swath of activities will allow progress on several fronts. The membrane-related activities of Task 1 employs state-of-the-art and leading-edge technologies to develop new, ceramic-substrate metallic membranes for the production of high-purity hydrogen, and develop techniques for the production of thin, defect-free platinum group element catalytic membranes for energy production and pollution control. The biomimetic work in Task 2 explores the use of substrate-attached hydrogen-producing enzymes and the encapsulation of palladium in virion-based protein coats to determine their utility for distributed hydrogen production. Task 3 work involves developing laser-induced breakdown spectroscopy (LIBS) as a real-time, in situ diagnostic technique to characterize PGEs nanoparticles for process monitoring and control. The systems engineering work in task 4

  5. Formation of coatings from a liquid phase on the surface of iron-base alloys

    Directory of Open Access Journals (Sweden)

    A. Tatarek

    2008-12-01

    Full Text Available The study discloses the present state of the art regarding the technology and investigations of the phenomena that take place during the formation and growth of aluminum and zinc coatings hot-dip formed on iron products. In its cognitive aspect, the study offers an in-depth analysis of the partial processes that proceed in metal bath at the solid body – liquid metal interface. It is expected that the present study will help in a more detailed description of the respective phenomena and in full explanation of the mechanism of the coating growth, taking as an example the growth of aluminum coatings. The obtained results can serve as a background for some general conclusions regarding the thickness evolution process in other hot-dip coatings.

  6. Solid-stabilized emulsion formation using stearoyl lactylate coated iron oxide nanoparticles

    Science.gov (United States)

    Vengsarkar, Pranav S.; Roberts, Christopher B.

    2014-10-01

    Iron oxide nanoparticles can exhibit highly tunable physicochemical properties that are extremely important in applications such as catalysis, biomedicine and environmental remediation. The small size of iron oxide nanoparticles can be used to stabilize oil-in-water Pickering emulsions due to their high energy of adsorption at the interface of oil droplets in water. The objective of this work is to investigate the effect of the primary particle characteristics and stabilizing agent chemistry on the stability of oil-in-water Pickering emulsions. Iron oxide nanoparticles were synthesized by the co-precipitation method using stoichiometric amounts of Fe2+ and Fe3+ salts. Sodium stearoyl lactylate (SSL), a Food and Drug Administration approved food additive, was used to functionalize the iron oxide nanoparticles. SSL is useful in the generation of fat-in-water emulsions due to its high hydrophilic-lipophilic balance and its bilayer-forming capacity. Generation of a monolayer or a bilayer coating on the nanoparticles was controlled through systematic changes in reagent concentrations. The coated particles were then characterized using various analytical techniques to determine their size, their crystal structure and surface functionalization. The capacity of these bilayer coated nanoparticles to stabilize oil-in-water emulsions under various salt concentrations and pH values was also systematically determined using various characterization techniques. This study successfully demonstrated the ability to synthesize iron oxide nanoparticles (20-40 nm) coated with SSL in order to generate stable Pickering emulsions that were pH-responsive and resistant to significant destabilization in a saline environment, thereby lending themselves to applications in advanced oil spill recovery and remediation.

  7. Microwave-Assisted Combustion Synthesis of Nano Iron Oxide/Iron-Coated Activated Carbon, Anthracite, Cellulose Fiber, and Silica, with Arsenic Adsorption Studies

    Directory of Open Access Journals (Sweden)

    Mallikarjuna N. Nadagouda

    2011-01-01

    Full Text Available Combustion synthesis of iron oxide/iron coated carbons such as activated carbon, anthracite, cellulose fiber, and silica is described. The reactions were carried out in alumina crucibles using a Panasonic kitchen microwave with inverter technology, and the reaction process was completed within a few minutes. The method used no additional fuel and nitrate, which is present in the precursor itself, to drive the reaction. The obtained samples were then characterized with X-ray mapping, scanning electron microscopy (SEM, energy dispersive X-ray analysis (EDS, selected area diffraction pattern (SAED, transmission electron microscopy (TEM, X-ray diffraction (XRD, and inductively coupled plasma (ICP spectroscopy. The size of the iron oxide/iron nanoparticle-coated activated carbon, anthracite, cellulose fiber, and silica samples were found to be in the nano range (50–400 nm. The iron oxide/iron nanoparticles mostly crystallized into cubic symmetry which was confirmed by SAED. The XRD pattern indicated that iron oxide/iron nano particles existed in four major phases. That is, γ-Fe2O3, α-Fe2O3, Fe3O4, and Fe. These iron-coated activated carbon, anthracite, cellulose fiber, and silica samples were tested for arsenic adsorption through batch experiments, revealing that few samples had significant arsenic adsorption.

  8. Phosphorus removal from aqueous solution using iron coated natural and engineered sorbents

    International Nuclear Information System (INIS)

    Boujelben, N.; Bouzid, J.; Elouear, Z.; Feki, M.; Jamoussi, F.; Montiel, A.

    2008-01-01

    New filtration materials covered with metallic oxides are good adsorbents for both cation and anion forms of pollutants. Sfax is one of the most important industrial towns in Tunisia. Its phosphate manufacture in particular is causing considerable amounts of water pollution. Therefore, there is a need to find out a new way of getting rid of this excessive phosphate from water. This work is aimed to examining the potential of three sorbent materials (synthetic iron oxide coated sand (SCS), naturally iron oxide coated sand (NCS) and iron oxide coated crushed brick (CB)) for removing phosphate ions from aqueous solutions. According to our literature survey CB was not used as adsorbent previously. Phosphate ions are used here as species model for the elimination of other similar pollutants (arsenates, antimonates). Optical microscope and scanning electron microscope (SEM) analyses were used to investigate the surface properties and morphology of the coated sorbents. Infra-red spectroscopy and X-ray diffraction techniques were also used to characterize the sorbent structures. Results showed that iron coated crushed brick possess more micro pores and a higher surface area owing to its clay nature. The comparative sorption of PO 4 3- from aqueous solutions by SCS, CB and NCS was investigated by batch experiments. The estimated optimum pH of phosphate ion retention for the considered sorbents was 5. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The sorption capacities of PO 4 3- at pH 5 were 1.5 mg/g for SCS, 1.8 mg/g for CB and 0.88 mg/g for NCS. The effect of temperature on sorption phenomenon was also investigated. The results indicated that adsorption is an endothermic process for phosphate ions removal. This study demonstrates that all the considered sorbents can be used as an alternative emerging technology for water treatment without any side effect or treatment process alteration

  9. In situ treatment of arsenic contaminated groundwater by aquifer iron coating: Experimental study.

    Science.gov (United States)

    Xie, Xianjun; Wang, Yanxin; Pi, Kunfu; Liu, Chongxuan; Li, Junxia; Liu, Yaqing; Wang, Zhiqiang; Duan, Mengyu

    2015-09-15

    In situ arsenic removal from groundwater by an aquifer iron coating method has great potential to be a cost effective and simple groundwater remediation technology, especially in rural and remote areas where groundwater is used as the main water source for drinking. The in situ arsenic removal technology was first optimized by simulating arsenic removal in various quartz sand columns under anoxic conditions. The effectiveness was then evaluated in an actual high-arsenic groundwater environment. The arsenic removal mechanism by the coated iron oxide/hydroxide was investigated under different conditions using scanning electron microscopy (SEM)/X-ray absorption spectroscopy, electron probe microanalysis, and Fourier transformation infrared spectroscopy. Aquifer iron coating method was developed via a 4-step alternating injection of oxidant, iron salt and oxygen-free water. A continuous injection of 5.0 mmol/L FeSO4 and 2.5 mmol/L NaClO for 96 h can form a uniform goethite coating on the surface of quartz sand without causing clogging. At a flow rate of 7.2 mL/min of the injection reagents, arsenic (as Na2HAsO4) and tracer fluorescein sodium to pass through the iron-coated quartz sand column were approximately at 126 and 7 column pore volumes, respectively. The retardation factor of arsenic was 23.0, and the adsorption capacity was 0.11 mol As per mol Fe. In situ arsenic removal from groundwater in an aquifer was achieved by simultaneous injections of As(V) and Fe(II) reagents. Arsenic fixation resulted from a process of adsorption/co-precipitation with fine goethite particles by way of bidentate binuclear complexes. Therefore, the study results indicate that the high arsenic removal efficiency of the in situ aquifer iron coating technology likely resulted from the expanded specific surface area of the small goethite particles, which enhanced arsenic sorption capability and/or from co-precipitation of arsenic on the surface of goethite particles. Copyright © 2015

  10. The Practical Realisation of Zinc-Iron CMA Coatings

    DEFF Research Database (Denmark)

    Jensen, Jens Dahl

    1998-01-01

    A detailed study of the production opportunities for composition modulated alloy electrodeposits by pulsed current techniques with Zinc-Iron alloys is reported. It is shown that by using a chloride solution, with the additional capability of variable agitation rates, a full range of alloy...... compositions is possible with nanometre layering attainable using single or double bath methods. Furthermore, by the use of a high concentration of ammonium chloride ostensibly as "conductivity" salt, the mechanism of deposition may be modified through control of a thin cathode oxide/hydroxide film....

  11. Clearance of iron oxide particles in rat liver: effect of hydrated particle size and coating material on liver metabolism.

    Science.gov (United States)

    Briley-Saebo, Karen C; Johansson, Lars O; Hustvedt, Svein Olaf; Haldorsen, Anita G; Bjørnerud, Atle; Fayad, Zahi A; Ahlstrom, Haakan K

    2006-07-01

    We sought to evaluate the effect of the particle size and coating material of various iron oxide preparations on the rate of rat liver clearance. The following iron oxide formulations were used in this study: dextran-coated ferumoxide (size = 97 nm) and ferumoxtran-10 (size = 21 nm), carboxydextran-coated SHU555A (size = 69 nm) and fractionated SHU555A (size = 12 nm), and oxidized-starch coated materials either unformulated NC100150 (size = 15 nm) or formulated NC100150 injection (size = 12 nm). All formulations were administered to 165 rats at 2 dose levels. Quantitative liver R2* values were obtained during a 63-day time period. The concentration of iron oxide particles in the liver was determined by relaxometry, and these values were used to calculate the particle half-lives in the liver. After the administration of a high dose of iron oxide, the half-life of iron oxide particles in rat liver was 8 days for dextran-coated materials, 10 days for carboxydextran materials, 14 days for unformulated oxidized-starch, and 29 days for formulated oxidized-starch. The results of the study indicate that materials with similar coating but different sizes exhibited similar rates of liver clearance. It was, therefore, concluded that the coating material significantly influences the rate of iron oxide clearance in rat liver.

  12. Effects of ph ON Ni Coating on Poly(ethylene Terephthalate) Substrate by Printing Prime in Combination with Palladium Activating

    Science.gov (United States)

    Huang, Junjun; Sun, Zhiping; Huang, Hongzhi; Liu, Qi; Gao, Min; Li, Mengyu; Zhao, Feng; Chen, Zhenming

    2016-04-01

    In this work, the primer-printed and then self-assembled poly(ethylene terephthalate) (PET) sheets were plated when the bath pH increased from 7 to 11. The effects of bath pH on the structural and electrical properties of electroless nickel plating were investigated systematically using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that the crystallographic structures of Ni-plated PET (NPP) sheets were face centered cubic, the preferential orientation of the coatings changes from (200) plane to (111) plane, the growth rate of plated nickel coating increased from 3.71μm/min to 8.13μm/min, the average Ni crystal size was increased from 0.23μm to 0.92μm, the average EMI-SE of NPP sheets was increased from 37.2dB to 38.6dB and the surface electrical resistivity of NPP sheets was decreased from 6235ohm ṡ cm to 0.03ohm ṡ cm with the increase of bath pH. The changes in structural and electrical properties were most possibly due to the fact that the thickness of coating increased.

  13. Effect of coating thickness of iron oxide nanoparticles on their relaxivity in the MRI

    Directory of Open Access Journals (Sweden)

    Farzaneh Hajesmaeelzadeh

    2016-02-01

    Full Text Available Objective(s:Iron oxide nanoparticles have found prevalent applications in various fields including drug delivery, cell separation and as contrast agents. Super paramagnetic iron oxide (SPIO nanoparticles allow researchers and clinicians to enhance the tissue contrast of an area of interest by increasing the relaxation rate of water. In this study, we evaluate the dependency of hydrodynamic size of iron oxide nanoparticles coated with Polyethylene  glycol (PEG on their relativities with 3 Tesla clinical MRI. Materials and Methods: We used three groups of nanoparticles with nominal sizes 20, 50 and 100 nm with a core size of 8.86 nm, 8.69 nm and 10.4 nm that they were covered with PEG 300 and 600 Da. A clinical magnetic resonance scanner determines the T1 and T2 relaxation times for various concentrations of PEG-coated nanoparticles. Results: The size measurement by photon correlation spectroscopy showed the hydrodynamic sizes of MNPs with nominal 20, 50 and 100 nm with 70, 82 and 116 nm for particles with PEG 600 coating and 74, 93 and 100 nm for  particles with PEG 300 coating, respectively. We foud that the relaxivity decreased with increasing overall particle size (via coating thickness. Magnetic resonance imaging showed that by increasing the size of the nanoparticles, r2/r1 increases linearly. Conclusion: According to the data obtained from this study it can be concluded that increments in coating thickness have more influence on relaxivities compared to the changes in core size of magnetic nanoparticles.

  14. Reductive Degradation of Perfluorinated Compounds in Water using Mg-aminoclay coated Nanoscale Zero Valent Iron

    OpenAIRE

    Arvaniti, Olga S.; Hwang, Yuhoon; Andersen, Henrik Rasmus; Stasinakis, Athanasios S.; Thomaidis , Nikolaos S.; Aloupi, Maria

    2015-01-01

    Perfluorinated Compounds (PFCs) are extremely persistent micropollutants that are detected worldwide. We studied the removal of PFCs (perfluorooctanoic acid; PFOA, perfluorononanoic acid; PFNA, perfluorodecanoic acid; PFDA and perfluorooctane sulfonate; PFOS) from water by different types of nanoscale zero-valent iron (nZVI). Batch experiments showed that an iron dose of 1 g•L-1 in the form of Mg-aminoclay (MgAC) coated nZVI, at an initial pH of 3.0 effectively removed 38 % to 96 % of individ...

  15. TiC Reinforcement Composite Coating Produced Using Graphite of the Cast Iron by Laser Cladding

    Directory of Open Access Journals (Sweden)

    Yanhui Liu

    2016-09-01

    Full Text Available In this study, a TiC-reinforced composite coating was produced to improve the wear resistance of a pearlite matrix grey iron using a pre-placed Ti powder by laser cladding. Results of scanning electron microscopy (SEM, X-ray diffractometer (XRD, and energy dispersive X-ray spectroscopy (EDS confirmed that the coating was composed of TiC particles and two kinds of α-Fe phase. The fine TiC particles were only a few microns in size and uniformly distributed on the matrix phase in the composite coating. The microstructure characteristic of the composite coating resulted in the microhardness rising to about 1000 HV0.3 (China GB/T 4342-1991 and the wear resistance significantly increased relative to the substrate. In addition, the fine and homogeneous solidification microstructure without graphite phase in the transition zone led to a good metallurgical bonding and transition between the coating and the substrate. It was of great significance for the cast iron to modify the surface and repair surface defects or surface damage.

  16. TiC Reinforcement Composite Coating Produced Using Graphite of the Cast Iron by Laser Cladding.

    Science.gov (United States)

    Liu, Yanhui; Qu, Weicheng; Su, Yu

    2016-09-30

    In this study, a TiC-reinforced composite coating was produced to improve the wear resistance of a pearlite matrix grey iron using a pre-placed Ti powder by laser cladding. Results of scanning electron microscopy (SEM), X-ray diffractometer (XRD), and energy dispersive X-ray spectroscopy (EDS) confirmed that the coating was composed of TiC particles and two kinds of α -Fe phase. The fine TiC particles were only a few microns in size and uniformly distributed on the matrix phase in the composite coating. The microstructure characteristic of the composite coating resulted in the microhardness rising to about 1000 HV0.3 (China GB/T 4342-1991) and the wear resistance significantly increased relative to the substrate. In addition, the fine and homogeneous solidification microstructure without graphite phase in the transition zone led to a good metallurgical bonding and transition between the coating and the substrate. It was of great significance for the cast iron to modify the surface and repair surface defects or surface damage.

  17. On Degradation of Cast Iron Surface-Protective Paint Coat Joint

    Directory of Open Access Journals (Sweden)

    Tupaj M.

    2016-09-01

    Full Text Available The paper is a presentation of a study on issues concerning degradation of protective paint coat having an adverse impact on aesthetic qualities of thin-walled cast-iron castings fabricated in furan resin sand. Microscopic examination and microanalyses of chemistry indicated that under the coat of paint covering the surface of a thin-walled casting, layers of oxides could be found presence of which can be most probably attributed to careless cleaning of the casting surface before the paint application process, as well as corrosion pits evidencing existence of damp residues under the paint layers contributing to creation of corrosion micro-cells

  18. Influence of dextran coating on the magnetic behaviour of iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Dutz, Silvio; Andrae, Wilfried; Hergt, Rudolf; Mueller, Robert; Oestreich, Christiane; Schmidt, Christopher; Toepfer, Jorg; Zeisberger, Matthias; Bellemann, Matthias E.

    2007-01-01

    Magnetic iron oxide nanoparticles with mean diameters in the range from 10 to 30 nm were prepared by modified chemical precipitation routes. The particles were suspended in an aqueous solution by coating of the particles with carboxymethyldextran. A stability against agglomeration was achieved over a period of more than 7 days. In the present investigation, the structural and the magnetic properties of the nanoparticles were investigated. The influence of the dextran shell on the strength of the dipole-dipole interactions between the neighbouring particles was determined by investigation of the remanence behaviour (Henkel plot) of coated as well as of uncoated particles

  19. Iron oxide coating films in soda-lime glass by triboadhesion

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, J. O.; Arjona, M. J. [Boulevard Bahia s/n esq. Ignacio Comonfort, Chetumal (Mexico); Rodriguez-Lelis, J. M. [Interior Internado Palmira s/n, Cuernavaca, Morelos (Mexico)

    2009-04-15

    In the triboadhesion process the coating material is passed through a rotating cotton mop and the substrate to be coated. The cotton mop rotates at high velocity and exerts pressure on the surface of the substrate. The combined effect of pressure and velocity of the coating mop on the substrate increases its temperature close to the melting point, allowing deposition and diffusion of the coating material within the substrate. After it is deposited, its particles are embedded within the base material forming a thin film composite. The amount of the coating material deposited on the substrate has its maximum at the surface and then decreases as a function of the local temperature within the base material. Bearing this in mind, in the present work, triboadhesion is employed to deposit iron oxide in a substrate of soda-lime glass, with the purpose of determining the feasibility of using this technique for solar control coatings. It was found, through electronic scan microscopy, that a composite material film is formed following the coating direction. Reflectance and transmittance tests were carried out on the glass samples. A 20% difference was found in the visible spectral region (VIS), and a reduction between 10 and 20% in the Near Infrared Region (NIR). These results showed that the triboadhesion is a promising technique for the application of thin films for solar control or solar cells

  20. Iron oxide coating films in soda-lime glass by triboadhesion

    International Nuclear Information System (INIS)

    Aguilar, J. O.; Arjona, M. J.; Rodriguez-Lelis, J. M.

    2009-01-01

    In the triboadhesion process the coating material is passed through a rotating cotton mop and the substrate to be coated. The cotton mop rotates at high velocity and exerts pressure on the surface of the substrate. The combined effect of pressure and velocity of the coating mop on the substrate increases its temperature close to the melting point, allowing deposition and diffusion of the coating material within the substrate. After it is deposited, its particles are embedded within the base material forming a thin film composite. The amount of the coating material deposited on the substrate has its maximum at the surface and then decreases as a function of the local temperature within the base material. Bearing this in mind, in the present work, triboadhesion is employed to deposit iron oxide in a substrate of soda-lime glass, with the purpose of determining the feasibility of using this technique for solar control coatings. It was found, through electronic scan microscopy, that a composite material film is formed following the coating direction. Reflectance and transmittance tests were carried out on the glass samples. A 20% difference was found in the visible spectral region (VIS), and a reduction between 10 and 20% in the Near Infrared Region (NIR). These results showed that the triboadhesion is a promising technique for the application of thin films for solar control or solar cells

  1. Room temperature trapping of stibine and bismuthine onto quartz substrates coated with nanostructured palladium for total reflection X-ray fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vanesa; Costas-Mora, Isabel; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

    2015-05-01

    In this work, a novel method for determining Sb and Bi based on the trapping of their covalent hydrides onto quartz reflectors coated with immobilized palladium nanoparticles (Pd NPs) followed by total reflection X-ray fluorescence (TXRF) analysis is proposed. Pd NPs were synthesized by chemical reduction of the metal precursor using a mixture of water:ethanol as mild reducing agent. Silanization using 3-mercaptopropyltrimethoxysilane (MPTMS) was performed for the immobilization of Pd NPs onto the quartz substrates. Volatile hydrides (stibine and bismuthine) generated by means of a continuous flow system were flushed onto the immobilized Pd NPs and retained by catalytic decomposition. As a result of the high catalytic activity of the nanostructured film, trapping can be performed at ambient temperature with good efficiency. Limits of detection (LODs) were 2.3 and 0.70 μg L{sup −1} for Sb and Bi, respectively. Enrichment factors of 534 and 192 were obtained for Sb and Bi, respectively. The new method was applied for the analysis of several matrices (milk, soil, sediment, cutaneous powder). Recoveries were in the range of 98.4–101% for both elements with a relative standard deviation of 2.5% (N = 5). - Highlights: • A novel method for trapping covalent hydrides of antimony and bismuth is proposed. • Emphasis is placed on the application of Pd nanoparticles as trapping surface. • The nanostructured surface provides high catalytic activity at ambient temperature. • Analysis by total reflection X-ray fluorescence is performed. • Determination of Bi and Sb in different matrices is carried out.

  2. Surface functionalization of dopamine coated iron oxide nanoparticles for various surface functionalities

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, Jennifer; Xu, Yaolin; Lovas, Kira [Chemical and Biological Engineering, The University of Alabama, Tuscaloosa , AL 35487 (United States); Qin, Ying [Alabama Innovation and Mentoring of Entrepreneurs, The University of Alabama, Tuscaloosa, AL 35487 (United States); Bao, Yuping, E-mail: ybao@eng.ua.edu [Chemical and Biological Engineering, The University of Alabama, Tuscaloosa , AL 35487 (United States)

    2017-04-01

    We present effective conjugation of four small molecules (glutathione, cysteine, lysine, and Tris(hydroxymethyl)aminomethane) onto dopamine-coated iron oxide nanoparticles. Conjugation of these molecules could improve the surface functionality of nanoparticles for more neutral surface charge at physiological pH and potentially reduce non-specific adsorption of proteins to nanoparticles surfaces. The success of conjugation was evaluated with dynamic light scattering by measuring the surface charge changes and Fourier transform infrared spectroscopy for surface chemistry analysis. The stability of dopamine-coated nanoparticles and the ability of conjugated nanoparticles to reduce the formation of protein corona were evaluated by measuring the size and charge of the nanoparticles in biological medium. This facile conjugation method opens up possibilities for attaching various surface functionalities onto iron oxide nanoparticle surfaces for biomedical applications.

  3. Surface functionalization of dopamine coated iron oxide nanoparticles for various surface functionalities

    International Nuclear Information System (INIS)

    Sherwood, Jennifer; Xu, Yaolin; Lovas, Kira; Qin, Ying; Bao, Yuping

    2017-01-01

    We present effective conjugation of four small molecules (glutathione, cysteine, lysine, and Tris(hydroxymethyl)aminomethane) onto dopamine-coated iron oxide nanoparticles. Conjugation of these molecules could improve the surface functionality of nanoparticles for more neutral surface charge at physiological pH and potentially reduce non-specific adsorption of proteins to nanoparticles surfaces. The success of conjugation was evaluated with dynamic light scattering by measuring the surface charge changes and Fourier transform infrared spectroscopy for surface chemistry analysis. The stability of dopamine-coated nanoparticles and the ability of conjugated nanoparticles to reduce the formation of protein corona were evaluated by measuring the size and charge of the nanoparticles in biological medium. This facile conjugation method opens up possibilities for attaching various surface functionalities onto iron oxide nanoparticle surfaces for biomedical applications.

  4. Reproductive performance of breeder quails fed diets supplemented with L-cysteine-coated iron oxide nanoparticles.

    Science.gov (United States)

    Mohammadi, H; Farzinpour, A; Vaziry, A

    2017-04-01

    The objective of this study was to investigate the effects of L-cysteine-coated iron oxide nanoparticles on reproductive performance in breeder quails. The five treatment diets consisted of (i) negative control diet not supplemented with iron, (ii) positive control diet supplemented with 60 mg/kg of Fe 3 O 4 and (iii) experimental diets supplemented with 0.6, 6 and 60 mg/kg of L-cysteine-coated iron oxide nanoparticles. A total of 100 seven-day-old quail chicks were weighed and randomly placed to five groups of five replicate cages. Four quails (one male and three females) were raised in each cage (50 × 15 × 17 cm). Egg production, feed consumption and egg weight were recorded daily and calculated on a hen per day basis. Egg components, fertility, hatchability and day-old chicks hatched from their eggs were measured at the end of the experiment. The percentage of egg production and egg mass of the 6 mg/kg Fe 3 O 4 -Cys NPs group were significantly higher than those of the control groups. Throughout the experimental period, the highest weekly egg weight was recorded for the 60 mg/kg Fe 3 O 4 -Cys NPs group. Fertility was improved by diet supplemented with iron, both FeSO 4 and Fe 3 O 4 -Cys NPs. The breeder fed Fe 3 O 4 -Cys NPs had the highest day-old chicks weight. The results of this study showed that Fe 3 O 4 nanoparticles that were coated by L-cysteine could improve availability and utilization of iron in diet. Finally, it was proposed that Fe 3 O 4 -Cys NPs could be used as feed additives in quails. © 2017 Blackwell Verlag GmbH.

  5. Electroerosion formation and technology of cast iron coatings on aluminum alloys

    Directory of Open Access Journals (Sweden)

    Smolentsev Vladislav P.

    2017-01-01

    Full Text Available At present in the course of designing basic production parts and industrial equipment designers pay more and more attention to aluminum alloys having a number of properties compared favorably with other materials. In particular, technological aluminum tool electrodes without coating in the presence of products of processing with alkali in the composition of operation environment are being destroyed at the expense of intensified material dissolution. It is shown in the paper that the method offered by the authors and covered by the patents on cast iron coating of products made of aluminum alloys, allows obtaining on a product surface the layers with high adhesion durability ensuring a high protection against destruction in the friction units including operation in hostile environment. Thereupon, aluminum, as compared with iron-based alloys used at manufacturing technological equipment for electrical methods of processing, has a high electrical and thermal conduction, its application will allow achieving considerable energy-saving in the course of parts production. A procedure for the design of a technological process of qualitative cast iron coatings upon aluminum tool electrodes and parts of basic production used in different branches of mechanical engineering is developed.

  6. Health implications of PAH release from coated cast iron drinking water distribution systems in The Netherlands.

    Science.gov (United States)

    Blokker, E J Mirjam; van de Ven, Bianca M; de Jongh, Cindy M; Slaats, P G G Nellie

    2013-05-01

    Coal tar and bitumen have been historically used to coat the insides of cast iron drinking water mains. Polycyclic aromatic hydrocarbons (PAHs) may leach from these coatings into the drinking water and form a potential health risk for humans. We estimated the potential human cancer risk from PAHs in coated cast iron water mains. In a Dutch nationwide study, we collected drinking water samples at 120 locations over a period of 17 days under various operational conditions, such as undisturbed operation, during flushing of pipes, and after a mains repair, and analyzed these samples for PAHs. We then estimated the health risk associated with an exposure scenario over a lifetime. During flushing, PAH levels frequently exceeded drinking water quality standards; after flushing, these levels dropped rapidly. After the repair of cast iron water mains, PAH levels exceeded the drinking water standards for up to 40 days in some locations. The estimated margin of exposure for PAH exposure through drinking water was > 10,000 for all 120 measurement locations, which suggests that PAH exposure through drinking water is of low concern for consumer health. However, factors that differ among water systems, such as the use of chlorination for disinfection, may influence PAH levels in other locations.

  7. Electrochemical reduction of nitroaromatic compounds by single sheet iron oxide coated electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Li-Zhi, E-mail: lizhi@plen.ku.dk [Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK–1871 Frederiksberg C (Denmark); Hansen, Hans Christian B. [Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK–1871 Frederiksberg C (Denmark); Bjerrum, Morten Jannik [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK–2100 København Ø (Denmark)

    2016-04-05

    Highlights: • Composite layers of single sheet iron oxides were coated on indium tin oxide electrodes. • Single sheet iron oxide is an electro-catalyst for reduction of nitroaromatic compounds in aqueous solution. • The reduction is well explained by a diffusion layer model. • The charge properties of the nitrophenols have an important influence on reduction. • Low-cost iron oxide based materials are promising electro-catalyst for water treatment. - Abstract: Nitroaromatic compounds are substantial hazard to the environment and to the supply of clean drinking water. We report here the successful reduction of nitroaromatic compounds by use of iron oxide coated electrodes, and demonstrate that single sheet iron oxides formed from layered iron(II)-iron(III) hydroxides have unusual electrocatalytic reactivity. Electrodes were produced by coating of single sheet iron oxides on indium tin oxide electrodes. A reduction current density of 10 to 30 μA cm{sup −2} was observed in stirred aqueous solution at pH 7 with concentrations of 25 to 400 μM of the nitroaromatic compound at a potential of −0.7 V vs. SHE. Fast mass transfer favors the initial reduction of the nitroaromatic compound which is well explained by a diffusion layer model. Reduction was found to comprise two consecutive reactions: a fast four-electron first-order reduction of the nitro-group to the hydroxylamine-intermediate (rate constant = 0.28 h{sup −1}) followed by a slower two-electron zero-order reduction resulting in the final amino product (rate constant = 6.9 μM h{sup −1}). The zero-order of the latter reduction was attributed to saturation of the electrode surface with hydroxylamine-intermediates which have a more negative half-wave potential than the parent compound. For reduction of nitroaromatic compounds, the SSI electrode is found superior to metal electrodes due to low cost and high stability, and superior to carbon-based electrodes in terms of high coulombic efficiency and

  8. Fabrication and properties of iron-based soft magnetic composites coated with parylene via chemical vapor deposition polymerization

    International Nuclear Information System (INIS)

    Wu, Shen; Sun, Aizhi; Lu, Zhenwen; Cheng, Chuan

    2015-01-01

    This paper focuses on novel iron-based soft magnetic composites synthesis utilizing low friction factor parylene C films to coat iron powder via chemical vapor deposition polymerization. The morphology, magnetic properties, density, and chemical stability of parylene insulated iron particles were investigated. The coated parylene insulating layer was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The thickness of parylene C film is averagely 300 nm according to the results of transmission electron microscopy. Parylene C film uniformly coated the powder surface resulting in reducing the permeability imaginary part, increasing electrical resistivity and increasing the operating frequency of the synthesized magnets. It was shown that the parylene C coated compacts exhibited noticeably higher density compared to the epoxy resin coated compacts at the same pressure, suppress at 800 MPa increased the density by 17.02%. The result of Tafel curves indicated that the resistance of the iron particles to corrosion by NaCl solution is obviously improved after being insulated with parylene C film. - Highlights: • Parylene C uniformly coated the powder, increased the operating frequency of SMCs. • Compared with epoxy coated, the density of SMCs increased by 17.02% at 800 MPa. • The resistance of the iron particles is obviously improved with parylene film insulated

  9. Microwave absorbing property of a hybrid absorbent with carbonyl irons coating on the graphite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai, 200438 (China); Yan, Zhenqiang; Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2015-11-30

    Graphical abstract: The absorbing property could be enhanced as the CIPs coated on the graphite. - Highlights: • Absorbers filled with CIPs coating on the graphite was fabricated. • The permittivity and permeability increased as CIPs coated. • The CIP materials enhanced the electromagnetic property. • The graphite coated CIPs were effective in 2–18 GHz. - Abstract: The hybrid absorbent filled with carbonyl iron particles (CIPs) coating on the graphite was prepared using a chemical vapor decomposition (CVD) process. X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. The results showed that α-Fe appeared in the super-lattice diffraction peaks in XRD graph. The composites added CIPs coating on the graphite had a higher permittivity and imaginary permeability due to the superior microwave dielectric loss and magnetic loss of the CIPs. The reflection loss (RL) result showed that composites filled with 5 vol% Fe-graphite had an excellent absorbing property in the 2–18 GHz, the minimum RL was −25.14 dB at 6 mm and −26.52 dB at 8 mm, respectively.

  10. Manganese Dioxide Coated Graphene Nanoribbons Supported Palladium Nanoparticles as an Efficient Catalyst for Ethanol Electrooxidation in Alkaline Media

    International Nuclear Information System (INIS)

    Liu, Qi; Jiang, Kun; Fan, Jinchen; Lin, Yan; Min, Yulin; Xu, Qunjie; Cai, Wen-Bin

    2016-01-01

    Design of appropriate supporting materials is an alternative route to yield efficient Pt-free catalysts for ethanol oxidation reaction, which in practice may determine the conversion efficiency of direct alkaline ethanol fuel cells. In this work, graphene nanoribbons (GNRs) coated with MnO_2 are used as a unique supporting material for loading and dispersing Pd nanoparticles. XRD, TEM and XPS are applied to characterize the structure of as-synthesized Pd/MnO_2/GNRs nanocomposite catalyst, revealing a good dispersion as well as a modification of electronic property of Pd nanoparticles. Electrochemical measurements demonstrate that the as-synthesized nanocomposite displays largely enhanced electrocatalytic activity and durability toward ethanol oxidation in alkaline media as compared to the other tested Pd-based catalysts with various supports.

  11. 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.

  12. Efficient internalization of silica-coated iron oxide nanoparticles of different sizes by primary human macrophages and dendritic cells

    International Nuclear Information System (INIS)

    Kunzmann, Andrea; Andersson, Britta; Vogt, Carmen; Feliu, Neus; Ye Fei; Gabrielsson, Susanne; Toprak, Muhammet S.; Buerki-Thurnherr, Tina; Laurent, Sophie; Vahter, Marie; Krug, Harald; Muhammed, Mamoun; Scheynius, Annika; Fadeel, Bengt

    2011-01-01

    Engineered nanoparticles are being considered for a wide range of biomedical applications, from magnetic resonance imaging to 'smart' drug delivery systems. The development of novel nanomaterials for biomedical applications must be accompanied by careful scrutiny of their biocompatibility. In this regard, particular attention should be paid to the possible interactions between nanoparticles and cells of the immune system, our primary defense system against foreign invasion. On the other hand, labeling of immune cells serves as an ideal tool for visualization, diagnosis or treatment of inflammatory processes, which requires the efficient internalization of the nanoparticles into the cells of interest. Here, we compare novel monodispersed silica-coated iron oxide nanoparticles with commercially available dextran-coated iron oxide nanoparticles. The silica-coated iron oxide nanoparticles displayed excellent magnetic properties. Furthermore, they were non-toxic to primary human monocyte-derived macrophages at all doses tested whereas dose-dependent toxicity of the smaller silica-coated nanoparticles (30 nm and 50 nm) was observed for primary monocyte-derived dendritic cells, but not for the similarly small dextran-coated iron oxide nanoparticles. No macrophage or dendritic cell secretion of pro-inflammatory cytokines was observed upon administration of nanoparticles. The silica-coated iron oxide nanoparticles were taken up to a significantly higher degree when compared to the dextran-coated nanoparticles, irrespective of size. Cellular internalization of the silica-coated nanoparticles was through an active, actin cytoskeleton-dependent process. We conclude that these novel silica-coated iron oxide nanoparticles are promising materials for medical imaging, cell tracking and other biomedical applications.

  13. Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Chang [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Fang Qingqing, E-mail: physfangqq@126.com [School of Physics and Material Science, Anhui University, Hefei 230036 (China) and Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China); Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong [School of Physics and Material Science, Anhui University, Hefei 230036 (China); Key Laboratory of Opto-electronic Information Acquisition and Manipulation Ministry of Education, Anhui University, Hefei 230039 (China)

    2012-05-15

    The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0-20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<-5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<-5 dB and RL<-8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was -29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: Black-Right-Pointing-Pointer We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. Black-Right-Pointing-Pointer ZnO dielectric property increased absorption effect and absorption bandwidth. Black-Right-Pointing-Pointer Absorbing frequence of composites is expanding to low frequency direction. Black-Right-Pointing-Pointer The craft of high energy ball milling is easy to realize commerce production.

  14. Enhanced microwave absorption in ZnO/carbonyl iron nano-composites by coating dielectric material

    International Nuclear Information System (INIS)

    Zhou Chang; Fang Qingqing; Yan Fangliang; Wang Weina; Wu Keyue; Liu Yanmei; Lv Qingrong; Zhang Hanming; Zhang Qiping; Li Jinguang; Ding Qiongqiong

    2012-01-01

    The microwave absorption properties of zinc oxide/carbonyl iron composite nanoparticles fabricated by high energy ball milling were studied at 0–20 GHz. Experiments showed that ZnO as a kind of dielectric material coating carbonyl iron particles made the bandwidth of reflection loss (RL)<−5 dB expanding to the low frequency, and enhanced absorption effect obviously. For a 3 mm thickness absorber of ZnO/carbonyl iron after 30 h milling, the values of RL<−5 dB and RL<−8 dB were obtained in the frequency range from 7.0 GHz to 17.8 GHz and from 9.8 dB to 14.9 dB, respectively, and its strongest RL peak was −29.34 dB at 13.59 GHz. The magnetic loss of carbonyl iron particles and the dielectric loss of ZnO particles were the main mechanisms of microwave absorption for the composites. - Highlights: ► We fabricated zinc oxide/carbonyl iron composites by high energy ball milling. ► ZnO dielectric property increased absorption effect and absorption bandwidth. ► Absorbing frequence of composites is expanding to low frequency direction. ► The craft of high energy ball milling is easy to realize commerce production.

  15. Electrochemical Study of Polymer and Ceramic-Based Nanocomposite Coatings for Corrosion Protection of Cast Iron Pipeline

    Directory of Open Access Journals (Sweden)

    Ameen Uddin Ammar

    2018-02-01

    Full Text Available Coating is one of the most effective measures to protect metallic materials from corrosion. Various types of coatings such as metallic, ceramic and polymer coatings have been investigated in a quest to find durable coatings to resist electrochemical decay of metals in industrial applications. Many polymeric composite coatings have proved to be resistant against aggressive environments. Two major applications of ferrous materials are in marine environments and in the oil and gas industry. Knowing the corroding behavior of ferrous-based materials during exposure to these aggressive applications, an effort has been made to protect the material by using polymeric and ceramic-based coatings reinforced with nano materials. Uncoated and coated cast iron pipeline material was investigated during corrosion resistance by employing EIS (electrochemical impedance spectroscopy and electrochemical DC corrosion testing using the “three electrode system”. Cast iron pipeline samples were coated with Polyvinyl Alcohol/Polyaniline/FLG (Few Layers Graphene and TiO2/GO (graphene oxide nanocomposite by dip-coating. The EIS data indicated better capacitance and higher impedance values for coated samples compared with the bare metal, depicting enhanced corrosion resistance against seawater and “produce water” of a crude oil sample from a local oil rig; Tafel scans confirmed a significant decrease in corrosion rate of coated samples.

  16. SYNTHESIS AND CORROSION PROTECTION BEHAVIOR OF EPOXYTiO2-MICACEOUS IRON OXIDE NANO - COMPOSITE COATING ON St-37

    Directory of Open Access Journals (Sweden)

    M. R. Khorram

    2016-03-01

    Full Text Available The micro layers micaceous iron oxide and nano-TiO 2 were incorporated into the epoxy resin by mechanical mixing and sonication process. Optical micrographs showed that the number and diameter size of nanoparticle agglomerates were decreased by sonication. The structure and composition of the nanocomposite was determined using transmission electron microscopy which showed the presence of dispersed nano-TiO 2 in the polymer matrix. The anticorrosive properties of the synthesized nano-composites coating were investigated using salt spray, electrochemical impedance spectroscopy and polarization measurement. The EIS results showed that coating resistance increased by addition of micaceous iron oxide micro layers and nano-TiO 2 particles to the epoxy coatings. It was observed that higher corrosion protection of nanocomposite coatings obtained by the addition of 3 %wt micaceous iron oxide and 4%wt nano-TiO 2 into epoxy resin.

  17. An ultrathin polymer coating of carboxylate self-assembled monolayer adsorbed on passivated iron to prevent iron corrosion in 0.1 M Na2SO4

    International Nuclear Information System (INIS)

    Aramaki, Kunitsugu; Shimura, Tadashi

    2010-01-01

    For preparing an ultrathin two-dimensional polymer coating adsorbed on passivated iron, a 16-hydroxyhexadecanoate ion HO(CH 2 ) 15 CO 2 - self-assembled monolayer (SAM) was modified with 1,2-bis(triethoxysilyl)ethane (C 2 H 5 O) 3 Si(CH 2 ) 2 Si(OC 2 H 5 ) 3 and octadecyltriethoxysilane C 18 H 37 Si(OC 2 H 5 ) 3 . Protection of passivated iron against passive film breakdown and corrosion of iron was investigated by monitoring of the open-circuit potential and repeated polarization measurements in an aerated 0.1 M Na 2 SO 4 solution during immersion for many hours. The time required for passive film breakdown of the polymer-coated electrode was markedly higher in this solution than that of the passivated one, indicating protection of the passive film from breakdown by coverage with the polymer coating. The protective efficiencies of the passive film covered with the coating were extremely high, more than 99.9% in 0.1 M Na 2 SO 4 before the passive film was broken down, showing prominent cooperative suppression of iron corrosion in the solution by coverage with the passive film and polymer coating. The polymer-coated surface was characterized by contact angle measurement and electron-probe microanalysis (EPMA). Prevention of passive film breakdown and iron corrosion for the polymer-coated electrode healed in 0.1 M NaNO 3 was also examined in 0.1 M Na 2 SO 4 .

  18. A general strategy toward graphitized carbon coating on iron oxides as advanced anodes for lithium-ion batteries.

    Science.gov (United States)

    Ding, Chunyan; Zhou, Weiwei; Wang, Bin; Li, Xin; Wang, Dong; Zhang, Yong; Wen, Guangwu

    2017-08-25

    Integration of carbon materials with benign iron oxides is blazing a trail in constructing high-performance anodes for lithium-ion batteries (LIBs). In this paper, a unique general, simple, and controllable strategy is developed toward in situ uniform coating of iron oxide nanostructures with graphitized carbon (GrC) layers. The basic synthetic procedure only involves a simple dip-coating process for the loading of Ni-containing seeds and a subsequent Ni-catalyzed chemical vapor deposition (CVD) process for the growth of GrC layers. More importantly, the CVD treatment is conducted at a quite low temperature (450 °C) and with extremely facile liquid carbon sources consisting of ethylene glycol (EG) and ethanol (EA). The GrC content of the resulting hybrids can be controllably regulated by altering the amount of carbon sources. The electrochemical results reveal remarkable performance enhancements of iron oxide@GrC hybrids compared with pristine iron oxides in terms of high specific capacity, excellent rate and cycling performance. This can be attributed to the network-like GrC coating, which can improve not only the electronic conductivity but also the structural integrity of iron oxides. Moreover, the lithium storage performance of samples with different GrC contents is measured, manifesting that optimized electrochemical property can be achieved with appropriate carbon content. Additionally, the superiority of GrC coating is demonstrated by the advanced performance of iron oxide@GrC compared with its corresponding counterpart, i.e., iron oxides with amorphous carbon (AmC) coating. All these results indicate the as-proposed protocol of GrC coating may pave the way for iron oxides to be promising anodes for LIBs.

  19. MR imaging of abscess by use of lipid-coated iron oxide particles

    International Nuclear Information System (INIS)

    Chan, T.W.; Eley, C.G.S.; Kressel, H.Y.

    1990-01-01

    The authors of this paper investigate the potential application of lipid-coated iron oxide particles as an MR contrast agent for imaging inflammatory process by using a rat subcutaneous abscess model induced by turpentine. Ten male Sprague-Dawley rats received subcutaneous injections of 0.1 mL of turpentine in the flank. At 24-36 hours later, the rats developed a subcutaneous abscess of 1-1.8 cm. An intravenous injection of lipid-coated iron oxide particles, Ferrosome (Vestar) at doses of 25, 40, 100, 200 μg/kg was administered. The animals were imaged at 12-24 hours later on a 1.5-T magnet using a 3-inch (7.62-cm) surface coil. Two animals were also imaged 5 days later. T1-weighted, T2-weighted, and multiplanar gradient-recalled (MPGR) sequences were obtained. The abscess was then excised and examined with routine H-E and iron staining

  20. Toxicity assessment of silica coated iron oxide nanoparticles and biocompatibility improvement by surface engineering.

    Directory of Open Access Journals (Sweden)

    Maria Ada Malvindi

    Full Text Available We have studied in vitro toxicity of iron oxide nanoparticles (NPs coated with a thin silica shell (Fe3O4/SiO2 NPs on A549 and HeLa cells. We compared bare and surface passivated Fe3O4/SiO2 NPs to evaluate the effects of the coating on the particle stability and toxicity. NPs cytotoxicity was investigated by cell viability, membrane integrity, mitochondrial membrane potential (MMP, reactive oxygen species (ROS assays, and their genotoxicity by comet assay. Our results show that NPs surface passivation reduces the oxidative stress and alteration of iron homeostasis and, consequently, the overall toxicity, despite bare and passivated NPs show similar cell internalization efficiency. We found that the higher toxicity of bare NPs is due to their stronger in-situ degradation, with larger intracellular release of iron ions, as compared to surface passivated NPs. Our results indicate that surface engineering of Fe3O4/SiO2 NPs plays a key role in improving particles stability in biological environments reducing both cytotoxic and genotoxic effects.

  1. Rapid microwave-assisted synthesis of dextran-coated iron oxide nanoparticles for magnetic resonance imaging.

    Science.gov (United States)

    Osborne, Elizabeth A; Atkins, Tonya M; Gilbert, Dustin A; Kauzlarich, Susan M; Liu, Kai; Louie, Angelique Y

    2012-06-01

    Currently, magnetic iron oxide nanoparticles are the only nanosized magnetic resonance imaging (MRI) contrast agents approved for clinical use, yet commercial manufacturing of these agents has been limited or discontinued. Though there is still widespread demand for these particles both for clinical use and research, they are difficult to obtain commercially, and complicated syntheses make in-house preparation unfeasible for most biological research labs or clinics. To make commercial production viable and increase accessibility of these products, it is crucial to develop simple, rapid and reproducible preparations of biocompatible iron oxide nanoparticles. Here, we report a rapid, straightforward microwave-assisted synthesis of superparamagnetic dextran-coated iron oxide nanoparticles. The nanoparticles were produced in two hydrodynamic sizes with differing core morphologies by varying the synthetic method as either a two-step or single-step process. A striking benefit of these methods is the ability to obtain swift and consistent results without the necessity for air-, pH- or temperature-sensitive techniques; therefore, reaction times and complex manufacturing processes are greatly reduced as compared to conventional synthetic methods. This is a great benefit for cost-effective translation to commercial production. The nanoparticles are found to be superparamagnetic and exhibit properties consistent for use in MRI. In addition, the dextran coating imparts the water solubility and biocompatibility necessary for in vivo utilization.

  2. Rapid microwave-assisted synthesis of dextran-coated iron oxide nanoparticles for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Osborne, Elizabeth A; Atkins, Tonya M; Kauzlarich, Susan M; Gilbert, Dustin A; Liu Kai; Louie, Angelique Y

    2012-01-01

    Currently, magnetic iron oxide nanoparticles are the only nanosized magnetic resonance imaging (MRI) contrast agents approved for clinical use, yet commercial manufacturing of these agents has been limited or discontinued. Though there is still widespread demand for these particles both for clinical use and research, they are difficult to obtain commercially, and complicated syntheses make in-house preparation unfeasible for most biological research labs or clinics. To make commercial production viable and increase accessibility of these products, it is crucial to develop simple, rapid and reproducible preparations of biocompatible iron oxide nanoparticles. Here, we report a rapid, straightforward microwave-assisted synthesis of superparamagnetic dextran-coated iron oxide nanoparticles. The nanoparticles were produced in two hydrodynamic sizes with differing core morphologies by varying the synthetic method as either a two-step or single-step process. A striking benefit of these methods is the ability to obtain swift and consistent results without the necessity for air-, pH- or temperature-sensitive techniques; therefore, reaction times and complex manufacturing processes are greatly reduced as compared to conventional synthetic methods. This is a great benefit for cost-effective translation to commercial production. The nanoparticles are found to be superparamagnetic and exhibit properties consistent for use in MRI. In addition, the dextran coating imparts the water solubility and biocompatibility necessary for in vivo utilization. (paper)

  3. Catalytic Ozonation by Iron Coated Pumice for the Degradation of Natural Organic Matters

    Directory of Open Access Journals (Sweden)

    Alper Alver

    2018-05-01

    Full Text Available The use of iron-coated pumice (ICP in heterogeneous catalytic ozonation significantly enhanced the removal efficiency of natural organic matters (NOMs in water, due to the synergistic effect of hybrid processes when compared to sole ozonation and adsorption. Multiple characterization analyses (BET, TEM, XRD, DLS, FT-IR, and pHPZC were employed for a systematic investigation of the catalyst surface properties. This analysis indicated that the ICP crystal structure was α-FeOOH, the surface hydroxyl group of ICP was significantly increased after coating, the particle size of ICP was about 200–250 nm, the BET surface area of ICP was about 10.56 m2 g−1, the pHPZC value of ICP was about 7.13, and that enhancement by iron loading was observed in the FT-IR spectra. The contribution of surface adsorption, hydroxyl radicals, and sole ozonation to catalytic ozonation was determined as 21.29%, 66.22%, and 12.49%, respectively. The reaction kinetic analysis with tert-Butyl alcohol (TBA was used as a radical scavenger, confirming that surface ferrous iron loading promoted the role of the hydroxyl radicals. The phosphate was used as an inorganic probe, and significantly inhibited the removal efficiency of catalytic NOM ozonation. This is an indication that the reactions which occur are more dominant in the solution phase.

  4. Genotoxicity assessment of magnetic iron oxide nanoparticles with different particle sizes and surface coatings

    International Nuclear Information System (INIS)

    Liu, Yanping; Xia, Qiyue; Liu, Ying; Zhang, Shuyang; Cheng, Feng; Wang, Li; Li, Hongxia; Xiao, Kai; Zhong, Zhihui

    2014-01-01

    Magnetic iron oxide nanoparticles (IONPs) have been widely used for various biomedical applications such as magnetic resonance imaging and drug delivery. However, their potential toxic effects, including genotoxicity, need to be thoroughly understood. In the present study, the genotoxicity of IONPs with different particle sizes (10, 30 nm) and surface coatings (PEG, PEI) were assessed using three standard genotoxicity assays, the Salmonella typhimurium reverse mutation assay (Ames test), the in vitro mammalian chromosome aberration test, and the in vivo micronucleus assay. In the Ames test, SMG-10 (PEG coating, 10 nm) showed a positive mutagenic response in all the five test bacterial strains with and without metabolic activation, whereas SEI-10 (PEI coating, 10 nm) showed no mutagenesis in all tester strains regardless of metabolic activation. SMG-30 (PEG coating, 30 nm) was not mutagenic in the absence of metabolic activation, and became mutagenic in the presence of metabolic activation. In the chromosomal aberration test, no increase in the incidence of chromosomal aberrations was observed for all three IONPs. In the in vivo micronucleus test, there was no evidence of increased micronuclei frequencies for all three IONPs, indicating that they were not clastogenic in vivo. Taken together, our results demonstrated that IONPs with PEG coating exhibited mutagenic activity without chromosomal and clastogenic abnormalities, and smaller IONPs (SMG-10) had stronger mutagenic potential than larger ones (SMG-30); whereas, IONPs with SEI coating (SEI-10) were not genotoxic in all three standard genotoxicity assays. This suggests that the mutagenicity of IONPs depends on their particle size and surface coating. (paper)

  5. Gold-coated iron nanoparticles in transparent Si{sub 3}N{sub 4} matrix thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Marcos, J. [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Madrid (Spain); Cespedes, E. [Keele University, Institute for Science and Technology in Medicine, Guy Hilton Research Centre (United Kingdom); Jimenez-Villacorta, F. [Northeastern University, Department of Chemical Engineering (United States); Munoz-Martin, A. [Universidad Autonoma de Madrid, Centro de Microanalisis de Materiales (Spain); Prieto, C., E-mail: cprieto@icmm.csic.es [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Madrid (Spain)

    2013-06-15

    A new method to prepare thin films containing gold-coated iron nanoparticles is presented. The ternary Fe-Au-Si{sub 3}N{sub 4} system prepared by sequential sputtering has revealed a progressive variation of microstructures from Au/Fe/Au/Si{sub 3}N{sub 4} multilayers to iron nanoparticles. Microstructural characterization by transmission electron microscopy, analysis of the magnetic properties and probing of the iron short-range order by X-ray absorption spectroscopy confirm the existence of a gold-coated iron nanoparticles of 1-2 nm typical size for a specific range of iron and gold contents per layer in the transparent silicon nitride ceramic matrix.

  6. Tuning dipolar magnetic interactions by controlling individual silica coating of iron oxide nanoparticles

    Science.gov (United States)

    Rivas Rojas, P. C.; Tancredi, P.; Moscoso Londoño, O.; Knobel, M.; Socolovsky, L. M.

    2018-04-01

    Single and fixed size core, core-shell nanoparticles of iron oxides coated with a silica layer of tunable thickness were prepared by chemical routes, aiming to generate a frame of study of magnetic nanoparticles with controlled dipolar interactions. The batch of iron oxides nanoparticles of 4.5 nm radii, were employed as cores for all the coated samples. The latter was obtained via thermal decomposition of organic precursors, resulting on nanoparticles covered with an organic layer that was subsequently used to promote the ligand exchange in the inverse microemulsion process, employed to coat each nanoparticle with silica. The amount of precursor and times of reaction was varied to obtain different silica shell thicknesses, ranging from 0.5 nm to 19 nm. The formation of the desired structures was corroborated by TEM and SAXS measurements, the core single-phase spinel structure was confirmed by XRD, and superparamagnetic features with gradual change related to dipolar interaction effects were obtained by the study of the applied field and temperature dependence of the magnetization. To illustrate that dipolar interactions are consistently controlled, the main magnetic properties are presented and analyzed as a function of center to center minimum distance between the magnetic cores.

  7. The effect of coating on heat generation properties of Iron oxide nanoparticles

    Science.gov (United States)

    Yuan, Yuan

    Magnetic nanoparticles have attracted more and more attention for their potential application as heating agents in cancer hyperthermia. The effectiveness of cancer hyperthermia can be increased by using particles that have a higher heat generation rate, quantified by specific absorption rate (SAR), at a smaller applied field. In order to optimize the functionality of nanoparticles as heating agents, it is essential to have a comprehensive understanding of factors that may influence SAR including coating and aggregation. In all biomedical applications, the magnetic particles are coated with surfactants and polymers to enhance biocompatibility, prevent agglomeration and add functionality. Coatings may profoundly influence particles' clustering behavior and magnetic properties. Yet its effect on the heat generation rate of the nanoparticles has been scarcely investigated. In this context, a systematic investigation was carried out in this dissertation in order to understand the impact of the surface coating of magnetic nanoparticles on their heat generation rate. The study also includes investigation of normal nerve cell viability in presence of biofunctionalized magnetic nanoparticles with and without exposure to magnetic heating. Commercially available suspensions of iron oxide nanoparticles with a diameter of approximately 10 nm and different coatings relevant to biomedical applications such as aminosilane, carboxymethyl-dextran, protein A, biotin were extensively characterized. First of all, magnetic phase reduction of magnetite nanoparticles was examined by studying the discrepancy between the volume fraction of magnetic phase calculated from magnetization curve and the magnetic core concentration obtained from Tiron chelation test. The findings indicated that coatings might interact with the surface atoms of the magnetic core and form a magnetically disordered layer reducing the total amount of the magnetic phase. Secondly, the impact of coating and aggregation

  8. Atherosclerotic imaging using 4 types of superparamagnetic iron oxides: New possibilities for mannan-coated particles

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, Keiko, E-mail: keikot@belle.shiga-medac.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Nitta, Norihisa, E-mail: r34nitta@yahoo.co.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Sonoda, Akinaga, E-mail: akinagasonoda@yahoo.co.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Otani, Hideji, E-mail: otani@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Takahashi, Masashi, E-mail: masashi@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Murata, Kiyoshi, E-mail: murata@belle.shiga-med.ac.jp [Department of Radiology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Shiomi, Masashi, E-mail: ieakusm@med.kobe-u.ac.jp [Institute for Experimental Animals, Kobe University School of Medicine, 7-5-1 Kusunoki-cho, Tyuoku, Kobe, Hyogo 650-0017 (Japan); Tabata, Yasuhiko, E-mail: yasuhiko@frontier.kyoto-u.ac.jp [Department of Biomaterials, Institute for Frontier Medical Sciences, Kyoto University, 53 Syogoin-Kawahara-cho, Sakyoku, Kyoto 606-8507 (Japan); Nohara, Satoshi, E-mail: s-nohara@meito-sangyo.co.jp [The Nagoya Research Laboratory, Meito Sangyo Co., Ltd., 25-5 Nishibiwajima-cho, Kiyosu, Aichi 452-0067 (Japan)

    2013-11-01

    Purpose: We used magnetic resonance imaging (MRI) and histologic techniques to compare the uptake by the rabbit atherosclerotic wall of 4 types of superparamagnetic iron oxide (SPIO) particles, i.e. SPIO, mannan-coated SPIO (M-SPIO), ultrasmall SPIO (USPIO), and mannan-coated USPIO (M-USPIO). Materials and methods: All experimental protocols were approved by our institutional animal experimentation committee. We intravenously injected 12 Watanabe heritable hyperlipidemic rabbits with one of the 4 types of SPIO (0.8 mmol Fe/kg). Two other rabbits served as the control. The rabbits underwent in vivo contrast-enhanced magnetic resonance angiography (MRA) before- and 5 days after these injections; excised aortae were subjected to in vitro MRI. In the in vivo and in vitro studies we assessed the signal intensity of the vessels at identical regions of interest (ROI) and calculated the signal-to-noise ratio (SNR). For histologic assessment we evaluated the iron-positive regions in Prussian blue-stained specimens. Results: There were significant differences in iron-positive regions where M-USPIO > USPIO, M-SPIO > SPIO, USPIO > SPIO (p < 0.05) but not between M-USPIO and M-SPIO. The difference between the pre- and post-injection SNR was significantly greater in rabbits treated with M-USPIO than USPIO and in rabbits injected with M-SPIO than SPIO (p < 0.05). On in vitro MRI scans SNR tended to be lower in M-USPIO- and M-SPIO- than USPIO- and SPIO-treated rabbits (p < 0.1). Conclusion: Histologic and imaging analysis showed that mannan-coated SPIO and USPIO particles were taken up more readily by the atherosclerotic rabbit wall than uncoated SPIO and USPIO.

  9. Stability of polyelectrolyte-coated iron nanoparticles for T2-weighted magnetic resonance imaging

    Science.gov (United States)

    McGrath, Andrew J.; Dolan, Ciaran; Cheong, Soshan; Herman, David A. J.; Naysmith, Briar; Zong, Fangrong; Galvosas, Petrik; Farrand, Kathryn J.; Hermans, Ian F.; Brimble, Margaret; Williams, David E.; Jin, Jianyong; Tilley, Richard D.

    2017-10-01

    Iron nanoparticles are highly-effective magnetic nanoparticles for T2 magnetic resonance imaging (MRI). However, the stability of their magnetic properties is dependent on good protection of the iron core from oxidation in aqueous media. Here we report the synthesis of custom-synthesized phosphonate-grafted polyelectrolytes (PolyM3) of various chain lengths, for efficient coating of iron nanoparticles with a native iron oxide shell. The size of the nanoparticle-polyelectrolyte assemblies was investigated by transmission electron microscopy and dynamic light scattering, while surface attachment was confirmed by Fourier transform infrared spectroscopy. Low cytotoxicity was observed for each of the nanoparticle-polyelectrolyte ("Fe-PolyM3") assemblies, with good cell viability (>80%) remaining up to 100 μg mL-1 Fe in HeLa cells. When applied in T2-weighted MRI, corresponding T2 relaxivities (r2) of the Fe-PolyM3 assemblies were found to be dependent on the chain length of the polyelectrolyte. A significant increase in contrast was observed when polyelectrolyte chain length was increased from 6 to 65 repeating units, implying a critical chain length required for stabilization of the α-Fe nanoparticle core.

  10. Magnetoelectric behavior of carbonyl iron mixed Mn oxide-coated ferrite nanoparticles

    Science.gov (United States)

    Ahad, Faris B. Abdul; Lee, Shang-Fan; Hung, Dung-Shing; Yao, Yeong-Der; Yang, Ruey-Bin; Lin, Chung-Kwei; Tsay, Chien-Yie

    2010-05-01

    The dielectric and magnetic properties of manganese oxide-coated Fe3O4 nanoparticles (NPs) were measured by the cavity perturbation method at x-band microwave frequencies ranging from 7-12.5 GHz with controlled external magnetic field up to 2.2 kOe at room temperature. Different ratios (5%, 10%, and 20% by weight) of coated NPs were prepared by sol-gel method then mixed with carbonyl iron powder in epoxy matrix. The saturation magnetization is inversely proportional to the NPs ratio in the mixture between 150 and 180 emu/g. The real part of the permittivity decreased with increasing NPs concentration, but the permittivity change by magnetic field increased. The tunability behavior is explained by insulator-ferromagnetic interface magnetoelectricity and the large surface volume ratio for the NPs.

  11. Chemical synthesis and characterization of hollow dopamine coated, pentagonal and flower shaped magnetic iron oxide nanoparticles

    Science.gov (United States)

    Riasat, Rabia; Kaynat, Sumbal

    2018-04-01

    Iron oxide nanoparticles have gained attention recently in the field of nanoscience and technology due to their unique physicochemical properties. We hereby chemically synthesized novel pentagonal flower shaped iron oxide nanoparticles by thermal decomposition of iron penta-carbonyl in a two way annealing process. Controlled oxidation by acid etching was performed for these nanoparticles. At first 13 nm core shell nanoparticles of iron oxide (Fe/Fe3O4) were synthesized at 120°C annealing temperature that act as template material. The core shell nanoparticles then converted into porous hollow core shell nanoparticles (PH Fe/ Fe3O4) in a two way annealing process of heating, first at 100°C then at 250°C and heating rate of 5°C was kept constant throughout the reaction time. X-Ray diffraction (XRD) was done for the phase confirmation of as synthesized nanoparticles. Transmission electron microscopy (TEM) and higher resolution transmission electron microscopy (HRTEM) clearly shows the flower like nanoparticles that are approx. 16 nm-18 nm in size having the 4-5 nm core of Fe and 1-2 nm of the pores in the shell while the cavity between the shell and core is about 2 nm and the shell is 4-5 nm in diameter according to the TEM micrographs. The as prepared nanoparticles were then surface functionalized by dopamine polymer to make them water dispersible. Fourier transform Infrared spectroscopy confirmed the dopamine coating on the nanoparticles and the magnetic saturation of 38 emu/g of nanoparticles was analyzed by vibrating sample magnetometer (VSM). Magnetic saturation persists in the dopamine coated nanoparticles. These nanoparticles were surface functionalized with dopamine and show dispersity in the aqueous media and can further be exploited in many nano-biotechnological applications including target specific therapeutic applications for several diseases.

  12. Effect of Iron Oxides (Ordinary and Nano and Municipal Solid Waste Compost (MSWC Coated Sulfur on Wheat (Triticum aestivum L. Plant Iron Concentration and Growth

    Directory of Open Access Journals (Sweden)

    S Mazaherinia

    2011-02-01

    Full Text Available Abstract A greenhouse study was conducted to compare the effects of ordinary iron oxide (0.02-0.06 mm and nano iron oxide (25-250 nm and five levels of both iron oxides (0, 0.05, 0.1, 0.5, and 1.0 %w/w and two levels of sulfurous granular compost (MSW (0 and 2% w/w on plant height, spike length, grain weight per spike, total plant dry matter weight and thousands grain weight of wheat. The experimental factors were combined in factorial arrangement in a completely randomized design with 3 replications. Results showed that nano iron oxide was superior over ordinary iron oxide in all parameters studied. Fe concentration, spike length, plant height, grain weight per spike, total plant dry weight and thousands grain weight showed increasing trend per increase in both of iron oxides levels. Also, all parameters studied in sulfurous granular compost (MSW treatment were superior over granular compost without sulfurous (MSW. This increase in all parameters were significantly higher when urban solid waste compost coated with sulfur coupled with nano iron oxide compared to urban sulfurous granular compost (MSW along with ordinary iron oxide. Keywords: Sulfurous granular compost (MSW, Nano and ordinary iron oxides, Wheat

  13. Preparation of nickel-coated titanium carbide particulates and their use in the production of reinforced iron matrix composites

    International Nuclear Information System (INIS)

    Yi, Danqing; Yu, Pengchao; Hu, Bin; Liu, Huiqun; Wang, Bin; Jiang, Yong

    2013-01-01

    Highlights: • Ni-coated TiC composite powders were prepared by electroless plating. • Iron-based composites reinforced by TiC particles was prepared by HIP. • Mechanical and wear properties were improved with the addition of Ni-coated TiC. • The nickel coating promotes the formation and growth of sintering neck. - Abstract: Ni-coated titanium carbide (TiC) composite powders were prepared by electroless plating (EP). Further, using hot isostatic pressing (HIP), iron matrix composites reinforced with 4 wt% Ni-coated TiC particulates with relative density close to 100% were prepared. The microstructure and phase composition of the Ni-coated powders and the composites were analyzed using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results showed that the TiC particles were distributed uniformly in the matrix and were free of segregation or coarsening. Compared to the TiC particles without Ni coating, the reinforced iron-based composites containing the Ni-coated particles showed higher relative densities and better mechanical properties. The density, hardness, tensile strength, and elongation were enhanced to 99.98%, 243 HV, 565 MPa, and 11.7%, respectively in composites containing Ni-coated TiC particles from 99.70%, 210 HV, 514 MPa, and 10.3%, respectively in composites that were prepared using particles without Ni coating. In addition, the mass losses in the composites containing the Ni-coated particles were reduced by 32–75% in the abrasive wear test with various vertical loads. We propose that the nickel coatings on the particulates had a beneficial effect on the microstructure and properties of the reinforced iron-based composites is due to promotion of neck formation and growth between TiC and iron powders during sintering, which enhanced the density of the sintered compact and the bonding strength between the TiC particles and the iron matrix

  14. Adsorption of arsenic(V) by iron-oxide-coated diatomite (IOCD).

    Science.gov (United States)

    Pan, Yi-Fong; Chiou, Cary T; Lin, Tsair-Fuh

    2010-09-01

    PURPOSES AND AIMS: Economically efficient methods for removing arsenic from the drinking water supply are urgently needed in many parts of the world. Iron oxides are known to have a strong affinity for arsenic in water. However, they are commonly present in the forms of fine powder or floc, which limits their utility in water treatment. In this study, a novel granular adsorbent, iron-oxide-coated diatomite (IOCD), was developed and examined for its adsorption of arsenic from water. An industrial-grade diatomite was used as the iron oxide support. The diatomite was first acidified and dried and then coated with iron oxide up to five times. The prepared IOCD samples were characterized for their morphology, composition, elemental content, and crystal properties by various instruments. Experiments of equilibrium and kinetic adsorption of As(V) on IOCD were conducted using 0.1- and 2-L polyethylene bottles, respectively, at different pH and temperatures. Iron oxide (alpha-Fe(2)O(3) hematite) coated onto diatomite greatly improves (by about 30 times) the adsorption of As(V) from water by IOCD as compared to using raw diatomite. This improvement was attributed to increases in both surface affinity and surface area of the IOCD. The surface area of IOCD increased to an optimal value. However, as the IOCD surface area (93 m(2)/g) was only 45% higher than that of raw diatomite (51 m(2)/g), the enhanced As(V) adsorption resulted primarily from the enhanced association of negatively charged As(V) ions with the partial positive surface charge of the iron oxide. The As(V) adsorption decreased when the solution pH was increased from 3.5 to 9.5, as expected from the partial charge interaction between As(V) and IOCD. The adsorption data at pH 5.5 and 7.5 could be well fitted to the Freundlich equation. A moderately high exothermic heat was observed for the As(V) adsorption, with the calculated molar isosteric heat ranging from -4 to -9 kcal/mol. The observed heats fall between those

  15. Ex vivo assessment of polyol coated-iron oxide nanoparticles for MRI diagnosis applications: toxicological and MRI contrast enhancement effects

    Science.gov (United States)

    Bomati-Miguel, Oscar; Miguel-Sancho, Nuria; Abasolo, Ibane; Candiota, Ana Paula; Roca, Alejandro G.; Acosta, Milena; Schwartz, Simó; Arus, Carles; Marquina, Clara; Martinez, Gema; Santamaria, Jesus

    2014-03-01

    Polyol synthesis is a promising method to obtain directly pharmaceutical grade colloidal dispersion of superparamagnetic iron oxide nanoparticles (SPIONs). Here, we study the biocompatibility and performance as T2-MRI contrast agents (CAs) of high quality magnetic colloidal dispersions (average hydrodynamic aggregate diameter of 16-27 nm) consisting of polyol-synthesized SPIONs (5 nm in mean particle size) coated with triethylene glycol (TEG) chains (TEG-SPIONs), which were subsequently functionalized to carboxyl-terminated meso-2-3-dimercaptosuccinic acid (DMSA) coated-iron oxide nanoparticles (DMSA-SPIONs). Standard MTT assays on HeLa, U87MG, and HepG2 cells revealed that colloidal dispersions of TEG-coated iron oxide nanoparticles did not induce any loss of cell viability after 3 days incubation with dose concentrations below 50 μg Fe/ml. However, after these nanoparticles were functionalized with DMSA molecules, an increase on their cytotoxicity was observed, so that particles bearing free terminal carboxyl groups on their surface were not cytotoxic only at low concentrations (MRI studies in mice indicated that both types of coated-iron oxide nanoparticles produced higher negative T2-MRI contrast enhancement than that measured for a similar commercial T2-MRI CAs consisting in dextran-coated ultra-small iron oxide nanoparticles (Ferumoxtran-10). In conclusion, the above attributes make both types of as synthesized coated-iron oxide nanoparticles, but especially DMSA-SPIONs, promising candidates as T2-MRI CAs for nanoparticle-enhanced MRI diagnosis applications.

  16. 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.

  17. Characterising palladium-silver and palladium-nickel alloy membranes using SEM, XRD and PIXE

    International Nuclear Information System (INIS)

    Keuler, J.N.; Lorenzen, L.; Sanderson, R.D.; Prozesky, V.; Przybylowicz, W.J.

    1999-01-01

    Palladium alloy membranes were prepared by successive electroless plating steps on an alumina-zirconia support membrane. Palladium, silver and nickel were deposited in layers and then the metal films were heat treated for 5 h in a hydrogen atmosphere at 650 deg. C. The topography of the metal coatings and cross-sections of the films (before and after heating) were characterised using scanning electron microscopy (SEM). XRD was used to determine the crystal phase of the alloy coatings. Both SEM and XRD provide only surface information and therefore micro-PIXE was used to extract depth information of the alloy coating. Concentration profiles across the thickness of the films were constructed to determine penetration of the coating into the support membrane pores during electroless plating and to investigate diffusion of coated layers during the heating step

  18. Iron-based soft magnetic composites with Mn-Zn ferrite nanoparticles coating obtained by sol-gel method

    Science.gov (United States)

    Wu, Shen; Sun, Aizhi; Xu, Wenhuan; Zhang, Qian; Zhai, Fuqiang; Logan, Philip; Volinsky, Alex A.

    2012-11-01

    This paper focuses on iron-based soft magnetic composites which were synthesized by utilizing Mn-Zn ferrite nanoparticles to coat iron powder. The nanocrystalline iron powders, with an average particle diameter of 20 nm, were obtained via the sol-gel method. Scanning electron microscopy, energy dispersive X-ray spectroscopy and distribution maps show that the iron particle surface is covered with a thin layer of Mn-Zn ferrites. Mn-Zn ferrite uniformly coated the surface of the powder particles, resulting in a reduced imaginary permeability, increased electrical resistivity and a higher operating frequency of the synthesized magnets. Mn-Zn ferrite coated samples have higher permeability and lower magnetic loss when compared with the non-magnetic epoxy resin coated compacts. The real part of permeability increases by 33.5% when compared with the epoxy resin coated samples at 10 kHz. The effects of heat treatment temperature on crystalline phase formation and on the magnetic properties of the Mn-Zn ferrite were investigated via X-ray diffraction and a vibrating sample magnetometer. Ferrites decomposed to FeO and MnO after annealing above 400 °C in nitrogen; thus it is the optimum annealing temperature to attain the desired permeability.

  19. Wear Resistant Thermal Sprayed Composite Coatings Based on Iron Self-Fluxing Alloy and Recycled Cermet Powders

    Directory of Open Access Journals (Sweden)

    Heikki SARJAS

    2012-03-01

    Full Text Available Thermal spray and WC-Co based coatings are widely used in areas subjected to abrasive wear. Commercial  cermet thermal spray powders for HVOF are relatively expensive. Therefore applying these powders in cost-sensitive areas like mining and agriculture are hindered. Nowadays, the use of cheap iron based self-fluxing alloy powders for thermal spray is limited. The aim of this research was to study properties of composite powders based on self-fluxing alloys and recycled cermets and to examine the properties of thermally sprayed (HVOF coatings from composite powders based on iron self-fluxing alloy and recycled cermet powders (Cr3C2-Ni and WC-Co. To estimate the properties of  recycled cermet powders, the sieving analysis, laser granulometry and morphology were conducted. For deposition of coatings High Velocity Oxy-Fuel spray was used. The structure and composition of powders and coatings were estimated by SEM and XRD methods. Abrasive wear performance of coatings was determined and compared with wear resistance of coatings from commercial powders. The wear resistance of thermal sprayed coatings from self-fluxing alloy and recycled cermet powders at abrasion is comparable with wear resistance of coatings from commercial expensive spray powders and may be an alternative in tribological applications in cost-sensitive areas.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1338

  20. Magnetically anisotropic additive for scalable manufacturing of polymer nanocomposite: iron-coated carbon nanotubes

    International Nuclear Information System (INIS)

    Yamamoto, Namiko; Manohara, Harish; Platzman, Ellen

    2016-01-01

    Novel nanoparticles additives for polymer nanocomposites were prepared by coating carbon nanotubes (CNTs) with ferromagnetic iron (Fe) layers, so that their micro-structures can be bulk-controlled by external magnetic field application. Application of magnetic fields is a promising, scalable method to deliver bulk amount of nanocomposites while maintaining organized nanoparticle assembly throughout the uncured polymer matrix. In this work, Fe layers (∼18 nm thick) were deposited on CNTs (∼38 nm diameter and ∼50 μm length) to form thin films with high aspect ratio, resulting in a dominance of shape anisotropy and thus high coercivity of ∼50–100 Oe. The Fe-coated CNTs were suspended in water and applied with a weak magnetic field of ∼75 G, and yet preliminary magnetic assembly was confirmed. Our results demonstrate that the fabricated Fe-coated CNTs are magnetically anisotropic and effectively respond to magnetic fields that are ∼10 3 times smaller than other existing work (∼10 5 G). We anticipate this work will pave the way for effective property enhancement and bulk application of CNT–polymer nanocomposites, through controlled micro-structure and scalable manufacturing. (paper)

  1. Interdiffusion behaviors of iron aluminide coatings on China low activation martensitic steel

    Science.gov (United States)

    Zhu, X. X.; Yang, H. G.; Yuan, X. M.; Zhao, W. W.; Zhan, Q.

    2014-12-01

    The iron aluminide coating on China Low Activation Martensitic (CLAM) steel was prepared by pack cementation and subsequent heat treatment. A surface Fe2Al5 layer was formed on CLAM substrate by pack cementation process with Fe2Al5 donor powder and NH4Cl activator. Diffusion heat treatment was performed in order to allow the phase transformation from Fe2Al5 to a phase with lower aluminum content. Morphology and composition of the coatings were characterized by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), glow discharge optical emission spectroscopy (GDOES) and X-ray diffraction (XRD). There is a need to study the interdiffusion behaviors in these Al containing systems, as a basis for controlling the formation and subsequent degradation of the coating. In this paper, a predictive model was developed to describe the phase transformation of Fe2Al5 as a function of processing parameters. The Wagner's equation was used to calculate the interdiffusion coefficients based on the analysis of the Al concentration profiles. The results showed that the interdiffusion coefficients in the FeAl and α-Fe(Al) phase strongly depends on Al content and showed a maximum at about 28 at.% Al.

  2. Interdiffusion behaviors of iron aluminide coatings on China low activation martensitic steel

    International Nuclear Information System (INIS)

    Zhu, X.X.; Yang, H.G.; Yuan, X.M.; Zhao, W.W.; Zhan, Q.

    2014-01-01

    The iron aluminide coating on China Low Activation Martensitic (CLAM) steel was prepared by pack cementation and subsequent heat treatment. A surface Fe 2 Al 5 layer was formed on CLAM substrate by pack cementation process with Fe 2 Al 5 donor powder and NH 4 Cl activator. Diffusion heat treatment was performed in order to allow the phase transformation from Fe 2 Al 5 to a phase with lower aluminum content. Morphology and composition of the coatings were characterized by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), glow discharge optical emission spectroscopy (GDOES) and X-ray diffraction (XRD). There is a need to study the interdiffusion behaviors in these Al containing systems, as a basis for controlling the formation and subsequent degradation of the coating. In this paper, a predictive model was developed to describe the phase transformation of Fe 2 Al 5 as a function of processing parameters. The Wagner’s equation was used to calculate the interdiffusion coefficients based on the analysis of the Al concentration profiles. The results showed that the interdiffusion coefficients in the FeAl and α-Fe(Al) phase strongly depends on Al content and showed a maximum at about 28 at.% Al

  3. Measurement of the thickness of the sprayed nickel coatings on large-sized cast iron products

    Directory of Open Access Journals (Sweden)

    В. А. Сясько

    2016-11-01

    Full Text Available Modern industries increasingly use automatic spraying of heat-resistant Nickel  coating with a thickness  of      T = 1-3 mm for large-size parts made of cast iron with nodular graphite. The process of coating application is characterized by time-dependent behavior of its relative magnetic permeability, μс , that is a function of relaxation time, which can be as long as 24 hours, and by μс deviation from point to point on the surface. Aspects of eddy-current phase method for measuring the T value are considered. The structure of four- winding eddy current transformer transducers is described and results of calculation and optimization of their parameters are presented. The influence of controlled and interfering parameters is considered. Based  on the above results, a two-channel combined transducer is developed  providing measurement  error  of ΔТ ≤ ±(0.03T + 0.02 mm  in the shop environment in the process of coating application and in the final product check. Results of tests on reference specimens and of application in production processes are presented.

  4. Cutting Performance of Low Stress Thick TiAlN PVD Coatings during Machining of Compacted Graphite Cast Iron (CGI

    Directory of Open Access Journals (Sweden)

    Kenji Yamamoto

    2018-01-01

    Full Text Available A new family of physical vapor deposited (PVD coatings is presented in this paper. These coatings are deposited by a superfine cathode (SFC using the arc method. They combine a smooth surface, high hardness, and low residual stresses. This allows the production of PVD coatings as thick as 15 µm. In some applications, in particular for machining of such hard to cut material as compacted graphite iron (CGI, such coatings have shown better tool life compared to the conventional PVD coatings that have a lower thickness in the range of up to 5 μm. Finite element modeling of the temperature/stress profiles was done for the SFC coatings to present the temperature/stress profiles during cutting. Comprehensive characterization of the coatings was performed using XRD, TEM, SEM/EDS studies, nano-hardness, nano-impact measurements, and residual stress measurements. Application of the coating with this set of characteristics reduces the intensity of buildup edge formation during turning of CGI, leading to longer tool life. Optimization of the TiAlN-based coatings composition (Ti/Al ratio, architecture (mono vs. multilayer, and thickness were performed. Application of the optimized coating resulted in a 40–60% improvement in the cutting tool life under finishing turning of CGI.

  5. Preparation and characterization of hydroxyapatite-coated iron oxide particles by spray-drying technique

    Directory of Open Access Journals (Sweden)

    karina Donadel

    2009-06-01

    Full Text Available Magnetic particles of iron oxide have been increasingly used in medical diagnosis by magnetic resonance imaging and in cancer therapies involving targeted drug delivery and magnetic hyperthermia. In this study we report the preparation and characterization of iron oxide particles coated with bioceramic hydroxyapatite by spray-drying. The iron oxide magnetic particles (IOMP were coated with hydroxyapatite (HAp by spray-drying using two IOMP/HAp ratios (0.7 and 3.2. The magnetic particles were characterized by way of scanning electronic microscopy, energy dispersive X-ray, X-ray diffraction, Fourier transformed infrared spectroscopy, flame atomic absorption spectrometry,vibrating sample magnetometry and particle size distribution (laser diffraction. The surface morphology of the coated samples is different from that of the iron oxide due to formation of hydroxyapatite coating. From an EDX analysis, it was verified that the surface of the coated magnetic particles is composed only of HAp, while the interior containsiron oxide and a few layers of HAp as expected. The results showed that spray-drying technique is an efficient and relatively inexpensive method for forming spherical particles with a core/shell structure.As partículas de óxido de ferro têm sido extensivamente usadas em diagnósticos médicos como agente de contraste para imagem por ressonância magnética e na terapia do câncer, dentre estas, liberação de fármacos em sitos alvos e hipertermia magnética. Neste estudo nós reportamos a preparação e caracterização de partículas magnéticas de óxido de ferro revestidas com a biocerâmica hidroxiapatita. As partículas magnéticasde óxido de ferro (PMOF foram revestidas com hidroxiapatita por spray-drying usando duas razões PMOF/HAp (0,7 e 3,2. As partículas magnéticas foram caracterizadas por microscopia eletrônica de varredura, energia dispersiva de raios X, difração de raios X, espectroscopia de absorção no infra

  6. Evaluation of Iron and Manganese-Coated Pumice Application for the Removal of as(v from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Leila Babaie Far

    2012-12-01

    Full Text Available Arsenic contamination of water has been recognized as a serious environmental issue and there are reports on its epidemiological problems to human health. The objective of this study was to evaluate the performances of iron-coated pumice and manganese-coated pumice as the adsorbents for removing arsenate from aqueous solutions. The effect of various parameters such as adsorbent dose, contact time, pH and initial concentration on removal efficiency of arsenate were evaluated in batch mode. The data obtained from the kinetic studies were analyzed using kinetic models of pseudo-first-order and pseudo-second-order. In addition, two isotherm models of Freundlich and Langmuir were used to fit the experimental data. The results showed that the optimum dosage of iron-coated pumice and manganese-coated pumice for arsenate removal were 40 and 80 g/L whereas the adsorption process reached equilibrium after 80 and 100 min, respectively. The maximum removal efficiency of arsenate using the two adsorbents were both recorded in pH=3 as the removal efficiency gradually declinedfollowing every increase in pH values of the solution. Iron-coated pumice also showed to have high removal efficiency when the initial concentration of arsenate was high while the low concentration of arsenate was efficiently removed by manganese-coated pumice. Moreover, it was depicted that the adsorption kinetics by bothadsorbents followed pseudo-second order equation and the uptake data of arsenate were well fitted with Langmuir isotherm model. Therefore, it could be concluded that iron and manganese-coated pumice could beconsidered as suitable adsorbents for arsenate removal from aqueous solutions.

  7. Iron-based soft magnetic composites with Mn–Zn ferrite nanoparticles coating obtained by sol–gel method

    International Nuclear Information System (INIS)

    Wu, Shen; Sun, Aizhi; Xu, Wenhuan; Zhang, Qian; Zhai, Fuqiang; Logan, Philip; Volinsky, Alex A.

    2012-01-01

    This paper focuses on iron-based soft magnetic composites which were synthesized by utilizing Mn–Zn ferrite nanoparticles to coat iron powder. The nanocrystalline iron powders, with an average particle diameter of 20 nm, were obtained via the sol–gel method. Scanning electron microscopy, energy dispersive X-ray spectroscopy and distribution maps show that the iron particle surface is covered with a thin layer of Mn–Zn ferrites. Mn–Zn ferrite uniformly coated the surface of the powder particles, resulting in a reduced imaginary permeability, increased electrical resistivity and a higher operating frequency of the synthesized magnets. Mn–Zn ferrite coated samples have higher permeability and lower magnetic loss when compared with the non-magnetic epoxy resin coated compacts. The real part of permeability increases by 33.5% when compared with the epoxy resin coated samples at 10 kHz. The effects of heat treatment temperature on crystalline phase formation and on the magnetic properties of the Mn–Zn ferrite were investigated via X-ray diffraction and a vibrating sample magnetometer. Ferrites decomposed to FeO and MnO after annealing above 400 °C in nitrogen; thus it is the optimum annealing temperature to attain the desired permeability. - Highlights: ► Uniformly coated Mn–Zn ferrite powder increased the operating frequency of SMCs. ► Compared with epoxy coated, the permeability of SMCs increased by 33.5% at 10 kHz. ► 400 °C is the optimum annealing temperature to attain the desired permeability.

  8. Biodistribution, pharmacokinetics, and toxicity of dendrimer-coated iron oxide nanoparticles in BALB/c mice

    Directory of Open Access Journals (Sweden)

    Salimi M

    2018-03-01

    Full Text Available Marzieh Salimi,1,2 Saeed Sarkar,1,2 Samaneh Fathi,3 Ali Mohammad Alizadeh,4 Reza Saber,2,3 Fatemeh Moradi,5 Hamid Delavari6 1Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran; 2Research Center of Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran; 3Department of Medical Nanotechnology, Tehran University of Medical Sciences, Tehran, Iran; 4Cancer Research Center, Tehran University of Medical Sciences, Tehran, Iran; 5Department of Medical Physiology, Tehran University of Medical Sciences, Tehran, Iran; 6Department of Materials Science and Engineering, Tarbiat Modares University, Tehran, Iran Background: The possibility of using a specific nanoparticle in nanomedicine highly depends on its biodistribution profile and biocompatibility. Due to growing demand for iron oxide nanoparticles (IONPs and dendrimers in biomedical applications, this study was performed to assess the biodistribution, pharmacokinetics, and toxicity of dendrimer-coated iron oxide nanoparticles (G4@IONPs. Materials and methods: IONPs were synthesized via co-precipitation and coated with the fourth generation (G4 of polyamidoamine (PAMAM dendrimer. To determine the biodistribution, 5 mg/mL G4@IONPs suspension was intraperitoneally injected into tumor-bearing BALB/c mice, and iron levels in blood and various organs, including the lung, liver, brain, heart, tumor, and kidney, were measured by inductively coupled plasma mass spectrometry (ICP-MS at 4, 8, 12, and 24 h after injection. Also, to investigate the toxicity of G4@IONPs, different concentrations of G4@IONPs were injected into BALB/c mice, and blood, renal, and hepatic factors were measured. Furthermore, histopathological staining was performed to investigate the effect of G4@IONPs on the liver and kidney tissues. Results: The results showed that the iron content was higher in the kidney, liver, and lung tissues 24 h after

  9. A density functional theory study of the carbon-coating effects on lithium iron borate battery electrodes

    DEFF Research Database (Denmark)

    Loftager, Simon; García Lastra, Juan Maria; Vegge, Tejs

    2017-01-01

    a density functional theory (DFT) study of the anchoring configurations of carbon coating on the LiFeBO3 electrode and its implications on the interfacial lithium diffusion. Due to large barriers associated with Li-ion diffusion through a parallel-oriented pristine graphene coating on the FeBO3 and LiFeBO3......Lithium iron borate (LiFeBO3) is a promising cathode material due to its high theoretical specific capacity, inexpensive components and a small volume change during operation. Yet, challenges relating to severe air- and moisture-induced degradation necessitate the application of a protective...... coating on the electrode which also improves the electronic conductivity. However, not much is known about the preferential geometries of the coating as well as how these coating–electrode interfaces influence the lithium diffusion between the coating and the electrode. Here, we therefore present...

  10. Discrepancy between different estimates of the hydrodynamic diameter of polymer-coated iron oxide nanoparticles in solution

    International Nuclear Information System (INIS)

    Regmi, R.; Gumber, V.; Subba Rao, V.; Kohli, I.; Black, C.; Sudakar, C.; Vaishnava, P.; Naik, V.; Naik, R.; Mukhopadhyay, A.; Lawes, G.

    2011-01-01

    We have synthesized iron oxide nanoparticles coated with a monolayer of dextran, with molecular weights of the polymer between 5 and 670 kDa. Transmission electron microscopy images confirm that the hard core has a crystalline diameter of approximately 12 nm. The hydrodynamic diameters of these coated nanoparticles in solution measured using dynamical light scattering and estimated from magnetic susceptibility studies vary from near 90 nm for the lightest polymer to 140 nm for the heaviest polymer. Conversely, fluorescence correlation spectroscopy measurements yield a diameter of approximately 55 nm for the 15–20 kDa dextran coated nanoparticles, which is consistent with the expected value estimated from the sum of the hard-core diameter and monolayer dextran coating. We discuss the implications of this discrepancy for applications involving polymer-coated magnetic nanoparticles.

  11. Methodology description for detection of cellular uptake of PVA coated superparamagnetic iron oxide nanoparticles (SPION) in synovial cells of sheep

    International Nuclear Information System (INIS)

    Schoepf, Bernhard; Neuberger, Tobias; Schulze, Katja; Petri, Alke; Chastellain, Matthieu; Hofmann, Margarete; Hofmann, Heinrich; Rechenberg, Brigitte von

    2005-01-01

    The detection of superparamagnetic iron oxide nanoparticles (SPION) in synoviocytes is reported. Synoviocytes were incubated for 2, 12, 24 and 48 h with 1.5 mg/ml of PVA coated SPION under the influence of magnets (12 h). Particles were well tolerated by the synoviocytes, were easily detected using the Turnbulls and Prussian blue reactions between 12 and 24 h

  12. Methodology description for detection of cellular uptake of PVA coated superparamagnetic iron oxide nanoparticles (SPION) in synovial cells of sheep

    Energy Technology Data Exchange (ETDEWEB)

    Schoepf, Bernhard [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland); Neuberger, Tobias [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland); Schulze, Katja [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland); Petri, Alke [Powder Technology Laboratory, Institute of Materials, Swiss Federal Institute of Technology Lausanne, EPFL, MX-D Ecublens, 1015 Lausanne (Switzerland); Chastellain, Matthieu [Powder Technology Laboratory, Institute of Materials, Swiss Federal Institute of Technology Lausanne, EPFL, MX-D Ecublens, 1015 Lausanne (Switzerland); Hofmann, Margarete [MatSearch, Ch. Jean Pavillard 14, 1009 Pully (Switzerland); Hofmann, Heinrich [Powder Technology Laboratory, Institute of Materials, Swiss Federal Institute of Technology Lausanne, EPFL, MX-D Ecublens, 1015 Lausanne (Switzerland); Rechenberg, Brigitte von [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland)]. E-mail: bvonrechenberg@vetclinics.unizh.ch

    2005-05-15

    The detection of superparamagnetic iron oxide nanoparticles (SPION) in synoviocytes is reported. Synoviocytes were incubated for 2, 12, 24 and 48 h with 1.5 mg/ml of PVA coated SPION under the influence of magnets (12 h). Particles were well tolerated by the synoviocytes, were easily detected using the Turnbulls and Prussian blue reactions between 12 and 24 h.

  13. Microstructure and wear behaviors of WC–12%Co coating deposited on ductile iron by electric contact surface strengthening

    International Nuclear Information System (INIS)

    Qi, Xiaoben; Zhu, Shigen; Ding, Hao; Zhu, Zhengkun; Han, Zhibing

    2013-01-01

    WC–12%Co powders deposited on ductile iron by electric contact strengthening were studied. This technology was based on the application of the contact resistance heating between the electrode and work piece to form a wear resistant layer on ductile iron. The microstructure, microhardness distribution, phase transformation and wear behaviors of the coating were investigated using optical microscope, scanning electron microscope, Vickers hardness (HV 0.5 ), X-ray diffraction, rolling contact wear tests. The results showed that the WC–12%Co coating by electric contact strengthening was metallurgically bonded to the ductile iron. Additionally, the effect of experimental parameters on microhardness and wear resistance of coatings were studied using orthogonal experiment. The results showed that compared with (A) electric current and (B) rotating speed, (C) contact force displays the most significant effect on microhardness and wear resistance of coatings. The coatings produced at A = 19 kA, B = 0.3 r/min and C = 700 N possessed highest microhardness of 1073 HV 0.5 and wear resistance.

  14. Study and modeling of the ironing process on a multi-layered polymer coated low-carbon steel

    Science.gov (United States)

    Selles Canto, Miguel Angel

    The ironing process is the most crucial step in the manufacture of cans. Sheet steel covered by three polymer layers can be used as the starting material, but this coating must neither break nor fail in any manner in order to be considered as a viable and effective alternative to traditional practice. During ironing, the deformations are severe and high pressures exist at the tool-workpiece interface. Thickness reductions inherent in ironing require a large amount of surface generation. Deterioration of the coating in this delicate operation might enable direct contact of the stored food or drink with the metal. As can be appreciated, the key to the use of polymer-coated steel sheets in the manufacture of cans lies in the survival of these layers during the ironing process. Another important issue is the roughness of the newly-generated surface, because it should be possible to decorate the can without any difficulty. Changing the traditional manufacture of metallic containers such as cans and using this new coated material permits great reduction in environmental contaminants produced as a result of avoiding the formation of Volatile Organic Compounds (VOCs) during the manufacture of the polymer layers. This reduction is even greater because of not using additional lubricants due to the self-lubricanting property of the solid polymer coating layers during the drawing process. These objectives, together with the improvement of the mechanical characteristics and the adhesion of the painting or decorative priming, are realized by the use of the proposed material. In the existing bibliography about ironing processes on coated materials, some authors propose the use of the Upper Bound Theorem for modeling the material behavior. The present research shows for the first time the modeling of the ironing process on a three-layer polymer coated material. In addition, it takes into account the cases in which successful ironing is produced and those in which ones the ironing

  15. Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

    International Nuclear Information System (INIS)

    Bloemen, Maarten; Brullot, Ward; Luong, Tai Thien; Geukens, Nick; Gils, Ann; Verbiest, Thierry

    2012-01-01

    Superparamagnetic iron oxide nanoparticles can provide multiple benefits for biomedical applications in aqueous environments such as magnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality water-dispersible nanoparticles around 10 nm in size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.

  16. Macrophage membrane-coated iron oxide nanoparticles for enhanced photothermal tumor therapy

    Science.gov (United States)

    Meng, Qian-Fang; Rao, Lang; Zan, Minghui; Chen, Ming; Yu, Guang-Tao; Wei, Xiaoyun; Wu, Zhuhao; Sun, Yue; Guo, Shi-Shang; Zhao, Xing-Zhong; Wang, Fu-Bing; Liu, Wei

    2018-04-01

    Nanotechnology possesses the potential to revolutionize the diagnosis and treatment of tumors. The ideal nanoparticles used for in vivo cancer therapy should have long blood circulation times and active cancer targeting. Additionally, they should be harmless and invisible to the immune system. Here, we developed a biomimetic nanoplatform with the above properties for cancer therapy. Macrophage membranes were reconstructed into vesicles and then coated onto magnetic iron oxide nanoparticles (Fe3O4 NPs). Inherited from the Fe3O4 core and the macrophage membrane shell, the resulting Fe3O4@MM NPs exhibited good biocompatibility, immune evasion, cancer targeting and light-to-heat conversion capabilities. Due to the favorable in vitro and in vivo properties, biomimetic Fe3O4@MM NPs were further used for highly effective photothermal therapy of breast cancer in nude mice. Surface modification of synthetic nanomaterials with biomimetic cell membranes exemplifies a novel strategy for designing an ideal nanoplatform for translational medicine.

  17. Mechanism of Dimercaptosuccinic Acid Coated Superparamagnetic Iron Oxide Nanoparticles with Human Serum Albumin.

    Science.gov (United States)

    Zhao, Lining; Song, Wei; Wang, Jing; Yan, Yunxing; Chen, Jiangwei; Liu, Rutao

    2015-12-01

    To research the mechanism of dimercaptosuccinic acid coated-superparamagnetic iron oxide nanoparticles (SPION) with human serum albumin (HSA), the methods of spectroscopy, molecular modeling calculation, and calorimetry were used in this paper. The inner filter effect of the fluorescence intensity was corrected to obtain the accurate results. Ultraviolet-visible absorption and circular dichroism spectra reflect that SPION changed the secondary structure with a loss of α-helix and loosened the protein skeleton of HSA; the activity of the protein was also affected by the increasing exposure of SPION. Fluorescence lifetime measurement indicates that the quenching mechanism type of this system was static quenching. The isothermal titration calorimetry measurement and molecular docking calculations prove that the predominant force of this system was the combination of Van der Waals' force and hydrogen bonds. © 2015 Wiley Periodicals, Inc.

  18. Effect of the Surface Layer of Iron Casting on the Growth of Protective Coating During Hot-Dip Galvanizing

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2016-03-01

    Full Text Available The paper presents the results of investigations of the growth of protective coating on the surface of ductile iron casting during the hot-dip galvanizing treatment. Ductile iron of the EN-GJS-600-3 grade was melted and two moulds made by different technologies were poured to obtain castings with different surface roughness parameters. After the determination of surface roughness, the hot-dip galvanizing treatment was carried out. Based on the results of investigations, the effect of casting surface roughness on the kinetics of the zinc coating growth was evaluated. It was found that surface roughness exerts an important effect on the thickness of produced zinc coating.

  19. Iron

    Science.gov (United States)

    Iron is a mineral that our bodies need for many functions. For example, iron is part of hemoglobin, a protein which carries ... It helps our muscles store and use oxygen. Iron is also part of many other proteins and ...

  20. Photoactive nanocomplex formed from chlorophyll assembly on TMA-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Barbaros, Sibel; Meray, Zeynep; Tecim, Tuğba; Genç, Rükan, E-mail: rukangnc@gmail.com [Mersin University, Functional Nanomaterials Laboratory, Chemical Engineering Department, Engineering Faculty (Turkey)

    2016-07-15

    In this study, hierarchical self-assembly of photocatalytic nanodisks through non-covalent interactions between spinach-extracted chlorophyll molecules and trimethylammonium hydroxide-coated magnetic iron oxide nanoparticles was discussed. Combination of chlorophyll molecules with iron oxide nanoparticles generated an alteration in light absorption at both visible and near-IR region with accompanying enhancement in fluorescence emission. Further, photocatalytic role of resulting molecular assembly was studied by means of the photoinduced degradation of methylene blue dye under UV light and direct sun irradiation at neutral pH. In order to enhance the long-term stability of the hybrid nanocatalyst, commercially available cellulose membrane was used as a support and magnetic recovery and reusability was achieved where the nanocatalyst retained more than 90 % of its efficiency even after four cycles. This simple strategy could initiate the development of new materials for wastewater treatment including membrane-based technologies. On the other hand, their sunlight-induced photocatalytic activity could easily be conducted to dye-synthesized solar cells or their enhanced photoluminescence can provide a strong basis for future bioimaging tools.Graphical Abstract.

  1. Iron aluminide weld overlay coatings for boiler tube protection in coal-fired low NOx boilers

    Energy Technology Data Exchange (ETDEWEB)

    Banovic, S.W.; DuPont, J.N.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center

    1997-12-01

    Iron aluminide weld overlay coatings are currently being considered for enhanced sulfidation resistance in coal-fired low NO{sub x} boilers. The use of these materials is currently limited due to hydrogen cracking susceptibility, which generally increases with an increase in aluminum concentration of the deposit. The overall objective of this program is to attain an optimum aluminum content with good weldability and improved sulfidation resistance with respect to conventional materials presently in use. Research has been initiated using Gas Tungsten Arc Welding (GTAW) in order to achieve this end. Under different sets of GTAW parameters (wire feed speed, current), both single and multiple pass overlays were produced. Characterization of all weldments was conducted using light optical microscopy, scanning electron microscopy, and electron probe microanalysis. Resultant deposits exhibited a wide range of aluminum contents (5--43 wt%). It was found that the GTAW overlays with aluminum contents above {approximately}10 wt% resulted in cracked coatings. Preliminary corrosion experiments of 5 to 10 wt% Al cast alloys in relatively simple H{sub 2}/H{sub 2}S gas mixtures exhibited corrosion rates lower than 304 stainless steel.

  2. Oleate coating of iron oxide nanoparticles in aqueous systems: the role of temperature and surfactant concentration

    Energy Technology Data Exchange (ETDEWEB)

    Roth, Hans-Christian; Schwaminger, Sebastian; Fraga García, Paula; Ritscher, Jonathan; Berensmeier, Sonja, E-mail: s.berensmeier@tum.de [Technische Universität München, Bioseparation Engineering Group (Germany)

    2016-04-15

    Coating magnetic nanoparticles (MNPs) with sodium oleate (SO) is known to be an excellent method to create biocompatible, stable colloids with a narrow size distribution. However, the mechanism of oleate adsorption on the MNP surface in aqueous systems, as well as its influence on colloidal stability, is not yet fully understood. In this context, we present here a physico-chemical study to provide a deeper understanding of surfactant interaction mechanisms with nanoparticles. We examined the effect of temperature and the SO/MNP ratio (w/w) on the adsorption process in water and observed the existence of a maximum for the adsorbed oleate amount at lower temperatures, whereas at higher temperatures, the isotherm can be adapted to the Langmuir model with constant capacity after saturation. The oleate load on the MNP surface was quantified using reversed-phase high-performance liquid chromatography measurements of samples in solution. The thermogravimetric analyses of the solid residues together with infrared spectroscopy analyses indicate a bilayer-similar structure at the MNP/water interface even for low oleate loads. The oleate interacts with the iron oxide surface through a bidentate coordination of the carboxyl group. Zeta potential measurements demonstrate the high stability of the coated system. The maximal oleate load per unit mass of MNPs reaches approximately 0.35 g{sub oleate} g{sub MNP}{sup −1}.Graphical abstract.

  3. Transmission electron microscopy of carbon-coated and iron-doped titania nanoparticles

    KAUST Repository

    Anjum, Dalaver H.

    2016-08-02

    We present a study on the properties of iron (Fe)-doped and carbon (C)-coated titania (TiO2) nanoparticles (NPs) which has been compiled by using x-ray diffraction (XRD), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). These TiO2 NPs were prepared by using the flame synthesis method. This method allows the simultaneous C coating and Fe doping of TiO2 NPs. XRD investigations revealed that the phase of the prepared NPs was anatase TiO2. Conventional TEM analysis showed that the average size of the TiO2 NPs was about 65 nm and that the NPs were uniformly coated with the element C. Furthermore, from the x-ray energy dispersive spectrometry analysis, it was found that about 8 at.% Fe was present in the synthesized samples. High-resolution TEM (HRTEM) revealed the graphitized carbon structure of the layer surrounding the prepared TiO2 NPs. HRTEM analysis further revealed that the NPs possessed the crystalline structure of anatase titania. Energy-filtered TEM (EFTEM) analysis showed the C coating and Fe doping of the NPs. The ratio of L3 and L2 peaks for the Ti-L23 and Fe-L23 edges present in the core loss electron energy loss spectroscopy (EELS) revealed a +4 oxidation state for the Ti and a +3 oxidation state for the Fe. These EELS results were further confirmed with XPS analysis. The electronic properties of the samples were investigated by applying Kramers-Kronig analysis to the low-loss EELS spectra acquired from the prepared NPs. The presented results showed that the band gap energy of the TiO2 NPs decreased from an original value of 3.2 eV to about 2.2 eV, which is quite close to the ideal band gap energy of 1.65 eV for photocatalysis semiconductors. The observed decrease in band gap energy of the TiO2 NPs was attributed to the presence of Fe atoms at the lattice sites of the anatase TiO2 lattice. In short, C-coated and Fe-doped TiO2 NPs were synthesized with a rather cost-effective and comparatively easily scalable method. The

  4. Laccases as palladium oxidases.

    Science.gov (United States)

    Mekmouche, Yasmina; Schneider, Ludovic; Rousselot-Pailley, Pierre; Faure, Bruno; Simaan, A Jalila; Bochot, Constance; Réglier, Marius; Tron, Thierry

    2015-02-01

    The first example of a coupled catalytic system involving an enzyme and a palladium(ii) catalyst competent for the aerobic oxidation of alcohol in mild conditions is described. In the absence of dioxygen, the fungal laccase LAC3 is reduced by a palladium(0) species as evidenced by the UV/VIS and ESR spectra of the enzyme. During the oxidation of veratryl alcohol performed in water, at room temperature and atmospheric pressure, LAC3 regenerates the palladium catalyst, is reduced and catalyzes the four-electron reduction of dioxygen into water with no loss of enzyme activity. The association of a laccase with a water-soluble palladium complex results in a 7-fold increase in the catalytic efficiency of the complex. This is the first step in the design of a family of renewable palladium catalysts for aerobic oxidation.

  5. A study on the corrosion and erosion behavior of electroless nickel and TiAlN/ZrN duplex coatings on ductile iron

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chung-Kwei [School of Dental Technology, Taipei Medical University, Taipei 110, Taiwan (China); Hsu, Cheng-Hsun, E-mail: chhsu@ttu.edu.tw [Department of Materials Engineering, Tatung University, Taipei 104, Taiwan (China); College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Cheng, Yin-Hwa [Department of Materials Engineering, Tatung University, Taipei 104, Taiwan (China); Ou, Keng-Liang [College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan (China); Department of Mechanical Engineering, National Central University, Taoyuan 320, Taiwan (China); Lee, Sheng-Long [Research Center for Biomedical Devices and Prototyping Production, Taipei Medical University, Taipei 110, Taiwan (China)

    2015-01-01

    Highlights: • Electroless nickel was used as an interlayer for TiAlZrN-coated ductile iron. • The duplex coatings evidently improved corrosion resistance of ductile iron. • The duplex coated ductile iron showed a good erosion resistance. - Abstract: This study utilized electroless nickel (EN) and cathodic arc evaporation (CAE) technologies to deposit protective coatings onto ductile iron. Polarization corrosion tests were performed in 3.5 wt.% sodium chloride, and also erosion tests were carried out by using Al{sub 2}O{sub 3} particles (∼177 μm in size and Mohr 7 scale) of about 5 g. Surface morphologies of the corroded and eroded specimens were observed separately. To further understand the coating effects on both the corrosive and erosive behavior of ductile iron, coating structure, morphology, and adhesion were analyzed using X-ray diffractormeter, scanning electron microscopy, and Rockwell-C indenter, respectively. The results showed that the EN exhibited an amorphous structure while the CAE-TiAlN/ZrN coating was a multilayered nanocrystalline. When the TiAlN/ZrN coated specimen with EN interlayer could effectively increase the adhesion strength between the CAE coating and substrate. Consequently, the combination of TiAlN/ZrN and EN delivered a better performance than did the monolithic EN or TiAlN/ZrN for both corrosion and erosion protection.

  6. A study on the corrosion and erosion behavior of electroless nickel and TiAlN/ZrN duplex coatings on ductile iron

    International Nuclear Information System (INIS)

    Lin, Chung-Kwei; Hsu, Cheng-Hsun; Cheng, Yin-Hwa; Ou, Keng-Liang; Lee, Sheng-Long

    2015-01-01

    Highlights: • Electroless nickel was used as an interlayer for TiAlZrN-coated ductile iron. • The duplex coatings evidently improved corrosion resistance of ductile iron. • The duplex coated ductile iron showed a good erosion resistance. - Abstract: This study utilized electroless nickel (EN) and cathodic arc evaporation (CAE) technologies to deposit protective coatings onto ductile iron. Polarization corrosion tests were performed in 3.5 wt.% sodium chloride, and also erosion tests were carried out by using Al 2 O 3 particles (∼177 μm in size and Mohr 7 scale) of about 5 g. Surface morphologies of the corroded and eroded specimens were observed separately. To further understand the coating effects on both the corrosive and erosive behavior of ductile iron, coating structure, morphology, and adhesion were analyzed using X-ray diffractormeter, scanning electron microscopy, and Rockwell-C indenter, respectively. The results showed that the EN exhibited an amorphous structure while the CAE-TiAlN/ZrN coating was a multilayered nanocrystalline. When the TiAlN/ZrN coated specimen with EN interlayer could effectively increase the adhesion strength between the CAE coating and substrate. Consequently, the combination of TiAlN/ZrN and EN delivered a better performance than did the monolithic EN or TiAlN/ZrN for both corrosion and erosion protection

  7. The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Makovec, Darko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Gyergyek, Sašo, E-mail: saso.gyergyek@ijs.si [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Primc, Darinka [Department for Materials Synthesis, Jožef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia); Plantan, Ivan [Lek Pharmaceuticals d.d., Mengeš (Slovenia)

    2015-03-01

    The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe{sup 3+}/Fe{sup 2+} ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe{sup 3+} ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles.

  8. The formation of magnetic carboxymethyl-dextrane-coated iron-oxide nanoparticles using precipitation from an aqueous solution

    International Nuclear Information System (INIS)

    Makovec, Darko; Gyergyek, Sašo; Primc, Darinka; Plantan, Ivan

    2015-01-01

    The formation of spinel iron-oxide nanoparticles during the co-precipitation of Fe 3+ /Fe 2+ ions from an aqueous solution in the presence of carboxymethyldextrane (CMD) was studied. To follow the formation of the nanoparticles, a mixture of the Fe ions, CMD and ammonia was heated to different temperatures, while the samples were taken, quenched in liquid nitrogen, freeze-dried and characterized using transmission electron microscopy (TEM), X-ray diffractometry (XRD) and magnetometry. The CMD plays a role in the reactions of the Fe ions' precipitation by partially immobilizing the Fe 3+ ions into a complex. At room temperature, the amorphous material is precipitated. Then, above approximately 30 °C, the spinel nanoparticles form inside the amorphous matrix, and at approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles. The CMD bonded to the nanoparticles' surfaces hinders the mass transport and thus prevents their growth. - Highlights: • The carboxymethyl-dextrane coated iron-oxide nanoparticles were synthesized. • The carboxymethyl-dextrane significantly modifies formation of the spinel nanoparticles. • The spinel nanoparticles are formed inside the amorphous matrix. • At approximately 40 °C the matrix decomposes into the suspension of carboxymethyl-dextrane-coated iron-oxide nanoparticles

  9. A density functional theory study of the carbon-coating effects on lithium iron borate battery electrodes.

    Science.gov (United States)

    Loftager, Simon; García-Lastra, Juan María; Vegge, Tejs

    2017-01-18

    Lithium iron borate (LiFeBO 3 ) is a promising cathode material due to its high theoretical specific capacity, inexpensive components and small volume change during operation. Yet, challenges related to severe air- and moisture-induced degradation have prompted the utilization of a protective coating on the electrode which also improves the electronic conductivity. However, not much is known about the preferential geometries of the coating as well as how these coating-electrode interfaces influence the lithium diffusion between the coating and the electrode. Here, we therefore present a density functional theory (DFT) study of the anchoring configurations of carbon coating on the LiFeBO 3 electrode and its implications on the interfacial lithium diffusion. Due to large barriers associated with Li-ion diffusion through a parallel-oriented pristine graphene coating on the FeBO 3 and LiFeBO 3 electrode surfaces, large structural defects in the graphene coating are required for fast Li-ion diffusion. However, such defects are expected to exist only in small concentrations due to their high formation energies. Alternative coating geometries were therefore investigated, and the configuration in which the coating layers were anchored normal to the electrode surface at B and O atoms was found to be most stable. Nudged elastic band (NEB) calculations of the lithium diffusion barriers across the interface between the optimally oriented coating layers and the electrode show no kinetic limitations for lithium extraction and insertion. Additionally, this graphite-coating configuration showed partial blocking of electrode-degrading species.

  10. Investigation on effect of iron and corundum content on corrosion resistance of the NiFe-Al2O3 coatings

    International Nuclear Information System (INIS)

    Starosta, R.; Zielinski, A.

    1999-01-01

    The alloy NiFe and composite NiFe-Al 2 O 3 coatings, obtained by electrodeposition on the base of cast iron, were investigated. The iron content in alloy coatings was dependent on iron content in galvanic bath, and was estimated by means of X-ray microanalysis at 18.5 wt. pct. and 41.2 wt. pct. No existence of ordered Ni 3 Fe phase was found by diffraction technique. Both potentiodynamic and impedance measurements disclosed that a presence of Al 2 O 3 or increasing iron content in the layer caused the decrease in corrosion resistance. (author)

  11. Cast iron cutting with nano TiN and multilayer TiN-CrN coated inserts

    International Nuclear Information System (INIS)

    Perucca, M; Durante, S; Semmler, U; Rüger, C; Fuentes, G G; Almandoz, E

    2012-01-01

    During the past decade great success has been achieved in the development of duplex and multilayer multi-functional surface systems. Among these surface systems outstanding properties have nanoscale multilayer coatings. Within the framework of the M3-2S project funded in the 7th European Framework Programme, several nanoscale multilayer coatings have been developed and investigated for experimental and industrial validation. This paper shows the performance of TiN and TiN/CrN nanoscale multilayer coatings on WC cutting inserts when machining GJL250 cast iron. The thin films have been deposited by cathodic arc evaporation in an industrial PVD system. The multilayer deposition characteristic and its properties are shown. The inserts have been investigated in systematic cutting experiments of cast iron bars on a turning machine specifically equipped for force measurements, accompanied by wear determination. Furthermore, equivalent experiments have been carried out on an industrial turning unit. Industrial validation criteria have been applied to assess the comparative performance of the coatings. The choice of the material and the machined parts is driven by an interest in automotive applications. The industrial tests show the need to further optimise the multi-scale modelling approach in order to reduce the lead time of the coating development as well as to improve simulation reliability.

  12. Cast iron cutting with nano TiN and multilayer TiN-CrN coated inserts

    Science.gov (United States)

    Perucca, M.; Durante, S.; Semmler, U.; Rüger, C.; Fuentes, G. G.; Almandoz, E.

    2012-09-01

    During the past decade great success has been achieved in the development of duplex and multilayer multi-functional surface systems. Among these surface systems outstanding properties have nanoscale multilayer coatings. Within the framework of the M3-2S project funded in the 7th European Framework Programme, several nanoscale multilayer coatings have been developed and investigated for experimental and industrial validation. This paper shows the performance of TiN and TiN/CrN nanoscale multilayer coatings on WC cutting inserts when machining GJL250 cast iron. The thin films have been deposited by cathodic arc evaporation in an industrial PVD system. The multilayer deposition characteristic and its properties are shown. The inserts have been investigated in systematic cutting experiments of cast iron bars on a turning machine specifically equipped for force measurements, accompanied by wear determination. Furthermore, equivalent experiments have been carried out on an industrial turning unit. Industrial validation criteria have been applied to assess the comparative performance of the coatings. The choice of the material and the machined parts is driven by an interest in automotive applications. The industrial tests show the need to further optimise the multi-scale modelling approach in order to reduce the lead time of the coating development as well as to improve simulation reliability.

  13. Characterization of PEI-coated superparamagnetic iron oxide nanoparticles for transfection: Size distribution, colloidal properties and DNA interaction

    Energy Technology Data Exchange (ETDEWEB)

    Steitz, Benedikt [Laboratory of Powder Technology, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne (Switzerland); Hofmann, Heinrich [Laboratory of Powder Technology, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne (Switzerland); Kamau, Sarah W. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zuerich, Zurich (Switzerland); Hassa, Paul O. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zuerich, Zurich (Switzerland); Hottiger, Michael O. [Institute of Veterinary Biochemistry and Molecular Biology, University of Zuerich, Zurich (Switzerland); Rechenberg, Brigitte von [Musculoskeletal Research Unit, Equine Hospital, Vetsuisse Faculty Zurich, University of Zurich, Winterthurerstr. 260, 8057 Zurich (Switzerland); Hofmann-Amtenbrink, Magarethe [MatSearch, Chemin Jean Pavillard 14, 1009 Pully (Switzerland); Petri-Fink, Alke [Laboratory of Powder Technology, Ecole Polytechnique Federale de Lausanne (EPFL), Lausanne (Switzerland)]. E-mail: alke.fink@epfl.ch

    2007-04-15

    Superparamagnetic iron oxide nanoparticles (SPIONs) were coated with polyethylenimine. Here, we briefly describe the synthesis as well as DNA:PEI:SPION complexes and the characterization of the compounds according to their particle size, {zeta}-potential, morphology, DNA complexing ability, magnetic sedimentation, and colloidal stability. PEI coating of SPIONs led to colloidally stable beads even in high salt concentrations over a wide pH range. DNA plasmids and PCR products encoding for green fluorescent protein were associated with the described beads. The complexes were added to cells and exposed to permanent and pulsating magnetic fields. Presence of these magnetic fields significantly increased the transfection efficiency.

  14. Characterization of PEI-coated superparamagnetic iron oxide nanoparticles for transfection: Size distribution, colloidal properties and DNA interaction

    International Nuclear Information System (INIS)

    Steitz, Benedikt; Hofmann, Heinrich; Kamau, Sarah W.; Hassa, Paul O.; Hottiger, Michael O.; Rechenberg, Brigitte von; Hofmann-Amtenbrink, Magarethe; Petri-Fink, Alke

    2007-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) were coated with polyethylenimine. Here, we briefly describe the synthesis as well as DNA:PEI:SPION complexes and the characterization of the compounds according to their particle size, ζ-potential, morphology, DNA complexing ability, magnetic sedimentation, and colloidal stability. PEI coating of SPIONs led to colloidally stable beads even in high salt concentrations over a wide pH range. DNA plasmids and PCR products encoding for green fluorescent protein were associated with the described beads. The complexes were added to cells and exposed to permanent and pulsating magnetic fields. Presence of these magnetic fields significantly increased the transfection efficiency

  15. Refinement of adsorptive coatings for fluorescent riboflavin-receptor-targeted iron oxide nanoparticles.

    Science.gov (United States)

    Tsvetkova, Yoanna; Beztsinna, Nataliia; Jayapaul, Jabadurai; Weiler, Marek; Arns, Susanne; Shi, Yang; Lammers, Twan; Kiessling, Fabian

    2016-01-01

    Flavin mononucleotide (FMN) is a riboflavin derivative that can be exploited to target the riboflavin transporters (RFTs) and the riboflavin carrier protein (RCP) in cells with high metabolic activity. In this study we present the synthesis of different FMN-coated ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs) and their efficiency as targeting contrast agents. Since FMN alone cannot stabilize the nanoparticles, we used adenosine phosphates--AMP, ADP and ATP--as spacers to obtain colloidally stable nanoparticles. Nucleotides with di- and triphosphate groups were intended to increase the USPIO charge and thus improve zeta potential and stability. However, all nanoparticles formed negatively charged clusters with similar properties in terms of zeta potential (-28 ± 2 mV), relaxivity (228-259 mM(-1) s(-1) at 3 T) and hydrodynamic radius (53-85 nm). Molecules with a higher number of phosphate groups, such as ADP and ATP, have a higher adsorption affinity towards iron oxide, which, instead of providing more charge, led to partial desorption and replacement of FMN. Hence, we obtained USPIOs carrying different amounts of targeting agent, which significantly influenced the nanoparticles' uptake. The nanoparticles' uptake by different cancer cells and HUVECs was evaluated photometrically and with MR relaxometry, showing that the cellular uptake of the USPIOs increases with the FMN amount on their surface. Thus, for USPIOs targeted with riboflavin derivatives the use of spacers with increasing numbers of phosphate groups does not improve either zeta potential or the particles' stability, but rather detaches the targeting moieties from their surface, leading to lower cellular uptake. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Subtle cytotoxicity and genotoxicity differences in superparamagnetic iron oxide nanoparticles coated with various functional groups

    Directory of Open Access Journals (Sweden)

    Hong SC

    2011-12-01

    Full Text Available Seong Cheol Hong1,*, Jong Ho Lee1,*, Jaewook Lee1, Hyeon Yong Kim1, Jung Youn Park2, Johann Cho3, Jaebeom Lee1, Dong-Wook Han11Department of Nanomedical Engineering, BK21 Nano Fusion Technology Division, College of Nanoscience and Nanotechnology, Pusan National University, 2Department of Biotechnology Research, National Fisheries Research and Development Institute, Busan, 3Electronic Materials Lab, Samsung Corning Precision Materials Co, Ltd, Gumi City, Gyeongsangbukdo, Korea*These authors contributed equally to this workAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs have been widely utilized for the diagnosis and therapy of specific diseases, as magnetic resonance imaging (MRI contrast agents and drug-delivery carriers, due to their easy transportation to targeted areas by an external magnetic field. For such biomedical applications, SPIONs must have multifunctional characteristics, including optimized size and modified surface. However, the biofunctionality and biocompatibility of SPIONs with various surface functional groups of different sizes have yet to be elucidated clearly. Therefore, it is important to carefully monitor the cytotoxicity and genotoxicity of SPIONs that are surfaced-modified with various functional groups of different sizes. In this study, we evaluated SPIONs with diameters of approximately 10 nm and 100~150 nm, containing different surface functional groups. SPIONs were covered with –O-groups, so-called bare SPIONs. Following this, they were modified with three different functional groups – hydroxyl (–OH, carboxylic (–COOH, and amine (–NH2 groups – by coating their surfaces with tetraethyl orthosilicate (TEOS, (3-aminopropyltrimethoxysilane (APTMS, TEOS-APTMS, or citrate, which imparted different surface charges and sizes to the particles. The effects of SPIONs coated with these functional groups on mitochondrial activity, intracellular accumulation of reactive oxygen species, membrane integrity

  17. Synthesizing the Nanocrytalline Cobalt-Iron Coating Through The Electrodeposition Process With Different Time Deposition

    Science.gov (United States)

    Rozlin Nik Masdek, Nik; Sorfian Hafiz Mansor, Mohd; Salleh, Zuraidah; Hyie, Koay Mei

    2018-03-01

    In the engineering world, electrodeposition or electroplating has become the most popular method of surface coating in improving corrosion behavior and mechanical properties of material. Therefore in this study, CoFe nanoparticle protective coating has been synthesized on the mild steel washer using electrodeposition method. The electrodeposition was conducted in the acidic environment with the pH value range from 1 to 2 with the controlled temperature of 50°C. The influence of deposition time (30, 60, 90 minutes) towards characteristic and properties such as particle size, surface morphology, corrosion behavior, and microhardness were studied in this investigation. Several results can be obtained by doing this experiment and testing. First, the surface morphology of Cobalt Iron (CoFe) on the electrodeposited mild steel washer are obtained. In addition, the microhardness of the mild steel washer due to the different deposition time are determined. Next, the observation on the difference in the grain size of CoFe that has been electrodeposited on the mild steel plate is made. Last but not least, the corrosion behavior was investigated. CoFe nanoparticles deposited for 30 minutes produced the smallest particle size and the highest microhardness of 86.17 and 236.84 HV respectively. The CoFe nanoparticles also exhibit the slowest corrosion rate at 30 minutes as compared to others. The crystalline size also increases when the time deposition is increased. The sample with 30 minute depositon time indicate the smallest crystalline size which is 15nm. The decrement of deposition time plays an important role in synthesizing CoFe nanoparticles with good corrosion resistance and microhardness. CoFe nanoparticles obtained at 30 minutes shows high corrosion resistance compared to others. In a nutshell, it was observed that the decrement of deposition time improved mechanical and corrosion properties of CoFe nanoparticles.

  18. Improved thermooxidation and sedimentation stability of covalently-coated carbonyl iron particles with cholesteryl groups and their influence on magnetorheology

    Czech Academy of Sciences Publication Activity Database

    Mrlík, M.; Ilčíková, M.; Pavlínek, V.; Mosnáček, J.; Peer, Petra; Filip, Petr

    2013-01-01

    Roč. 396, april (2013), s. 146-151 ISSN 0021-9797 R&D Projects: GA ČR GA202/09/1626 Grant - others:GA MŠk(CZ) ED2.1.00/03.0111 Institutional support: RVO:67985874 Keywords : covalent coating * carbonyl iron * cholesteryl chloroformate * thermooxidation * Magnetorheology Subject RIV: BK - Fluid Dynamics Impact factor: 3.552, year: 2013

  19. Adsorption characteristics of As(III) from aqueous solution on iron oxide coated cement (IOCC)

    International Nuclear Information System (INIS)

    Kundu, Sanghamitra; Gupta, A.K.

    2007-01-01

    Contamination of potable groundwater with arsenic is a serious health hazard, which calls for proper treatment before its use as drinking water. The objective of the present study is to assess the effectiveness of iron oxide coated cement (IOCC) for As(III) adsorption from aqueous solution. Batch studies were conducted to study As(III) adsorption onto IOCC at ambient temperature as a function of adsorbent dose, pH, contact time, initial arsenic concentration and temperature. Kinetics reveal that the uptake of As(III) ion is very rapid and most of fixation occurs within the first 20 min of contact. The pseudo-second order rate equation successfully described the adsorption kinetics. Langmuir, Freundlich, Redlich-Peterson (R-P), and Dubinin-Radushkevich (D-R) models were used to describe the adsorption isotherms at different initial As(III) concentrations and at 30 g l -1 fixed adsorbent dose. The maximum adsorption capacity of IOCC for As(III) determined from the Langmuir isotherm was 0.69 mg g -1 . The mean free energy of adsorption (E) calculated from the D-R isotherm was found to be 2.86 kJ mol -1 which suggests physisorption. Thermodynamic parameters indicate an exothermic nature of adsorption and a spontaneous and favourable process. The results suggest that IOCC can be suitably used for As(III) removal from aqueous solutions

  20. In-situ Lead Removal by Iron Nano Particles Coated with Nickel

    Directory of Open Access Journals (Sweden)

    Mohammadreza Fadaei-tehrani

    2016-01-01

    Full Text Available This study investigates the potential of nano-zero-valent iron particles coated with nickel in the removal of lead (Pb2+ from porous media. For this purpose, the nano-particles were initially synthesized and later stablilized using the strach biopolymer prior to conducting batch and continuous experiments. The results of the batch experiments revealed that the reaction kinetics fitted well with the pseudo-first-order adsorption model and that the reaction rate ranged from 0.001 to 0.035 g/mg/min depending on solution pH and the molar ratio of Fe/Pb. Continuous experiments showed that lead remediation was mostly influenced not only by seepage velocity but also by the quantity and freshness of nZVI as well as the grain type of the porous media. Maximum Pb2+ removal rates obtained in the batch and lab models were 95% and 80%, respectively. Based on the present study, S-nZVI may be suggested as an efficient agent for in-situ remediation of groundwater contaminated with lead.

  1. From oleic acid-capped iron oxide nanoparticles to polyethyleneimine-coated single-particle magnetofectins

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Acuña, Melissa [University of Florida, J. Crayton Pruitt Family Department of Biomedical Engineering (United States); Maldonado-Camargo, Lorena [University of Florida, Department of Chemical Engineering (United States); Dobson, Jon; Rinaldi, Carlos, E-mail: carlos.rinaldi@bme.ufl.edu [University of Florida, J. Crayton Pruitt Family Department of Biomedical Engineering (United States)

    2016-09-15

    Various inorganic nanoparticle designs have been developed and used as non-viral gene carriers. Magnetic gene carriers containing polyethyleneimine (PEI), a well-known transfection agent, have been shown to improve DNA transfection speed and efficiency in the presence of applied magnetic field gradients that promote particle–cell interactions. Here we report a method to prepare iron oxide nanoparticles conjugated with PEI that: preserves the narrow size distribution of the nanoparticles, conserves magnetic properties throughout the process, and results in efficient transfection. We demonstrate the ability of the particles to electrostatically bind with DNA and transfect human cervical cancer (HeLa) cells by the use of an oscillating magnet array. Their transfection efficiency is similar to that of Lipofectamine 2000™, a commercial transfection reagent. PEI-coated particles were subjected to acidification, and acidification in the presence of salts, before DNA binding. Results show that although these pre-treatments did not affect the ability of particles to bind DNA they did significantly enhanced transfection efficiency. Finally, we show that these magnetofectins (PEI-MNP/DNA) complexes have no effect on the viability of cells at the concentrations used in the study. The systematic preparation of magnetic vectors with uniform physical and magnetic properties is critical to progressing this non-viral transfection technology.

  2. Synthesis and magnetic property of T4 virus-supported gold-coated iron ternary nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Xu Ziming; Sun Hongjing; Gao Faming, E-mail: fmgao@ysu.edu.cn; Hou Li; Li Na [Yanshan University, Key Laboratory of Applied Chemistry (China)

    2012-12-15

    Herein, we present a novel method based on the use of the symmetrical T4 bacteriophage capsid as a scaffold for preparing the gold-coated iron ternary core/shell nanostructure. Results showed that the thick gold shell was obtained to effectively protect Fe core from oxidation. Magnetic measurements showed that the nanocomposites were superparamagnetic at room temperature with a blocking temperature of about 35 K. At 3 K, its coercivity of 1142.86 Oe was larger than the existing experimental values. The magnetic property of Au/T4 was also tested, demonstrating the source of the magnetic sample arising from the Fe core only. The absorption spectrum of the Fe-Au/T4 complex was measured and compared with gold/virus. Different thickness gold shells were controlled in the synthesis by tuning the Au salt addition. On the basis of results and discussion, we further speculated the general growing mechanism of the template-supported Fe-Au process.

  3. Synthesis and magnetic property of T4 virus-supported gold-coated iron ternary nanocomposite

    Science.gov (United States)

    Xu, Ziming; Sun, Hongjing; Gao, Faming; Hou, Li; Li, Na

    2012-12-01

    Herein, we present a novel method based on the use of the symmetrical T4 bacteriophage capsid as a scaffold for preparing the gold-coated iron ternary core/shell nanostructure. Results showed that the thick gold shell was obtained to effectively protect Fe core from oxidation. Magnetic measurements showed that the nanocomposites were superparamagnetic at room temperature with a blocking temperature of about 35 K. At 3 K, its coercivity of 1142.86 Oe was larger than the existing experimental values. The magnetic property of Au/T4 was also tested, demonstrating the source of the magnetic sample arising from the Fe core only. The absorption spectrum of the Fe@Au/T4 complex was measured and compared with gold/virus. Different thickness gold shells were controlled in the synthesis by tuning the Au salt addition. On the basis of results and discussion, we further speculated the general growing mechanism of the template-supported Fe@Au process.

  4. Electrochemical synthesis and spectroscopic characterization of poly(N-phenylpyrrole coatings in an organic medium on iron and platinum electrodes

    Directory of Open Access Journals (Sweden)

    A.K.D. Diaw

    2008-12-01

    Full Text Available The electrochemical synthesis of poly(N-phenylpyrrole film was achieved on pretreated iron and platinum electrodes in acetonitrile solutions containing 0.1 M N-phenylpyrrole as the monomer and 0.1 M tetrabutylammonium trifluoromethane sulfonate (Bu4NCF3SO3 as the supporting-salt. The results showed that a surface treatment by 10 % aqueous nitric acid inhibits iron dissolution without preventing the N-phenylpyrrole oxidation. Very strongly adherent films were obtained at constant-potential, constant-current and cyclic voltammetry. XPS measurements, infrared (FT-IR and electronic absorption (UV-vis spectroscopies were used to characterize the iron and platinum-coated electrodes. Finally the anticorrosion properties of the PΦP film were evidenced.

  5. Wear and Corrosion Resistance of Fe Based Coatings by HVOF Sprayed on Gray Cast-Iron for Automotive Application

    Directory of Open Access Journals (Sweden)

    M.S. Priyan

    2014-12-01

    Full Text Available In this study, commercially available FeSiNiCr and FeBCr alloy powders were designed with suitable compositions, gas atomized and then coated on gray cast-iron substrate. The microstructures of the feed stock Fe based alloy powders and the coatings were investigated by means of optical microscopy (OM, X-Ray diffraction (XRD, Thermogravimetric analysis (TGA and Scanning Electron Microscopy (SEM. In the present study, both the coating materials experienced two-body wear mechanisms. The results showed that for loads of 0.05 N, 0.1 N and 0.2 N, the wear resistance of FeBCr coating was less than FeSiNiCr by 44 %, 40 % and 31 %, respectively. The results indicated that the coated substrates exhibited lower corrosion current densities and lower corrosion rates, when placed in 20 wt.% H2SO4 solutions. In addition, the use of optimal spraying parameters/conditions gave improvements to the corrosion resistance of the substrates that had been treated with the crystalline coating.

  6. Caveolin-1 and CDC42 mediated endocytosis of silica-coated iron oxide nanoparticles in HeLa cells

    Directory of Open Access Journals (Sweden)

    Nils Bohmer

    2015-01-01

    Full Text Available Nanomedicine is a rapidly growing field in nanotechnology, which has great potential in the development of new therapies for numerous diseases. For example iron oxide nanoparticles are in clinical use already in the thermotherapy of brain cancer. Although it has been shown, that tumor cells take up these particles in vitro, little is known about the internalization routes. Understanding of the underlying uptake mechanisms would be very useful for faster and precise development of nanoparticles for clinical applications. This study aims at the identification of key proteins, which are crucial for the active uptake of iron oxide nanoparticles by HeLa cells (human cervical cancer as a model cell line. Cells were transfected with specific siRNAs against Caveolin-1, Dynamin 2, Flotillin-1, Clathrin, PIP5Kα and CDC42. Knockdown of Caveolin-1 reduces endocytosis of superparamagnetic iron oxide nanoparticles (SPIONs and silica-coated iron oxide nanoparticles (SCIONs between 23 and 41%, depending on the surface characteristics of the nanoparticles and the experimental design. Knockdown of CDC42 showed a 46% decrease of the internalization of PEGylated SPIONs within 24 h incubation time. Knockdown of Dynamin 2, Flotillin-1, Clathrin and PIP5Kα caused no or only minor effects. Hence endocytosis in HeLa cells of iron oxide nanoparticles, used in this study, is mainly mediated by Caveolin-1 and CDC42. It is shown here for the first time, which proteins of the endocytotic pathway mediate the endocytosis of silica-coated iron oxide nanoparticles in HeLa cells in vitro. In future studies more experiments should be carried out with different cell lines and other well-defined nanoparticle species to elucidate possible general principles.

  7. Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part I – Moulding technologies vs. zinc coating

    Directory of Open Access Journals (Sweden)

    Szczęsny A.

    2017-03-01

    Full Text Available Studies have demonstrated that in the process of hot dip galvanizing the decisive influence on the mechanism of zinc coating formation and properties has the quality of the mechanically untreated (raw surface layer of the galvanized product. The terms “casting surface layer” denote various parameters of the microstructure, including the type of metal matrix, the number of grains and the size of graphite nodules, possible presence of hard spots (the precipitates of eutectic cementite and parameters of the surface condition. The completed research has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing.

  8. Analysis of Crystal Structure of Fe3O4 Thin Films Based on Iron Sand Growth by Spin Coating Method

    Science.gov (United States)

    Rianto, D.; Yulfriska, N.; Murti, F.; Hidayati, H.; Ramli, R.

    2018-04-01

    Recently, iron sand used as one of base materials in the steel industry. However, the content of iron sand can be used as starting materials in sensor technology in the form of thin films. In this paper, we report the analysis of crystal structure of magnetite thin film based on iron sand from Tiram’s Beach. The magnetic content of sand separated by a permanent magnet, then it was milled at 30 hours milling time. In order to increase the purity of magnetite, it washed after milling using aquades under magnetic separation by a magnet permanent. The thin film has been prepared using iron (III) nitrate by sol–gel technique. The precursor is resulted by dissolving magnetite in oxalic acid and nitric acid. Then, solution of iron (III) nitrate dissolved in ethylene glycol was applied on glass substrates by spin coating. The X-Ray Diffraction is operated thin film characterization. The structure of magnetite has been studied based on X-Ray Peaks that correspond to magnetite content of thin films.

  9. Separation of Platinum from Palladium and Iridium in Iron Meteorites and Accurate High-Precision Determination of Platinum Isotopes by Multi-Collector ICP-MS.

    Science.gov (United States)

    Hunt, Alison C; Ek, Mattias; Schönbächler, Maria

    2017-12-01

    This study presents a new measurement procedure for the isolation of Pt from iron meteorite samples. The method also allows for the separation of Pd from the same sample aliquot. The separation entails a two-stage anion-exchange procedure. In the first stage, Pt and Pd are separated from each other and from major matrix constituents including Fe and Ni. In the second stage, Ir is reduced with ascorbic acid and eluted from the column before Pt collection. Platinum yields for the total procedure were typically 50-70%. After purification, high-precision Pt isotope determinations were performed by multi-collector ICP-MS. The precision of the new method was assessed using the IIAB iron meteorite North Chile. Replicate analyses of multiple digestions of this material yielded an intermediate precision for the measurement results of 0.73 for ε 192 Pt, 0.15 for ε 194 Pt and 0.09 for ε 196 Pt (2 standard deviations). The NIST SRM 3140 Pt solution reference material was passed through the measurement procedure and yielded an isotopic composition that is identical to the unprocessed Pt reference material. This indicates that the new technique is unbiased within the limit of the estimated uncertainties. Data for three iron meteorites support that Pt isotope variations in these samples are due to exposure to galactic cosmic rays in space.

  10. Polyethylene Glycol Modified, Cross-Linked Starch Coated Iron Oxide Nanoparticles for Enhanced Magnetic Tumor Targeting

    Science.gov (United States)

    Cole, Adam J.; David, Allan E.; Wang, Jianxin; Galbán, Craig J.; Hill, Hannah L.; Yang, Victor C.

    2010-01-01

    While successful magnetic tumor targeting of iron oxide nanoparticles has been achieved in a number of models, the rapid blood clearance of magnetically suitable particles by the reticuloendothelial system (RES) limits their availability for targeting. This work aimed to develop a long-circulating magnetic iron oxide nanoparticle (MNP) platform capable of sustained tumor exposure via the circulation and, thus, enhanced magnetic tumor targeting. Aminated, cross-linked starch (DN) and aminosilane (A) coated MNPs were successfully modified with 5 kDa (A5, D5) or 20 kDa (A20, D20) polyethylene glycol (PEG) chains using simple N-Hydroxysuccinimide (NHS) chemistry and characterized. Identical PEG-weight analogues between platforms (A5 & D5, A20 & D20) were similar in size (140–190 nm) and relative PEG labeling (1.5% of surface amines – A5/D5, 0.4% – A20/D20), with all PEG-MNPs possessing magnetization properties suitable for magnetic targeting. Candidate PEG-MNPs were studied in RES simulations in vitro to predict long-circulating character. D5 and D20 performed best showing sustained size stability in cell culture medium at 37°C and 7 (D20) to 10 (D5) fold less uptake in RAW264.7 macrophages when compared to previously targeted, unmodified starch MNPs (D). Observations in vitro were validated in vivo, with D5 (7.29 hr) and D20 (11.75 hr) showing much longer half-lives than D (0.12 hr). Improved plasma stability enhanced tumor MNP exposure 100 (D5) to 150 (D20) fold as measured by plasma AUC0-∞ Sustained tumor exposure over 24 hours was visually confirmed in a 9L-glioma rat model (12 mg Fe/kg) using magnetic resonance imaging (MRI). Findings indicate that both D5 and D20 are promising MNP platforms for enhanced magnetic tumor targeting, warranting further study in tumor models. PMID:21176955

  11. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    MATHIEU, JOHANNA L.; GADGIL, ASHOK J.; ADDY, SUSAN E.A.; KOWOLIK, KRISTIN

    2010-06-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (~;;$0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R2 = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6x10-6 mol/g (0.20 mg/g). Time-to-90percent (defined as the time interval for ARUBA to remove 90percent of the total amount of arsenic that is removed at equilibrium) is less than one hour. Reaction rates (pseudo-second-order kinetic model, R2>_ 0.99) increase from 2.4x105 to 7.2x105 g mol-1 min-1 as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to

  12. Hydraulic characterisation of iron-oxide-coated sand and gravel based on nuclear magnetic resonance relaxation mode analyses

    Directory of Open Access Journals (Sweden)

    S. Costabel

    2018-03-01

    Full Text Available The capability of nuclear magnetic resonance (NMR relaxometry to characterise hydraulic properties of iron-oxide-coated sand and gravel was evaluated in a laboratory study. Past studies have shown that the presence of paramagnetic iron oxides and large pores in coarse sand and gravel disturbs the otherwise linear relationship between relaxation time and pore size. Consequently, the commonly applied empirical approaches fail when deriving hydraulic quantities from NMR parameters. Recent research demonstrates that higher relaxation modes must be taken into account to relate the size of a large pore to its NMR relaxation behaviour in the presence of significant paramagnetic impurities at its pore wall. We performed NMR relaxation experiments with water-saturated natural and reworked sands and gravels, coated with natural and synthetic ferric oxides (goethite, ferrihydrite, and show that the impact of the higher relaxation modes increases significantly with increasing iron content. Since the investigated materials exhibit narrow pore size distributions, and can thus be described by a virtual bundle of capillaries with identical apparent pore radius, recently presented inversion approaches allow for estimation of a unique solution yielding the apparent capillary radius from the NMR data. We found the NMR-based apparent radii to correspond well to the effective hydraulic radii estimated from the grain size distributions of the samples for the entire range of observed iron contents. Consequently, they can be used to estimate the hydraulic conductivity using the well-known Kozeny–Carman equation without any calibration that is otherwise necessary when predicting hydraulic conductivities from NMR data. Our future research will focus on the development of relaxation time models that consider pore size distributions. Furthermore, we plan to establish a measurement system based on borehole NMR for localising iron clogging and controlling its remediation

  13. Hydraulic characterisation of iron-oxide-coated sand and gravel based on nuclear magnetic resonance relaxation mode analyses

    Science.gov (United States)

    Costabel, Stephan; Weidner, Christoph; Müller-Petke, Mike; Houben, Georg

    2018-03-01

    The capability of nuclear magnetic resonance (NMR) relaxometry to characterise hydraulic properties of iron-oxide-coated sand and gravel was evaluated in a laboratory study. Past studies have shown that the presence of paramagnetic iron oxides and large pores in coarse sand and gravel disturbs the otherwise linear relationship between relaxation time and pore size. Consequently, the commonly applied empirical approaches fail when deriving hydraulic quantities from NMR parameters. Recent research demonstrates that higher relaxation modes must be taken into account to relate the size of a large pore to its NMR relaxation behaviour in the presence of significant paramagnetic impurities at its pore wall. We performed NMR relaxation experiments with water-saturated natural and reworked sands and gravels, coated with natural and synthetic ferric oxides (goethite, ferrihydrite), and show that the impact of the higher relaxation modes increases significantly with increasing iron content. Since the investigated materials exhibit narrow pore size distributions, and can thus be described by a virtual bundle of capillaries with identical apparent pore radius, recently presented inversion approaches allow for estimation of a unique solution yielding the apparent capillary radius from the NMR data. We found the NMR-based apparent radii to correspond well to the effective hydraulic radii estimated from the grain size distributions of the samples for the entire range of observed iron contents. Consequently, they can be used to estimate the hydraulic conductivity using the well-known Kozeny-Carman equation without any calibration that is otherwise necessary when predicting hydraulic conductivities from NMR data. Our future research will focus on the development of relaxation time models that consider pore size distributions. Furthermore, we plan to establish a measurement system based on borehole NMR for localising iron clogging and controlling its remediation in the gravel pack of

  14. Optical Properties of Fe3O4 Thin Films Prepared from the Iron Sand by Spin Coating Method

    Science.gov (United States)

    Yulfriska, N.; Rianto, D.; Murti, F.; Darvina, Y.; Ramli, R.

    2018-04-01

    Research on magnetic oxide is growing very rapidly. This magnetic oxide can be found in nature that is in iron sand. One of the beaches in Sumatera Barat containing iron sand is Tiram Beach, Padang Pariaman District, Sumatera Barat. The content of iron sand is generally in the form of magnetic minerals such as magnetite, hematite, and maghemit. Magnetite has superior properties that can be developed into thin films. The purpose of this research is to investigate the optical properties of transmittance, absorbance, reflectance and energy gap from Fe3O4 thin films. This type of research is an experimental research. The iron sand obtained from nature is first purified using a permanent magnet, then made in nanoparticle size using HEM-E3D with milling time for 30 hours. After that, the process of making thin film with sol-gel spin coating method. In this research, variation of rotation speed from spin coating is 1000 rpm, 2000 rpm and 3000 rpm. Based on XRD results indicated that the iron sand of Tiram beach contains magnetite minerals and the SEM results show that the thickness of the thin films formed is 25μm, 24μm and 11μm. The characterization tool used for characterizing optical properties is the UV-VIS Spectrophotometer. So it can be concluded that the greater the speed of rotation the thickness of the thin layer will be smaller, resulting in the transmittance and reflectance will be greater, while the absorbance will be smaller. Energy gap obtained from this research is 3,75eV, 3,75eV and 3,74eV. So the average energy gap obtained is 3,75eV.

  15. Effect of HSA coated iron oxide labeling on human umbilical cord derived mesenchymal stem cells

    Science.gov (United States)

    Sanganeria, Purva; Chandra, Sudeshna; Bahadur, Dhirendra; Khanna, Aparna

    2015-03-01

    Human umbilical cord derived mesenchymal stem cells (hUC-MSCs) are known for self-renewal and differentiation into cells of various lineages like bone, cartilage and fat. They have been used in biomedical applications to treat degenerative disorders. However, to exploit the therapeutic potential of stem cells, there is a requirement of sensitive non-invasive imaging techniques which will offer the ability to track transplanted cells, bio-distribution, proliferation and differentiation. In this study, we have analyzed the efficacy of human serum albumin coated iron oxide nanoparticles (HSA-IONPs) on the differentiation of hUC-MSCs. The colloidal stability of the HSA-IONPs was tested over a long period of time (≥20 months) and the optimized concentration of HSA-IONPs for labeling the stem cells was 60 μg ml-1. Detailed in vitro assays have been performed to ascertain the effect of the nanoparticles (NPs) on stem cells. Lactate dehydrogenase (LDH) assay showed minimum release of LDH depicting the least disruptions in cellular membrane. At the same time, mitochondrial impairment of the cells was also not observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry analysis revealed lesser generation of reactive oxygen species in HSA-IONPs labeled hUC-MSCs in comparison to bare and commercial IONPs. Transmission electron microscopy showed endocytic engulfment of the NPs by the hUC-MSCs. During the process, the gross morphologies of the actin cytoskeleton were found to be intact as shown by immunofluorescence microscopy. Also, the engulfment of the HSA-IONPs did not show any detrimental effect on the differentiation potential of the stem cells into adipocytes, osteocytes and chondrocytes, thereby confirming that the inherent properties of stem cells were maintained.

  16. Lipid-coated iron oxide nanoparticles for dual-modal imaging of hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Liang J

    2017-03-01

    Full Text Available Jinying Liang,1–3 Xinxin Zhang,2 Yunqiu Miao,2 Juan Li,1 Yong Gan2 1Department of Pharmaceutics, China Pharmaceutical University, Nanjing, People’s Republic of China; 2Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, People’s Republic of China; 3School of Pharmacy, Xinxiang Medical University, Xinxiang, People’s Republic of China Abstract: The development of noninvasive imaging techniques for the accurate diagnosis of progressive hepatocellular carcinoma (HCC is of great clinical significance and has always been desired. Herein, a hepatocellular carcinoma cell-targeting fluorescent magnetic nanoparticle (NP was obtained by conjugating near-infrared fluorescence to the surface of Fe3O4 (NIRF-Fe3O4 NPs, followed by coating the lipids consisting of tumoral hepatocytes-targeting polymer (Gal-P123. This magnetic NP (GPC@NIRF-Fe3O4 with superparamagnetic behavior showed high stability and safety in physiological conditions. In addition, GPC@NIRF-Fe3O4 achieved more specific uptake of human liver cancer cells than free Fe3O4 NPs. Importantly, with superparamagnetic iron oxide and strong NIR absorbance, GPC@NIRF-Fe3O4 NPs demonstrate prominent tumor-contrasted imaging performance both on fluorescent and T2-weighted magnetic resonance (MR imaging modalities in a living body. The relative MR signal enhancement of GPC@NIRF-Fe3O4 NPs achieved 5.4-fold improvement compared with NIR-Fe3O4 NPs. Therefore, GPC@NIRF-Fe3O4 NPs may be potentially used as a candidate for dual-modal imaging of tumors with information covalidated and directly compared by combining fluorescence and MR imaging. Keywords: dual-imaging, magnetic resonance imaging, hepatocellular carcinoma, tumor-targeting

  17. Degradation and in vitro cell–material interaction studies on hydroxyapatite-coated biodegradable porous iron for hard tissue scaffolds

    Directory of Open Access Journals (Sweden)

    Nurizzati Mohd Daud

    2014-10-01

    Full Text Available This paper describes degradation and cell–material interaction studies on hydroxyapatite (HA-coated biodegradable porous iron proposed for hard tissue scaffolds. Porous iron scaffolds are expected to serve as an ideal platform for bone regeneration. To couple their inherent mechanical strength, pure HA and HA/poly(ε-caprolactone (HA/PCL were coated onto porous iron using dip coating technique. The HA/PCL mixture was prepared to provide a more stable and flexible coating than HA alone. Degradation of the samples was evaluated by weight loss and potentiodynamic polarisation. Human skin fibroblast (HSF and human mesenchymal stem cells (hMSC were put in contact with the samples and their interaction was observed. Results showed that coated samples degraded ∼10 times slower (0.002 mm/year for HA/PCL-Fe, 0.003 mm/year for HA-Fe than the uncoated ones (0.031 mm/year, indicating an inhibition effect of the coating on degradation. Both HSF and hMSC maintained high viability when in contact with the coated samples (100–110% control for hMSC during 2–5 days of incubation, indicating the effect of HA in enhancing cytocompatibility of the surface. This study provided early evidence of the potential translation of biodegradable porous iron scaffolds for clinical use in orthopedic surgery. However, further studies including in vitro and in vivo tests are necessary.

  18. Fabrication and Properties of Iron-based Soft Magnetic Composites Coated with NiZnFe2O4

    Directory of Open Access Journals (Sweden)

    WU Shen

    2017-07-01

    Full Text Available This paper focuses on iron-based soft magnetic composites which were synthesized by utilizing the sol-gel method prepared Ni-Zn ferrite particles as insulating compound to coat iron powder, and the influence of NiZnFe2O4 content and molding pressure on the magnetic properties was studied. The morphology, magnetic properties and density of Ni-Zn ferrite insulated compacts were investigated. Scanning electron microscope,line-scan EDX analysis and distribution maps show that the iron particle surface is covered with a thin layer of uniform Ni-Zn ferrites. The existing of the insulating layer can effectively improve the electrical resistivity of soft magnetic composites. Magnetic measurements show that the real part of permeability decreases with the increase of the Ni-Zn ferrite content, and the sample with 3%(mass fraction, the same below Ni-Zn ferrite has an acceptable real part and minimum imaginary part of permeability in comparison with other samples. Results show that the addition of NiZnFe2O4 can dramatically decrease the internal magnetic loss, the magnetic loss of coated samples decreases by 83.8% as compared with that of uncoated samples at 100kHz. The density of the Fe-3%NiZnFe2O4 compacts reaches 7.14g/cm3 and the saturation magnetization is 1.47T when the molding pressure is 1000MPa.

  19. Confined palladium colloids in mesoporous frameworks for carbon nanotube growth

    NARCIS (Netherlands)

    Berenguer-Murcia, A.; Rebrov, E.V.; Cabaj, M.; Wheatley, A.E.H.; Johnson, B.F.G.; Robertson, J.; Schouten, J.C.

    2009-01-01

    Palladium colloidal nanoparticles with an average size of approximately 2.4 nm have been incorporated into mesoporous inorganic thin films following a multistep approach. This involves the deposition of mesoporous titania thin films with a thickness of 200 nm by spin-coating on titanium plates with

  20. Palladium Nanoparticle Hydrogen Sensor

    Directory of Open Access Journals (Sweden)

    I. Pavlovsky

    2006-12-01

    Full Text Available An innovative hydrogen sensor based on palladium (Pd nanoparticle networks is described in the article. Made by Applied Nanotech Inc. sensor has a fast response time, in the range of seconds, which is increased at 80 °C due to higher hydrogen diffusion rates into the palladium lattice. The low detection limit of the sensor is 10 ppm of H2, and the high limit is 40,000 ppm. This is 100% of a lowest flammability level of hydrogen. This range of sensitivities complies with the requirements that one would expect for a reliable hydrogen sensor.

  1. Iron

    DEFF Research Database (Denmark)

    Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

    2014-01-01

    and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...... of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1β facilitates divalent metal transporter 1 (DMT1)-induced β-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides...

  2. Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

    International Nuclear Information System (INIS)

    Majidi, V.; Robertson, J.D.

    1991-01-01

    Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author)

  3. Investigation of high temperature reactions on solid substrates with Rutherford backscattering spectrometry: interaction of palladium with selenium on heated graphite surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Majidi, V.; Robertson, J.D. (Kentucky Univ., Lexington, KY (United States). Dept. of Chemistry)

    1991-01-01

    Selenium and palladium interactions on heated pyrolytically coated graphite substrates were investigated using Rutherford backscattering spectrometry. The studies were performed using selenium alone, palladium alone, and a combination of selenium and palladium deposited on the graphite substrates. The results indicate that palladium instantaneously stabilizes selenium at ambient temperatures and prevents the diffusion of selenium into the graphite. As the substrate is heated, temperature dependent diffusion of all analytes into the graphite is observed. Furthermore, it appears that the stabilization of selenium is due to the formation of a stoichiometric compound with palladium and oxygen. This compound decomposes at a temperature between 1070 and 1770 K. (author).

  4. Synthesis and In Vitro Performance of Polypyrrole-Coated Iron-Platinum Nanoparticles for Photothermal Therapy and Photoacoustic Imaging

    Science.gov (United States)

    Phan, Thi Tuong Vy; Bui, Nhat Quang; Moorthy, Madhappan Santha; Lee, Kang Dae; Oh, Junghwan

    2017-10-01

    Multifunctional nano-platform for the combination of photo-based therapy and photoacoustic imaging (PAI) for cancer treatment has recently attracted much attention to nanotechnology development. In this study, we developed iron-platinum nanoparticles (FePt NPs) with the polypyrrole (PPy) coating as novel agents for combined photothermal therapy (PTT) and PAI. The obtained PPy-coated FePt NPs (FePt@PPy NPs) showed excellent biocompatibility, photothermal stability, and high near-infrared (NIR) absorbance for the combination of PTT and PAI. In vitro investigation experimentally demonstrated the effectiveness of FePt@PPy NPs in killing cancer cells with NIR laser irradiation. Moreover, the phantom test of PAI used in conjunction with FePt@PPy NPs showed a strong photoacoustic signal. Thus, the novel FePt@PPy NPs could be considered as promising multifunctional nanoparticles for further applications of photo-based diagnosis and treatment.

  5. Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand

    Science.gov (United States)

    Wang, Dengjun; Bradford, Scott A.; Harvey, Ronald W.; Gao, Bin; Cang, Long; Zhou, Dongmei

    2012-01-01

    Hydroxyapatite nanoparticles (nHAP) have been widely used to remediate soil and wastewater contaminated with metals and radionuclides. However, our understanding of nHAP transport and fate is limited in natural environments that exhibit significant variability in solid and solution chemistry. The transport and retention kinetics of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated packed columns that encompassed a range of humic acid concentrations (HA, 0–10 mg L–1), fractional surface coverage of iron oxyhydroxide coatings on sand grains (λ, 0–0.75), and pH (6.0–10.5). HA was found to have a marked effect on the electrokinetic properties of ARS-nHAP, and on the transport and retention of ARS-nHAP in granular media. The transport of ARS-nHAP was found to increase with increasing HA concentration because of enhanced colloidal stability and the reduced aggregate size. When HA = 10 mg L–1, greater ARS-nHAP attachment occurred with increasing λ because of increased electrostatic attraction between negatively charged nanoparticles and positively charged iron oxyhydroxides, although alkaline conditions (pH 8.0 and 10.5) reversed the surface charge of the iron oxyhydroxides and therefore decreased deposition. The retention profiles of ARS-nHAP exhibited a hyperexponential shape for all test conditions, suggesting some unfavorable attachment conditions. Retarded breakthrough curves occurred in sands with iron oxyhydroxide coatings because of time-dependent occupation of favorable deposition sites. Consideration of the above effects is necessary to improve remediation efficiency of nHAP for metals and actinides in soils and subsurface environments.

  6. Scanning tunneling microscopy measurements of the spin Hall effect in tungsten films by using iron-coated tungsten tips

    Directory of Open Access Journals (Sweden)

    Ting Xie

    2018-05-01

    Full Text Available Scanning tunneling microscopy experiments using iron-coated tungsten tips and current-carrying tungsten films have been conducted. An asymmetry of the tunneling current with respect to the change of the direction of the bias current through a tungsten film has been observed. It is argued that this asymmetry is a manifestation of the spin Hall effect in the current-carrying tungsten film. Nanoscale variations of this asymmetry across the tungsten film have been studied by using the scanning tunneling microscopy technique.

  7. Scanning tunneling microscopy measurements of the spin Hall effect in tungsten films by using iron-coated tungsten tips

    Science.gov (United States)

    Xie, Ting; Dreyer, Michael; Bowen, David; Hinkel, Dan; Butera, R. E.; Krafft, Charles; Mayergoyz, Isaak

    2018-05-01

    Scanning tunneling microscopy experiments using iron-coated tungsten tips and current-carrying tungsten films have been conducted. An asymmetry of the tunneling current with respect to the change of the direction of the bias current through a tungsten film has been observed. It is argued that this asymmetry is a manifestation of the spin Hall effect in the current-carrying tungsten film. Nanoscale variations of this asymmetry across the tungsten film have been studied by using the scanning tunneling microscopy technique.

  8. Iron

    Science.gov (United States)

    ... Share: Search the ODS website Submit Search NIH Office of Dietary Supplements Consumer Datos en español Health ... eating a variety of foods, including the following: Lean meat, seafood, and poultry. Iron-fortified breakfast cereals ...

  9. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings

    International Nuclear Information System (INIS)

    Farmer, J C; Haslam, J J; Wong, F; Ji, X; Day, S D; Branagan, D J; Marshall, M C; Meacham, B E; Buffa, E J; Blue, C A; Rivard, J K; Beardsley, M B; Weaver, D T; Aprigliano, L F; Kohler, L; Bayles, R; Lemieux, E J; Wolejsza, T M; Martin, F J; Yang, N; Lucadamo, G; Perepezko, J H; Hildal, K; Kaufman, L; Heuer, A H; Ernst, F; Michal, G M; Kahn, H; Lavernia, E J

    2004-01-01

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an ''integral drip shield'' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  10. Contribution of coated humic acids calculated through their surface coverage on nano iron oxides for ofloxacin and norfloxacin sorption.

    Science.gov (United States)

    Peng, Hongbo; Liang, Ni; Li, Hao; Chen, Fangyuan; Zhang, Di; Pan, Bo; Xing, Baoshan

    2015-09-01

    Sorption of organic contaminants on organo-mineral complexes has been investigated extensively, but the sorption contribution of mineral particles was not properly addressed before calculating KOC, especially for ionic organic contaminants. We measured the surface coverage of a humic acid (HA) on nano iron oxides (n-Fe2O3) in a series of synthesized organo-mineral complexes. The contribution of the coated HA to ofloxacin (OFL) and norfloxacin (NOR) sorption in HA-n-Fe2O3 complexes was over 80% of the total sorption with the surface coverage of 36% and fOC of 1.6%. All the coated HA showed higher sorption to NOR and OFL in comparison to the original HA, suggesting HA fractionation and/or physical re-conformation during organo-mineral complex formation. The decreased KOC with multilayer coating may suggest the importance of site-specific interactions for OFL sorption, while the increased KOC with multilayer coating may suggest the importance of partitioning in hydrophobic region for NOR sorption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms

    International Nuclear Information System (INIS)

    Herrling, Maria P.; Lackner, Susanne; Tatti, Oleg; Guthausen, Gisela; Delay, Markus; Franzreb, Matthias; Horn, Harald

    2016-01-01

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe_3O_4-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe_3O_4-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe_3O_4-NP at short contact times (5 min) in flow cells and complementary, scFe_3O_4-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe_3O_4-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe_3O_4-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3 h in the MBBR. The biosorption depended on the exposure concentration of scFe_3O_4-NP, but less on the contact time. Most scFe_3O_4-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe_3O_4-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in technical biofilm systems and give indications for future investigations needed

  12. Iron oxide shell coating on nano silicon prepared from the sand for lithium-ion battery application

    Science.gov (United States)

    Furquan, Mohammad; Vijayalakshmi, S.; Mitra, Sagar

    2018-05-01

    Elemental silicon, due to its high specific capacity (4200 mAh g-1) and non-toxicity is expected to be an attractive anode material for Li-ion battery. But its huge expansion volume (> 300 %) during charging of battery, leads to pulverization and cracking in the silicon particles and causes sudden failure of the Li-ion battery. In this work, we have designed yolk-shell type morphology of silicon, prepared from carbon coated silicon nanoparticles soaked in aqueous solution of ferric nitrate and potassium hydroxide. The soaked silicon particles were dried and finally calcined at 800 °C for 30 minutes. The product obtained is deprived of carbon and has a kind of yolk-shell morphology of nano silicon with iron oxide coating (Si@Iron oxide). This material has been tested for half-cell lithium-ion battery configuration. The discharge capacity is found to be ≈ 600 mAh g-1 at a current rate of 1.0 A g-1 for 200 cycles. It has shown a stable performance as anode for Li-ion battery application.

  13. Effect of surface charge on the colloidal stability and in vitro uptake of carboxymethyl dextran-coated iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Ayala, Vanessa; Herrera, Adriana P.; Latorre-Esteves, Magda; Torres-Lugo, Madeline; Rinaldi, Carlos

    2013-01-01

    Nanoparticle physicochemical properties such as surface charge are considered to play an important role in cellular uptake and particle–cell interactions. In order to systematically evaluate the role of surface charge on the uptake of iron oxide nanoparticles, we prepared carboxymethyl-substituted dextrans with different degrees of substitution, ranging from 38 to 5 groups per chain, and reacted them using carbodiimide chemistry with amine–silane-coated iron oxide nanoparticles with narrow size distributions in the range of 33–45 nm. Surface charge of carboxymethyl-substituted dextran-coated nanoparticles ranged from −50 to 5 mV as determined by zeta potential measurements, and was dependent on the number of carboxymethyl groups incorporated in the dextran chains. Nanoparticles were incubated with CaCo-2 human colon cancer cells. Nanoparticle–cell interactions were observed by confocal laser scanning microscopy and uptake was quantified by elemental analysis using inductively coupled plasma mass spectroscopy. Mechanisms of internalization were inferred using pharmacological inhibitors for fluid-phase, clathrin-mediated, and caveola-mediated endocytosis. Results showed increased uptake for nanoparticles with greater negative charge. Internalization patterns suggest that uptake of the most negatively charged particles occurs via non-specific interactions

  14. Effect of surface charge on the colloidal stability and in vitro uptake of carboxymethyl dextran-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, Vanessa; Herrera, Adriana P.; Latorre-Esteves, Magda; Torres-Lugo, Madeline [University of Puerto Rico, Department of Chemical Engineering (United States); Rinaldi, Carlos, E-mail: carlos.rinaldi@bme.ufl.edu [University of Florida, J. Crayton Pruitt Family Department of Biomedical Engineering (United States)

    2013-08-15

    Nanoparticle physicochemical properties such as surface charge are considered to play an important role in cellular uptake and particle-cell interactions. In order to systematically evaluate the role of surface charge on the uptake of iron oxide nanoparticles, we prepared carboxymethyl-substituted dextrans with different degrees of substitution, ranging from 38 to 5 groups per chain, and reacted them using carbodiimide chemistry with amine-silane-coated iron oxide nanoparticles with narrow size distributions in the range of 33-45 nm. Surface charge of carboxymethyl-substituted dextran-coated nanoparticles ranged from -50 to 5 mV as determined by zeta potential measurements, and was dependent on the number of carboxymethyl groups incorporated in the dextran chains. Nanoparticles were incubated with CaCo-2 human colon cancer cells. Nanoparticle-cell interactions were observed by confocal laser scanning microscopy and uptake was quantified by elemental analysis using inductively coupled plasma mass spectroscopy. Mechanisms of internalization were inferred using pharmacological inhibitors for fluid-phase, clathrin-mediated, and caveola-mediated endocytosis. Results showed increased uptake for nanoparticles with greater negative charge. Internalization patterns suggest that uptake of the most negatively charged particles occurs via non-specific interactions.

  15. Removal of dissolved heavy metals from pre-settled stormwater runoff by iron-oxide coated sand (IOCS)

    DEFF Research Database (Denmark)

    Møller, J.; Ledin, Anna; Mikkelsen, Peter Steen

    2002-01-01

    (Pb=20, Cu=40, Zn=110, and Cr=15 ppb). Column experiments were conducted to test the influence of the infiltration rate (1 or 3 m/h) and the type of iron(hydr)oxide mineral (amorphous ferrihydrite and goethite coated sand). The results show that at least 90% of lead, copper and zinc can be removed......Sorption to iron-oxide coated sand (IOCS) is a promosing technology for removal of the dissolved heavy metal fraction in stormwater runoff. The development of a new technology is necessary since studies of stormwater runoff from traffic areas indicate that an oil separator and detention pond may...... by IOCS after 480 pore volumes. Control columns with uncoated filter sand show that lead, copper and zinc were removed with >95%, 35% and 5%, respectively. The removal of the negative metaloxy-ion, CrO4-3 was insignificant in both IOCS and sand columns at pH=7.7. Destruction of the columns after...

  16. Towards an integrated system for bio-energy: hydrogen production by Escherichia coli and use of palladium-coated waste cells for electricity generation in a fuel cell.

    Science.gov (United States)

    Orozco, R L; Redwood, M D; Yong, P; Caldelari, I; Sargent, F; Macaskie, L E

    2010-12-01

    Escherichia coli strains MC4100 (parent) and a mutant strain derived from this (IC007) were evaluated for their ability to produce H(2) and organic acids (OAs) via fermentation. Following growth, each strain was coated with Pd(0) via bioreduction of Pd(II). Dried, sintered Pd-biomaterials ('Bio-Pd') were tested as anodes in a proton exchange membrane (PEM) fuel cell for their ability to generate electricity from H(2). Both strains produced hydrogen and OAs but 'palladised' cells of strain IC007 (Bio-Pd(IC007)) produced ~threefold more power as compared to Bio-Pd(MC4100) (56 and 18 mW respectively). The power output used, for comparison, commercial Pd(0) powder and Bio-Pd made from Desulfovibrio desulfuricans, was ~100 mW. The implications of these findings for an integrated energy generating process are discussed.

  17. Water-dispersible sugar-coated iron oxide nanoparticles. An evaluation of their relaxometric and magnetic hyperthermia properties.

    Science.gov (United States)

    Lartigue, Lenaic; Innocenti, Claudia; Kalaivani, Thangavel; Awwad, Azzam; Sanchez Duque, Maria del Mar; Guari, Yannick; Larionova, Joulia; Guérin, Christian; Montero, Jean-Louis Georges; Barragan-Montero, Véronique; Arosio, Paolo; Lascialfari, Alessandro; Gatteschi, Dante; Sangregorio, Claudio

    2011-07-13

    Synthesis of functionalized magnetic nanoparticles (NPs) for biomedical applications represents a current challenge. In this paper we present the synthesis and characterization of water-dispersible sugar-coated iron oxide NPs specifically designed as magnetic fluid hyperthermia heat mediators and negative contrast agents for magnetic resonance imaging. In particular, the influence of the inorganic core size was investigated. To this end, iron oxide NPs with average size in the range of 4-35 nm were prepared by thermal decomposition of molecular precursors and then coated with organic ligands bearing a phosphonate group on one side and rhamnose, mannose, or ribose moieties on the other side. In this way a strong anchorage of the organic ligand on the inorganic surface was simply realized by ligand exchange, due to covalent bonding between the Fe(3+) atom and the phosphonate group. These synthesized nanoobjects can be fully dispersed in water forming colloids that are stable over very long periods. Mannose, ribose, and rhamnose were chosen to test the versatility of the method and also because these carbohydrates, in particular rhamnose, which is a substrate of skin lectin, confer targeting properties to the nanosystems. The magnetic, hyperthermal, and relaxometric properties of all the synthesized samples were investigated. Iron oxide NPs of ca. 16-18 nm were found to represent an efficient bifunctional targeting system for theranostic applications, as they have very good transverse relaxivity (three times larger than the best currently available commercial products) and large heat release upon application of radio frequency (RF) electromagnetic radiation with amplitude and frequency close to the human tolerance limit. The results have been rationalized on the basis of the magnetic properties of the investigated samples.

  18. Antimony Adsorption from Zarshouran Gold Mineral Processing Plant Wastewater by Nano Zero Valent Iron Coated on Bentonite

    Directory of Open Access Journals (Sweden)

    nader nosrati

    2015-03-01

    Full Text Available The effluent from Zarshouran gold mineral processing plant contains high quantities of arsenic, antimony, mercury, and bismuth. These metals and metalloids are soluble in water and very toxic when they enter the environment. Their solubility in water causes the polluted area to extend beyond their point of origin. In this article, different methods of antimony removal from water and wastewater were reviewed and the zero-valent iron nanoparticles coated on Bentonite were selected as an effective and low cost material for removing antimony from wastewater. For the purposes of this study, zero-valent iron nanoparticles of 40-100 nanometers in size were synthesized by dropwise addition of sodium borohydride solution to an Iron (III aqueous solution at  ambient temperature and mixed with nitrogen gas. To avoid particle agglomeration and to enhance the product’s environmentally safe application, the  nanoparticles were coated on Bentonite and characterized by SEM/EDAX and BET. The experiments were carried out by intense mixing of the adsorbent with 10ml of real/synthtic wastewater samples in 20ml bottles.  The effects of pH, contact time, temperature, and adsorbent dosage on antimony removal efficiency were investigated under intense mixing using a magnetic mixer. Finally, the effluents were filtered upon completion of the experiments and used for atomic adsorption analysis. The results of the experiments showed that the adsorption isotherms of the synthesized nanoparticles obeyed the Langmuir and Freundlich models. The experiments carried out on real samples showed that antimony adsorption capacity for B-nZVI was 2.6 mg/g of the adsorbent and that the highest antimony removal efficiency was 99.56%.

  19. Aging study on carboxymethyl cellulose-coated zero-valent iron nanoparticles in water: Chemical transformation and structural evolution

    International Nuclear Information System (INIS)

    Dong, Haoran; Zhao, Feng; Zeng, Guangming; Tang, Lin; Fan, Changzheng; Zhang, Lihua; Zeng, Yalan; He, Qi; Xie, Yankai; Wu, Yanan

    2016-01-01

    Highlights: • The chemical transformation and structural evolution of CMC-nZVI were investigated. • CMC could slow down the aging rate of nZVI and alter the species transformation. • Fe_3O_4 and/or γ-Fe_2O_3 are the dominant corrosion products of bare nZVI after aging. • γ-FeOOH is the primary corrosion product of CMC-nZVI after aging. - Abstract: To assess the long-term fate and the associated risks of nanoscale zero-valent iron (nZVI) used in the water remediation, it is essential to understand the chemical transformations during aging of nZVI in water. This study investigated the compositional and structural evolution of bare nZVI and carboxymethyl cellulose (CMC) coated nZVI in static water over a period of 90 days. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the corrosion products of nZVI and CMC-nZVI. Results show that both the structures and the compositions of the corrosion products change with the process of aging, but the coating of CMC could slow down the aging rate of nZVI (as indicated by the slower drop in Fe"0 intensity in XRD pattern). For the bare nZVI, magnetite (Fe_3O_4) and/or maghemite (γ-Fe_2O_3) are the dominant corrosion products after 90 days of aging. However, for the CMC-nZVI, the core-shell spheres collapses to acicular-shaped structures after aging with crystalline lepidocrocite (γ-FeOOH) as the primary end product. Moreover, more lepidocrocite present in the corrosion products of CMC-nZVI with higher loading of CMC, which reveals that the CMC coating could influence the transformation of iron oxides.

  20. Simple and Efficient Synthesis of Iron Oxide-Coated Silica Gel Adsorbents for Arsenic Removal: Adsorption Isotherms and Kinetic Study

    Energy Technology Data Exchange (ETDEWEB)

    Arifin, Eric; Lee, Jiukyu [Interdisciplinary Program in Nanoscience and Technology, Virginia (United States); Cha, Jinmyung [Seoul National Univ., Seoul (Korea, Republic of)

    2013-08-15

    Iron oxide (ferrihydrite, hematite, and magnetite) coated silica gels were prepared using a low-cost, easily-scalable and straightforward method as the adsorbent material for arsenic removal application. Adsorption of the anionic form of arsenic oxyacids, arsenite (AsO{sup 2-}) and arsenate (AsO{sub 4}{sup -3}), onto hematite coated silica gel was fitted against non-linear 3-parameter-model Sips isotherm and 2-parameter-model Langmuir and Freundlich isotherm. Adsorption kinetics of arsenic could be well described by pseudo-second-order kinetic model and value of adsorption energy derived from non-linear Dubinin-Radushkevich isotherm suggests chemical adsorption. Although arsenic adsorption process was not affected by the presence of sulfate, chloride, and nitrate anions, as expected, bicarbonate and silicate gave moderate negative effects while the presence of phosphate anions significantly inhibited adsorption process of both arsenite and arsenate. When the actual efficiency to remove arsenic was tested against 1 L of artificial arsenic-contaminated groundwater (0.6 mg/L) in the presence competing anions, the reasonable amount (20 g) of hematite coated silica gel could reduce arsenic concentration to below the WHO permissible safety limit of drinking water of 10 μg/L without adjusting pH and temperature, which would be highly advantageous for practical field application.

  1. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    International Nuclear Information System (INIS)

    Liu Lidong; Duan Yuping; Ma Lixin; Liu Shunhua; Yu Zhen

    2010-01-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  2. Microwave absorption properties of a wave-absorbing coating employing carbonyl-iron powder and carbon black

    Science.gov (United States)

    Liu, Lidong; Duan, Yuping; Ma, Lixin; Liu, Shunhua; Yu, Zhen

    2010-11-01

    To prevent serious electromagnetic interference, a single-layer wave-absorbing coating employing complex absorbents composed of carbonyl-iron powder (CIP) and carbon black (CB) with epoxy resin as matrix was prepared. The morphologies of CIP and CB were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The electromagnetic parameters of CIP and CB were measured in the frequency range of 2-18 GHz by transmission/reflection technology, and the electromagnetic loss mechanisms of the two particles were discussed, respectively. The microwave absorption properties of the coatings were investigated by measuring reflection loss (RL) using arch method. The effects of CIP ratio, CB content and thickness on the microwave absorption properties were discussed, respectively. The results showed that the higher thickness, CIP or CB content could make the absorption band shift towards the lower frequency range. Significantly, the wave-absorbing coating could be applied in different frequency ranges according to actual demand by controlling the content of CIP or CB in composites.

  3. Evaluation of Surface Roughness and Power Consumption in Machining FCD 450 Cast Iron using Coated and Uncoated Irregular Milling Tools

    International Nuclear Information System (INIS)

    Yusoff, Ahmad Razlan; Arsyad, Fitriyanti

    2016-01-01

    In this project, the effects of different cutting parameters on surface roughness and power consumption when machining FCD450 cast iron were studied using coated and uncoated irregular milling tool geometry of variable helix and pitch. Their responses on roughness and power consumption were evaluated based on the spindle speed, feed rate, and depth of cut, machining length and machining time. Results showed that except spindle speed and machining length, other parameters such as feed rate, axial and radial depth of cut and also machining time proportionate with surface roughness. The power consumption proportionately increase for all cutting parameters except feedrate. It is showed that the average decrement 27.92 percent for surface roughness and average decrement 9.32 percent for power consumption by using coated compared to uncoated tool. Optimum cutting parameters for both minimum surface roughness and power consumption can be determined. The coated tools performed better than uncoated milling tools for responses of surface roughness and power consumption to increase machining productivity and profit. (paper)

  4. Studying the effect of particle size and coating type on the blood kinetics of superparamagnetic iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Roohi F

    2012-08-01

    Full Text Available Farnoosh Roohi, Jessica Lohrke, Andreas Ide, Gunnar Schütz, Katrin DasslerMR and CT Contrast Media Research, Bayer Pharma AG, Berlin, GermanyPurpose: Magnetic resonance imaging (MRI, one of the most powerful imaging techniques available, usually requires the use of an on-demand designed contrast agent to fully exploit its potential. The blood kinetics of the contrast agent represent an important factor that needs to be considered depending on the objective of the medical examination. For particulate contrast agents, such as superparamagnetic iron oxide nanoparticles (SPIOs, the key parameters are particle size and characteristics of the coating material. In this study we analyzed the effect of these two properties independently and systematically on the magnetic behavior and blood half-life of SPIOs.Methods: Eleven different SPIOs were synthesized for this study. In the first set (a, seven carboxydextran (CDX-coated SPIOs of different sizes (19–86 nm were obtained by fractionating a broadly size-distributed CDX–SPIO. The second set (b contained three SPIOs of identical size (50 nm that were stabilized with different coating materials, polyacrylic acid (PAA, polyethylene glycol, and starch. Furthermore, small PAA–SPIOs (20 nm were synthesized to gain a global insight into the effects of particle size vs coating characteristics. Saturation magnetization and proton relaxivity were determined to represent the magnetic and imaging properties. The blood half-life was analyzed in rats using MRI, time-domain nuclear magnetic resonance, and inductively coupled plasma optical emission spectrometry.Results: By changing the particle size without modifying any other parameters, the relaxivity r2 increased with increasing mean particle diameter. However, the blood half-life was shorter for larger particles. The effect of the coating material on magnetic properties was less pronounced, but it had a strong influence on blood kinetics depending on the

  5. Studying the effect of particle size and coating type on the blood kinetics of superparamagnetic iron oxide nanoparticles.

    Science.gov (United States)

    Roohi, Farnoosh; Lohrke, Jessica; Ide, Andreas; Schütz, Gunnar; Dassler, Katrin

    2012-01-01

    Magnetic resonance imaging (MRI), one of the most powerful imaging techniques available, usually requires the use of an on-demand designed contrast agent to fully exploit its potential. The blood kinetics of the contrast agent represent an important factor that needs to be considered depending on the objective of the medical examination. For particulate contrast agents, such as superparamagnetic iron oxide nanoparticles (SPIOs), the key parameters are particle size and characteristics of the coating material. In this study we analyzed the effect of these two properties independently and systematically on the magnetic behavior and blood half-life of SPIOs. Eleven different SPIOs were synthesized for this study. In the first set (a), seven carboxydextran (CDX)-coated SPIOs of different sizes (19-86 nm) were obtained by fractionating a broadly size-distributed CDX-SPIO. The second set (b) contained three SPIOs of identical size (50 nm) that were stabilized with different coating materials, polyacrylic acid (PAA), poly-ethylene glycol, and starch. Furthermore, small PAA-SPIOs (20 nm) were synthesized to gain a global insight into the effects of particle size vs coating characteristics. Saturation magnetization and proton relaxivity were determined to represent the magnetic and imaging properties. The blood half-life was analyzed in rats using MRI, time-domain nuclear magnetic resonance, and inductively coupled plasma optical emission spectrometry. By changing the particle size without modifying any other parameters, the relaxivity r(2) increased with increasing mean particle diameter. However, the blood half-life was shorter for larger particles. The effect of the coating material on magnetic properties was less pronounced, but it had a strong influence on blood kinetics depending on the ionic character of the coating material. In this report we systematically demonstrated that both particle size and coating material influence blood kinetics and magnetic properties of

  6. Short and long term biosorption of silica-coated iron oxide nanoparticles in heterotrophic biofilms

    Energy Technology Data Exchange (ETDEWEB)

    Herrling, Maria P. [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Lackner, Susanne [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Urban Bioengineering for Resource Recovery, Bauhaus-Institute for Infrastructure Solutions, Bauhaus-Universität Weimar, Coudraystraße 7, 99423 Weimar (Germany); Tatti, Oleg [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Guthausen, Gisela [Pro" 2NMR, Institute for Biological Interfaces 4 and Institute for Mechanical Process Engineering and Mechanics, Karlsruhe Institute of Technology, Adenauerring 20b, 76131 Karlsruhe (Germany); Delay, Markus [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); Franzreb, Matthias [Institute of Functional Interfaces, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Horn, Harald, E-mail: harald.horn@kit.edu [Engler-Bunte-Institut, Chair of Water Chemistry and Water Technology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany); DVGW Research Laboratories for Water Chemistry and Water Technology, Engler-Bunte-Ring 1, 76131 Karlsruhe (Germany)

    2016-02-15

    The increased application of engineered nanoparticles (ENP) in industrial processes and consumer products has raised concerns about their impact on health and environmental safety. When ENP enter the global water cycle by e.g. wastewater streams, wastewater treatment plants (WWTP) represent potential sinks for ENP. During biological WWT, the attachment of ENP to biofilms is responsible for the desired removal of ENP from the water phase avoiding their release into the aquatic environment. However, the fundamental mechanisms guiding the interactions between ENP and biofilms are not yet fully understood. Therefore, this study investigates the behavior and biosorption of inorganic ENP, here magnetic iron oxide nanoparticles coated with silica (scFe{sub 3}O{sub 4}-NP), with heterotrophic biofilms at different time scales. Their magnetic properties enable to follow scFe{sub 3}O{sub 4}-NP in the biofilm system by a magnetic susceptibility balance and magnetic resonance imaging. Biofilms were exposed to scFe{sub 3}O{sub 4}-NP at short contact times (5 min) in flow cells and complementary, scFe{sub 3}O{sub 4}-NP were introduced into a moving bed biofilm reactor (MBBR) to be observed for 27 d. Mass balances revealed that scFe{sub 3}O{sub 4}-NP sorbed to the biofilm within a few minutes, but that the total biosorption was rather low (3.2 μg Fe/mg TSS). scFe{sub 3}O{sub 4}-NP mainly sorbed to the biofilm surface inducing the detachment of outer biofilm parts starting after an exposure time of 3 h in the MBBR. The biosorption depended on the exposure concentration of scFe{sub 3}O{sub 4}-NP, but less on the contact time. Most scFe{sub 3}O{sub 4}-NP exited the flow cell (up to 65%) and the MBBR (57%) via the effluent. This effect was favored by the stabilization of scFe{sub 3}O{sub 4}-NP in the bulk liquid by organic matter leading to a low retention capacity of the MBBR system. The results contribute to improve our understanding about the fate of ENP in environmental and in

  7. A comparison of iron oxide-rich joint coatings and rock chips as geochemical sampling media in exploration for disseminated gold deposits

    Science.gov (United States)

    Crone, W.; Larson, L.T.; Carpenter, R.H.; Chao, T.T.; Sanzolone, R.F.

    1984-01-01

    We evaluated the effectiveness of iron oxide-rich fracture coatings as a geochemical sampling medium for disseminated gold deposits, as compared with conventional lithogeochemical methods, for samples from the Pinson mine and Preble prospect in southeastern Humboldt County, Nevada. That disseminated gold mineralization is associated with Hg, As, and Sb is clearly demonstrated in these deposits for both fracture coatings and rock chip samples. However, the relationship is more pronounced for fracture coatings. Fracture coatings at Pinson contain an average of 3.61, 5.13, 14.37, and 3.42 times more Au, As, Sb and Hg, respectively, than adjacent rock samples. At Preble, fracture coatings contain 3.13, 9.72, 9.18, and 1.85 times more Au, As, Sb and Hg, respectively, than do adjacent rock samples. Geochemical anomalies determined from fracture coatings are thus typically more intense than those determined from rock samples for these elements. The sizes of anomalies indicated by fracture coatings are also somewhat larger, but this is less obvious. In both areas, Sb anomalies are more extensive in fracture coatings. At Preble, some Hg and Au anomalies are also more extensive in fracture coatings. In addition to halos formed by the Hg, As and Sb, high values for Au/Ag and Zn/(Fe + Mn) are closely associated with gold mineralization at the Pinson mine. The large enhancement in geochemical response afforded by fracture coatings indicates a definite potential in the search for buried disseminated gold deposits. ?? 1984.

  8. Blocked-micropores, surface functionalized, bio-compatible and silica-coated iron oxide nanocomposites as advanced MRI contrast agent

    International Nuclear Information System (INIS)

    Darbandi, Masih; Laurent, Sophie; Busch, Martin; Li Zian; Yuan Ying; Krüger, Michael; Farle, Michael; Winterer, Markus; Vander Elst, Luce; Muller, Robert N.; Wende, Heiko

    2013-01-01

    Biocompatible magnetic nanoparticles have been found promising in several biomedical applications for tagging, imaging, sensing and separation in recent years. In this article, a systematic study of the design and development of surface-modification schemes for silica-coated iron oxide nanoparticles (IONP) via a one-pot, in situ method at room temperature is presented. Silica-coated IONP were prepared in a water-in-oil microemulsion, and subsequently the surface was modified via addition of organosilane reagents to the microemulsion system. The structure and the morphology of the as synthesized nanoparticles have been investigated by means of transmission electron microscopy (TEM) and measurement of N 2 adsorption–desorption. Electron diffraction and high-resolution transmission electron microscopic (TEM) images of the nanoparticles showed the highly crystalline nature of the IONP structures. Nitrogen adsorption indicates microporous and blocked-microporous structures for the silica-coated and amine functionalized silica-coated IONP, respectively which could prove less cytotoxicity of the functionalized final product. Besides, the colloidal stability of the final product and the presence of the modified functional groups on top of surface layer have been proven by zeta-potential measurements. Owing to the benefit from the inner IONP core and the hydrophilic silica shell, the as-synthesized nanocomposites were exploited as an MRI contrast enhancement agent. Relaxometric results prove that the surface functionalized IONP have also signal enhancement properties. These surface functionalized nanocomposites are not only potential candidates for highly efficient contrast agents for MRI, but could also be used as ultrasensitive biological-magnetic labels, because they are in nanoscale size, having magnetic properties, blocked-microporous and are well dispersible in biological environment.

  9. Diffusion Coefficient in the Zinc Coating Shaped on the Surface of Cast Iron and Steel Alloys

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2015-06-01

    Full Text Available The article presents the method to assess the diffusion coefficient D in the sub-layer of intermetallic phases formed during hot-dip galvanizing “Armco” iron and ductile cast iron EN-GJS-500-7. Hot-dip galvanizing is one of the most popular forms of long-term protection of Fe-C alloys against corrosion. The process for producing a protective layer of sufficient quality is closely related to diffusion of atoms of zinc and iron. The simulation consist in performed a hot-dip galvanizing in laboratory condition above Fe-C alloys, in the Department of Engineering of Cast Alloys and Composites. Galvanizing time ranged from 15 to 300 seconds. Then metallographic specimens were prepared, intermetallic layers were measured and diffusion coefficient (D were calculated. It was found that the diffusion coefficient obtained during hot-dip galvanizing “Armco” iron and zinc is about two orders of magnitude less than the coefficient obtained on ductile cast iron EN-GJS-500-7.

  10. Dextran and Polymer Polyethylene Glycol (PEG Coating Reduce Both 5 and 30 nm Iron Oxide Nanoparticle Cytotoxicity in 2D and 3D Cell Culture

    Directory of Open Access Journals (Sweden)

    Alisa Morss Clyne

    2012-05-01

    Full Text Available Superparamagnetic iron oxide nanoparticles are widely used in biomedical applications, yet questions remain regarding the effect of nanoparticle size and coating on nanoparticle cytotoxicity. In this study, porcine aortic endothelial cells were exposed to 5 and 30 nm diameter iron oxide nanoparticles coated with either the polysaccharide, dextran, or the polymer polyethylene glycol (PEG. Nanoparticle uptake, cytotoxicity, reactive oxygen species (ROS formation, and cell morphology changes were measured. Endothelial cells took up nanoparticles of all sizes and coatings in a dose dependent manner, and intracellular nanoparticles remained clustered in cytoplasmic vacuoles. Bare nanoparticles in both sizes induced a more than 6 fold increase in cell death at the highest concentration (0.5 mg/mL and led to significant cell elongation, whereas cell viability and morphology remained constant with coated nanoparticles. While bare 30 nm nanoparticles induced significant ROS formation, neither 5 nm nanoparticles (bare or coated nor 30 nm coated nanoparticles changed ROS levels. Furthermore, nanoparticles were more toxic at lower concentrations when cells were cultured within 3D gels. These results indicate that both dextran and PEG coatings reduce nanoparticle cytotoxicity, however different mechanisms may be important for different size nanoparticles.

  11. Conversion electron Moessbauer spectroscopic studies on the chemical states of surface layers of corroded tin plates and tin-coated iron plates

    International Nuclear Information System (INIS)

    Kato, Akinori; Endo, Kazutoyo; Sano, Hirotoshi

    1980-01-01

    By means of the conversion electron Moessbauer spectroscopy (CEMS), we studied surface layers of ''tin'' plates and tin-coated iron plates corroded by various acids. Transmission Moessbauer spectra and X-ray diffraction patterns were also measured. Metastannic acid was formed, when the ''tin'' plate was corroded by nitric acid solution. In corrosion by phosphoric acid solution, the X-ray diffractometry revealed the formation of tin(IV) pyrophosphate. In corrosion by various organic acid solutions, the formation of oxides was identified by the 119 Sn CEMS, but not by the X-ray diffractometry because of the too thin corrosion layer. In corrosion of tin-coated iron plates, maleic acid, malonic acid, formic acid, and oxalic acid were used. It was determined by CEMS that the corrosion products caused by these acids were tin(IV) oxides, although they could not be identified by the X-ray diffractometry. CEMS also confirmed that the surface of uncorroded tin-coated iron plate was already oxidized by air. Colorimetric determinations of Sn and Fe dissolved from tin-coated iron plates to various acid solutions confirmed that maleic acid had the strongest corrosion effect among the organic acids studied. (author)

  12. Mechanisms of complement activation by dextran-coated superparamagnetic iron oxide (SPIO) nanoworms in mouse versus human serum

    DEFF Research Database (Denmark)

    Banda, Nirmal K; Mehta, Gaurav; Chao, Ying

    2014-01-01

    BACKGROUND: The complement system is a key component of innate immunity implicated in the neutralization and clearance of invading pathogens. Dextran coated superparamagnetic iron oxide (SPIO) nanoparticle is a promising magnetic resonance imaging (MRI) contrast agent. However, dextran SPIO has...... the mechanisms of human complement activation. Mouse data were analyzed by non-paired t-test, human data were analyzed by ANOVA followed by multiple comparisons with Student-Newman-Keuls test. RESULTS: In mouse sera, SPIO NW triggered the complement activation via the LP, whereas the AP contributes via...... the CP, but that did not affect the total level of C3 deposition on the particles. CONCLUSIONS: There were important differences and similarities in the complement activation by SPIO NW in mouse versus human sera. Understanding the mechanisms of immune recognition of nanoparticles in mouse and human...

  13. Doxorubicin loaded PEG-b-poly(4-vinylbenzylphosphonate) coated magnetic iron oxide nanoparticles for targeted drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hałupka-Bryl, Magdalena, E-mail: magdalenahalupka@op.pl [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Bednarowicz, Magdalena [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Dobosz, Bernadeta; Krzyminiewski, Ryszard [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Division of Medical Physics, Faculty of Physics, Adam Mickiewicz University, Poznań (Poland); Zalewski, Tomasz [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Wereszczyńska, Beata [Department of Macromolecular Physics, Adam Mickiewicz University, Poznań (Poland); Nowaczyk, Grzegorz; Jarek, Marcin [The NanoBioMedical Centre, Adam Mickiewicz University, Poznań (Poland); Nagasaki, Yukio [Department of Materials Sciences, Graduate School of Pure and Applied Sciences, University of Tsukuba (Japan); Master’s School of Medicinal Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba (Japan); International Centre for Materials Nanoarchitectonics Satellite (WPI-MANA), National Institute For Materials Sciences (NIMS) and University of Tsukuba (Japan)

    2015-06-15

    Due to their unique physical properties, superparamagnetic iron oxide nanoparticles are increasingly used in medical applications. They are very useful carriers for delivering antitumor drugs in targeted cancer treatment. Magnetic nanoparticles with chemiotherapeutic were synthesized by coprecipitation method followed by coating with biocompatible polymer. The aim of this work is to characterize physical and magnetic properties of synthesized nanoparicles. Characterization was carried out using EPR, HRTEM, X-ray diffraction, SQUID and NMR methods. The present findings show that synthesized nanosystem is promising tool for potential magnetic drug delivery. - Highlights: • Synthesized PEG-PIONs/DOX have excellent physical properties. • PEG-PIONs/DOX have a potential to in vivo application. • PEG-PIONs/DOX could be used as drug delivery system as well as contrast agents.

  14. Evaluation of the corrosion resistance of an epoxy-polyamide coating containing different ratios of micaceous iron oxide/Al pigments

    International Nuclear Information System (INIS)

    Nikravesh, B.; Ramezanzadeh, B.; Sarabi, A.A.; Kasiriha, S.M.

    2011-01-01

    Research highlights: → The corrosion resistance of the coating was improved using MIO and Al pigments. → The greatest coating corrosion resistance was observed at MIO/Al ratio of 10/90. → The cathodic disbonded area of the coating was decreased using MIO and Al particles. → The lowest disbonded area was observed at MIO/Al ratio of 10/90. → Al particles had high capability of reacting with the OH - ions. - Abstract: The corrosion resistance of an epoxy coating reinforced with different ratios of MIO/Al pigments was studied. The coatings properties were investigated by an electrochemical impedance spectroscopy (EIS), salt spray test, cathodic disbonding and a scanning electron microscope (SEM). The corrosion resistance of the epoxy coating was improved using MIO (micaceous iron oxide) and Al pigments. The corrosion resistance of the purely Al pigmented coating was considerably greater than the purely MIO pigmented coating. The cathodic disbonded area of coating was decreased using MIO and Al pigments. The decrease in disbonded area was more pronounced in the presence of Al particles.

  15. Treatment of heavy metals by iron oxide coated and natural gravel media in Sustainable urban Drainage Systems.

    Science.gov (United States)

    Norris, M J; Pulford, I D; Haynes, H; Dorea, C C; Phoenix, V R

    2013-01-01

    Sustainable urban Drainage Systems (SuDS) filter drains are simple, low-cost systems utilized as a first defence to treat road runoff by employing biogeochemical processes to reduce pollutants. However, the mechanisms involved in pollution attenuation are poorly understood. This work aims to develop a better understanding of these mechanisms to facilitate improved SuDS design. Since heavy metals are a large fraction of pollution in road runoff, this study aimed to enhance heavy metal removal of filter drain gravel with an iron oxide mineral amendment to increase surface area for heavy metal scavenging. Experiments showed that amendment-coated and uncoated (control) gravel removed similar quantities of heavy metals. Moreover, when normalized to surface area, iron oxide coated gravels (IOCGs) showed poorer metal removal capacities than uncoated gravel. Inspection of the uncoated microgabbro gravel indicated that clay particulates on the surface (a natural product of weathering of this material) augmented heavy metal removal, generating metal sequestration capacities that were competitive compared with IOCGs. Furthermore, when the weathered surface was scrubbed and removed, metal removal capacities were reduced by 20%. When compared with other lithologies, adsorption of heavy metals by microgabbro was 10-70% higher, indicating that both the lithology of the gravel, and the presence of a weathered surface, considerably influence its ability to immobilize heavy metals. These results contradict previous assumptions which suggest that gravel lithology is not a significant factor in SuDS design. Based upon these results, weathered microgabbro is suggested to be an ideal lithology for use in SuDS.

  16. Analysis of timber and coating material on an iron anchor recovered off Aguada Bay, Goa

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.; Rao, B.R.; Shashikala, S.; Rao, R.V.; Khedekar, V.D.

    Shanked iron anchor measuring 3.30 m long with a 4.37 m wooden stock was recovered off Aguada Bay, Goa at a water depth of 11 m. The anchor has been tentatively dated contemporary with the maritime history of Goa and Portugal between the 16th and 17th...

  17. Multifunctional Silver Coated E-33/Iron Oxide Water Filters: Inhibition of Biofilm Growth and Arsenic Removal

    Science.gov (United States)

    Bayoxide® E33 (E-33, Goethite) is a widely used commercial material for arsenic adsorption. It is a mixture of iron oxyhydroxide and oxides. E-33 is primarily used to remove arsenic from water and to a lesser extent, other anions, but generally lacks multifunctuality. It is a non...

  18. Labeling transplanted mice islet with polyvinylpyrrolidone coated superparamagnetic iron oxide nanoparticles for in vivo detection by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huang Hai; Xie Qiuping; Kang Muxing; Zhang Bo; Wu Yulian [Department of Surgery, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Zhang Hui; Chen Jin; Zhai Chuanxin; Yang Deren [State Key Lab of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Jiang Biao, E-mail: wuyulian@medmail.com.c, E-mail: yulianwu2003@yahoo.c [Department of Radiology, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2009-09-09

    Superparamagnetic iron oxide nanoparticles (SPIO) are emerging as a novel probe for noninvasive cell tracking with magnetic resonance imaging (MRI) and have potential wide usage in medical research. In this study, we have developed a method using high-temperature hydrolysis of chelate metal alkoxide complexes to synthesize polyvinylpyrrolidone coated iron oxide nanoparticles (PVP-SPIO), as a biocompatible magnetic agent that can efficiently label mice islet {beta}-cells. The size, crystal structure and magnetic properties of the as-synthesized nanoparticles have been characterized. The newly synthesized PVP-SPIO with high stability, crystallinity and saturation magnetization can be efficiently internalized into {beta}-cells, without affecting viability and function. The imaging of 100 PVP-SPIO-labeled mice islets in the syngeneic renal subcapsular model of transplantation under a clinical 3.0 T MR imager showed high spatial resolution in vivo. These results indicated the great potential application of the PVP-SPIO as an MRI contrast agent for monitoring transplanted islet grafts in the clinical management of diabetes in the near future.

  19. Labeling transplanted mice islet with polyvinylpyrrolidone coated superparamagnetic iron oxide nanoparticles for in vivo detection by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Huang Hai; Xie Qiuping; Kang Muxing; Zhang Bo; Wu Yulian; Zhang Hui; Chen Jin; Zhai Chuanxin; Yang Deren; Jiang Biao

    2009-01-01

    Superparamagnetic iron oxide nanoparticles (SPIO) are emerging as a novel probe for noninvasive cell tracking with magnetic resonance imaging (MRI) and have potential wide usage in medical research. In this study, we have developed a method using high-temperature hydrolysis of chelate metal alkoxide complexes to synthesize polyvinylpyrrolidone coated iron oxide nanoparticles (PVP-SPIO), as a biocompatible magnetic agent that can efficiently label mice islet β-cells. The size, crystal structure and magnetic properties of the as-synthesized nanoparticles have been characterized. The newly synthesized PVP-SPIO with high stability, crystallinity and saturation magnetization can be efficiently internalized into β-cells, without affecting viability and function. The imaging of 100 PVP-SPIO-labeled mice islets in the syngeneic renal subcapsular model of transplantation under a clinical 3.0 T MR imager showed high spatial resolution in vivo. These results indicated the great potential application of the PVP-SPIO as an MRI contrast agent for monitoring transplanted islet grafts in the clinical management of diabetes in the near future.

  20. Magnetic resonance imaging of mouse islet grafts labeled with novel chitosan-coated superparamagnetic iron oxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Jyuhn-Huarng Juang

    Full Text Available To better understand the fate of islet isografts and allografts, we utilized a magnetic resonance (MR imaging technique to monitor mouse islets labeled with a novel MR contrast agent, chitosan-coated superparamagnetic iron oxide (CSPIO nanoparticles.After being incubated with and without CSPIO (10 µg/ml, C57BL/6 mouse islets were examined under transmission electron microscope (TEM and their insulin secretion was measured. Cytotoxicity was examined in α (αTC1 and β (NIT-1 and βTC cell lines as well as islets. C57BL/6 mice were used as donors and inbred C57BL/6 and Balb/c mice were used as recipients of islet transplantation. Three hundred islets were transplanted under the left kidney capsule of each mouse and then MR was performed in the recipients periodically. At the end of study, the islet graft was removed for histology and TEM studies.After incubation of mouse islets with CSPIO (10 µg/mL, TEM showed CSPIO in endocytotic vesicles of α- and β-cells at 8 h. Incubation with CSPIO did not affect insulin secretion from islets and death rates of αTC1, NIT-1 and βTC cell lines as well as islets. After syngeneic and allogeneic transplantation, grafts of CSPIO-labeled islets were visualized on MR scans as persistent hypointense areas. At 8 weeks after syngeneic transplantation and 31 days after allogeneic transplantation, histology of CSPIO-labeled islet grafts showed colocalized insulin and iron staining in the same areas but the size of allografts decreased with time. TEM with elementary iron mapping demonstrated CSPIO distributed in the cytoplasm of islet cells, which maintained intact ultrastructure.Our results indicate that after syngeneic and allogeneic transplantation, islets labeled with CSPIO nanoparticles can be effectively and safely imaged by MR.

  1. Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

    International Nuclear Information System (INIS)

    Catalano, E; Di Benedetto, A

    2017-01-01

    Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe 3 O 4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m -1 ) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml -1 ) is fully in agreement with cancer therapy and biomedical applications. (paper)

  2. Characterization of physicochemical and colloidal properties of hydrogel chitosan-coated iron-oxide nanoparticles for cancer therapy

    Science.gov (United States)

    Catalano, E.; Di Benedetto, A.

    2017-05-01

    Superparamagnetic iron oxide nanoparticles have recently been investigated for their potential to kill cancer cells with promising results, owing to their ability to be targeted and heated by magnetic fields. In this study, novel hydrogel, chitosan Fe3O4 magnetic nanoparticles were synthesized to induce magnetic hyperthermia, and targeted delivering of chemotherapeutics in the cancer microenvironment. The characteristic properties of synthesized bare and CS-MNPs were analyzed by various analytical methods: X-ray diffraction, Fourier transformed infrared spectroscopy, Scanning electron microscopy and Thermo-gravimetric analysis/differential thermal analysis. Magnetic nanoparticles were successfully synthesized using the co-precipitation method. This synthesis technique resulted in nanoparticles with an average particle size of 16 nm. The pure obtained nanoparticles were then successfully encapsulated with 4-nm-thick chitosan coating. The formation of chitosan on the surface of nanoparticles was confirmed by physicochemical analyses. Heating experiments at safe magnetic field (f = 100 kHz, H =10-20 kA m-1) revealed that the maximum achieved temperature of water stable chitosan-coated nanoparticles (50 mg ml-1) is fully in agreement with cancer therapy and biomedical applications.

  3. Self-Assembled Lipid Nanoparticles for Oral Delivery of Heparin-Coated Iron Oxide Nanoparticles for Theranostic Purposes.

    Science.gov (United States)

    Truzzi, Eleonora; Bongio, Chiara; Sacchetti, Francesca; Maretti, Eleonora; Montanari, Monica; Iannuccelli, Valentina; Vismara, Elena; Leo, Eliana

    2017-06-09

    Recently, solid lipid nanoparticles (SLNs) have attracted increasing attention owing to their potential as an oral delivery system, promoting intestinal absorption in the lymphatic circulation which plays a role in disseminating metastatic cancer cells and infectious agents throughout the body. SLN features can be exploited for the oral delivery of theranostics. Therefore, the aim of this work was to design and characterise self-assembled lipid nanoparticles (SALNs) to encapsulate and stabilise iron oxide nanoparticles non-covalently coated with heparin (Fe@hepa) as a model of a theranostic tool. SALNs were characterised for physico-chemical properties (particle size, surface charge, encapsulation efficiency, in vitro stability, and heparin leakage), as well as in vitro cytotoxicity by methyl thiazole tetrazolium (MTT) assay and cell internalisation in CaCo-2, a cell line model used as an indirect indication of intestinal lymphatic absorption. SALNs of about 180 nm, which are stable in suspension and have a high encapsulation efficiency (>90%) were obtained. SALNs were able to stabilise the heparin coating of Fe@hepa, which are typically unstable in physiological environments. Moreover, SALNs-Fe@hepa showed no cytotoxicity, although their ability to be internalised into CaCo-2 cells was highlighted by confocal microscopy analysis. Therefore, the results indicated that SALNs can be considered as a promising tool to orally deliver theranostic Fe@hepa into the lymphatic circulation, although further in vivo studies are needed to comprehend further potential applications.

  4. Magnetic relaxation switch and colorimetric detection of thrombin using aptamer-functionalized gold-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Liang Guohai; Cai Shaoyu; Zhang Peng [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Peng Youyuan [Department of Chemistry, Quanzhou Normal University, Quanzhou 362000 (China); Chen Hui; Zhang Song [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Kong Jilie, E-mail: jlkong@fudan.edu.cn [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China)

    2011-03-18

    We describe a sensitive biosensing system combining magnetic relaxation switch diagnosis and colorimetric detection of human {alpha}-thrombin, based on the aptamer-protein interaction induced aggregation of Fe{sub 3}O{sub 4}-Au nanoparticles. To demonstrate the concept, gold-coated iron oxide nanoparticle was synthesized by iterative reduction of HAuCl{sub 4} onto the dextran-coated Fe{sub 3}O{sub 4} nanoparticles. The resulting core-shell structure had a flowerlike shape with pretty narrow size distribution (referred to as 'nanorose'). The two aptamers corresponding to human {alpha}-thrombin were conjugated separately to two distinct nanorose populations. Once a solution containing human {alpha}-thrombin was introduced, the nanoroses switched from a well dispersed state to an aggregated one, leading to a change in the spin-spin relaxation time (T{sub 2}) as well as the UV-Vis absorption spectra of the solution. Thus the qualitative and quantitative detection method for human {alpha}-thrombin was established. The dual-mode detection is clearly advantageous in obtaining a more reliable result; the detection range is widened as well. By using the dual-mode detection method, a detectable T{sub 2} change is observed with 1.0 nM human {alpha}-thrombin, and the detection range is from 1.6 nM to 30.4 nM.

  5. High impact of in situ dextran coating on biocompatibility, stability and magnetic properties of iron oxide nanoparticles.

    Science.gov (United States)

    Shaterabadi, Zhila; Nabiyouni, Gholamreza; Soleymani, Meysam

    2017-06-01

    Biocompatible ferrofluids based on dextran coated iron oxide nanoparticles were fabricated by conventional co-precipitation method. The experimental results show that the presence of dextran in reaction medium not only causes to the appearance of superparamagnetic behavior but also results in significant suppression in saturation magnetization of dextran coated samples. These results can be attributed to size reduction originated from the role of dextran as a surfactant. Moreover, weight ratio of dextran to magnetic nanoparticles has a remarkable influence on size and magnetic properties of nanoparticles, so that the sample prepared with a higher weight ratio of dextran to nanoparticles has the smaller size and saturation magnetization compare with the other samples. In addition, the ferrofluids containing such nanoparticles have an excellent stability at physiological pH for several months. Furthermore, the biocompatibility studies reveal that surface modification of nanoparticles by dextran dramatically decreases the cytotoxicity of bare nanoparticles and consequently improves their potential application for diagnostic and therapeutic purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Interactions between sub-10-nm iron and cerium oxide nanoparticles and 3T3 fibroblasts: the role of the coating and aggregation state

    Science.gov (United States)

    Safi, M.; Sarrouj, H.; Sandre, O.; Mignet, N.; Berret, J.-F.

    2010-04-01

    Recent nanotoxicity studies revealed that the physico-chemical characteristics of engineered nanomaterials play an important role in the interactions with living cells. Here, we report on the toxicity and uptake of cerium and iron oxide sub-10-nm nanoparticles by NIH/3T3 mouse fibroblasts. Coating strategies include low-molecular weight ligands (citric acid) and polymers (poly(acrylic acid), MW = 2000 g mol - 1). Electrostatically adsorbed on the surfaces, the organic moieties provide a negatively charged coating in physiological conditions. We find that most particles were biocompatible, as exposed cells remained 100% viable relative to controls. Only the bare and the citrate-coated nanoceria exhibit a slight decrease in mitochondrial activity at very high cerium concentrations (>1 g l - 1). We also observe that the citrate-coated particles are internalized/adsorbed by the cells in large amounts, typically 250 pg/cell after 24 h incubation for iron oxide. In contrast, the polymer-coated particles are taken up at much lower rates (<30 pg/cell). The strong uptake shown by the citrated particles is related to the destabilization of the dispersions in the cell culture medium and their sedimentation down to the cell membranes. In conclusion, we show that the uptake of nanomaterials by living cells depends on the coating of the particles and on its ability to preserve the colloidal nature of the dispersions.

  7. Interactions between sub-10-nm iron and cerium oxide nanoparticles and 3T3 fibroblasts: the role of the coating and aggregation state

    International Nuclear Information System (INIS)

    Safi, M; Sarrouj, H; Berret, J-F; Sandre, O; Mignet, N

    2010-01-01

    Recent nanotoxicity studies revealed that the physico-chemical characteristics of engineered nanomaterials play an important role in the interactions with living cells. Here, we report on the toxicity and uptake of cerium and iron oxide sub-10-nm nanoparticles by NIH/3T3 mouse fibroblasts. Coating strategies include low-molecular weight ligands (citric acid) and polymers (poly(acrylic acid), M W = 2000 g mol -1 ). Electrostatically adsorbed on the surfaces, the organic moieties provide a negatively charged coating in physiological conditions. We find that most particles were biocompatible, as exposed cells remained 100% viable relative to controls. Only the bare and the citrate-coated nanoceria exhibit a slight decrease in mitochondrial activity at very high cerium concentrations (>1 g l -1 ). We also observe that the citrate-coated particles are internalized/adsorbed by the cells in large amounts, typically 250 pg/cell after 24 h incubation for iron oxide. In contrast, the polymer-coated particles are taken up at much lower rates (<30 pg/cell). The strong uptake shown by the citrated particles is related to the destabilization of the dispersions in the cell culture medium and their sedimentation down to the cell membranes. In conclusion, we show that the uptake of nanomaterials by living cells depends on the coating of the particles and on its ability to preserve the colloidal nature of the dispersions.

  8. Interactions between sub-10-nm iron and cerium oxide nanoparticles and 3T3 fibroblasts: the role of the coating and aggregation state

    Energy Technology Data Exchange (ETDEWEB)

    Safi, M; Sarrouj, H; Berret, J-F [Matiere et Systemes Complexes, UMR 7057 CNRS, Universite Denis Diderot Paris VII, Batiment Condorcet, 10 rue Alice Domon et Leonie Duquet, F-75205 Paris (France); Sandre, O [UPMC Universite Paris VI-Laboratoire de Physico-chimie des Electrolytes, Colloides et Sciences Analytiques, UMR 7195 UPMC Universite Paris 6/CNRS/ESPCI Paristech, 4 place Jussieu, F-75252 Paris Cedex 05 (France); Mignet, N, E-mail: jean-francois.berret@univ-paris-diderot.fr [CNRS UMR 8151, Faculte de Pharmacie, 4 avenue de l' Observatoire, F-75270 Paris (France)

    2010-04-09

    Recent nanotoxicity studies revealed that the physico-chemical characteristics of engineered nanomaterials play an important role in the interactions with living cells. Here, we report on the toxicity and uptake of cerium and iron oxide sub-10-nm nanoparticles by NIH/3T3 mouse fibroblasts. Coating strategies include low-molecular weight ligands (citric acid) and polymers (poly(acrylic acid), M{sub W} = 2000 g mol{sup -1}). Electrostatically adsorbed on the surfaces, the organic moieties provide a negatively charged coating in physiological conditions. We find that most particles were biocompatible, as exposed cells remained 100% viable relative to controls. Only the bare and the citrate-coated nanoceria exhibit a slight decrease in mitochondrial activity at very high cerium concentrations (>1 g l{sup -1}). We also observe that the citrate-coated particles are internalized/adsorbed by the cells in large amounts, typically 250 pg/cell after 24 h incubation for iron oxide. In contrast, the polymer-coated particles are taken up at much lower rates (<30 pg/cell). The strong uptake shown by the citrated particles is related to the destabilization of the dispersions in the cell culture medium and their sedimentation down to the cell membranes. In conclusion, we show that the uptake of nanomaterials by living cells depends on the coating of the particles and on its ability to preserve the colloidal nature of the dispersions.

  9. Synthesis and characterization of the superparamagnetic iron oxide nanoparticles modified with cationic chitosan and coated with silica shell

    International Nuclear Information System (INIS)

    Lewandowska-Łańcucka, Joanna; Staszewska, Magdalena; Szuwarzyński, Michał; Kępczyński, Mariusz; Romek, Marek; Tokarz, Waldemar; Szpak, Agnieszka; Kania, Gabriela; Nowakowska, Maria

    2014-01-01

    Highlights: • The new, facile methodology for synthesis of silica covered SPIONs is proposed. • The SPIONs was modified with cationic chitosan and coated with silica shell. • Negatively charged, rounded in shape particles of ca. 330 nm were obtained. • The product exhibits the superparamagnetic properties. • The product properties imply its potential applications in biomedicine areas. -- Abstract: Novel method for synthesis of superparamagnetic iron oxide nanoparticles (SPION) modified with a cationic chitosan (CCh) and coated with a silica shell, SPION-CCh-SiO 2 was developed. The process was carried out in two steps. In the first step the chitosan coated SPIONs were obtained by co-precipitation of Fe 2+ and Fe 3+ with ammonium hydroxide in aqueous solution of CCh. In the second one, the silica shell is formed on their surfaces. The formation of SPION-CCh-SiO 2 was achieved by direct decomposition of tetraethoxysilane (TEOS) adsorbed on a surface of SPION-CCh dispersed in aqueous phase under sonication and mechanical stirring at room temperature. The chemical composition and physicochemical properties of the materials were determined using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and zeta potential measurements. The morphology of the particles was evaluated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Magnetic properties were confirmed using Atomic Force Microscopy/Magnetic Force Microscopy (AFM/MFM) and magnetization measurements. The resulting products are negatively charged, rounded in shape and exhibit the superparamagnetic properties what implies their potential applications in engineering and biomedicine areas

  10. Synthesis and characterization of the superparamagnetic iron oxide nanoparticles modified with cationic chitosan and coated with silica shell

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowska-Łańcucka, Joanna, E-mail: lewandow@chemia.uj.edu.pl [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Staszewska, Magdalena; Szuwarzyński, Michał; Kępczyński, Mariusz [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland); Romek, Marek [Department of Cytology and Histology, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Krakow (Poland); Tokarz, Waldemar [Department of Solid State Physics, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Szpak, Agnieszka; Kania, Gabriela; Nowakowska, Maria [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow (Poland)

    2014-02-15

    Highlights: • The new, facile methodology for synthesis of silica covered SPIONs is proposed. • The SPIONs was modified with cationic chitosan and coated with silica shell. • Negatively charged, rounded in shape particles of ca. 330 nm were obtained. • The product exhibits the superparamagnetic properties. • The product properties imply its potential applications in biomedicine areas. -- Abstract: Novel method for synthesis of superparamagnetic iron oxide nanoparticles (SPION) modified with a cationic chitosan (CCh) and coated with a silica shell, SPION-CCh-SiO{sub 2} was developed. The process was carried out in two steps. In the first step the chitosan coated SPIONs were obtained by co-precipitation of Fe{sup 2+} and Fe{sup 3+} with ammonium hydroxide in aqueous solution of CCh. In the second one, the silica shell is formed on their surfaces. The formation of SPION-CCh-SiO{sub 2} was achieved by direct decomposition of tetraethoxysilane (TEOS) adsorbed on a surface of SPION-CCh dispersed in aqueous phase under sonication and mechanical stirring at room temperature. The chemical composition and physicochemical properties of the materials were determined using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and zeta potential measurements. The morphology of the particles was evaluated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). Magnetic properties were confirmed using Atomic Force Microscopy/Magnetic Force Microscopy (AFM/MFM) and magnetization measurements. The resulting products are negatively charged, rounded in shape and exhibit the superparamagnetic properties what implies their potential applications in engineering and biomedicine areas.

  11. Aging study on carboxymethyl cellulose-coated zero-valent iron nanoparticles in water: Chemical transformation and structural evolution

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Haoran, E-mail: dongh@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082 (China); Zhao, Feng; Zeng, Guangming; Tang, Lin; Fan, Changzheng; Zhang, Lihua; Zeng, Yalan; He, Qi; Xie, Yankai; Wu, Yanan [College of Environmental Science and Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, Hunan 410082 (China)

    2016-07-15

    Highlights: • The chemical transformation and structural evolution of CMC-nZVI were investigated. • CMC could slow down the aging rate of nZVI and alter the species transformation. • Fe{sub 3}O{sub 4} and/or γ-Fe{sub 2}O{sub 3} are the dominant corrosion products of bare nZVI after aging. • γ-FeOOH is the primary corrosion product of CMC-nZVI after aging. - Abstract: To assess the long-term fate and the associated risks of nanoscale zero-valent iron (nZVI) used in the water remediation, it is essential to understand the chemical transformations during aging of nZVI in water. This study investigated the compositional and structural evolution of bare nZVI and carboxymethyl cellulose (CMC) coated nZVI in static water over a period of 90 days. Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were used to characterize the corrosion products of nZVI and CMC-nZVI. Results show that both the structures and the compositions of the corrosion products change with the process of aging, but the coating of CMC could slow down the aging rate of nZVI (as indicated by the slower drop in Fe{sup 0} intensity in XRD pattern). For the bare nZVI, magnetite (Fe{sub 3}O{sub 4}) and/or maghemite (γ-Fe{sub 2}O{sub 3}) are the dominant corrosion products after 90 days of aging. However, for the CMC-nZVI, the core-shell spheres collapses to acicular-shaped structures after aging with crystalline lepidocrocite (γ-FeOOH) as the primary end product. Moreover, more lepidocrocite present in the corrosion products of CMC-nZVI with higher loading of CMC, which reveals that the CMC coating could influence the transformation of iron oxides.

  12. Characterization of Coated Sand Cores from Two Different Binder Systems for Grey Iron Castings

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Tiedje, Niels Skat; Poulsen, Thomas

    or veining and metal penetration defects. The use of refractory coatings on cores is fundamental to obtaining acceptable casting surface quality and is used on resin bonded cores in production foundries. In this study new sol gel-coated sand cores made from coldbox and furan binder systems were investigated......Expansion defects on the surface of the castings include sand burn-in, metal penetration and/or veining, finning or scab. Veining or finning and metal penetration are of interest. These defects are associated with silica sand and result from the penetration of liquid metal into cracks formed during...... differential expansion of the core during heating. The rapid expansion of silica sand up to 600 oC and especially at 573 oC, where the α – β phase transformation occurs, is the cause of stresses in the core system. These stresses cause crack formation and metal melt flows into these cracks causing finning...

  13. Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

    International Nuclear Information System (INIS)

    Hwang, Sangchul; Martinez, Diana; Perez, Priscilla; Rinaldi, Carlos

    2011-01-01

    This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENP Fe-surf ) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ∼8.7% of ENP Fe-surf applied were present in the effluent stream. The stable presence of ENP Fe-surf was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENP Fe-surf deteriorated the effluent water quality at a statistically significant level (p Fe-surf would be introduced into environmental receptors through the treated effluent and could potentially impact them. - Highlights: → Surfactant-coated engineered iron oxide nanoparticles (ENP Fe-surf ) were assessed. → Effluent quality was analyzed from a sequencing batch reactor with ENP Fe-surf . → ∼8.7% of ENP Fe-surf applied was present in the effluent. → ENP Fe-surf significantly (p Fe-surf will be introduced into environmental receptors. - Stable presence of surfactant-coated engineered iron oxides nanoparticles deteriorated the effluent water quality at a statistically significant level (p < 0.05).

  14. Surface anisotropy of iron oxide nanoparticles and slabs from first principles: Influence of coatings and ligands as a test of the Heisenberg model

    Energy Technology Data Exchange (ETDEWEB)

    Brymora, Katarzyna; Calvayrac, Florent, E-mail: Florent.Calvayrac@univ-lemans.fr

    2017-07-15

    Highlights: • A new method is given to extract surface anisotropies from ab initio calculations. • Heisenberg model for magnetic clusters and surfaces is validated in simple cases. • Ligands, metallic clusters, or coatings degrade the validity of the Heisenberg model. • Values for surface anisotropies, volume anisotropies, exchange constants are computed. • Results are in agreement with experimental data, previous theoretical findings. - Abstract: We performed ab initio computations of the magnetic properties of simple iron oxide clusters and slabs. We considered an iron oxide cluster functionalized by a molecule or glued to a gold cluster of the same size. We also considered a magnetite slab coated by cobalt oxide or a mixture of iron oxide and cobalt oxide. The changes in magnetic behavior were explored using constrained magnetic calculations. A possible value for the surface anisotropy was estimated from the fit of a classical Heisenberg model on ab initio results. The value was found to be compatible with estimations obtained by other means, or inferred from experimental results. The addition of a ligand, coating, or of a metallic nanoparticle to the systems degraded the quality of the description by the Heisenberg Hamiltonian. Proposing a change in the anisotropies allowing for the proportion of each transition atom we could get a much better description of the magnetism of series of hybrid cobalt and iron oxide systems.

  15. On the development of polypyrrole coatings with self-healing properties for iron corrosion protection

    International Nuclear Information System (INIS)

    Paliwoda-Porebska, G.; Stratmann, M.; Rohwerder, M.; Potje-Kamloth, K.; Lu, Y.; Pich, A.Z.; Adler, H.-J.

    2005-01-01

    This paper presents studies on the efficacy and on the limits of polypyrrole (Ppy) doped with either MoO 4 2- or [PMo 12 O 40 ] 3- as self-healing corrosion protecting coatings. The kinetics of the cathodic delamination were studied by means of the Scanning Kelvin Probe (SKP). This method, in combination with cyclic voltammetry, UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS), shows a potential driven anion release from the Ppy coating that results in an inhibition of the corrosion process taking place in the defect. Thus, an intelligent release of inhibitor occurs only when the potential at the interface decreases. Inhibitor anions are released only due to an active defect. However, the release mechanism can be easily negatively affected by the presence of small cations and/or by too high pH values at the buried interface. Hence, such a self-healing coating has to be carefully designed in order to ensure an effective performance

  16. Influence of New Sol-gel Refractory Coating on the Casting Properties of Cold Box and Furan Cores for Grey Cast iron

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Bischoff, C

    2010-01-01

    New Sol-Gel coated sand cores made from coldbox and furan binder systems were investigated. The idea of the coating was to improve the surface quality of castings. Grey iron was cast on the cores in a sand casting process. The effect of the high temperature of the melt on the cores was assessed...... by measuring the heating curves. The viscosity of the coating, moisture content and the permeability of the cores were evaluated. The surface quality of the castings was investigated using SEM and OM. The results show that the moisture content of the cores affected the permeability. In furan cores the vapour...... transport zone (VTZ) when in contact with the melt is larger than it is in a coldbox which means the furan cores have higher moisture content. The new sol-gel coating has the potential for improving the surface quality of castings without negative effects on the graphite distribution. The surface...

  17. Shaping optimal zinc coating on the surface of high-quality ductile iron casting. Part II – Technological formula and value of diffusion coefficient

    Directory of Open Access Journals (Sweden)

    Kopyciński D.

    2017-03-01

    Full Text Available The completed research presented in the first part of the article has allowed linking the manufacturing technology of ductile iron castings with the process of hot dip galvanizing. On the basis of these data simulations were carried out to examine the behaviour of zinc diffusion coefficient D in the galvanized coating. The adopted model of zinc coating growth helped to explain the cases of excessive growth of the intermetallic phases in this type of coating. The paper analyzes covered the relationship between the roughness and phase composition of the top layer of product and the thickness and kinetics of zinc coating growth referred to individual sub-layers of the intermetallic phases.Roughness and phase composition in the surface layer of product were next related to the diffusion coefficient D examined in respective sublayers of the intermetallic phases.

  18. Evaluation of umbilical cord mesenchymal stem cells labeling with superparamagnetic iron oxide nanoparticles coated with dextran and complexed with Poly-L-Lysine

    International Nuclear Information System (INIS)

    Sibov, Tatiana Tais; Mamani, Javier Bustamante; Pavon, Lorena Favaro; Cardenas, Walter Humberto; Gamarra, Lionel Fernel; Miyaki, Liza Aya Mabuchi; Marti, Luciana Cavalheiro; Sardinha, Luiz Roberto; Oliveira, Daniela Mara de

    2012-01-01

    Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37 deg C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxyfluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/ dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide

  19. Magnetic properties of iron-based soft magnetic composites with SiO{sub 2} coating obtained by reverse microemulsion method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Shen [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Sun, Aizhi, E-mail: sunaizhi@126.com [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Zhenwen; Cheng, Chuan [School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Gao, Xuexu [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2015-05-01

    In this work, iron-based soft magnetic composites coated with the amorphous SiO{sub 2} layer have been fabricated by utilizing tetraethoxysilane in the reverse microemulsion method, and then the effects of addition amount of SiO{sub 2} and annealing temperature on the magnetic properties were investigated. The results show that the surface of iron powders contains a thin amorphous SiO{sub 2} insulation layer, which effectively decreases the magnetic loss of synthesized magnets. The magnetic loss of coated samples decreased by 87.8% as compared with that of uncoated samples at 150 kHz. Magnetic measurements show that the sample with 1.25 wt% SiO{sub 2} has an acceptable real part and minimum imaginary part of permeability in comparison with other samples. Also, the annealing treatment increased the initial permeability, the maximum permeability and the magnetic induction and decreased the coercivity with increasing temperature in the range 300–600 °C. The results of the loss separation imply that the annealed SMCs have a higher hysteresis loss coefficient (k{sub 2}) and lower eddy current loss coefficient (k{sub 3}) as compared with the pure iron compacts after the same heat treatment due to the preservation of the SiO{sub 2} layer. - Highlights: • SiO{sub 2} coated the iron powder by reverse microemulsion method, decreased the magnetic loss of SMCs. • 25 wt% is the optimum coating amount to attain the desired permeability. • The influence of annealing temperature on the magnetic performance of the core was discussed. • Compare with the pure iron compacts, the annealed SMCs have lower value of eddy current coefficient.

  20. Thermal Transformations of Iron Cations in the System Metal-Vitreous Enamel Coat. Moessbauer Spectroscopic Study

    International Nuclear Information System (INIS)

    Barcova, K.; Mashlan, M.; Zboril, R.; Hrabovska, K.

    2005-01-01

    Vitreous enameling on steel is carried out to provide a protective layer against chemical corrosion from the surrounding environment. The glass bonds with the steel to form a composite material. The Moessbauer spectroscopy was firstly applied to study the vitreous enameling in which the complex of processes, as diffusion of species, adhesion between the glass and the steel, galvanic reactions, plays an important role. The Moessbauer spectroscopy provides unique information about the Fe-phase structure of the vitreous enamel layer and that of the steel-enamel interface. Diffusion of iron from steel surface towards enamel layer and formation of a new Fe2+ phase was proved

  1. Structure and magnetic properties of iron-based soft magnetic composite with Ni-Cu-Zn ferrite-silicone insulation coating

    Science.gov (United States)

    Li, Wangchang; Wang, Wei; Lv, Junjun; Ying, Yao; Yu, Jing; Zheng, Jingwu; Qiao, Liang; Che, Shenglei

    2018-06-01

    This paper investigates the structure and magnetic properties of Ni-Cu-Zn ferrite-silicone coated iron-based soft magnetic composites (SMCs). Scanning electron microscopy coupled with a energy-dispersive spectroscopy (EDS) analysis revealed that the Ni-Cu-Zn ferrite and silicone resin were uniformly coated on the surface of iron powders. By controlling the composition of the coating layer, low total core loss of 97.7 mW/cm3 (eddy current loss of 48 mW/cm3, hysteresis loss of 49.7 mW/cm3, measured at 100 kHz and 0.02 T) and relatively high effective permeability of 72.5 (measured at 100 kHz) were achieved. In addition, the as-prepared SMCs displayed higher electrical resistivity, good magnetic characteristics over a wide range of frequencies (20-200 kHz) and ideal the D-C bias properties (more than 75% at H = 50 Oe). Furthermore, higher elastic modulus and hardness of SMCs, which means that the coating layer has good mechanical properties and is not easily damaged during the pressing process, were obtained in this paper. The results of this work indicate that the Ni-Cu-Zn ferrite-silicone coated SMCs have desirable properties which would make them suitable for application in the fields of the electric-magnetic switching devices, such as inductance coils, transformer cores, synchronous electric motors and resonant inductors.

  2. Investigation of washing and storage strategy on aging Of Mg-aminoclay (MgAC) coated nanoscale zero-valent iron (nZVI) particles

    DEFF Research Database (Denmark)

    Hwang, Yuhoon; Lee, Young-Chul; Mines, Paul D.

    2014-01-01

    The tendency towards agglomeration and oxidation of nanoscale zero-valent iron (nZVI) particles limits its application for in situ groundwater and soil remediation. Although the effect of surface coatings on nanoparticle stabilization has been commonly practiced, the effect of preparation...... correlations (r2 > 0.95, p one another. Pre-storage washing, followed by addition of MgAC, exhibits high stability as pre-storage washing, as well as high reactivity as post-storage washing. Here, it is found that the proper washing procedure is crucial in coated nZVI preparation...

  3. Palladium nanoparticle anchored polyphosphazene nanotubes ...

    Indian Academy of Sciences (India)

    607–610. c Indian Academy of Sciences. Palladium ... 2Department of Chemistry, APA College of Arts and Culture, Palani, Tamil Nadu 624 601, India. 3Department of .... K Dinakaran acknowledges the financial support from. Department of ...

  4. Multifunctional PEG-carboxylate copolymer coated superparamagnetic iron oxide nanoparticles for biomedical application

    Science.gov (United States)

    Illés, Erzsébet; Szekeres, Márta; Tóth, Ildikó Y.; Szabó, Ákos; Iván, Béla; Turcu, Rodica; Vékás, Ladislau; Zupkó, István; Jaics, György; Tombácz, Etelka

    2018-04-01

    Biocompatible magnetite nanoparticles (MNPs) were prepared by post-coating the magnetic nanocores with a synthetic polymer designed specifically to shield the particles from non-specific interaction with cells. Poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers and acrylic acid (AA) small molecular monomers were chemically coupled by quasi-living atom transfer radical polymerization (ATRP) to a comb-like copolymer, P(PEGMA-co-AA) designated here as P(PEGMA-AA). The polymer contains pendant carboxylate moieties near the backbone and PEG side chains. It is able to bind spontaneously to MNPs; stabilize the particles electrostatically via the carboxylate moieties and sterically via the PEG moieties; provide high protein repellency via the structured PEG layer; and anchor bioactive proteins via peptide bond formation with the free carboxylate groups. The presence of the P(PEGMA-AA) coating was verified in XPS experiments. The electrosteric (i.e., combined electrostatic and steric) stabilization is efficient down to pH 4 (at 10 mM ionic strength). Static magnetization and AC susceptibility measurements showed that the P(PEGMA-AA)@MNPs are superparamagnetic with a saturation magnetization value of 55 emu/g and that both single core nanoparticles and multicore structures are present in the samples. The multicore components make our product well suited for magnetic hyperthermia applications (SAR values up to 17.44 W/g). In vitro biocompatibility, cell internalization, and magnetic hyperthermia studies demonstrate the excellent theranostic potential of our product.

  5. Nano-Structured Magnesium Oxide Coated Iron Ore: Its Application to the Remediation of Wastewater Containing Lead.

    Science.gov (United States)

    Nagarajah, Ranjini; Jang, Min; Pichiah, Saravanan; Cho, Jongman; Snyder, Shane A

    2015-12-01

    Magnetically separable nano-structured magnesium oxide coated iron ore (IO(MgO)) was prepared using environmentally benign chemicals, such as iron ore (IO), magnesium(II) nitrate hexahydrate [Mg(NO3)2 x 6H2O] and urea; via an easy and fast preparation method. The lO(MgO) was characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) and alternating gradient magnetometer (AGM) analyses. The isotherm and kinetic studies indicated that lO(MgO) has a comparably higher Langmuir constant (K(L), 1.69 L mg(-1)) and maximum sorption capacity (33.9 mg g(-1)) for lead (Pb) than other inorganic media. Based on MgO amount, the removal capacity of Pb by IO(MgO) was 2,724 mg Pb (g MgO)(-1), which was higher than that (1,980 mg g(-1)) for flowerlike magnesium oxide nanostructures reported by Cao et al. The kinetics, FE-SEM, elemental mapping and XRD results revealed that the substitution followed by precipitation was identified as the mechanism of Pb removal and plumbophyllite (Pb2Si4O10 x H2O) was the precipitated phase of Pb. A leaching test revealed that IOMgO) had negligible concentrations of leached Fe at pH 4-9. Since the base material, IO, is cheap and easily available, lO(MgO) could be produced in massive amounts and used for remediation of wastewater containing heavy metals, applying simple and fast magnetic separation.

  6. Albumin and Hyaluronic Acid-Coated Superparamagnetic Iron Oxide Nanoparticles Loaded with Paclitaxel for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2017-06-01

    Full Text Available Super paramagnetic iron oxide nanoparticles (SPION were augmented by both hyaluronic acid (HA and bovine serum albumin (BSA, each covalently conjugated to dopamine (DA enabling their anchoring to the SPION. HA and BSA were found to simultaneously serve as stabilizing polymers of Fe3O4·DA-BSA/HA in water. Fe3O4·DA-BSA/HA efficiently entrapped and released the hydrophobic cytotoxic drug paclitaxel (PTX. The relative amount of HA and BSA modulates not only the total solubility but also the paramagnetic relaxation properties of the preparation. The entrapping of PTX did not influence the paramagnetic relaxation properties of Fe3O4·DA-BSA. Thus, by tuning the surface structure and loading, we can tune the theranostic properties of the system.

  7. Synthesis and characterization of polystyrene coated iron oxide nanoparticles and asymmetric assemblies by phase inversion

    KAUST Repository

    Xie, Yihui

    2014-09-02

    Films with a gradient concentration of magnetic iron oxide nanoparticles are reported, based on a phase inversion membrane process. Nanoparticles with ∼13 nm diameter were prepared by coprecipitation in aqueous solution and stabilized by oleic acid. They were further functionalized by ATRP leading to grafted polystyrene brush. The final nanoparticles of 33 nm diameter were characterized by TGA, FTIR spectroscopy, GPC, transmission electron microscopy, and dynanmic light scattering. Asymmetric porous nanoparticle assemblies were then prepared by solution casting and immersion in water. The nanocomposite film production with functionalized nanoparticles is fast and technically scalable. The morphologies of films were characterized by scanning electron microscopy and atomic force microscopy, demonstrating the presence of sponge-like structures and finger-like cavities when 50 and 13 wt % casting solutions were, respectively, used. The magnetic properties were evaluated using vibrating sample magnetometer.

  8. Sensitization to palladium in Europe

    DEFF Research Database (Denmark)

    Muris, Joris; Goossens, An; Gonçalo, Margarida

    2015-01-01

    BACKGROUND: Recently, sodium tetrachloropalladate (Na2 PdCl4 ) was found to be a more sensitive palladium patch test allergen than palladium dichloride (PdCl2 ). OBJECTIVES: To determine the optimal test concentration of Na2 PdCl4 , to evaluate the prevalence of palladium sensitization with Na2 P...... patch test concentration. Sensitization to palladium is almost as prevalent as sensitization to nickel. The sex distribution is different between nickel-sensitized and palladium-sensitized patients, suggesting different sources of exposure.......Cl4 and PdCl2 , and to compare the results with nickel sensitization in a European multicentre study. MATERIALS AND METHODS: In addition to the European or national baseline series including NiSO4 ·6H2 0 5% pet., consecutive patients were tested with PdCl2 and Na2 PdCl4 2%, 3% and 4% pet. in eight...... European dermatology clinics. The age and sex distributions were also evaluated in patients sensitized to nickel and palladium. RESULTS: In total, 1651 patients were tested. Relative to 3% Na2 PdCl4 , 4% Na2 PdCl4 did not add any information. Two per cent Na2 PdCl4 resulted in more doubtful reactions...

  9. Microbial processes associated with roots of bulbous rush coated with iron plaques

    Energy Technology Data Exchange (ETDEWEB)

    Kusel, K.; Chabbi, A.; Trinkwalter, T. [University of Bayreuth, Bayreuth (Germany). BITOEK

    2003-11-01

    The objectives of this work were to enumerate the microbes involved in the turnover of iron and organic root exudates in the rhizoplane, to investigate the effect of oxygen and pH on the utilization of these exudates by the rhizobacteria, and to study the ability of the root-colonizing microbiota to reduce sulfate. Enumeration studies done at pH 3 demonstrated that 10{sup 6} Fe(III) reducers and 10{sup 7} Fe(II) oxidizers g (fresh wt root){sup -1} were associated with Juncus roots. When roots were incubated in goethite-containing medium without and with supplemental glucose, Fe(II) was formed at rates approximating 1.1 mmol g (fresh wt root) {sup -1} d{sup -1} and 3.6 mmol g (fresh wt root){sup -1} d{sup -1} under anoxic conditions, respectively. These results suggest that a rapid microbially mediated cycling of iron occurs in the rhizosphere of Juncus roots under changing redox conditions. Most-probable-number estimates of aerobes and anaerobes capable of consuming root exudates at pH 3 were similar in the rhizosphere sediment and in Juncus roots, but numbers of aerobes were significantly higher than those of anaerobes. At pH 3, supplemental organic exudates were primarily subject to aerobic oxidation to CO{sub 2} and not subject to fermentation. However, at pH 4.5, root exudates were also rapidly utilized under anoxic conditions. Root-associated sulfate reduction was not observed at pH 3 to 4.5 but was observed at pH 4.9. The pH increased during all root-incubation studies both under oxic and anoxic conditions. Thus, as result of the microbial turnover of organic root exudates, pH and CO{sub 2} levels might be elevated at the root surface and favor Juncus plants to colonize acidic habitats.

  10. Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications

    International Nuclear Information System (INIS)

    Maleki, H.; Simchi, A.; Imani, M.; Costa, B.F.O.

    2012-01-01

    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe 3+ and Fe 2+ ], the concentration of ammonium hydroxide as reducing agent, and molar ratio of water to surfactant. The biocompatibility of the obtained NPs, at various concentrations, was evaluated via MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and the results showed that the NPs were non-toxic at concentrations 3 O 4 core/Au shell particles demonstrate strong plasmon resonance absorption and can be separated from solution using an external magnetic field. Experimental data from both physical and chemical determinations of the changes in particle size, surface plasmon resonance optical band, phase components, core–shell surface composition, and magnetic properties have confirmed the formation of the mono-dispersed core–shell nanostructure. - Highlights: ► Increasing the concentration of iron salts, cubic-shape SPION NPs were formed. The magnetic saturation of the SPIONs was also increased. ► The concentration of reducing agent exhibited marginal effect on the size of SPIONs but influenced the crystallinity of the NPs. A lower magnetic saturation was obtained at higher NH 4 OH concentrations. ► Mono-dispersed SPIONs can be prepared by nano-emulsion procedure at w=23, [Fe]=2.12 M, and [NH 4 OH]=30%. Under this condition, NPs with dimension of 9±3 nm and magnetic saturation of 54 emu/g are obtained. The synthesized SPIONs exhibited acceptable biocompatibility, >80% viability after 24 h incubation in L929 cells at concentrations <0

  11. Radiation dose rate affects the radiosensitization of MCF-7 and HeLa cell lines to X-rays induced by dextran-coated iron oxide nanoparticles.

    Science.gov (United States)

    Khoshgard, Karim; Kiani, Parvaneh; Haghparast, Abbas; Hosseinzadeh, Leila; Eivazi, Mohammad Taghi

    2017-08-01

    The aim of radiotherapy is to deliver lethal damage to cancerous tissue while preserving adjacent normal tissues. Radiation absorbed dose of the tumoral cells can increase when high atomic nanoparticles are present in them during irradiation. Also, the dose rate is an important aspect in radiation effects that determines the biological results of a given dose. This in vitro study investigated the dose-rate effect on the induced radiosensitivity by dextran-coated iron oxide in cancer cells. HeLa and MCF-7 cells were cultured in vitro and incubated with different concentrations of dextran-coated iron oxide nanoparticles. They were then irradiated with 6 MV photons at dose rates of 43, 185 and 370 cGy/min. The MTT test was used to obtain the cells' survival after 48 h of irradiations. Incubating the cells with the nanoparticles at concentrations of 10, 40 and 80 μg/ml showed no significant cytotoxicity effect. Dextran-coated iron oxide nanoparticles showed more radiosensitivity effect by increasing the dose rate and nanoparticles concentration. Radiosensitization enhancement factors of MCF-7 and HeLa cells at a dose-rate of 370 cGy/min and nanoparticles' concentration of 80 μg/ml were 1.21 ± 0.06 and 1.19 ± 0.04, respectively. Increasing the dose rate of 6 MV photons irradiation in MCF-7 and HeLa cells increases the radiosensitization induced by the dextran-coated iron nanoparticles in these cells.

  12. Factors affecting the corrosion of SiC layer by fission product palladium

    International Nuclear Information System (INIS)

    Dewita, E.

    2000-01-01

    HTR is one of the advanced nuclear reactors which has inherent safety system, graphite moderated and helium gas cooled. In general, these reactors are designed with the TRISO coated particle consist of four coating layers that are porous pyrolytic carbon (PyC). inner dense PyC (IPyC), silicon carbide (SiC), and outer dense PyC (OPyC). Among the four coating layers, the SiC plays an important role beside in retaining metallic fission products, it also provides mechanical strength to fuel particle. However, results of post irradiation examination indicate that fission product palladium can react with and corrode SiC layer, This assessment is conducted to get the comprehension about resistance of SiC layer on irradiation effects, especially in order to increase the fuel bum-up. The result of this shows that the corrosion of SiC layer by fission product palladium is beside depend on the material characteristics of SiC, and also there are other factors that affect on the SiC layer corrosion. Fuel enrichment, bum-up, and irradiation time effect on the palladium flux in fuel kernel. While, the fuel density, vapour pressure of palladium (the degree depend on the irradiation temperature and kernel composition) effect on palladium migration in fuel particle. (author)

  13. Comparison of Heavy-Duty Scuffing Behavior between Chromium-Based Ceramic Composite and Nickel-Chromium-Molybdenum-Coated Ring Sliding against Cast Iron Liner under Starvation

    Directory of Open Access Journals (Sweden)

    Yan Shen

    2017-10-01

    Full Text Available A running-in and starved lubrication experiment is designed to investigate the heavy-duty scuffing behavior of piston ring coatings against cast iron (Fe cylinder liner using the piston ring reciprocating liner test rig. The scuffing resistance of the piston ring with the chromium-based ceramic composite coating (CKS, and that with the thermally sprayed nickel-chromium-molybdenum coating (NCM is compared at different nominal pressures (40~100 MPa and temperatures (180~250 °C. With the failure time as a criterion, the rank order is as follows: NCM/Fe > CKS/Fe. Before the scoring occurs at the interface of the piston ring and cylinder liner (PRCL, the cast iron liner enters into a “polish wear” stage, and iron-based adhesive materials begin to form on the piston ring surface. With the macroscopic adhesion formation, the plastic shearing cycle causes surface damages mainly due to abrasive effects for the CKS/Fe pairs and adhesive effects for the NCM/Fe pairs.

  14. Excellent improvement in the static and dynamic magnetic properties of carbon coated iron nanoparticles for microwave absorption

    Energy Technology Data Exchange (ETDEWEB)

    Khani, Omid, E-mail: omidkhani@mut-es.ac.ir; Shoushtari, Morteza Zargar; Farbod, Mansoor

    2015-11-15

    Carbon coated iron nanoparticles were synthesized, using a simple arc-discharge method. The morphology and the internal structure of the core/shell nanoparticles were studied, using field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction analysis showed that both magnetic α-Fe and nonmagnetic γ-Fe phases existed in the as-prepared particles. In order to improve the static and dynamic magnetic properties of the core/shell nanoparticles, the produced nanocapsules were annealed in argon atmosphere at two different temperatures. Hysteresis loops revealed that the value of the saturation magnetization (M{sub S}) increased more than 4.1 times of its original value by annealing and this led to 70% increase in the imaginary part of the permeability. Phase analysis showed that heat treatment eliminated the nonmagnetic γ-Fe phase completely. The reflection loss plots were studied for composite layers containing 20 vol% of the annealed and not annealed nanocapsules. One of the absorber layers which contained annealed nanocapsules showed at least −10 dB loss in the whole G, C, X and Ku frequency bands and the optimal absorption exceeded −37 dB at 5.8 GHz for the as-prepared sample with a thickness of 3.2 mm. The results revealed that the magnetic properties of the arc-made Fe/C core/shell nanoparticle can be improved significantly by annealing in argon.

  15. Fabrication of polyaniline coated iron oxide hybrid particles and their dual stimuli-response under electric and magnetic fields

    Directory of Open Access Journals (Sweden)

    B. Sim

    2015-08-01

    Full Text Available Polyaniline (PANI-coated iron oxide (Fe3O4 sphere particles were fabricated and applied to a dual stimuliresponsive material under electric and magnetic fields, respectively. Sphere Fe3O4 particles were synthesized by a solvothermal process and protonated after acidification. The aniline monomer tended to surround the surface of the Fe3O4 core due to the electrostatic and hydrogen bond interactions. A core-shell structured product was finally formed by the oxidation polymerization of PANI on the surface of Fe3O4. The formation of Fe3O4@PANI particles was examined by scanning electron microscope and transmission electron microscope. The bond between Fe3O4 and PANI was confirmed by Fourier transform-infrared spectroscope and magnetic properties were analyzed by vibration sample magnetometer. A hybrid of a conducting and magnetic particle-based suspension displayed dual stimuli-response under electric and magnetic fields. The suspension exhibited typical electrorheological and magnetorheological behaviors of the shear stress, shear viscosity and dynamic yield stress, as determined using a rotational rheometer. Sedimentation stability was also compared between Fe3O4 and Fe3O4@PANI suspension.

  16. Implications of exposure to dextran-coated and uncoated iron oxide nanoparticles to developmental toxicity in zebrafish

    Science.gov (United States)

    de Oliveira, Giovanna Medeiros Tavares; de Oliveira, Elisa Magno Nunes; Pereira, Talita Carneiro Brandão; Papaléo, Ricardo Meurer; Bogo, Maurício Reis

    2017-12-01

    Iron oxide nanoparticles (IONPS) have been widely investigated as a platform for a new class of multifunctional theranostic agents. They are considered biocompatible, and some formulations are already available in the market for clinical use. However, contradictory results regarding toxicity of IONPs raise a concern about the potential harm of these nanoparticles. Changes in the nanoparticle (NP) physicochemical properties or exposure media can significantly alter their behavior and, as a consequence, their toxic effects. Here, behavior and two-step RT-qPCR were employed to access the potential toxicological effects of dextran-coated IONPs (CLIO-NH2) and uncoated IONPs (UCIO) in zebrafish larvae. Animals were exposed for 7 days to NP solutions ranging from 0.1-100 μg/mL directly mixed to the system water. UCIO showed high decantation and instability in solution, altering zebrafish mortality but showing no alterations in behavior and molecular expression analysis. CLIO-NH2 exposure did not cause significant mortality or changes in hatching rate of zebrafish larvae; however, behavior and expression profiles of the group exposed to lower concentration (1 μg/mL) presented a tendency to decrease the locomotor activity and apoptotic pathway activation.

  17. Iron oxide nanoparticles surface coating and cell uptake affect biocompatibility and inflammatory responses of endothelial cells and macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Orlando, Antonina [University of Milano-Bicocca, Department of Health Sciences (Italy); Colombo, Miriam; Prosperi, Davide [University of Milano-Bicocca, Department of Biotechnology and Biosciences (Italy); Gregori, Maria; Panariti, Alice; Rivolta, Ilaria; Masserini, Massimo; Cazzaniga, Emanuela, E-mail: emanuela.cazzaniga@unimib.it [University of Milano-Bicocca, Department of Health Sciences (Italy)

    2015-09-15

    Engineered iron oxide nanoparticles (IONP) offer the possibility of a wide range of medical uses, from clinical imaging to magnetically based hyperthermia for tumor treatment. These applications require their systemic administration in vivo. An important property of nanoparticles is their stability in biological media. For this purpose, a multicomponent nanoconstruct combining high colloidal stability and improved physical properties was synthesized and characterized. IONP were coated with an amphiphilic polymer (PMA), which confers colloidal stability, and were pegylated in order to obtain the nanoconstruct PEG-IONP-PMA. The aim of this study was to utilize cultured human endothelial cells (HUVEC) and murine macrophages, taken as model of cells exposed to NP after systemic administration, to assess the biocompatibility of PEG-IONP-PMA (23.1 ± 1.4 nm) or IONP-PMA (15.6 ± 3.4 nm). PEG-IONP-PMA, tested at different concentrations as high as 20 μg mL{sup −1}, exhibited no cytotoxicity or inflammatory responses. By contrast, IONP-PMA showed a concentration-dependent increase of cytotoxicity and of TNF-α production by macrophages and NO production by HUVECs. Cell uptake analysis suggested that after PEGylation, IONP were less internalized either by macrophages or by HUVEC. These results suggest that the choice of the polymer and the chemistry of surface functionalization are a crucial feature to confer to IONP biocompatibility.

  18. Nafion Coated Electrodes as Voltammetric Sensors for Iron Analysis in Sediments and Pore Waters: an Example from the Lagoon of Venice

    Directory of Open Access Journals (Sweden)

    Emanuele Argese

    2001-09-01

    Full Text Available Glassy carbon electrodes coated with Nafion are used for the ion-exchange voltammetric (IEV determination of Fe(II in the pore-waters and acidic extracts of sediments of the lagoon of Venice (Italy. The coated electrodes give reversible voltammetric signals, well resolved from background currents, which can be used for quantitative determinations. The yield of iron extracted by HCl from the sediment depends on the experimental conditions, in particular on the concentration of hydrochloric acid. By combining IEV on the acid extract with trapping and analysis of gaseous H2S evolved it is possible to obtain quantitative information both on the total content of iron dissolved by the acid attack and on the fraction of iron present in the form of acid volatile sulphides (AVS. As far as pore-waters are concerned, in this kind of samples the IEV determination of iron can be performed simply after dilution with HCl. The pore-waters here examined were sampled without alteration of their equilibrium conditions by using a suitable “in situ” sampler. IEV data obtained in samples from the lagoon of Venice (Italy show satisfactory correlation with previous results obtained using different analytical techniques.

  19. Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Maleki, H. [Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Simchi, A., E-mail: simchi@sharif.edu [Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Department of Material Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Imani, M. [Novel Drug Delivery Systems Department, Iran Polymer and Petrochemical Institute, Tehran (Iran, Islamic Republic of); Costa, B.F.O. [CEMDRX, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

    2012-11-15

    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe{sup 3+} and Fe{sup 2+}], the concentration of ammonium hydroxide as reducing agent, and molar ratio of water to surfactant. The biocompatibility of the obtained NPs, at various concentrations, was evaluated via MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and the results showed that the NPs were non-toxic at concentrations <0.1 mg/mL. Surface functionalization was performed by conformal coating of the NPs with a thin shell of gold ({approx}4 nm) through chemical reduction of attached gold salts at the surface of the SPIONs. The Fe{sub 3}O{sub 4} core/Au shell particles demonstrate strong plasmon resonance absorption and can be separated from solution using an external magnetic field. Experimental data from both physical and chemical determinations of the changes in particle size, surface plasmon resonance optical band, phase components, core-shell surface composition, and magnetic properties have confirmed the formation of the mono-dispersed core-shell nanostructure. - Highlights: Black-Right-Pointing-Pointer Increasing the concentration of iron salts, cubic-shape SPION NPs were formed. The magnetic saturation of the SPIONs was also increased. Black-Right-Pointing-Pointer The concentration of reducing agent exhibited marginal effect on the size of SPIONs but influenced the crystallinity of the NPs. A lower magnetic saturation was obtained at higher NH{sub 4}OH concentrations. Black-Right-Pointing-Pointer Mono-dispersed SPIONs can be prepared

  20. Magnetic removal of Entamoeba cysts from water using chitosan oligosaccharide-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Shukla S

    2015-07-01

    Full Text Available Sudeep Shukla,1 Vikas Arora,2 Alka Jadaun,3 Jitender Kumar,1 Nishant Singh,1 Vinod Kumar Jain1 1School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, Delhi, India; 2Department of Chemistry, Indian Institute of Technology, New Delhi, Delhi, India; 3School of Biotechnology, Jawaharlal Nehru University, New Delhi, Delhi, India Abstract: Amebiasis, a major health problem in developing countries, is the second most common cause of death due to parasitic infection. Amebiasis is usually transmitted by the ingestion of Entamoeba histolytica cysts through oral–fecal route. Herein, we report on the use of chitosan oligosaccharide-functionalized iron oxide nanoparticles for efficient capture and removal of pathogenic protozoan cysts under the influence of an external magnetic field. These nanoparticles were synthesized through a chemical synthesis process. The synthesized particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and zeta potential analysis. The particles were found to be well dispersed and uniform in size. The capture and removal of pathogenic cysts were demonstrated by fluorescent microscopy, transmission electron microscopy, and scanning electron microscopy (SEM. Three-dimensional modeling of various biochemical components of cyst walls, and thereafter, flexible docking studies demonstrate the probable interaction mechanism of nanoparticles with various components of E. histolytica cyst walls. Results of the present study suggest that E. histolytica cysts can be efficiently captured and removed from contaminated aqueous systems through the application of synthesized nanoparticles. Keywords: amebiasis, water treatment, nanotechnology

  1. Development and characterization of magnetic iron oxide nanoparticles with a cisplatin-bearing polymer coating for targeted drug delivery

    Directory of Open Access Journals (Sweden)

    Unterweger H

    2014-08-01

    Full Text Available Harald Unterweger,1 Rainer Tietze,1 Christina Janko,1 Jan Zaloga,1 Stefan Lyer,1 Stephan Dürr,1 Nicola Taccardi,2 Ourania-Menti Goudouri,3 Alexander Hoppe,3 Dietmar Eberbeck,4 Dirk W Schubert,5 Aldo R Boccaccini,3 Christoph Alexiou1 1ENT Department, Section of Experimental Oncology and Nanomedicine (SEON, Else Kroener-Fresenius-Stiftung-Professorship, University Hospital Erlangen, 2Chair of Chemical Engineering I (Reaction Engineering, 3Institute of Biomaterials, Department of Materials Science and Engineering, University Erlangen-Nuremberg, Erlangen, 4Physikalisch-Technische Bundesanstalt, Berlin, 5Institute of Polymer Materials, Department of Materials Science and Engineering, University Erlangen-Nuremberg, Erlangen, Germany Abstract: A highly selective and efficient cancer therapy can be achieved using magnetically directed superparamagnetic iron oxide nanoparticles (SPIONs bearing a sufficient amount of the therapeutic agent. In this project, SPIONs with a dextran and cisplatin-bearing hyaluronic acid coating were successfully synthesized as a novel cisplatin drug delivery system. Transmission electron microscopy images as well as X-ray diffraction analysis showed that the individual magnetite particles were around 4.5 nm in size and monocrystalline. The small crystallite sizes led to the superparamagnetic behavior of the particles, which was exemplified in their magnetization curves, acquired using superconducting quantum interference device measurements. Hyaluronic acid was bound to the initially dextran-coated SPIONs by esterification. The resulting amide bond linkage was verified using Fourier transform infrared spectroscopy. The additional polymer layer increased the vehicle size from 22 nm to 56 nm, with a hyaluronic acid to dextran to magnetite weight ratio of 51:29:20. A maximum payload of 330 µg cisplatin/mL nanoparticle suspension was achieved, thus the particle size was further increased to around 77 nm with a zeta

  2. Polyethylenimine-coated iron oxide magnetic nanoparticles for high efficient gene delivery

    Science.gov (United States)

    Nguyen, Anh H.; Abdelrasoul, Gaser N.; Lin, Donghai; Maadi, Hamid; Tong, Junfeng; Chen, Grace; Wang, Richard; Anwar, Afreen; Shoute, Lian; Fang, Qiang; Wang, Zhixiang; Chen, Jie

    2018-04-01

    Properties of magnetic nanoparticles (MNPs) are of notable interest in many fields of biomedical engineering, especially for gene therapy. In this paper, we report a method for synthesis and delivery of MNPs loaded with DNAs, which overcomes the drawbacks of high cost and cytotoxicity associated with current delivery techniques (chemical- and liposome-based designs). 24-nm MNPs (Fe3O4) were synthesized, functionalized and characterized by analytical techniques to understand the surface properties for DNA binding and cellular uptake. The simple surface functionalization with polyethylenimine (PEI) through glutaraldehyde linker activation gave the complex of PEI-coated MNPs, resulting in high stability with a positive surface charge of about + 31 mV. Under the guidance of an external magnetic field, the functionalized MNPs with a loaded isothiocyanate (FITC) or green fluorescent protein (GFP) will enter the cells, which can be visualized by the fluorescence of FITC or GFP. We also examined the cytotoxicity of our synthesized MNPs by MTT assay. We showed that the IC50s of these MNPs for COS-7 and CHO cells were low and at 0.2 and 0.26 mg/mL, respectively. Moreover, our synthesized MNPs that were loaded with plasmids encoding GFP showed high transfection rate, 38.3% for COS-7cells and 27.6% for CHO cells. In conclusion, we established a promising method with low cost, low toxicity, and high transfection efficiency for siRNA and gene delivery.

  3. Effect of heat treatment on the wear and corrosion behaviors of a gray cast iron coated with a COLMONOY 88 alloy deposited by high velocity oxygen fuel (HVOF thermal spray

    Directory of Open Access Journals (Sweden)

    A. Öz

    2013-07-01

    Full Text Available The present work has been conducted in order to determine the influence of heat treatment on the wear and corrosion behaviours of a gray cast iron substrate coated with a Ni base coating deposited by HVOF thermal spray. The wear resistance of the coatings was obtained using a reciprocating wear tester by rubbing a 10 mm diameter steel ball on the coatings at normal atmospheric conditions. Corrosion tests were performed using potentiodynamic polarization measurements in a 3,5 % NaCl solution. It was observed that the corrosion and wear resistance of the coatings increased along with the reduction of porosity and roughness by the heat treatment.

  4. Gold-Coated Iron Composite Nanospheres Targeted the Detection of Escherichia coli

    Directory of Open Access Journals (Sweden)

    İlker Dinçer

    2013-03-01

    Full Text Available We report the preparation and characterization of spherical core-shell structured Fe3O4–Au magnetic nanoparticles, modified with two component self-assembled monolayers (SAMs consisting of 3–mercaptophenylboronic acid (3–MBA and 1–decanethiol (1–DT. The rapid and room temperature synthesis of magnetic nanoparticles was achieved using the hydroxylamine reduction of HAuCl4 on the surface of ethylenediaminetetraacetic acid (EDTA-immobilized iron (magnetite Fe3O4 nanoparticles in the presence of an aqueous solution of hexadecyltrimetylammonium bromide (CTAB as a dispersant. The reduction of gold on the surface of Fe3O4 nanoparticles exhibits a uniform, highly stable, and narrow particle size distribution of Fe3O4–Au nanoparticles with an average diameter of 9 ± 2 nm. The saturation magnetization value for the resulting nanoparticles was found to be 15 emu/g at 298 K. Subsequent surface modification with SAMs against glucoside moieties on the surface of bacteria provided effective magnetic separation. Comparison of the bacteria capturing efficiency, by means of different molecular recognition agents 3–MBA, 1–DT and the mixed monolayer of 3–MBA and 1–DT was presented. The best capturing efficiency of E. coli was achieved with the mixed monolayer of 3–MBA and 1–DT-modified nanoparticles. Molecular specificity and selectivity were also demonstrated by comparing the surface-enhanced Raman scattering (SERS spectrum of E. coli-nanoparticle conjugates with bacterial growth media.

  5. Impact of natural organic matter coatings on the microbial reduction of iron oxides

    Science.gov (United States)

    Poggenburg, Christine; Mikutta, Robert; Schippers, Axel; Dohrmann, Reiner; Guggenberger, Georg

    2018-03-01

    Iron (Fe) oxyhydroxides are important constituents of the soil mineral phase known to stabilize organic matter (OM) under oxic conditions. In an anoxic milieu, however, these Fe-organic associations are exposed to microbial reduction, releasing OM into soil solution. At present, only few studies have addressed the influence of adsorbed natural OM (NOM) on the reductive dissolution of Fe oxyhydroxides. This study therefore examined the impact of both the composition and concentration of adsorbed NOM on microbial Fe reduction with regard to (i) electron shuttling, (ii) complexation of Fe(II,III), (iii) surface site coverage and/or pore blockage, and (iv) aggregation. Adsorption complexes with varying carbon loadings were synthesized using different Fe oxyhydroxides (ferrihydrite, lepidocrocite, goethite, hematite, magnetite) and NOM of different origin (extracellular polymeric substances from Bacillus subtilis, OM extracted from soil Oi and Oa horizons). The adsorption complexes were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), N2 gas adsorption, electrophoretic mobility and particle size measurements, and OM desorption. Incubation experiments under anaerobic conditions were conducted for 16 days comparing two different strains of dissimilatory Fe(III)-reducing bacteria (Shewanella putrefaciens, Geobacter metallireducens). Mineral transformation during reduction was assessed via XRD and FTIR. Microbial reduction of the pure Fe oxyhydroxides was controlled by the specific surface area (SSA) and solubility of the minerals. For Shewanella putrefaciens, the Fe reduction of adsorption complexes strongly correlated with the concentration of potentially usable electron-shuttling molecules for NOM concentrations <2 mg C L-1, whereas for Geobacter metallireducens, Fe reduction depended on the particle size and thus aggregation of the adsorption complexes. These diverging results suggest that

  6. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings

    International Nuclear Information System (INIS)

    Farmer, J; Choi, J; Haslam, J; Day, S; Yang, N; Headley, T; Lucadamo, G; Yio, J; Chames, J; Gardea, A; Clift, M; Blue, G; Peters, W; Rivard, J; Harper, D; Swank, D; Bayles, R; Lemieux, E; Brown, R; Wolejsza, T; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Lavernia, E; Schoenung, J; Ajdelsztajn, L; Dannenberg, J; Graeve, O; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Boudreau, J

    2007-01-01

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  7. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Choi, J; Haslam, J; Day, S; Yang, N; Headley, T; Lucadamo, G; Yio, J; Chames, J; Gardea, A; Clift, M; Blue, G; Peters, W; Rivard, J; Harper, D; Swank, D; Bayles, R; Lemieux, E; Brown, R; Wolejsza, T; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Aprigliano, L; Branagan, D; Marshall, M; Meacham, B; Lavernia, E; Schoenung, J; Ajdelsztajn, L; Dannenberg, J; Graeve, O; Lewandowski, J; Perepezko, J; Hildal, K; Kaufman, L; Boudreau, J

    2007-09-20

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  8. Determination of palladium content in palladium-alumina/palladium-silica/palladium-tin oxide catalyst for nuclear reactor applications

    International Nuclear Information System (INIS)

    Sharma, P.K.; Bassan, M.K.T.; Avhad, D.K.; Singhal, R.K.

    2012-01-01

    Alumina and silica act as support for finely divided palladium metal powder in synthesis of catalyst. These catalyst (Pd-Al 2 O 3 , Pd-SiO 2 and Pd-SnO 2 ) used in nuclear power reactor (moderator cover gas system) for the conversion of hydrogen. In Indian nuclear power programme these catalyst are regularly used in Kaiga 1 and 2 and Rajasthan atomic power plant 3 and 4. The performance of the catalyst, solely depends on the concentration of palladium, which is the active component in this catalyst composition. Therefore it is highly desirable to have rouged analytical methodology for the accurate estimation of palladium. Leaching of Pd from the bulk matrix is tedious due to the less reactive nature of Pd therefore complete solubilization of the matrix is carried out by fusion method

  9. Advanced zirconia-coated carbonyl-iron particles for acidic magnetorheological finishing of chemical-vapor-deposited ZnS and other IR materials

    Science.gov (United States)

    Salzman, S.; Giannechini, L. J.; Romanofsky, H. J.; Golini, N.; Taylor, B.; Jacobs, S. D.; Lambropoulos, J. C.

    2015-10-01

    We present a modified version of zirconia-coated carbonyl-iron (CI) particles that were invented at the University of Rochester in 2008. The amount of zirconia on the coating is increased to further protect the iron particles from corrosion when introduced to an acidic environment. Five low-pH, magnetorheological (MR) fluids were made with five acids: acetic, hydrochloric, nitric, phosphoric, and hydrofluoric. All fluids were based on the modified zirconia-coated CI particles. Off-line viscosity and pH stability were measured for all acidic MR fluids to determine the ideal fluid composition for acidic MR finishing of chemical-vapor-deposited (CVD) zinc sulfide (ZnS) and other infrared (IR) optical materials, such as hot-isostatic-pressed (HIP) ZnS, CVD zinc selenide (ZnSe), and magnesium fluoride (MgF2). Results show significant reduction in surface artifacts (millimeter-size, pebble-like structures on the finished surface) for several standard-grade CVD ZnS substrates and good surface roughness for the non-CVD MgF2 substrate when MR finished with our advanced acidic MR fluid.

  10. Immobilization of bacterial S-layer proteins from Caulobacter crescentus on iron oxide-based nanocomposite: synthesis and spectroscopic characterization of zincite-coated Fe₂O₃ nanoparticles.

    Science.gov (United States)

    Habibi, Neda

    2014-05-05

    Zinc oxide was coated on Fe2O3 nanoparticles using sol-gel spin-coating. Caulobacter crescentus have a crystalline surface layer (S-layer), which consist of one protein or glycoprotein species. The immobilization of bacterial S-layers obtained from C. crescentus on zincite-coated nanoparticles of iron oxide was investigated. The SDS PAGE results of S-layers isolated from C. crescentus showed the weight of 50 KDa. Nanoparticles of the Fe2O3 and zinc oxide were synthesized by a sol-gel technique. Fe2O3 nanoparticles with an average size of 50 nm were successfully prepared by the proper deposition of zinc oxide onto iron oxide nanoparticles surface annealed at 450 °C. The samples were characterized by field-emission scanning electron microscope (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Sol-gel synthesized of nanocomposite palladium-alumina ceramic membrane for H{sub 2} permeability: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, A.L.; Mustafa, N.N.N. [School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Penang (Malaysia)

    2007-08-15

    Palladium-alumina membrane with mesopore and narrow pore size distribution was prepared by the sol-gel method. Effect of the finely dispersed metal on the microstructure and the characteristic properties of the palladium-alumina membrane were investigated. Observations were made on membrane weight loss, morphology, pore structure, pore size, surface area, pore surface fractal and membrane's crystal structure. Autosorb analysis, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) analysis were employed in the membrane characterization. Autosorb analysis found that, BET surface area decreased and pore size of the membrane increased with the increasing of calcinations temperature (500-1100{sup o}C) and with the increasing of palladium amount in the membrane. FTIR and TG/DTA analysis show that the suitable temperature for calcinations of palladium-alumina membrane is at 700{sup o}C. Palladium metals are highly dispersed at calcinations temperature of 700{sup o}C as observed by TEM analysis. The fine crystallinity of the palladium and {gamma}-alumina phase was obtained after calcined at 700{sup o}C. The SEM morphology shows a smooth and free crack layer of palladium-alumina membrane after repeating the process of dipping, drying and calcinations at temperature of 700{sup o}C. The membrane also successfully coated with a good adhesion on support. The thickness of the final membrane layer was estimated as 9{mu} m. (author)

  12. Effect of iron doping on structural and optical properties of TiO2 thin film by sol–gel routed spin coating technique

    Directory of Open Access Journals (Sweden)

    Stephen Lourduraj

    2017-08-01

    Full Text Available Thin films of iron (Fe-doped titanium dioxide (Fe:TiO2 were prepared by sol–gel spin coating technique and further calcined at 450∘C. The structural and optical properties of Fe-doped TiO2 thin films were investigated by X-ray diffraction (XRD, scanning electron microscopy (SEM, ultraviolet–visible spectroscopy (UV–vis and atomic force microscopic (AFM techniques. The XRD results confirm the nanostructured TiO2 thin films having crystalline nature with anatase phase. The characterization results show that the calcined thin films having high crystallinity and the effect of iron substitution lead to decreased crystallinity. The SEM investigations of Fe-doped TiO2 films also gave evidence that the films were continuous spherical shaped particles with a nanometric range of grain size and film was porous in nature. AFM analysis establishes that the uniformity of the TiO2 thin film with average roughness values. The optical measurements show that the films having high transparency in the visible region and the optical band gap energy of Fe-doped TiO2 film with iron (Fe decrease with increase in iron content. These important requirements for the Fe:TiO2 films are to be used as window layers in solar cells.

  13. Palladium alloys for hydrogen diffusion

    International Nuclear Information System (INIS)

    1977-01-01

    A palladium-base alloy with tin and/or a silicon addition and its use in the production of hydrogen from water via a cycle of chemical reactions, of which the decomposition of HI into H 2 and I 2 is the most important, is described

  14. Palladium-Catalysed Coupling Reactions

    NARCIS (Netherlands)

    de Vries, Johannes G.; Beller, M; Blaser, HU

    2012-01-01

    Palladium-catalysed coupling reactions have gained importance as a tool for the production of pharmaceutical intermediates and to a lesser extent also for the production of agrochemicals, flavours and fragrances, and monomers for polymers. In this review only these cases are discussed where it seems

  15. Method for palladium activating molybdenum metallized features on a ceramic substrate

    International Nuclear Information System (INIS)

    Kumar, A.H.; Schwartz, B.

    1985-01-01

    A molybdenum or tungsten metallurgical pattern is formed on or in a dielectric green sheet. Palladium, nickel, platinum or rhodium is coated on a layer of polyvinyl butyral which is carried on a polyester film. The metal layer of this assembly is laminated to a dielectric green sheet which carries the molybdenum or tungsten metallurgy. The polyester film is stripped off. The resulting assembly is sintered to a fired structure, whereby the polyvinyl butyral is volatilized off and the palladium, nickel, platinum or rhodium is alloyed with the molybdenum or tungsten metallurgy to provide a densified metallurgy whose surface is free of glass

  16. Cotransport of microorganisms and metallic colloids in quartz sand or iron oxide-coated sand under real site hydrogeological conditions

    Science.gov (United States)

    Yu, Tong; Wen, Yujuan; Yang, Xinyao; Yang, Yuesuo

    2017-04-01

    plays an important part in many soil and water processes. The column experiments were carried out using homogeneously charged (quartz sand) and heterogeneously charged (iron oxide-coated sand) porous media. References: Yang, X., Zhang, Y., Chen, F., & Yang, Y. (2015). Interplay of natural organic matter with flow rate and particle size on colloid transport: Experimentation, visualization, and modeling. Environmental science & technology, 49(22), 13385-13393. Yang, X., Yin, Z., Chen, F., Hu, J., & Yang, Y. (2015). Organic matter induced mobilization of polymer-coated silver nanoparticles from water-saturated sand. Science of the Total Environment, 529, 182-190. Wen, Y. J., Yang, Y. S., Ren, H. J., Du, X. Q., Yang, X. Y., Zhang, L. Y., & Wang, X. S. (2015). Chemical-biological hybrid reactive zones and their impact on biodiversity of remediation of the nitrobenzene and aniline contaminated groundwater. Chemical Engineering Journal, 280, 233-240.

  17. Cold Extrusion but Not Coating Affects Iron Bioavailability from Fortified Rice in Young Women and Is Associated with Modifications in Starch Microstructure and Mineral Retention during Cooking.

    Science.gov (United States)

    Hackl, Laura; Speich, Cornelia; Zeder, Christophe; Sánchez-Ferrer, Antoni; Adelmann, Horst; de Pee, Saskia; Tay, Fabian; Zimmermann, Michael B; Moretti, Diego

    2017-12-01

    Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared. Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1 ) iron and zinc absorption with the use of stable isotopes, 2 ) iron and zinc retention during cooking, and 3 ) starch microstructure. Methods: We conducted 2 studies in young women: in study 1 [ n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m 2 ): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate ( 57 FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing 57 FePP, ZnO, citric acid, and micronutrients (CER); in study 2 ( n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing 57 FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure. Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] ( P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] ( P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] ( P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] ( P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc

  18. The study of hydrogen electrosorption in layered nickel foam/palladium/carbon nanofibers composite electrodes

    International Nuclear Information System (INIS)

    Skowronski, J.M.; Czerwinski, A.; Rozmanowski, T.; Rogulski, Z.; Krawczyk, P.

    2007-01-01

    In the present work, the process of hydrogen electrosorption occurring in alkaline KOH solution on the nickel foam/palladium/carbon nanofibers (Ni/Pd/CNF) composite electrodes is examined. The layered Ni/Pd/CNF electrodes were prepared by a two-step method consisting of chemical deposition of a thin layer of palladium on the nickel foam support to form Ni/Pd electrode followed by coating the palladium layer with carbon nanofibers layer by means of the CVD method. The scanning electron microscope was used for studying the morphology of both the palladium and carbon layer. The process of hydrogen sorption/desorption into/from Ni/Pd as well as Ni/Pd/CNF electrode was examined using the cyclic voltammetry method. The amount of hydrogen stored in both types of composite electrodes was shown to increase on lowering the potential of hydrogen sorption. The mechanism of the anodic desorption of hydrogen changes depending on whether or not CNF layer is present on the Pd surface. The anodic peak corresponding to the removal of hydrogen from palladium is lower for Ni/Pd/CNF electrode as compared to that measured for Ni/Pd one due to a partial screening of the Pd surface area by CNF layer. The important feature of Ni/Pd/CNF electrode is anodic peak appearing on voltammetric curves at potential ca. 0.4 V more positive than the peak corresponding to hydrogen desorption from palladium. The obtained results showed that upon storing the hydrogen saturated Ni/Pd/CNF electrode at open circuit potential, diffusion of hydrogen from carbon to palladium phase occurs due to interaction between carbon fibers and Pd sites on the nickel foam support

  19. Preparation and characterization of iron oxide (Fe3O4) nanoparticles coated with polyvinylpyrrolidone/polyethylenimine through a facile one-pot deposition route

    Science.gov (United States)

    Karimzadeh, Isa; Aghazadeh, Mustafa; Ganjali, Mohammad Reza; Doroudi, Taher; Kolivand, Peir Hossein

    2017-07-01

    In this article, we report the electrochemical synthesis and simultaneous in situ coating of magnetic iron oxide nanoparticles (MNPs) with polyvinylpyrrolidone (PVP) and polyethylenimine (PEI). The cathodic deposition was carried out through electro-generation of OH- on the surface of cathode. An aqueous solution of Fe(NO3)3·9H2O (3.4 g/L) and FeCl2·4H2O (1.6 g/L) was used as the deposition bath. The electrochemical precipitation experiments were performed in the direct current mode under a 10 mA cm-2 current density for 30 min. Polymer coating was performed in an identical deposition bath containing of 0.5 g PVP and 0.5 g PEI. The deposited uncoated and PVP-PEI coated MNPs were characterized through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), and field-emission scanning and transmission electron microscopies (FE-SEM and TEM). Structural XRD and IR analyses revealed both samples to be composed of pure crystalline magnetite (Fe3O4). Morphological observations through FE-SEM and TEM proved the product to be spherical nanoparticles in the range of 10-15 nm. The presence of two coating polymers (i.e. PVP and PEI) on the surface of the electro-synthesized MNPs was proved by FTIR and DLS results. The percentage of the polymer coating (31.8%) on the MNPs surface was also determined based on DSC-TGA data. The high magnetization value, coercivity and remanence values measured by VSM indicated the superparamagnetic nature of both prepared MNPs. The obtained results confirmed that the prepared Fe3O4 nanoparticles had suitable physico-chemical and magnetic properties for biomedical applications.

  20. Non-immunogenic dextran-coated superparamagnetic iron oxide nanoparticles: a biocompatible, size-tunable contrast agent for magnetic resonance imaging.

    Science.gov (United States)

    Unterweger, Harald; Janko, Christina; Schwarz, Marc; Dézsi, László; Urbanics, Rudolf; Matuszak, Jasmin; Őrfi, Erik; Fülöp, Tamás; Bäuerle, Tobias; Szebeni, János; Journé, Clément; Boccaccini, Aldo R; Alexiou, Christoph; Lyer, Stefan; Cicha, Iwona

    2017-01-01

    Iron oxide-based contrast agents have been in clinical use for magnetic resonance imaging (MRI) of lymph nodes, liver, intestines, and the cardiovascular system. Superparamagnetic iron oxide nanoparticles (SPIONs) have high potential as a contrast agent for MRI, but no intravenous iron oxide-containing agents are currently approved for clinical imaging. The aim of our work was to analyze the hemocompatibility and immuno-safety of a new type of dextran-coated SPIONs (SPIONdex) and to characterize these nanoparticles with ultra-high-field MRI. Key parameters related to nanoparticle hemocompatibility and immuno-safety were investigated in vitro and ex vivo. To address concerns associated with hypersensitivity reactions to injectable nanoparticulate agents, we analyzed complement activation-related pseudoallergy (CARPA) upon intravenous administration of SPIONdex in a pig model. Furthermore, the size-tunability of SPIONdex and the effects of size reduction on their biocompatibility were investigated. In vitro, SPIONdex did not induce hemolysis, complement or platelet activation, plasma coagulation, or leukocyte procoagulant activity, and had no relevant effect on endothelial cell viability or endothelial-monocytic cell interactions. Furthermore, SPIONdex did not induce CARPA even upon intravenous administration of 5 mg Fe/kg in pigs. Upon SPIONdex administration in mice, decreased liver signal intensity was observed after 15 minutes and was still detectable 24 h later. In addition, by changing synthesis parameters, a reduction in particle size contrast agent.

  1. In vivo magnetic resonance and fluorescence dual imaging of tumor sites by using dye-doped silica-coated iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Jang, Haeyun; Lee, Chaedong; Nam, Gi-Eun; Quan, Bo; Choi, Hyuck Jae; Yoo, Jung Sun; Piao, Yuanzhe

    2016-01-01

    The difficulty in delineating tumor is a major obstacle for better outcomes in cancer treatment of patients. The use of single-imaging modality is often limited by inadequate sensitivity and resolution. Here, we present the synthesis and the use of monodisperse iron oxide nanoparticles coated with fluorescent silica nano-shells for fluorescence and magnetic resonance dual imaging of tumor. The as-synthesized core–shell nanoparticles were designed to improve the accuracy of diagnosis via simultaneous tumor imaging with dual imaging modalities by a single injection of contrast agent. The iron oxide nanocrystals (∼11 nm) were coated with Rhodamine B isothiocyanate-doped silica shells via reverse microemulsion method. Then, the core–shell nanoparticles (∼54 nm) were analyzed to confirm their size distribution by transmission electron microscopy and dynamic laser scattering. Photoluminescence spectroscopy was used to characterize the fluorescent property of the dye-doped silica shell-coated nanoparticles. The cellular compatibility of the as-prepared nanoparticles was confirmed by a trypan blue dye exclusion assay and the potential as a dual-imaging contrast agent was verified by in vivo fluorescence and magnetic resonance imaging. The experimental results show that the uniform-sized core–shell nanoparticles are highly water dispersible and the cellular toxicity of the nanoparticles is negligible. In vivo fluorescence imaging demonstrates the capability of the developed nanoparticles to selectively target tumors by the enhanced permeability and retention effects and ex vivo tissue analysis was corroborated this. Through in vitro phantom test, the core/shell nanoparticles showed a T2 relaxation time comparable to Feridex ® with smaller size, indicating that the as-made nanoparticles are suitable for imaging tumor. This new dual-modality-nanoparticle approach has promised for enabling more accurate tumor imaging.

  2. In vivo magnetic resonance and fluorescence dual imaging of tumor sites by using dye-doped silica-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Haeyun; Lee, Chaedong [Seoul National University, Program in Nano Science and Technology, Graduate School of Convergence Science and Technology (Korea, Republic of); Nam, Gi-Eun [University of Ulsan College of Medicine, Department of Radiology, Asan Medical Center (Korea, Republic of); Quan, Bo [Seoul National University, Program in Nano Science and Technology, Graduate School of Convergence Science and Technology (Korea, Republic of); Choi, Hyuck Jae [University of Ulsan College of Medicine, Department of Radiology, Asan Medical Center (Korea, Republic of); Yoo, Jung Sun [Seoul National University, Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Smart Humanity Convergence Center (Korea, Republic of); Piao, Yuanzhe, E-mail: parkat9@snu.ac.kr [Seoul National University, Program in Nano Science and Technology, Graduate School of Convergence Science and Technology (Korea, Republic of)

    2016-02-15

    The difficulty in delineating tumor is a major obstacle for better outcomes in cancer treatment of patients. The use of single-imaging modality is often limited by inadequate sensitivity and resolution. Here, we present the synthesis and the use of monodisperse iron oxide nanoparticles coated with fluorescent silica nano-shells for fluorescence and magnetic resonance dual imaging of tumor. The as-synthesized core–shell nanoparticles were designed to improve the accuracy of diagnosis via simultaneous tumor imaging with dual imaging modalities by a single injection of contrast agent. The iron oxide nanocrystals (∼11 nm) were coated with Rhodamine B isothiocyanate-doped silica shells via reverse microemulsion method. Then, the core–shell nanoparticles (∼54 nm) were analyzed to confirm their size distribution by transmission electron microscopy and dynamic laser scattering. Photoluminescence spectroscopy was used to characterize the fluorescent property of the dye-doped silica shell-coated nanoparticles. The cellular compatibility of the as-prepared nanoparticles was confirmed by a trypan blue dye exclusion assay and the potential as a dual-imaging contrast agent was verified by in vivo fluorescence and magnetic resonance imaging. The experimental results show that the uniform-sized core–shell nanoparticles are highly water dispersible and the cellular toxicity of the nanoparticles is negligible. In vivo fluorescence imaging demonstrates the capability of the developed nanoparticles to selectively target tumors by the enhanced permeability and retention effects and ex vivo tissue analysis was corroborated this. Through in vitro phantom test, the core/shell nanoparticles showed a T2 relaxation time comparable to Feridex{sup ®} with smaller size, indicating that the as-made nanoparticles are suitable for imaging tumor. This new dual-modality-nanoparticle approach has promised for enabling more accurate tumor imaging.

  3. Comparison of iron and copper doped manganese cobalt spinel oxides as protective coatings for solid oxide fuel cell interconnects

    Science.gov (United States)

    Talic, Belma; Molin, Sebastian; Wiik, Kjell; Hendriksen, Peter Vang; Lein, Hilde Lea

    2017-12-01

    MnCo2O4, MnCo1.7Cu0.3O4 and MnCo1.7Fe0.3O4 are investigated as coatings for corrosion protection of metallic interconnects in solid oxide fuel cell stacks. Electrophoretic deposition is used to deposit the coatings on Crofer 22 APU alloy. All three coating materials reduce the parabolic oxidation rate in air at 900 °C and 800 °C. At 700 °C there is no significant difference in oxidation rate between coated samples and uncoated pre-oxidized Crofer 22 APU. The cross-scale area specific resistance (ASR) is measured in air at 800 °C using La0.85Sr0.1Mn1.1O3 (LSM) contact plates to simulate the interaction with the cathode in a SOFC stack. All coated samples have three times lower ASR than uncoated Crofer 22 APU after 4370 h aging. The ASR increase with time is lowest with the MnCo2O4 coating, followed by the MnCo1.7Fe0.3O4 and MnCo1.7Cu0.3O4 coatings. LSM plates contacted to uncoated Crofer 22 APU contain significant amounts of Cr after aging, while all three coatings effectively prevent Cr diffusion into the LSM. A complex Cr-rich reaction layer develops at the coating-alloy interface during oxidation. Cu and Fe doping reduce the extent of this reaction layer at 900 °C, while at 800 °C the effect of doping is insignificant.

  4. Synthesized of PEG-6000 coated MgFe2O4 nanoparticles based on natural iron sand by co-precipitation method

    Science.gov (United States)

    Setiadi, E. A.; Simbolon, S.; Saputra, A. S. P.; Marlianto, E.; Djuhana; Kurniawan, C.; Yunus, M.; Sebayang, P.

    2018-02-01

    The polymer coated Magnesium Ferrite nanoparticles (MgFe2O4) based on natural iron sand, Mg(CH3COO)2.4H2O, and PEG-6000 have been successfully prepared by co-precipitation method. The mass variation of PEG-6000 content was from 0 to 12 gram. It was prepared at synthesize temperature of 70°C. The PEG coating reduced the effect of agglomeration, so the coercivity value can be closed to soft magnets. The nanoparticle of synthesized has MgFe2O4 single phase and cubic spinel structure. The bonding of MgFe2O4 and PEG-6000 as a coating material was confirmed by FTIR curve. The MgFe2O4 density decreased with the increasing of PEG 6000 content. On the other hand, the coercivity value was slightly reduced as the addition of PEG-6000, with the lowest value was obtained on 8 gram PEG content. The optimum condition is obtained at addition of 8 gram PEG 6000 to MgFe2O4, with coercivity, saturation, and remanence are 198.41 Oe, 52.53 emu/g, and 8.51 emu/g, respectively. So that, the sample is widely used as absorbance material of heavy metal.

  5. Development, characterization and evaluation of iron-coated honeycomb briquette cinders for the removal of As(V from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Tiantian Sheng

    2014-01-01

    Full Text Available The adsorptive removal of As(V from aqueous solutions using iron-coated honeycomb briquette cinder (Fe-HBC is presented. Low cost mechanical granulation process was integrated with surface amendment technology to prepare iron-oxide modified granular adsorbent for clean water production. Detailed characterizations were performed using FTIR, XRD, EDS and SEM techniques. Operating parameters including initial As(V concentration, pH, contact time, adsorbent dose, iron leaching and the effects of competing ions on As(V removal were evaluated. Results demonstrated that high amount of arsenate (961.5 μg g−1 was adsorbed at pH 7.5 in 14 h contact time. Langmuir, Freundlich and Temkin isotherm models were used to analyze the adsorption data, whereas Langmuir model was found to best represent the data with a correlation co-efficient (R2 = 0.999. Thus, As(V sorption on Fe-HBC surface suggested monolayer adsorption and indicated surface homogeneity. Moreover, the dimensionless parameter (RL value calculated to be about 0.118 that reiterated the process is favorable and spontaneous. The influences of competing ions on As(V removal decreased in the following order:PO43−>HCO3−>F−>Cl−. The profound inhibition effects ofPO43− revealed a high affinity toward iron(oxy hydroxide. Life-cycle assessment confirmed that spent HBC is non-hazardous and can be used as a promising sorbent for arsenic removal.

  6. Preparation of palladium impregnated alumina adsorbents: Thermal and neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Sumanta; Gupta, N.K.; Roy, S.P.; Dash, S.; Kumar, A.; Bamankar, Y.R.; Rao, T.V. Vittal [Product Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, N. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Naik, Y., E-mail: ynaik@barc.gov.in [Product Development Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2016-02-10

    Highlights: • Pd/Al{sub 2}O{sub 3} composite microspheres particles with high surface area were prepared sol–gel process. • Scanning electron microscopy (SEM) studies on silver coated particle. • Content of the palladium was determined using Neutron Activation Analysis (NAA). • Decomposition study has been done by quadrupole mass analyser. - Abstract: Pd/Al{sub 2}O{sub 3} composite microspheres particles with high surface area were prepared sol–gel process. The decomposition of dried gel-particles was studied by TGA/DTA and FT-IR technique. TGA studies indicated that formation of palladium is marked by a broad exothermic peak with a loss of water and oxidation of trapped HMTA/Urea nitrate mixture. The main decomposition reaction took place in the temperature range of 660–1250 K in helium and relatively lower temperature of 400 K to 1250 K in oxygen. Optical microscopy indicated that the distribution of palladium is uniform. SEM studies on silver coated particle indicated that there was surface erosion of some gel spheres while in few of them micro cracks were seen at high resolution. Content of the palladium was determined using Neutron Activation Analysis (NAA). Decomposition at various temperatures was studied using Residual gas analyser and decomposition species were identified using quadrupole mass analyser.

  7. Comparison of iron and copper doped manganese cobalt spinel oxides as protective coatings for solid oxide fuel cell interconnects

    DEFF Research Database (Denmark)

    Talic, Belma; Molin, Sebastian; Wiik, Kjell

    2017-01-01

    MnCo2O4, MnCo1.7Cu0.3O4 and MnCo1.7Fe0.3O4 are investigated as coatings for corrosion protection of metallic interconnects in solid oxide fuel cell stacks. Electrophoretic deposition is used to deposit the coatings on Crofer 22 APU alloy. All three coating materials reduce the parabolic oxidation...... rate in air at 900 °C and 800 °C. At 700 °C there is no significant difference in oxidation rate between coated samples and uncoated pre-oxidized Crofer 22 APU. The cross-scale area specific resistance (ASR) is measured in air at 800 °C using La0.85Sr0.1Mn1.1O3 (LSM) contact plates to simulate...... contain significant amounts of Cr after aging, while all three coatings effectively prevent Cr diffusion into the LSM. A complex Cr-rich reaction layer develops at the coating-alloy interface during oxidation. Cu and Fe doping reduce the extent of this reaction layer at 900 °C, while at 800 °C the effect...

  8. HIGHWAY INFRASTRUCTURE FOCUS AREA NEXT-GENERATION INFRASTRUCTURE MATERIALS VOLUME I - TECHNICAL PROPOSAL & MANAGEMENTENHANCEMENT OF TRANSPORTATION INFRASTRUCTURE WITH IRON-BASED AMORPHOUS-METAL AND CERAMIC COATINGS

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J C

    2007-12-04

    The infrastructure for transportation in the United States allows for a high level of mobility and freight activity for the current population of 300 million residents, and several million business establishments. According to a Department of Transportation study, more than 230 million motor vehicles, ships, airplanes, and railroads cars were used on 6.4 million kilometers (4 million miles) of highways, railroads, airports, and waterways in 1998. Pipelines and storage tanks were considered to be part of this deteriorating infrastructure. The annual direct cost of corrosion in the infrastructure category was estimated to be approximately $22.6 billion in 1998. There were 583,000 bridges in the United States in 1998. Of this total, 200,000 bridges were steel, 235,000 were conventional reinforced concrete, 108,000 bridges were constructed using pre-stressed concrete, and the balance was made using other materials of construction. Approximately 15 percent of the bridges accounted for at this point in time were structurally deficient, primarily due to corrosion of steel and steel reinforcement. Iron-based amorphous metals, including SAM2X5 (Fe{sub 49.7}Cr{sub 17.7}Mn{sub 1.9}Mo{sub 7.4}W{sub 1.6}B{sub 15.2}C{sub 3.8}Si{sub 2.4}) and SAM1651 (Fe{sub 48}Mo{sub 14}Cr{sub 15}Y{sub 2}C{sub 15}B{sub 6}) have been developed, and have very good corrosion resistance. These materials have been prepared as a melt-spun ribbons, as well as gas atomized powders and thermal-spray coatings. During electrochemical testing in several environments, including seawater at 90 C, the passive film stabilities of these materials were found to be comparable to that of more expensive high-performance alloys, based on electrochemical measurements of the passive film breakdown potential and general corrosion rates. These materials also performed very well in standard salt fog tests. Chromium (Cr), molybdenum (Mo) and tungsten (W) provided corrosion resistance, and boron (B) enabled glass formation

  9. Palladium allergy in relation to dentistry

    NARCIS (Netherlands)

    Muris, J.

    2015-01-01

    Palladium is a metal that is used as alloying metal for dental crowns and bridges. This thesis focusses on the possible impact of oral exposure to this metal on the immune system, and allergy in particular. An alternative skin test allergen for diagnosing palladium allergy is introduced: (di)sodium

  10. Preparation and characterization of iron oxide (Fe{sub 3}O{sub 4}) nanoparticles coated with polyvinylpyrrolidone/polyethylenimine through a facile one-pot deposition route

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, Isa [Shefa Neuroscience Research Center, Khatam ol Anbia Specialty and Subspecialty Hospital, Tehran (Iran, Islamic Republic of); Department of Physics, Faculty of Science, Central Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Aghazadeh, Mustafa, E-mail: maghazadeh@aeoi.org.ir [NFCRS, Nuclear Science and Technology Research Institute (NSTRI), P.O. Box 14395-834, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Doroudi, Taher; Kolivand, Peir Hossein [Shefa Neuroscience Research Center, Khatam ol Anbia Specialty and Subspecialty Hospital, Tehran (Iran, Islamic Republic of)

    2017-07-01

    Highlights: • MNPs were prepared by cathodic electrodeposition. • In situ double polymer coating was achieved during electrodeposition. • The prepared MNPs have proper size and properties for biomedical applications. - Abstract: In this article, we report the electrochemical synthesis and simultaneous in situ coating of magnetic iron oxide nanoparticles (MNPs) with polyvinylpyrrolidone (PVP) and polyethylenimine (PEI). The cathodic deposition was carried out through electro-generation of OH{sup −} on the surface of cathode. An aqueous solution of Fe(NO{sub 3}){sub 3}·9H{sub 2}O (3.4 g/L) and FeCl{sub 2}·4H{sub 2}O (1.6 g/L) was used as the deposition bath. The electrochemical precipitation experiments were performed in the direct current mode under a 10 mA cm{sup −2} current density for 30 min. Polymer coating was performed in an identical deposition bath containing of 0.5 g PVP and 0.5 g PEI. The deposited uncoated and PVP-PEI coated MNPs were characterized through powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), dynamic light scattering (DLS), vibrating sample magnetometer (VSM), and field-emission scanning and transmission electron microscopies (FE-SEM and TEM). Structural XRD and IR analyses revealed both samples to be composed of pure crystalline magnetite (Fe{sub 3}O{sub 4}). Morphological observations through FE-SEM and TEM proved the product to be spherical nanoparticles in the range of 10–15 nm. The presence of two coating polymers (i.e. PVP and PEI) on the surface of the electro-synthesized MNPs was proved by FTIR and DLS results. The percentage of the polymer coating (31.8%) on the MNPs surface was also determined based on DSC-TGA data. The high magnetization value, coercivity and remanence values measured by VSM indicated the superparamagnetic nature of both prepared MNPs. The obtained results confirmed that the prepared Fe{sub 3}O{sub 4} nanoparticles had suitable physico

  11. Corrosion Resistance of a Cast-Iron Material Coated With a Ceramic Layer Using Thermal Spray Method

    Science.gov (United States)

    Florea, C. D.; Bejinariu, C.; Munteanu, C.; Istrate, B.; Toma, S. L.; Alexandru, A.; Cimpoesu, R.

    2018-06-01

    Cast-iron 250 used for breake systems present many corrosion signs after a mean usage time based on the environment conditions they work. In order to improve them corrosion resistance we propose to cover the active part of the material using a ceramic material. The deposition process is an industrial deposition system based on thermal spraying that can cover high surfaces in low time. In this articol we analyze the influence of a ceramic layer (40-50 µm) on the corrosion resistance of FC250 cast iron. The results were analyzed using scanning electron microscopy (SEM), X-ray energy dispersive (EDS) and linear and cyclic potentiometry.

  12. Abrasive Wear Resistance of the Iron- and WC-based Hardfaced Coatings Evaluated with Scratch Test Method

    Directory of Open Access Journals (Sweden)

    A. Vencl

    2013-06-01

    Full Text Available Abrasive wear is one of the most common types of wear, which makesabrasive wear resistance very important in many industries. Thehard facing is considered as useful and economical way to improve theperformance of components submitted to severe abrasive wear conditions, with wide range of applicable filler materials. The abrasive wear resistance of the three different hardfaced coatings (two iron‐based and one WC‐based, which were intended to be used for reparation of the impact plates of the ventilation mill, was investigated and compared. Abrasive wear tests were carried‐out by using the scratch tester under the dry conditions. Three normal loads of 10, 50 and 100 N and the constant sliding speed of 4 mm/s were used. Scratch test was chosen as a relatively easy and quick test method. Wear mechanism analysis showed significant influence of the hardfaced coatings structure, which, along with hardness, has determined coatings abrasive wear resistance.

  13. An Analysis of the Weldability of Ductile Cast Iron Using Inconel 625 for the Root Weld and Electrodes Coated in 97.6% Nickel for the Filler Welds

    Directory of Open Access Journals (Sweden)

    Francisco-Javier Cárcel-Carrasco

    2016-11-01

    Full Text Available This article examines the weldability of ductile cast iron when the root weld is applied with a tungsten inert gas (TIG welding process employing an Inconel 625 source rod, and when the filler welds are applied with electrodes coated with 97.6% Ni. The welds were performed on ductile cast iron specimen test plates sized 300 mm × 90 mm × 10 mm with edges tapered at angles of 60°. The plates were subjected to two heat treatments. This article analyzes the influence on weldability of the various types of electrodes and the effect of preheat treatments. Finally, a microstructure analysis is made of the material next to the weld in the metal-weld interface and in the weld itself. The microstructure produced is correlated with the strength of the welds. We treat an alloy with 97.6% Ni, which prevents the formation of carbides. With a heat treatment at 900 °C and 97.6% Ni, there is a dissolution of all carbides, forming nodules in ferritic matrix graphite.

  14. Comparing the detection of iron-based pottery pigment on a carbon-coated sherd by SEM-EDS and by Micro-XRF-SEM.

    Science.gov (United States)

    Pendleton, Michael W; Washburn, Dorothy K; Ellis, E Ann; Pendleton, Bonnie B

    2014-03-01

    The same sherd was analyzed using a scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and a micro X-ray fluorescence tube attached to a scanning electron microscope (Micro-XRF-SEM) to compare the effectiveness of elemental detection of iron-based pigment. To enhance SEM-EDS mapping, the sherd was carbon coated. The carbon coating was not required to produce Micro-XRF-SEM maps but was applied to maintain an unbiased comparison between the systems. The Micro-XRF-SEM analysis was capable of lower limits of detection than that of the SEM-EDS system, and therefore the Micro-XRF-SEM system could produce elemental maps of elements not easily detected by SEM-EDS mapping systems. Because SEM-EDS and Micro-XRF-SEM have been used for imaging and chemical analysis of biological samples, this comparison of the detection systems should be useful to biologists, especially those involved in bone or tooth (hard tissue) analysis.

  15. pH responsive controlled release of anti-cancer hydrophobic drugs from sodium alginate and hydroxyapatite bi-coated iron oxide nanoparticles.

    Science.gov (United States)

    Manatunga, Danushika C; de Silva, Rohini M; de Silva, K M Nalin; de Silva, Nuwan; Bhandari, Shiva; Yap, Yoke Khin; Costha, N Pabakara

    2017-08-01

    Developing a drug carrier system which could perform targeted and controlled release over a period of time is utmost concern in the pharmaceutical industry. This is more relevant when designing drug carriers for poorly water soluble drug molecules such as curcumin and 6-gingerol. Development of a drug carrier system which could overcome these limitations and perform controlled and targeted drug delivery is beneficial. This study describes a promising approach for the design of novel pH sensitive sodium alginate, hydroxyapatite bilayer coated iron oxide nanoparticle composite (IONP/HAp-NaAlg) via the co-precipitation approach. This system consists of a magnetic core for targeting and a NaAlg/HAp coating on the surface to accommodate the drug molecules. The nanocomposite was characterized using FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. The loading efficiency and loading capacity of curcumin and 6-gingerol were examined. In vitro drug releasing behavior of curcumin and 6-gingerol was studied at pH 7.4 and pH 5.3 over a period of seven days at 37°C. The mechanism of drug release from the nanocomposite of each situation was studied using kinetic models and the results implied that, the release is typically via diffusion and a higher release was observed at pH 5.3. This bilayer coated system can be recognized as a potential drug delivery system for the purpose of curcumin and 6-gingerol release in targeted and controlled manner to treat diseases such as cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Iodinated oil-loaded, fluorescent mesoporous silica-coated iron oxide nanoparticles for magnetic resonance imaging/computed tomography/fluorescence trimodal imaging

    Directory of Open Access Journals (Sweden)

    Xue S

    2014-05-01

    Full Text Available Sihan Xue,1 Yao Wang,1 Mengxing Wang,2 Lu Zhang,1 Xiaoxia Du,2 Hongchen Gu,1 Chunfu Zhang1,31School of Biomedical Engineering and Med-X Research Institute, Shanghai Jiao Tong University, 2Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, 3State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People’s Republic of ChinaAbstract: In this study, a novel magnetic resonance imaging (MRI/computed tomography (CT/fluorescence trifunctional probe was prepared by loading iodinated oil into fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (i-fmSiO4@SPIONs. Fluorescent mesoporous silica-coated superparamagnetic iron oxide nanoparticles (fmSiO4@SPIONs were prepared by growing fluorescent dye-doped silica onto superparamagnetic iron oxide nanoparticles (SPIONs directed by a cetyltrimethylammonium bromide template. As prepared, fmSiO4@SPIONs had a uniform size, a large surface area, and a large pore volume, which demonstrated high efficiency for iodinated oil loading. Iodinated oil loading did not change the sizes of fmSiO4@SPIONs, but they reduced the MRI T2 relaxivity (r2 markedly. I-fmSiO4@SPIONs were stable in their physical condition and did not demonstrate cytotoxic effects under the conditions investigated. In vitro studies indicated that the contrast enhancement of MRI and CT, and the fluorescence signal intensity of i-fmSiO4@SPION aqueous suspensions and macrophages, were intensified with increased i-fmSiO4@SPION concentrations in suspension and cell culture media. Moreover, for the in vivo study, the accumulation of i-fmSiO4@SPIONs in the liver could also be detected by MRI, CT, and fluorescence imaging. Our study demonstrated that i-fmSiO4@SPIONs had great potential for MRI/C/fluorescence trimodal imaging.Keywords: multifunctional probe, SPIONs, mesoporous silica

  17. Cholesteryl-coated carbonyl iron particles with improved anti-corrosion stability and their viscoelastic behaviour under magnetic field

    Czech Academy of Sciences Publication Activity Database

    Mrlik, M.; Ilčíková, M.; Sedlačík, M.; Mosnáček, J.; Peer, Petra; Filip, Petr

    2014-01-01

    Roč. 292, č. 9 (2014), s. 2137-2143 ISSN 0303-402X R&D Projects: GA ČR(CZ) GP14-32114P Grant - others:GA MŠk(CZ) ED2.1.00/03.0111 Institutional support: RVO:67985874 Keywords : carbonyl iron * cholesteryl chloroformate * silicone oil suspensions * viscoelasticity * magnetorheology Subject RIV: BK - Fluid Dynamics Impact factor: 1.865, year: 2014

  18. Synthesis and magnetorheological characteristics of ribbon-like, polypyrrole-coated carbonyl iron suspensions under oscillatory shear

    Czech Academy of Sciences Publication Activity Database

    Mrlik, M.; Sedlačík, M.; Pavlinek, V.; Bažant, P.; Sáha, P.; Peer, Petra; Filip, Petr

    2013-01-01

    Roč. 128, č. 5 (2013), s. 2977-2982 ISSN 0021-8995 Grant - others:GA MŠk(CZ) ED2.1.00/03.0111; UTB Zlín(CZ) IGA/1/FT/11/D Institutional support: RVO:67985874 Keywords : carbonyl iron * core-shell * magnetorheological fluid * polypyrrole * viscoelasticity * ribbon-like particles Subject RIV: BK - Fluid Dynamics Impact factor: 1.640, year: 2013

  19. Synthesis and magnetorheological characteristics of ribbon-like, polypyrrole-coated carbonyl iron suspensions under oscillatory shear

    Czech Academy of Sciences Publication Activity Database

    Mrlik, M.; Sedlačík, M.; Pavlinek, V.; Bažant, P.; Sáha, P.; Peer, Petra; Filip, Petr

    2013-01-01

    Roč. 128, č. 5 (2013), s. 2977-2982 ISSN 0021-8995 Grant - others:GA MŠk(CZ) ED2.1.00/03.0111; UTB Zlín(CZ) IGA/1/FT/11/D Institutional support: RVO:67985874 Keywords : carbonyl iron * core - shell * magnetorheological fluid * polypyrrole * viscoelasticity * ribbon-like particles Subject RIV: BK - Fluid Dynamics Impact factor: 1.640, year: 2013

  20. Selective extraction of palladium with caffeine from acidic chloride media; Sansei enkabutsu yoeki karano kafuein ni yoru parajiumu no sentakuteki chushutsu

    Energy Technology Data Exchange (ETDEWEB)

    Kaikake, K.; Baba, Y. [Miyazaki University, Miyazaki (Japan). Faculty of Engineering

    1999-06-10

    In order to examine the possibility of caffeine as an extractant, the extraction of metal ions from acidic chloride media was studied at 298 K using the mixture solvent of chloroform and 2-ethyl-1-hexanol. Caffeine has exhibited a high selectivity for palladium (2) over base metals such as copper (2), nickel (2), and iron (3), and over precious metal such as platinum (4). The stoichiometric relation in the extraction of palladium (2) with caffeine was elucidated by examining the effects of chloride ion, hydrogen ion, and caffeine concentrations on its extractability. In addition, palladium (2) was found to be extracted selectively with caffeine from the mixture containing a 25-fold amount of platinum (4) or copper (2). The stripping of palladium (2) was performed to an extent of 80% by a single batchwise treatment with an aqueous mixture solution of hydrochloric acid and thiourea. (author)

  1. Evaluation of iron aluminide weld overlays for erosion - corrosion resistant boiler tube coatings in low NO{sub x} boilers

    Energy Technology Data Exchange (ETDEWEB)

    DuPont, J.N.; Banovic, S.W.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States)

    1996-08-01

    Low NOx burners are being installed in many fossil fired power plants in order to comply with new Clean Air Regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion is often enhanced and premature tube failures can occur. Failures due to oxidation and solid particle erosion are also a concern. A program was initiated in early 1996 to evaluate the use of iron aluminide weld overlays for erosion/corrosion protection of boiler tubes in Low NOx boilers. Composite iron/aluminum wires will be used with the Gas Metal Arc Welding (GMAW) process to prepare overlays on boiler tubes steels with aluminum contents from 8 to 16wt%. The weldability of the composite wires will be evaluated as a function of chemical composition and welding parameters. The effect of overlay composition on corrosion (oxidation and sulfidation) and solid particle erosion will also be evaluated. The laboratory studies will be complemented by field exposures of both iron aluminide weld overlays and co-extruded tubing under actual boiler conditions.

  2. Anionic Palladium(0) and Palladium(II) Ate Complexes.

    Science.gov (United States)

    Kolter, Marlene; Böck, Katharina; Karaghiosoff, Konstantin; Koszinowski, Konrad

    2017-10-16

    Palladium ate complexes are frequently invoked as important intermediates in Heck and cross-coupling reactions, but so far have largely eluded characterization at the molecular level. Here, we use electrospray-ionization mass spectrometry, electrical conductivity measurements, and NMR spectroscopy to show that the electron-poor catalyst [L 3 Pd] (L=tris[3,5-bis(trifluoromethyl)phenyl]phosphine) readily reacts with Br - ions to afford the anionic, zero-valent ate complex [L 3 PdBr] - . In contrast, more-electron-rich Pd catalysts display lower tendencies toward the formation of ate complexes. Combining [L 3 Pd] with LiI and an aryl iodide substrate (ArI) results in the observation of the Pd II ate complex [L 2 Pd(Ar)I 2 ] - . © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Superparamagnetic iron oxide coated on the surface of cellulose nanospheres for the rapid removal of textile dye under mild condition

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yunfeng [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, and College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Qin, Zongyi, E-mail: phqin@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, and College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Liu, Yannan; Cheng, Miao; Qian, Pengfei [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, and College of Material Science and Engineering, Donghua University, Shanghai 201620 (China); Wang, Qian, E-mail: drwangqian23@163.com [Department of Orthopaedics, Shanghai First People' s Hospital, Shanghai Jiaotong University, 100 Haining Road, Hongkou District, Shanghai 200080 (China); Zhu, Meifang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, and College of Material Science and Engineering, Donghua University, Shanghai 201620 (China)

    2015-12-01

    Graphical abstract: - Highlights: • Anchoring superparamagnetic iron oxide on the surface of cellulose nanospheres as magnetically recyclable nanocatalys. • Achieving highly efficient Fenton-like reaction on the surface of composite nanospheres for rapid removal of textile dye. • Reaching nearly 98.0% degradation of Navy blue within 5 min under mild condition. - Abstract: Magnetic composite nanoparticles (MNPs) were prepared by anchoring iron oxide (Fe{sub 3}O{sub 4}) on the surface of carboxyl cellulose nanospheres through a facile chemical co-precipitation method. The as-prepared MNPs were characterized by atomic force microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, wide-angle X-ray diffraction measurement, thermal gravity analysis and vibrating sample magnetometry. These MNPs were of a generally spherical shape with a narrow size distribution, and exhibited superparamagnetic behaviors with high saturation magnetization. High efficient removal of Navy blue in aqueous solution was demonstrated at room temperature in a Fenton-like system containing the MNPs and H{sub 2}O{sub 2}, which benefited from small particle size, large surface area, high chemical activity, and good dispersibility of the MNPs. The removal efficiency of Navy blue induced by the MNPs prepared at a weight ratio of cellulose to iron of 1:2 were 90.6% at the first minute of the degradation reaction, and 98.0% for 5 min. Furthermore, these MNPs could be efficiently recycled and reused by using an external magnetic field. The approach presented in this paper promotes the use of renewable natural resources as templates for the preparation and stabilization of various inorganic nanomaterials for the purpose of catalysis, magnetic resonance imaging, biomedical and other potential applications.

  4. Determination of palladium by flame photometry

    International Nuclear Information System (INIS)

    Parellada Bellod, R.

    1964-01-01

    A study on the determination of palladium by lame photometry, fixing the most convent experimental conditions and using solvents to increase the emission of this elements is carried out. Among the organic solvents, acetone has been found the most efficient. The interferences produced by anions and cations have also been studied and an analytical method is related, in which lines of calibration of 0 to 100 ppm palladium re used. (Author) 7 refs

  5. Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

    KAUST Repository

    Sinha, Shahnawaz

    2011-09-30

    The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated mic - rosand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of C eq = 10 μg/L were 500 mg/L for AA and GFH, 520–1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60–95 % .

  6. Microstructure and Wear Behavior of TiC Coating Deposited on Spheroidized Graphite Cast Iron Using Laser Surfacing

    Directory of Open Access Journals (Sweden)

    E. R. I. Mahmoud

    2014-10-01

    Full Text Available Spheroidal graphite cast iron was laser cladded with TiC powder using a YAG fiber laser at powers of 700, 1000, 1500 and 2000 W. The powder was preplaced on the surface of the specimens with 0.5 mm thickness. Sound cladding and fusion zones were observed at 700, 1000 and 1500 W powers. However, at 2000 W, cracking was observed in the fusion zone. At 700 W, a build-up zone consisted of fine TiC dendrites inside a matrix composed of martensite, cementite (Fe3C, and some blocks of retained austenite was observed. In this zone, all graphite nodules were totally melted. In the fusion zone, some undissolved and partially dissolved graphite nodules appeared in a matrix containing bainite, ferrite, martensite and retained austenite. At 1500 W, the fusion zone had more iron carbides and ferrite, and the HAZ consisted of martensitic structure. At 2000 W, the build-up zone was consisted of TiC particles precipitated in a matrix of eutectic carbides, martensite plus an inter-lamellar retained austenite. The hardness of the cladded area was remarkably improved (1330 HV in case of 700 W: 5.5 times of the hardness of substrate

  7. Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications

    Science.gov (United States)

    Maleki, H.; Simchi, A.; Imani, M.; Costa, B. F. O.

    2012-11-01

    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe3+ and Fe2+], the concentration of ammonium hydroxide as reducing agent, and molar ratio of water to surfactant. The biocompatibility of the obtained NPs, at various concentrations, was evaluated via MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay and the results showed that the NPs were non-toxic at concentrations gold (˜4 nm) through chemical reduction of attached gold salts at the surface of the SPIONs. The Fe3O4 core/Au shell particles demonstrate strong plasmon resonance absorption and can be separated from solution using an external magnetic field. Experimental data from both physical and chemical determinations of the changes in particle size, surface plasmon resonance optical band, phase components, core-shell surface composition, and magnetic properties have confirmed the formation of the mono-dispersed core-shell nanostructure.

  8. Graphene oxide coated with porous iron oxide ribbons for 2, 4-Dichlorophenoxyacetic acid (2,4-D) removal.

    Science.gov (United States)

    Nethaji, S; Sivasamy, A

    2017-04-01

    Graphene oxide (GO) was prepared from commercially available graphite powder. Porous iron oxide ribbons were grown on the surface of GO by solvothermal process. The prepared GO-Fe 3 O 4 nanocomposites are characterized by FT-IR, XRD, VSM, SEM, TEM, Raman spectroscopy, surface functionality and zero point charge studies. The morphology of the iron oxide ribbons grown on GO is demonstrated with TEM at various magnifications. The presence of magnetite nanoparticles is evident from XRD peaks and the magnetization value is found to be 37.28emu/g. The ratio of intensity of D-peak to G-peak from Raman spectrum is 0.995. The synthesized Graphene oxide-Fe 3 O 4 nanocomposites (GO-Fe 3 O 4 ) were explored for its surface adsorptive properties by using a model organic compound, 2,4-Dichlorophenoxy acetic acid (2,4-D) from aqueous solution. Batch adsorption studies were performed and the equilibrium data are modelled with Langmuir, Freundlich and Temkin isotherms. The maximum monolayer capacity from Langmuir isotherm is 67.26mg/g. Kinetic studies were also carried out and the studied adsorption process followed pseudo second-order rate equation. Mechanism of the adsorption process is studied by fitting the data with intraparticle diffusion model and Boyd plot. The studied adsorption process is both by film diffusion and intraparticle diffusion. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Migration behavior of palladium in UO2, (3)

    International Nuclear Information System (INIS)

    Yoneyama, Mitsuru; Sato, Seichi; Ohashi, Hiroshi; Ogawa, Toru; Ito, Akinori; Fukuda, Kousaku.

    1992-08-01

    Palladium (Pd) is easily released from UO 2 kernels in HTGR coated fuel particles, and reacts with SiC coating layer. In addition, Pd is one of metallic fission products in irradiation UO 2 , which constitutes in dissoluble residue in reprocessing of LWR fuels. In the present investigation, the migration of palladium in UO 2 was examined by heating diffusion pairs sandwiched Pd foil between UO 2 wafers at 1300 ∼ 1800degC. Experiments were also carried out on affinity of Pd to UP 2 and a formation of U-Pd alloy. Pd was found mainly in the pores of UO 2 . The maximum depth intruded by Pd in fairly large amount was more than 100 μm for UO 2 with 90%TD and 50μm for UO 2 with 95%TD, while the maximum length of open pores was 330 μm for UO 2 with 90%TD, and 50 m for that with 95%TD. Fused Pd wetted UO 2 very much. Pd intruded deeply into UO 2 , especially in the edge of Pd droplet. Furthermore, U was detected either in precipitates or the Pd source with α-Pd phase of U-Pd alloy containing Pd at about 10at%. This fact indicates that Pd highly reacts with UO 2 . From the above results, the transport of Pd in UO 2 was explained by the model of gaseous diffusion through pores in UO 2 , which is retarded by formation of U-Pd alloy. It is also indicated that UPd 3 forms even at the oxygen potential condition of O/U ratio, which is a little higher than 2.00 on the basis of thermodynamic calculation. (author)

  10. Labeling mesenchymal cells with DMSA-coated gold and iron oxide nanoparticles: assessment of biocompatibility and potential applications.

    Science.gov (United States)

    Silva, Luisa H A; da Silva, Jaqueline R; Ferreira, Guilherme A; Silva, Renata C; Lima, Emilia C D; Azevedo, Ricardo B; Oliveira, Daniela M

    2016-07-18

    Nanoparticles' unique features have been highly explored in cellular therapies. However, nanoparticles can be cytotoxic. The cytotoxicity can be overcome by coating the nanoparticles with an appropriated surface modification. Nanoparticle coating influences biocompatibility between nanoparticles and cells and may affect some cell properties. Here, we evaluated the biocompatibility of gold and maghemite nanoparticles functionalized with 2,3-dimercaptosuccinic acid (DMSA), Au-DMSA and γ-Fe2O3-DMSA respectively, with human mesenchymal stem cells. Also, we tested these nanoparticles as tracers for mesenchymal stem cells in vivo tracking by computed tomography and as agents for mesenchymal stem cells magnetic targeting. Significant cell death was not observed in MTT, Trypan Blue and light microscopy analyses. However, ultra-structural alterations as swollen and degenerated mitochondria, high amounts of myelin figures and structures similar to apoptotic bodies were detected in some mesenchymal stem cells. Au-DMSA and γ-Fe2O3-DMSA labeling did not affect mesenchymal stem cells adipogenesis and osteogenesis differentiation, proliferation rates or lymphocyte suppression capability. The uptake measurements indicated that both inorganic nanoparticles were well uptaken by mesenchymal stem cells. However, Au-DMSA could not be detected in microtomograph after being incorporated by mesenchymal stem cells. γ-Fe2O3-DMSA labeled cells were magnetically responsive in vitro and after infused in vivo in an experimental model of lung silicosis. In terms of biocompatibility, the use of γ-Fe2O3-DMSA and Au-DMSA as tracers for mesenchymal stem cells was assured. However, Au-DMSA shown to be not suitable for visualization and tracking of these cells in vivo by standard computed microtomography. Otherwise, γ-Fe2O3-DMSA shows to be a promising agent for mesenchymal stem cells magnetic targeting.

  11. CD163-Macrophages Are Involved in Rhabdomyolysis-Induced Kidney Injury and May Be Detected by MRI with Targeted Gold-Coated Iron Oxide Nanoparticles.

    Science.gov (United States)

    Rubio-Navarro, Alfonso; Carril, Mónica; Padro, Daniel; Guerrero-Hue, Melanie; Tarín, Carlos; Samaniego, Rafael; Cannata, Pablo; Cano, Ainhoa; Villalobos, Juan Manuel Amaro; Sevillano, Ángel Manuel; Yuste, Claudia; Gutiérrez, Eduardo; Praga, Manuel; Egido, Jesús; Moreno, Juan Antonio

    2016-01-01

    Macrophages play an important role in rhabdomyolysis-acute kidney injury (AKI), although the molecular mechanisms involved in macrophage differentiation are poorly understood. We analyzed the expression and regulation of CD163, a membrane receptor mainly expressed by anti-inflammatory M2 macrophages, in rhabdomyolysis-AKI and developed targeted probes for its specific detection in vivo by MRI. Intramuscular injection of glycerol in mice promoted an early inflammatory response, with elevated proportion of M1 macrophages, and partial differentiation towards a M2 phenotype in later stages, where increased CD163 expression was observed. Immunohistological studies confirmed the presence of CD163-macrophages in human rhabdomyolysis-AKI. In cultured macrophages, myoglobin upregulated CD163 expression via HO-1/IL-10 axis. Moreover, we developed gold-coated iron oxide nanoparticles vectorized with an anti-CD163 antibody that specifically targeted CD163 in kidneys from glycerol-injected mice, as determined by MRI studies, and confirmed by electron microscopy and immunological analysis. Our findings are the first to demonstrate that CD163 is present in both human and experimental rhabdomyolysis-induced AKI, suggesting an important role of this molecule in this pathological condition. Therefore, the use of probes targeting CD163-macrophages by MRI may provide important information about the cellular composition of renal lesion in rhabdomyolysis.

  12. Influences of the iron ion (Fe3+)-doping on structural and optical properties of nanocrystalline TiO2 thin films prepared by sol-gel spin coating

    International Nuclear Information System (INIS)

    Ben Naceur, J.; Mechiakh, R.; Bousbih, F.; Chtourou, R.

    2011-01-01

    Titanium dioxide (TiO 2 ) thin films doping of various iron ion (Fe 3+ ) concentrations were deposited on silicon (Si) (100) and quartz substrates by sol-gel Spin Coating technique followed by a thermal treatment at 600 deg. C. The structure, surface morphology and optical properties, as a function of the doping, have been studied by X-ray diffractometer (XRD), Raman, ultraviolet-visible (UV-vis) and Spectroscopic Ellipsometry (SE). XRD and Raman analyzes of our thin films show that the crystalline phase of TiO 2 thin films comprised only the anatase TiO 2 , but the crystallinity decreased when the Fe 3+ content increased from 0% to 20%. During the Fe 3+ addition to 20%, the phase of TiO 2 thin film still maintained the amorphous state. The grain size calculated from XRD patterns varies from 29.3 to 22.6 nm. The complex index and the optical band gap (E g ) of the films were determined by the spectroscopic ellipsometry analysis. We have found that the optical band gap decreased with an increasing Fe 3+ content.

  13. Poly (dopamine) coated superparamagnetic iron oxide nanocluster for noninvasive labeling, tracking, and targeted delivery of adipose tissue-derived stem cells

    Science.gov (United States)

    Liao, Naishun; Wu, Ming; Pan, Fan; Lin, Jiumao; Li, Zuanfang; Zhang, Da; Wang, Yingchao; Zheng, Youshi; Peng, Jun; Liu, Xiaolong; Liu, Jingfeng

    2016-01-01

    Tracking and monitoring of cells in vivo after transplantation can provide crucial information for stem cell therapy. Magnetic resonance imaging (MRI) combined with contrast agents is believed to be an effective and non-invasive technique for cell tracking in living bodies. However, commercial superparamagnetic iron oxide nanoparticles (SPIONs) applied to label cells suffer from shortages such as potential toxicity, low labeling efficiency, and low contrast enhancing. Herein, the adipose tissue-derived stem cells (ADSCs) were efficiently labeled with SPIONs coated with poly (dopamine) (SPIONs cluster@PDA), without affecting their viability, proliferation, apoptosis, surface marker expression, as well as their self-renew ability and multi-differentiation potential. The labeled cells transplanted into the mice through tail intravenous injection exhibited a negative enhancement of the MRI signal in the damaged liver-induced by carbon tetrachloride, and subsequently these homed ADSCs with SPIONs cluster@PDA labeling exhibited excellent repair effects to the damaged liver. Moreover, the enhanced target-homing to tissue of interest and repair effects of SPIONs cluster@PDA-labeled ADSCs could be achieved by use of external magnetic field in the excisional skin wound mice model. Therefore, we provide a facile, safe, noninvasive and sensitive method for external magnetic field targeted delivery and MRI based tracking of transplanted cells in vivo.

  14. Effect of pH and Calcium on the Adsorptive Removal of Cadmium and Copper by Iron Oxide–Coated Sand and Granular Ferric Hydroxide

    KAUST Repository

    Uwamariya, V.

    2015-08-17

    Iron oxide-coated sand (IOCS) and granular ferric hydroxide (GFH) were used to study the effect of Ca2+ and pH on the adsorptive removal of Cu2+ and Cd2+ from groundwater using batch adsorption experiments and kinetic modeling. It was observed that Cu2+ and Cd2+ were not stable in synthetic waters. The extent of precipitation increased with increasing pH. Removal of Cu2+ and Cd2+ was achieved through both precipitation and adsorption, with IOCS showing higher adsorption efficiency. Increase of pH (from 6 to 8) resulted in a higher overall removal efficiency of both Cu2+ and Cd2+, with precipitation as predominant removal mechanisms at higher pH values, especially for Cu2+. An increase in Ca2+ concentration increased the precipitation of Cu2+ [as Cu2(OH)2CO3 and Cu3(OH)2(CO3)2] and Cd2+ [as Cd(OH)2 and CdCO3]. In addition, Ca2+ competes with Cu2+ and Cd2+ for surface adsorption sites on IOCS and GFH, and reduces their adsorption capacity. The kinetic modeling revealed that the adsorption of Cd2+ onto IOCS is a complex process, with limited contribution of chemisorption that increases in the presence of Ca2+. © 2015 American Society of Civil Engineers.

  15. Characteristics and optical properties of iron ion (Fe{sup 3+})-doped titanium oxide thin films prepared by a sol-gel spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, M.C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan (China); Lin, H.J. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China)], E-mail: hjlin@nuu.edu.tw; Yang, T.S. [Department of Materials Science and Engineering, National United University, 1 Lein-Da, Kung-Ching Li, Miao-Li 36003, Taiwan (China)

    2009-04-03

    Titanium dioxide (TiO{sub 2}) thin films doping of various iron ion (Fe{sup 3+}) concentrations have been prepared on a glass substrate by the sol-gel spin coating process. Characteristics and optical properties of TiO{sub 2} thin films doping of various Fe content were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-vis) and spectroscopic ellipsometry. The crystalline phase of TiO{sub 2} thin films comprised only the anatase TiO{sub 2}, but the crystallinity decreased when the Fe{sup 3+} content increased from 0 to 25.0 wt%. During the Fe{sup 3+} addition to 25.0 wt%, the phase of TiO{sub 2} thin film still maintained the amorphous state. The absorption edge of TiO{sub 2} thin films shifted towards longer wavelengths (i.e. red shifted) from 355 to 415 nm when the Fe{sup 3+}-doped concentration increased from 0 to 25.0 wt%. The values of the refractive index (n), and extinction coefficient (k), decreased with an increasing Fe{sup 3+} content. Moreover, the band-gap energy of TiO{sub 2} thin films also decreased from 3.29 to 2.83 eV with an increase in the Fe{sup 3+} content from 0 to 25.0 wt%.

  16. Poly (dopamine) coated superparamagnetic iron oxide nanocluster for noninvasive labeling, tracking, and targeted delivery of adipose tissue-derived stem cells.

    Science.gov (United States)

    Liao, Naishun; Wu, Ming; Pan, Fan; Lin, Jiumao; Li, Zuanfang; Zhang, Da; Wang, Yingchao; Zheng, Youshi; Peng, Jun; Liu, Xiaolong; Liu, Jingfeng

    2016-01-05

    Tracking and monitoring of cells in vivo after transplantation can provide crucial information for stem cell therapy. Magnetic resonance imaging (MRI) combined with contrast agents is believed to be an effective and non-invasive technique for cell tracking in living bodies. However, commercial superparamagnetic iron oxide nanoparticles (SPIONs) applied to label cells suffer from shortages such as potential toxicity, low labeling efficiency, and low contrast enhancing. Herein, the adipose tissue-derived stem cells (ADSCs) were efficiently labeled with SPIONs coated with poly (dopamine) (SPIONs cluster@PDA), without affecting their viability, proliferation, apoptosis, surface marker expression, as well as their self-renew ability and multi-differentiation potential. The labeled cells transplanted into the mice through tail intravenous injection exhibited a negative enhancement of the MRI signal in the damaged liver-induced by carbon tetrachloride, and subsequently these homed ADSCs with SPIONs cluster@PDA labeling exhibited excellent repair effects to the damaged liver. Moreover, the enhanced target-homing to tissue of interest and repair effects of SPIONs cluster@PDA-labeled ADSCs could be achieved by use of external magnetic field in the excisional skin wound mice model. Therefore, we provide a facile, safe, noninvasive and sensitive method for external magnetic field targeted delivery and MRI based tracking of transplanted cells in vivo.

  17. Palladium-cobalt particles as oxygen-reduction electrocatalysts

    Science.gov (United States)

    Adzic, Radoslav [East Setauket, NY; Huang, Tao [Manorville, NY

    2009-12-15

    The present invention relates to palladium-cobalt particles useful as oxygen-reducing electrocatalysts. The invention also relates to oxygen-reducing cathodes and fuel cells containing these palladium-cobalt particles. The invention additionally relates to methods for the production of electrical energy by using the palladium-cobalt particles of the invention.

  18. Unexpectedly high uptake of palladium by bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, J. [Research Lab. for Mining Chemistry, Hungarian Academy of Sciences, Miskolc-Egyetemvaros (Hungary); Brown, S.D.; Snape, C.E. [Univ. of Strathclyde, Dept. of Pure and Applied Chemistry, Glasgow (United Kingdom)

    1997-12-31

    The uptake of palladium as a conversion catalyst onto coals of different rank was investigated. Palladium fixation occurs by a different mode to that for alkaline earth and first row transition metals. Therefore, the dispersion of relatively high concentration of palladium by an ion sorption process is even possible for bituminous coals. (orig.)

  19. : Recyclable, ligand free palladium(II) catalyst for Heck reaction

    Indian Academy of Sciences (India)

    well as heterogeneous palladium catalysts, generated from either palladium(0) compounds or palladium(II) acetate or chloride salts.6 Several ligands such as phosphines, phoshites, carbenes, thioethers have been successfully employed for this reaction.7 However, homogeneous catalysis results in problems of recovery.

  20. Palladium transport in SiC

    International Nuclear Information System (INIS)

    Olivier, E.J.; Neethling, J.H.

    2012-01-01

    Highlights: ► We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. ► The high temperature mobility of palladium silicides within polycrystalline SiC was studied. ► Corrosion of SiC by Pd was seen in all cases. ► The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. ► The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd 2 Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  1. Palladium transport in SiC

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, E.J., E-mail: jolivier@nmmu.ac.za [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Neethling, J.H. [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. Black-Right-Pointing-Pointer The high temperature mobility of palladium silicides within polycrystalline SiC was studied. Black-Right-Pointing-Pointer Corrosion of SiC by Pd was seen in all cases. Black-Right-Pointing-Pointer The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. Black-Right-Pointing-Pointer The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd{sub 2}Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  2. Surface plasmon resonance enhanced light absorption and wavelength tuneable in gold-coated iron oxide spherical nanoparticle

    Science.gov (United States)

    Dasri, Thananchai; Chingsungnoen, Artit

    2018-06-01

    Surface plasmon in nano-sized particles, such as gold, silver, copper and their composites, has recently attracted a great deal of attention due to its possible uses in many applications, especially in life sciences. It is desirable for application devices with a tenability of surface plasmon wavelength and optical properties enhancement. This article presents enhanced optical light absorption and tunable wavelength in gold-coated magnetite (Fe3O4@Au core-shell) nanoparticles embedded in water using the theoretical method of discrete dipole approximation (DDA). The absorption spectra in the wavelengths from 350 to 900 nm were found to be the spectra obtained from Fe3O4@Au core-shell nanoparticles, and when compared with pure Fe3O4 nanoparticles, the surface plasmon resonance can be enhanced and tuned over the entire visible spectrum (viz. 350-800 nm) of the electromagnetic spectrum by varying the Au shell thickness (2-5 nm). Similarly, the Faraday rotation spectra can also be obtained.

  3. Optical properties of palladium nanoparticles under exposure of hydrogen and inert gas prepared by dewetting synthesis of thin-sputtered layers

    Energy Technology Data Exchange (ETDEWEB)

    Kracker, Michael, E-mail: Michael.Kracker@uni-jena.de; Worsch, Christian; Ruessel, Christian [Otto-Schott-Institut, Jena University (Germany)

    2013-04-15

    Thin layers of palladium with a thickness of 5 nm were sputtered on fused silica substrates. Subsequently, the coated glasses were annealed at a temperature of 900 Degree-Sign C for 1 h. This resulted in the formation of small and well-separated palladium nanoparticles with diameters in the range from 20 to 200 nm on the glass surface. The existence of a palladium oxide layer can be detected using optical absorption spectroscopy. Purging with hydrogen leads to an irreversible change in the optical spectra due to the reduction of PdO to metallic palladium. Changing the gas atmosphere from hydrogen to argon leads to significant reversible changes in the optical properties of the particle layer. Based on Mie theory and the respective dielectric functions, the spectra were calculated using the real particle size distribution, weighted dispersions relation to adapt the geometrical conditions and complex dielectric functions of palladium and palladium hydride. A good agreement with measured spectra was found and the dependency of the surrounding media can be explained.Graphical Abstract.

  4. Non-immunogenic dextran-coated superparamagnetic iron oxide nanoparticles: a biocompatible, size-tunable contrast agent for magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Unterweger H

    2017-07-01

    Full Text Available Harald Unterweger,1,* Christina Janko,1,* Marc Schwarz,2 László Dézsi,3 Rudolf Urbanics,4 Jasmin Matuszak,1 Erik Őrfi,3 Tamás Fülöp,3 Tobias Bäuerle,2 János Szebeni,3,4 Clément Journé,5 Aldo R Boccaccini,6 Christoph Alexiou,1 Stefan Lyer,1 Iwona Cicha1 1Cardiovascular Nanomedicine Unit, Section of Experimental Oncology und Nanomedicine (SEON, Else Kröner-Fresenius-Stiftung-Professorship, ENT Department, University Hospital Erlangen, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, 2Preclinical Imaging Platform Erlangen (PIPE, Institute of Radiology, University Hospital Erlangen, Erlangen, Germany; 3Nanomedicine Research and Education Center, Semmelweis University, 4SeroScience Ltd., Budapest, Hungary; 5Inserm U1148, Fédération de Recherche en Imagerie Multimodalités (FRIM, X Bichat Hospital, Paris Diderot University, Paris, France; 6Institute of Biomaterials, Department of Materials Science and Engineering, University Erlangen-Nuremberg, Erlangen, Germany *These authors contributed equally to this work Abstract: Iron oxide-based contrast agents have been in clinical use for magnetic resonance imaging (MRI of lymph nodes, liver, intestines, and the cardiovascular system. Superparamagnetic iron oxide nanoparticles (SPIONs have high potential as a contrast agent for MRI, but no intravenous iron oxide-containing agents are currently approved for clinical imaging. The aim of our work was to analyze the hemocompatibility and immuno-safety of a new type of dextran-coated SPIONs (SPIONdex and to characterize these nanoparticles with ultra-high-field MRI. Key parameters related to nanoparticle hemocompatibility and immuno-safety were investigated in vitro and ex vivo. To address concerns associated with hypersensitivity reactions to injectable nanoparticulate agents, we analyzed complement activation-related pseudoallergy (CARPA upon intravenous administration of SPIONdex in a pig model. Furthermore, the size-tunability of SPIONdex and

  5. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  6. Silver-Palladium Surfaces Inhibit Biofilm Formation

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Schroll, Casper; Hilbert, Lisbeth Rischel

    2009-01-01

    Undesired biofilm formation is a major concern in many areas. In the present study, we investigated biofilm-inhibiting properties of a silver-palladium surface that kills bacteria by generating microelectric fields and electrochemical redox processes. For evaluation of the biofilm inhibition...... efficacy and study of the biofilm inhibition mechanism, the silver-sensitive Escherichia coli J53 and the silver-resistant E. coli J53[pMG101] strains were used as model organisms, and batch and flow chamber setups were used as model systems. In the case of the silver-sensitive strain, the silver......-palladium surfaces killed the bacteria and prevented biofilm formation under conditions of low or high bacterial load. In the case of the silver-resistant strain, the silver-palladium surfaces killed surface-associated bacteria and prevented biofilm formation under conditions of low bacterial load, whereas under...

  7. Palladium-Catalyzed Asymmetric Quaternary Stereocenter Formation

    NARCIS (Netherlands)

    Gottumukkala, Aditya L.; Matcha, Kiran; Lutz, Martin; de Vries, Johannes G.; Minnaard, Adriaan J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of beta,beta-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and

  8. Palladium-catalyzed asymmetric quaternary stereocenter formation

    NARCIS (Netherlands)

    Gottumukkala, A.L.; Matcha, K.; Lutz, M.; de Vries, J.G.; Minnaard, A.J.

    2012-01-01

    An efficient palladium catalyst is presented for the formation of benzylic quaternary stereocenters by conjugate addition of arylboronic acids to a variety of β,β-disubstituted carbocyclic, heterocyclic, and acyclic enones. The catalyst is readily prepared from PdCl2, PhBOX, and AgSbF6, and provides

  9. Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance.

    Science.gov (United States)

    Qin, Yiheng; Alam, Arif U; Pan, Si; Howlader, Matiar M R; Ghosh, Raja; Selvaganapathy, P Ravi; Wu, Yiliang; Deen, M Jamal

    2016-01-01

    Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass substrates and annealed at low temperature to generate Pd and PdO. The percentages of PdO at the surface and in the bulk of the electrodes are correlated to their sensing performance, which was studied by using the X-ray photoelectron spectroscope. Large amounts of PdO introduced by prolonged annealing improve the electrode's sensitivity and long-term stability. Atomic force microscopy study showed that the low-temperature annealing results in a smooth electrode surface, which contributes to a fast response. Nano-voids at the electrode surfaces were observed by scanning electron microscope, indicating a reason for the long-term degradation of the pH sensitivity. Using the optimized annealing parameters of 200°C for 48 h, a linear pH response with sensitivity of 64.71±0.56 mV/pH is obtained for pH between 2 and 12. These electrodes show a response time shorter than 18 s, hysteresis less than 8 mV and stability over 60 days. High reproducibility in the sensing performance is achieved. This low-temperature solution-processed sensing electrode shows the potential for the development of pH sensing systems on flexible substrates over a large area at low cost without using vacuum equipment. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Adhesion enhancement between electroless nickel and polyester fabric by a palladium-free process

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yinxiang, E-mail: yxlu@fudan.edu.cn [Department of Materials Science, Fudan University, 220 Handan Road, Shanghai 200433 (China); Xue Longlong; Li Feng [Department of Materials Science, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2011-01-15

    A new, efficient, palladium- and etchant-free process for the electroless nickel plating of poly(ethylene terephthalate) (PET) fabric has been developed. PET electroless plating can be prepared in three steps, namely: (i) the grafting of thiol group onto PET, (ii) the silver Ag{sup 0} seeding of the PET surface, and (iii) the nickel metallization using electroless plating bath. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectrometer, X-ray diffraction (XRD), and thermogravimetric analysis (TG) were used to characterize the samples in the process, and the nickel loading was quantified by weighing. This process successfully compares with the traditional one based on KMnO{sub 4}/H{sub 2}SO{sub 4} etching and palladium-based seed layer. The nickel coating obtained in this palladium-free process can pass through ultrasonic washing challenge, and shows excellent adhesion with the PET substrate. However, the sample with Pd catalyst via traditional process was damaged during the testing experiment.

  11. Density functional theory metadynamics of silver, caesium and palladium diffusion at β-SiC grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Rabone, Jeremy, E-mail: jeremy.rabone@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, D-76125 Karlsruhe (Germany); López-Honorato, Eddie [Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV), Unidad Saltillo, Industria Metalúrgica 1062, Parque Industrial, Ramos Arizpe 25900, Coahuila (Mexico)

    2015-03-15

    Highlights: • DFT metadynamics of diffusion of Pd, Ag and Cs on grain boundaries in β-SiC. • The calculated diffusion rates for Pd and Ag tally with experimental release rates. • A mechanism of release other than grain boundary diffusion seems likely for Cs. - Abstract: The use of silicon carbide in coated nuclear fuel particles relies on this materials impermeability towards fission products under normal operating conditions. Determining the underlying factors that control the rate at which radionuclides such as Silver-110m and Caesium-137 can cross the silicon carbide barrier layers, and at which fission products such as palladium could compromise or otherwise alter the nature of this layer, are of paramount importance for the safety of this fuel. To this end, DFT-based metadynamics simulations are applied to the atomic diffusion of silver, caesium and palladium along a Σ5 grain boundary and to palladium along a carbon-rich Σ3 grain boundary in cubic silicon carbide at 1500 K. For silver, the calculated diffusion coefficients lie in a similar range (7.04 × 10{sup −19}–3.69 × 10{sup −17} m{sup 2} s{sup −1}) as determined experimentally. For caesium, the calculated diffusion rates are very much slower (3.91 × 10{sup −23}–2.15 × 10{sup −21} m{sup 2} s{sup −1}) than found experimentally, suggesting a different mechanism to the simulation. Conversely, the calculated atomic diffusion of palladium is very much faster (7.96 × 10{sup −11}–7.26 × 10{sup −9} m{sup 2} s{sup −1}) than the observed penetration rate of palladium nodules. This points to the slow dissolution and rapid regrowth of palladium nodules as a possible ingress mechanism in addition to the previously suggested migration of entire nodules along grain boundaries. The diffusion rate of palladium along the Σ3 grain boundary was calculated to be slightly slower (2.38 × 10{sup −11}–8.24 × 10{sup −10} m{sup 2} s{sup −1}) than along the Σ5 grain boundary. Rather

  12. Study of electroplated silver-palladium biofouling inhibiting coating

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Møller, Per

    The undesired microbial and biofilm adhesions on the surfaces of food industrial facilities, water supply systems and etc. are so called as “biofouling”. Biofouling can cause many undesirable effects. Until now for solving biofouling, there are few non-toxic inhibiting treatments. In this study, ...

  13. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO and DOE OCRWM Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-01-01

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  14. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO & DOE OCRWM Co-Sponsored Advanced Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-09-19

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent.

  15. Phosphorus collectors from filter paper and synthetic cloth coated with iron or aluminium oxide to provide phosphorus by diffusion in soils

    Directory of Open Access Journals (Sweden)

    Eduardo Bernardi Luchese

    2000-01-01

    Full Text Available Phosphorus collectors made from filter paper and synthetic cloth, were tested to evaluate their feasibility of determining the need for phosphate application. The collectors were coated with two types of oxides, iron oxide and aluminium oxide. The capacity of the collectors was tested by placing them in a 2 mL of solution containing phosphorus (PO4(3- in the concentration of 0.0, 1.00, 3.00, 5.00, 7.00, 9.00 and 11.00 µ g.mL-1, respectively, after which they were placed in contact with four types of soil (LBa, LRd, LEd and Ca and incubed for 0.0 and 24 h. In this test the soils were kept at a humidity equivalent to 150 mmHg suction. The amount of phosphorus extracted from the solutions was tested at intervals between 0,0 and 11.0 µ g of phosphorus/mL. Results indicated that collectors were most efficient in Dystrophic Dark-Red Latosol (LEd and less efficient in "Bruno álico" Latosol (LBa and Cambisol (Ca. Synthetic cloth was the support yielding the best performance, whereas iron oxide lining was the most adequate lining material. Phosphorus collection increased with time of incubation.Coletores de fósforo feitos de papel filtro e pano sintético (perfex foram usados no estudo da determinação da necessidade de adubação fosfatada. Foram preparados coletores impregnados com óxido de ferro e outros com óxido de alumínio. A capacidade foi testada colocando-os em 2 mL de uma solução padrão de fósforo (na forma de fosfato com 0,0; 1,00; 3,00; 5,00; 7,00; 9,00 e 11;00 µg.mL-1 , depois foram colocados em contato com 4 tipos de solos (Lba, LRd, Led e Ca e incubados por 0,0 e 24 horas. No teste, os solos foram mantidos com uma umidade equivalente a 150 mmHg de sucção. Os resultados mostraram que os coletores foram mais eficientes, na extração de fósforo, no solo LED e menos eficiente no LBa e Ca (Cambissolo. O pano sintético foi a matriz (material suporte que proporcionou melhores resultados. O óxido de ferro foi o substrato foi o

  16. Dendritic surface morphology of palladium hydride produced by electrolytic deposition

    International Nuclear Information System (INIS)

    Julin, Peng; Bursill, L.A.

    1990-01-01

    Conventional and high-resolution electron microscopic studies of electrolytically-deposited palladium hydride reveal a fascinating variety of surface profile morphologies. The observations provide direct information concerning the surface structure of palladium electrodes and the mechanism of electrolytic deposition of palladium black. Both classical electrochemical mechanisms and recent 'modified diffusion-limited-aggregation' computer simulations are discussed in comparison with the experimental results. 13 refs., 9 figs

  17. Adsorption of palladium ions by modified carbons from rice husks

    International Nuclear Information System (INIS)

    Mostafa, M.R.

    1994-01-01

    Steam activated carbon of high surface area does not show palladium ions adsorption. Treatment of this carbon with HF acid increases to a great extent the gas adsorption capacity expressed as nitrogen surface area as well as the adsorption capacity of palladium ions from aqueous solution. HHB was loaded in different amounts on to these carbons. The acid sites represent the active fraction of the surface on which the adsorption palladium ions proceed. The uptake of palladium ions by HHB treated carbons is related to the total number of HHB molecules loaded on the carbon surface. (author)

  18. Development of Separation Materials Containing Palladium for Hydrogen Isotopes Separation

    International Nuclear Information System (INIS)

    Deng Xiaojun; Luo Deli; Qian Xiaojing

    2010-01-01

    Displacement chromatography (DC) is a ascendant technique for hydrogen isotopes separation. The performance of separation materials is a key factor to determine the separation effect of DC. At present,kinds of materials are researched, including palladium materials and non-palladium materials. It is hardly replaceable because of its excellent separation performance, although palladium is expensive. The theory of hydrogen isotopes separation using DC was introduced at a brief manner, while several palladium separation materials were expatiated in detail(Pd/K, Pd-Al 2 O 3 , Pd-Pt alloy). Development direction of separation materials for DC was forecasted elementarily. (authors)

  19. FABRICATION OF GAS-FILLED TUNGSTEN-COATED GLASS SHELLS

    International Nuclear Information System (INIS)

    NIKROO, A; BAUGH, W; STEINMAN, D.A.

    2003-09-01

    OAK-B135 Deuterium (D 2 ) filled glass shells coated with a high Z element are needed for high energy density (HED) experiments by researchers at Los Alamos National Laboratory. They report here on our initial attempt to produce such shells. Glass shells made using the drop tower technique were coated with gold, palladium or tungsten, or a mixture of two of these elements. It was found that gold and palladium coatings did not stick well to the glass and resulted in poor or delaminated films. Tungsten coatings resulted in films suitable for these targets. Bouncing of shells during coating resulted in uniform tungsten coatings, but the surface of such coatings were filled with small nodules. Proper agitation of shells using a tapping technique resulted in smooth films with minimal particulate contamination. For coating rates of ∼ 0.15 (micro)m/hr coatings with ∼ 2 nm RMS surface finish could be deposited. The surface roughness of coatings at higher rates, 0.7 (micro)m/hr, was considerably worse (∼ 100 nm RMS). The columnar structure of the coatings allowed permeation filling of the tungsten coated glass shells with deuterium at 300 C

  20. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  1. Chondroitin sulfate-polyethylenimine copolymer-coated superparamagnetic iron oxide nanoparticles as an efficient magneto-gene carrier for microRNA-encoding plasmid DNA delivery

    Science.gov (United States)

    Lo, Yu-Lun; Chou, Han-Lin; Liao, Zi-Xian; Huang, Shih-Jer; Ke, Jyun-Han; Liu, Yu-Sheng; Chiu, Chien-Chih; Wang, Li-Fang

    2015-04-01

    MicroRNA-128 (miR-128) is an attractive therapeutic molecule with powerful glioblastoma regulation properties. However, miR-128 lacks biological stability and leads to poor delivery efficacy in clinical applications. In our previous study, we demonstrated two effective transgene carriers, including polyethylenimine (PEI)-decorated superparamagnetic iron oxide nanoparticles (SPIONs) as well as chemically-conjugated chondroitin sulfate-PEI copolymers (CPs). In this contribution, we report optimized conditions for coating CPs onto the surfaces of SPIONs, forming CPIOs, for magneto-gene delivery systems. The optimized weight ratio of the CPs and SPIONs is 2 : 1, which resulted in the formation of a stable particle as a good transgene carrier. The hydrodynamic diameter of the CPIOs is ~136 nm. The gel electrophoresis results demonstrate that the weight ratio of CPIO/DNA required to completely encapsulate pDNA is >=3. The in vitro tests of CPIO/DNA were done in 293 T, CRL5802, and U87-MG cells in the presence and absence of an external magnetic field. The magnetofection efficiency of CPIO/DNA was measured in the three cell lines with or without fetal bovine serum (FBS). CPIO/DNA exhibited remarkably improved gene expression in the presence of the magnetic field and 10% FBS as compared with a gold non-viral standard, PEI/DNA, and a commercial magnetofection reagent, PolyMag/DNA. In addition, CPIO/DNA showed less cytotoxicity than PEI/DNA and PolyMag/DNA against the three cell lines. The transfection efficiency of the magnetoplex improved significantly with an assisted magnetic field. In miR-128 delivery, a microRNA plate array and fluorescence in situ hybridization were used to demonstrate that CPIO/pMIRNA-128 indeed expresses more miR-128 with the assisted magnetic field than without. In a biodistribution test, CPIO/Cy5-DNA showed higher accumulation at the tumor site where an external magnet is placed nearby.MicroRNA-128 (miR-128) is an attractive therapeutic molecule

  2. Functionalized Palladium Nanoparticles for Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    H. Baccar

    2011-01-01

    Full Text Available We present a comparison between two biosensors for hydrogen peroxide (H2O2 detection. The first biosensor was developed by the immobilization of Horseradish Peroxidase (HRP enzyme on thiol-modified gold electrode. The second biosensor was developed by the immobilization of cysteamine functionalizing palladium nanoparticles on modified gold surface. The amino groups can be activated with glutaraldehyde for horseradish peroxidase immobilization. The detection of hydrogen peroxide was successfully observed in PBS for both biosensors using the cyclic voltammetry and the chronoamperometry techniques. The results show that the limit detection depends on the large surface-to-volume ratio attained with palladium nanoparticles. The second biosensor presents a better detection limit of 7.5 μM in comparison with the first one which is equal to 75 μM.

  3. Oxygen isotope exchange on palladium catalysts

    International Nuclear Information System (INIS)

    Kravchuk, L.S.; Beschetvertnaya, T.I.; Novorodskij, V.G.; Novikova, M.G.; Zaretskij, M.V.; Valieva, S.V.

    1983-01-01

    Oxygen heteromolecular isotope exchange on unreduced palladium catalysts, distingushing by metal content is studied. Content of 18 O in gaseous phase is eoual to 46%. Calculations of heteroexchange rates are conducted with decrease of the 18 O in the gaseous phase over solid sample. Method of oxygen thermodesorption has been used to establish that palladium, deposited on γ-Al 2 O 3 during exchange process is in oxidized state; in this case strength of Pd-O bond is determined by content dispersity) of the metal. It is shown that significant increase of exchange rate on the samples with Pd >> 0.5 mass.% content can be induced as by side decomposition reaction of its oxide and corresponding dilution of gaseous mixture by ''light'' oxygen so by possibility of exchange with oxygen of PdO phase

  4. Extracellular Palladium Nanoparticle Production using Geobacter sulfurreducens

    KAUST Repository

    Yates, Matthew D.

    2013-09-03

    Sustainable methods are needed to recycle precious metals and synthesize catalytic nanoparticles. Palladium nanoparticles can be produced via microbial reduction of soluble Pd(II) to Pd(0), but in previous tests using dissimilatory metal reducing bacteria (DMRB), the nanoparticles were closely associated with the cells, occupying potential reductive sites and eliminating the potential for cell reuse. The DMRB Geobacter sulfurreducens was shown here to reduce soluble Pd(II) to Pd(0) nanoparticles primarily outside the cell, reducing the toxicity of metal ions, and allowing nanoparticle recovery without cell destruction that has previously been observed using other microorganisms. Cultures reduced 50 ± 3 mg/L Pd(II) with 1% hydrogen gas (v/v headspace) in 6 h incubation tests [100 mg/L Pd(II) initially], compared to 8 ± 3 mg/L (10 mM acetate) without H2. Acetate was ineffective as an electron donor for palladium removal in the presence or absence of fumarate as an electron acceptor. TEM imaging verified that Pd(0) nanoparticles were predominantly in the EPS surrounding cells in H2-fed cultures, with only a small number of particles visible inside the cell. Separation of the cells and EPS by centrifugation allowed reuse of the cell suspensions and effective nanoparticle recovery. These results demonstrate effective palladium recovery and nanoparticle production using G. sulfurreducens cell suspensions and renewable substrates such as H2 gas. © 2013 American Chemical Society.

  5. Iron and its complexes in silicon

    Science.gov (United States)

    Istratov, A. A.; Hieslmair, H.; Weber, E. R.

    This article is the first in a series of two reviews on the properties of iron in silicon. It offers a comprehensive of the current state of understanding of fundamental physical properties of iron and its complexes in silicon. The first section of this review discusses the position of iron in the silicon lattice and the electrical properties of interstitial iron. Updated expressions for the solubility and the diffusivity of iron in silicon are presented, and possible explanations for conflicting experimental data obtained by different groups are discussed. The second section of the article considers the electrical and the structural properties of complexes of interstitial iron with shallow acceptors (boron, aluminum, indium, gallium, and thallium), shallow donors (phosphorus and arsenic) and other impurities (gold, silver, platinum, palladium, zinc, sulfur, oxygen, carbon, and hydrogen). Special attention is paid to the kinetics of iron pairing with shallow acceptors, the dissociation of these pairs, and the metastability of iron-acceptor pairs. The parameters of iron-related defects in silicon are summarized in tables that include more than 30 complexes of iron as detected by electron paramagnetic resonance (EPR) and almost 20 energy levels in the band gap associated with iron. The data presented in this review illustrate the enormous complexing activity of iron, which is attributed to the partial or complete (depending on the temperature and the conductivity type) ionization of iron as well as the high diffusivity of iron in silicon. It is shown that studies of iron in silicon require exceptional cleanliness of experimental facilities and highly reproducible diffusion and temperature ramping (quenching) procedures. Properties of iron that are not yet completely understood and need further research are outlined.

  6. Biotemplated Palladium Catalysts Can Be Stabilized on Different Support Materials

    KAUST Repository

    Yates, Matthew D.; Logan, Bruce E.

    2014-01-01

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Sustainably biotemplated palladium catalysts generated on different carbon-based support materials are examined for durability under electrochemical (oxidative) and mechanical-stress conditions. Biotemplated catalysts on carbon paper under both stresses retain 95% (at 0.6V) of the initial catalytic activity as opposed to 70% for carbon cloth and 60% for graphite. Graphite electrodes retain 95% of initial catalytic activity under a single stress. Using electrodeposited polyaniline (PANI) and polydimethylsiloxane binder increases the current density after the stress tests by 22%, as opposed to a 30% decrease for Nafion. PANI-coated electrodes retain more activity than carbon-paper electrodes under elevated mechanical (94 versus 70%) or increased oxidative (175 versus 62%) stress. Biotemplated catalytic electrodes may be useful alternatives to synthetically produce catalysts for some electrochemical applications. Sustainable electrode fabrication: The biotemplated synthesis of catalytic porous electrodes is a sustainable process and, according to the results of durability tests under electrochemical and mechanical stress, these electrodes (e.g. the Pd/carbon paper electrode shown in the picture) are durable enough to replace catalytic electrodes based on synthetic materials in certain applications.

  7. Biotemplated Palladium Catalysts Can Be Stabilized on Different Support Materials

    KAUST Repository

    Yates, Matthew D.

    2014-07-30

    © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Sustainably biotemplated palladium catalysts generated on different carbon-based support materials are examined for durability under electrochemical (oxidative) and mechanical-stress conditions. Biotemplated catalysts on carbon paper under both stresses retain 95% (at 0.6V) of the initial catalytic activity as opposed to 70% for carbon cloth and 60% for graphite. Graphite electrodes retain 95% of initial catalytic activity under a single stress. Using electrodeposited polyaniline (PANI) and polydimethylsiloxane binder increases the current density after the stress tests by 22%, as opposed to a 30% decrease for Nafion. PANI-coated electrodes retain more activity than carbon-paper electrodes under elevated mechanical (94 versus 70%) or increased oxidative (175 versus 62%) stress. Biotemplated catalytic electrodes may be useful alternatives to synthetically produce catalysts for some electrochemical applications. Sustainable electrode fabrication: The biotemplated synthesis of catalytic porous electrodes is a sustainable process and, according to the results of durability tests under electrochemical and mechanical stress, these electrodes (e.g. the Pd/carbon paper electrode shown in the picture) are durable enough to replace catalytic electrodes based on synthetic materials in certain applications.

  8. Theranostic MUC-1 aptamer targeted gold coated superparamagnetic iron oxide nanoparticles for magnetic resonance imaging and photothermal therapy of colon cancer

    DEFF Research Database (Denmark)

    Azhdarzadeh, Morteza; Atyabi, Fatemeh; Saei, Amir Ata

    2016-01-01

    Favorable physiochemical properties and the capability to accommodate targeting moieties make superparamegnetic iron oxide nanoparticles (SPIONs) popular theranostic agents. In this study, we engineered SPIONs for magnetic resonance imaging (MRI) and photothermal therapy of colon cancer cells...

  9. Thermosonic wire bonding of IC devices using palladium wire

    International Nuclear Information System (INIS)

    Shze, J.H.; Poh, M.T.; Tan, R.M.

    1996-01-01

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  10. Thermodynamics of the hybrid interaction of hydrogen with palladium nanoparticles

    NARCIS (Netherlands)

    Griessen, R.P.; Strohfeldt, N.; Giessen, H.

    2015-01-01

    Palladium-hydrogen is a prototypical metal-hydrogen system. It is therefore not at all surprising that a lot of attention has been devoted to the absorption and desorption of hydrogen in nanosized palladium particles. Several seminal articles on the interaction of H with Pd nanocubes and

  11. Chemical recovery of a palladium-103 from irradiated silver target

    International Nuclear Information System (INIS)

    Lapshina, E.V.; Kokhanyuk, V.M.; Zhuikov, B.L.; Myasoedova, G.V.; Zakhartchenko, E.A.; Phillips, D.R.; Jamriska, D.J.

    2003-01-01

    The goal of this work is to develop an extraction method of no-carrier-added palladium-103 from silver. Metallic silver targets were irradiated by protons with the energy of 60-140 MeV to generate palladium-103. Other radioactive isotopes of rhodium, ruthenium, technetium, palladium and silver are also formed at the same time. Two methods of Pd-103 recovering from irradiated silver target are considered. The first one includes the dissolving of the irradiated silver target in nitric acid followed by adding of hydrochloric acid to the solution. Palladium with rhodium, ruthenium and technetium completely remained in solution while silver was precipitated in the form of silver chloride. Extraction of palladium from the obtained solution was provided by the formation of palladium complex with a chelate sorbent which is specific to palladium in acidic solutions. The sorbent makes it possible to separate palladium from admixtures of rhodium, ruthenium and technetium isotopes. The polymeric complex-forming sorbent of fibrous structure with the groups of 3 (5) - methylpyrazole (POLYORGS-15n) is used. An other possible method has been also studied. It includes again dissolving of metallic silver in nitric acid, but does not need silver chloride precipitation. Silver may be sorbed by the complex-forming sorbents, but its sorption is very sensitive to acid concentration. Chelate sorbents of fibrous structure with the groups of amidoxime and hydrazidine (POLYORGS-33n) have been successfully used in our experiments. A high efficiency of palladium extraction by POLYORGS-33n from 2-4 M nitric acid solutions was achieved. Concentrated hydrochloric acid (without heating) was used for palladium desorption with higher yield than in the first method. (authors)

  12. Surface plasmon resonance-based fiber-optic hydrogen gas sensor utilizing palladium supported zinc oxide multilayers and their nanocomposite.

    Science.gov (United States)

    Tabassum, Rana; Gupta, Banshi D

    2015-02-10

    We analyze surface plasmon resonance-based fiber-optic sensor for sensing of small concentrations of hydrogen gas in the visible region of the electromagnetic spectrum. One of the two probes considered has multilayers of zinc oxide (ZnO) and palladium (Pd) while the other has layer of their composite over a silver coated unclad core of the fiber. The analysis is carried out for different volume fractions of palladium nanoparticles dispersed in zinc oxide host material in the nanocomposite layer. For the analysis, a Maxwell-Garnett model is adopted for calculating the dielectric function of a ZnO:Pd nanocomposite having nanoparticles of dimensions smaller than the wavelength of radiation used. The effects of the volume fraction of the nanoparticles in the nanocomposite and the thickness of the nanocomposite layer on the figure of merit of the sensor have been studied. The film thickness of the layer and the volume fraction of nanoparticles in the ZnO:Pd nanocomposite layer have been optimized to achieve the maximum value of the figure of merit of the sensor. It has been found that the figure of merit of the sensing probe coated with ZnO:Pd nanocomposite is more than twofold of the sensing probe coated with multilayers of Pd and ZnO over a silver coated unclad core of the fiber; hence, the sensor with a nanocomposite layer works better than that with multilayers of zinc oxide and palladium. The sensor can be used for online monitoring and remote sensing of hydrogen gas.

  13. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    International Nuclear Information System (INIS)

    Ghaedi, M.; Tavallali, H.; Shokrollahi, A.; Zahedi, M.; Montazerozohori, M.; Soylak, M.

    2009-01-01

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L -1 HNO 3 . The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  14. Metal-dusting resistance of uncoated and coated iron and nickel base materials against metal-dusting in heat treatment furnaces with carbonaceous atmospheres

    International Nuclear Information System (INIS)

    Kleingries, Mirko; Ackermann, Helen; Lucka, Klaus; Hoja, Timo; Mehner, Andeas; Zoch, Hans-Werner; Altena, Herwig

    2010-01-01

    Metal-Dusting is a well-known corrosion problem that occurs in carburizing atmospheres in industrial thermal processing plants. In literature almost no quantitative data on the metal dusting resistance of typical alloys employed in industrial furnaces are available. Therefore, a series of experiments with uncoated and sol gel ZrO 2 coated high temperature materials was conducted in order to quantify their metal dusting behaviour under conditions close to those in case hardening furnaces. The experimental results show a strong influence of the surface conditions on the alloys resistance and a noticeable enhancement of the resistance by sol gel coatings. (orig.)

  15. Tritium evolution from various morphologies of palladium

    International Nuclear Information System (INIS)

    Tuggle, D.G.; Claytor, T.N.; Taylor, S.F.

    1994-01-01

    The authors have been able to extend the tritium production techniques to various novel morphologies of palladium. These include small solid wires of various diameters and a type of pressed powder wire and a plasma cell. In most successful experiments, the amount of palladium required, for an equivalent tritium output, has been reduced by a factor of 100 over the older powder methods. In addition, they have observed rates of tritium production (>5 nCi/h) that far exceed most of the previous results. Unfortunately, the methods that they currently use to obtain the tritium are poorly understood and consequently there are numerous variables that need to be investigated before the new methods are as reliable and repeatable as the previous techniques. For instance, it seems that surface and/or bulk impurities play a major role in the successful generation of any tritium. In those samples with total impurity concentrations of >400 ppM essentially no tritium has been generated by the gas loading and electrical simulation methods

  16. Overlay metallic-cermet alloy coating systems

    International Nuclear Information System (INIS)

    Gedwill, M.A.; Glasgow, T.K.; Levine, S.R.

    1982-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures

  17. Overlay metallic-cermet alloy coating systems

    Science.gov (United States)

    Gedwill, M. A.; Levine, S. R.; Glasgow, T. K. (Inventor)

    1984-01-01

    A substrate, such as a turbine blade, vane, or the like, which is subjected to high temperature use is coated with a base coating of an oxide dispersed, metallic alloy (cermet). A top coating of an oxidation, hot corrosion, erosion resistant alloy of nickel, cobalt, or iron is then deposited on the base coating. A heat treatment is used to improve the bonding. The base coating serves as an inhibitor to interdiffusion between the protective top coating and the substrate. Otherwise, the protective top coating would rapidly interact detrimentally with the substrate and degrade by spalling of the protective oxides formed on the outer surface at elevated temperatures.

  18. Enhanced capacity and stability of K_2FeO_4 cathode with poly(3-hexylthiophene) coating for alkaline super-iron battery

    International Nuclear Information System (INIS)

    Wang, Suqin; Wang, Yaoyao; Chen, Shuiliang; Hou, Haoqing; Li, Hongbo

    2016-01-01

    Highlights: • Conductive polymer coating allows improving capacity and stability of K_2FeO_4. • P3HT-coated K_2FeO_4 is prepared. • High capacity is recorded after storing 6 h (314 mAh g"−"1) for P3HT-coated K_2FeO_4. • Partly oxidized P3HT coating is formed due to the reaction between P3HT and K_2FeO_4. • The mechanism of improving capacity and stability of K_2FeO_4 is proposed. - Abstract: Poly(3-hexylthiophene)-coated K_2FeO_4 (K_2FeO_4@P3HT) was prepared to enhance capacity and stability of K_2FeO_4. Scanning electron microscopy (SEM), Fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectra (XPS) were performed to characterize K_2FeO_4@P3HT. Discharge performance results showed that the Poly(3-hexylthiophene) (P3HT) coating layer enhanced the capacity of the K_2FeO_4 in 10 mol L"−"1 KOH electrolyte. K_2FeO_4@P3HT-1% electrode showed a high discharge capacity of 351 mAh g"−"1, about 13% increase comparing to the K_2FeO_4 electrode. Moreover, the stability of K_2FeO_4 electrode was obviously enhanced by P3HT coating, and the discharge capacity of the electrode which was stored in electrolyte for 6 h was improved to 314 mAh g"−"1, increasing about 22.6% compared to that of 314 mAh g"−"1. These desirable properties can be attributed to the in-situ formation of two-layer film on the surface of K_2FeO_4 crystal, which keep electrolyte from directly contacting with K_2FeO_4 and reduce the resistance of charge transfer.

  19. Fabrication of palladium-based microelectronic devices by microcontact printing

    International Nuclear Information System (INIS)

    Wolfe, Daniel B.; Love, J. Christopher; Paul, Kateri E.; Chabinyc, Michael L.; Whitesides, George M.

    2002-01-01

    This letter demonstrates the patterning of thin films of metallic palladium by microcontact printing (μCP) of octadecanethiol, and the use of the patterned films in the fabrication of a functional sensor. This technique was also used to prepare templates of palladium for the electroless deposition of copper. The resistivity of the palladium and copper microstructures was 13.8 and 2.8 μΩ cm, respectively; these values are approximately 40% larger than the values for the pure bulk metals. Palladium patterned into serpentine wires using μCP functioned as a hydrogen sensor with sensitivity of 0.03 vol % H 2 in N 2 , and a response time of ∼10 s (at room temperature)

  20. Antibacterial properties of palladium nanostructures sputtered on polyethylene naphthalate

    Czech Academy of Sciences Publication Activity Database

    Polívková, M.; Válová, M.; Siegel, J.; Rimpelová, S.; Hubáček, Tomáš; Lyutakov, O.; Švorčík, V.

    2015-01-01

    Roč. 5, č. 90 (2015), s. 73767-73774 ISSN 2046-2069 Institutional support: RVO:60077344 Keywords : polymer * palladium sputtering * annealing * nanostructure * antibacterial effect Subject RIV: JJ - Other Materials Impact factor: 3.289, year: 2015

  1. Palladium-catalysed arylation of sulfonamide stabilised enolates

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2005-03-07

    Full Text Available Alpha-Arylation of inethanesulfonamides using palladium catalysis is described. For example, treatment of N-benzyl-Nmethylmethanesulfonamide with catalytic Pd (OAc) (2) in the presence of sodium tert-butoxide, triphenylphosphine and toluene afforded...

  2. Palladium silicide - a new contact for semiconductor radiation detectors

    International Nuclear Information System (INIS)

    Totterdell, D.H.J.

    1981-11-01

    Silicide layers can be used as low resistance contacts in semiconductor devices. The formation of a metal rich palladium silicide Pd 2 Si is discussed. A palladium film 100A thick is deposited at 300 0 C and the resulting silicide layer used as an ohmic contact in an n + p silicon detector. This rugged contact has electrical characteristics comparable with existing evaporated gold contacts and enables the use of more reproducible bonding techniques. (author)

  3. Toward Efficient Palladium-Catalyzed Allylic C-H Alkylation

    DEFF Research Database (Denmark)

    Jensen, Thomas; Fristrup, Peter

    2009-01-01

    Recent breakthroughs have proved that direct palladium (II)-catalyzed allylic C-H alkylation can be achieved. This new procedure shows that the inherent requirement for a leaving group in the Tsuji-Trost palladium-catalyzed allylic alkylation can be lifted. These initial reports hold great promise...... for the development of allylic C-H alkylation into a widely applicable methodology, thus providing a means to enhance synthetic efficiency in these reactions....

  4. Fission products silver, palladium, and cadmium identification in neutron-irradiated SiC TRISO particles using a Cs-Corrected HRTEM

    Energy Technology Data Exchange (ETDEWEB)

    Rooyen, I.J. van, E-mail: isabella.vanrooyen@inl.gov [Fuel Design and Development Department, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID, 83415-6188 (United States); Olivier, E.J.; Neethling, J.H. [Centre for High Resolution Electron Microscopy, Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2016-08-01

    Electron microscopy investigations of selected coated particles from the first advanced gas reactor experiment at Idaho National Laboratory provided important information on fission product distribution and chemical composition in the silicon-carbide (SiC) layer. Silver precipitates were nano-sized, and therefore high-resolution transmission electron microscopy (HRTEM) was used to provide more information at the atomic level. Based on gamma-ray analysis, this particle which was irradiated to an average burnup of 19.38% fissions per initial metal atom, may have released as much as 10% of its available Ag-110 m inventory during irradiation. The HRTEM investigation focused on silver, palladium, and cadmium due to interest in silver transport mechanisms and possible correlation with palladium and silver previously found. Palladium, silver, and cadmium were found to co-exist in some of the SiC grain boundaries and triple junctions. This study confirmed palladium both at inter and intragranular sites. Phosphor was identified in SiC grain boundaries and triple points. - Highlights: • First high resolution electron microscopy fission product nano-structural locations of irradiated TRISO coated particles. • Pd observed inside SiC grains in proximity to planar defects e.g. stacking faults. • Ag co-exists with Pd and Cd only may suggest a Pd-assisted transport mechanism. • First finding of neutron transmutation product P, in SiC layer of TRISO coated particles. No direct link to Ag transport. • No significant Pd corrosion of SiC observed even at this high resolution images.

  5. Evaluation of umbilical cord mesenchymal stem cells labeling with superparamagnetic iron oxide nanoparticles coated with dextran and complexed with Poly-L-Lysine; Avaliacao da marcacao de celulas-tronco mesenquimais de cordao umbilical com nanoparticulas superparamagneticas de oxido de ferro recobertas com Dextran e complexadas a Poli-L-Lisina

    Energy Technology Data Exchange (ETDEWEB)

    Sibov, Tatiana Tais; Mamani, Javier Bustamante; Pavon, Lorena Favaro; Cardenas, Walter Humberto; Gamarra, Lionel Fernel, E-mail: tatianats@einstein.br [Instituto do Cerebro - InCe, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Miyaki, Liza Aya Mabuchi [Faculdade de Enfermagem, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Marti, Luciana Cavalheiro; Sardinha, Luiz Roberto [Centro de Pesquisa Experimental, Hospital Israelita Albert Einstein - HIAE, Sao Paulo, SP (Brazil); Oliveira, Daniela Mara de [Universidade de Brasilia - UnB, Brasilia, DF (Brazil)

    2012-04-15

    Objective: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. Methods: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37 deg C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxyfluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. Results: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/ dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/polyL-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide

  6. Carbon in palladium catalysts: A metastable carbide

    International Nuclear Information System (INIS)

    Seriani, Nicola; Mittendorfer, Florian; Kresse, Georg

    2010-01-01

    The catalytic activity of palladium towards selective hydrogenation of hydrocarbons depends on the partial pressure of hydrogen. It has been suggested that the reaction proceeds selectively towards partial hydrogenation only when a carbon-rich film is present at the metal surface. On the basis of first-principles simulations, we show that carbon can dissolve into the metal because graphite formation is delayed by the large critical nucleus necessary for graphite nucleation. A bulk carbide Pd 6 C with a hexagonal 6-layer fcc-like supercell forms. The structure is characterized by core level shifts of 0.66-0.70 eV in the core states of Pd, in agreement with experimental x-ray photoemission spectra. Moreover, this phase traps bulk-dissolved hydrogen, suppressing the total hydrogenation reaction channel and fostering partial hydrogenation. (author)

  7. Nickel foam/polyaniline-based carbon/palladium composite electrodes for hydrogen storage

    International Nuclear Information System (INIS)

    Skowronski, Jan M.; Urbaniak, Jan

    2008-01-01

    The sandwich-like nickel/palladium/carbon electrodes exhibiting ability to absorb hydrogen in alkaline solution are presented. Electrodes were prepared by successive deposition of palladium and polyaniline layers on nickel foam substrate followed by heat treatment to give Ni/Pd/C electrode. It was shown that thermal conversion of polymer into carbon layer and subsequent thermal activation of carbon component bring about the modification of the mechanism of reversible hydrogen sorption. It was proven that carbon layer, interacting with Pd catalyst, plays a considerable role in the process of hydrogen storage. In the other series of experiments, Pd particles were dispersed electrochemically on carbon coating leading to Ni/C/Pd system. The adding of the next carbon layer resulted in Ni/C/Pd/C electrodes. Electrochemical properties of the electrodes depend on both the sequence of Pd and C layers and the preparation/activation of carbon coating. Electrochemical behavior of sandwich-like electrodes in the reaction of hydrogen sorption/desorption was characterized in 6 M KOH using the cyclic voltammetry method and the results obtained were compared to those for Ni/Pd electrode. The anodic desorption of hydrogen from electrodes free and containing carbon layer was considered after the potentiodynamic as well as potentiostatic sorption of hydrogen. The influence of the sorption potential and the time of rest of electrodes at a cut-off circuit on the kinetics of hydrogen recovery were examined. The results obtained for Ni/Pd/C electrodes indicate that the displacement of hydrogen between C and Pd phase takes place during the rest at a cut-off circuit. Electrodes containing carbon layer require longer time for hydrogen electrosorption. On the other hand, the presence of carbon layer in electrodes is advantageous because a considerable longer retention of hydrogen is possible, as compared to Pd/Ni electrode. Hydrogen stored in sandwich-like electrodes can instantly be

  8. Enhanced catalysis and enantioselective resolution of racemic naproxen methyl ester by lipase encapsulated within iron oxide nanoparticles coated with calix[8]arene valeric acid complexes.

    Science.gov (United States)

    Sayin, Serkan; Akoz, Enise; Yilmaz, Mustafa

    2014-09-14

    In this study, two types of nanoparticles have been used as additives for the encapsulation of Candida rugosa lipase via the sol-gel method. In one case, the nanoparticles were covalently linked with a new synthesized calix[8]arene octa valeric acid derivative (C[8]-C4-COOH) to produce new calix[8]arene-adorned magnetite nanoparticles (NP-C[8]-C4-COOH), and then NP-C[8]-C4-COOH was used as an additive in the sol-gel encapsulation process. In the other case, iron oxide nanoparticles were directly added into the sol-gel encapsulation process in order to interact electrostatically with both C[8]-C4-COOH and Candida rugosa lipase. The catalytic activities and enantioselectivities of two novel encapsulated lipases (Enc-NP-C[8]-C4-COOH and Enc-C[8]-C4-COOH@Fe3O4) in the hydrolysis reaction of racemic naproxen methyl ester were evaluated. The results showed that the activity and enantioselectivity of the lipase were improved when the lipase was encapsulated in the presence of calixarene-based additives. Indeed, the encapsulated lipases have an excellent rate of enantioselectivity, with E = 371 and 265, respectively, as compared to the free enzyme (E = 137). The lipases encapsulated with C[8]-C4-COOH and iron oxide nanoparticles (Enc-C[8]-C4-COOH@Fe3O4) retained more than 86% of their initial activities after 5 repeated uses and 92% with NP-C[8]-C4-COOH.

  9. Recovery of Elemental Palladium by Shewanella putrefaciens

    Science.gov (United States)

    Akasaka, S.; Xia, X.; Sawada, K.; Enokida, Y.; Yamamoto, I.; Ohnuki, T.

    2006-12-01

    Microbial reduction of metals plays an important role in environmental behavior and provides a technique for the recovery of metals from industrial wastewater. Recently, demand for platinum group metals (PGMs) increases by their catalytic properties. The extreme rarity of PGMs have led to a growing interest in their recovery. Palladium, one of PGMs, has different oxidation states of Pd(II) and Pd(0). The oxidized form of Pd(II) is soluble, while the reduced form of Pd(0) is insoluble. In this study, microbial reduction of palladium by Fe(III)- reducing bacterium, Shewanella putrefaceins was conducted. This bacterium is known to be capable of reducing metals, such as Mn(IV), U(VI), or Tc(VII) with organic C or H2 as an electron donor. In order to investigate the potential of S. putrefaciens to reduce Pd(II) in solution, resting cells or heat-killed cells were suspended under anaerobic conditions with lactate or H2 as an electron donor. The cells of S. putrefaciens (NBRC3908) were grown in aerobic medium, harvested by centrifugation, and then washed with 25 mmol/dm3 HEPES and 100 mmol/dm3 NaCl (HEPES-NaCl) solution (pH 7.0). The heat-killed cells were autoclaved for 20 min at 121 degrees C. The cell suspension (21.5 mg in dry weight) was resuspended in the HEPES-NaCl solution which contained 1.0 mmol/dm3 Na2PdCl4 (Wako Pure chemical Industries, Ltd). The suspensions were bubbled with N2 for 15 min before 10 mmol/dm3 lactate or 4.8 v/v% H2 was added. The suspensions were then incubated at 30 degrees C. Redox potential (Eh) and pH of the solutions were measured in an inert glove box with Ar gas. Concentration of Pd(II) was measured by Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Deposited Pd and cells were analyzed by X-ray powder diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy-Dispersive Spectroscopy (EDS). Approximately 86% of Pd(II) of the initial concentration was removed from solution by the resting cells within 24 h when

  10. Colloidal stability, surface characterisation and intracellular accumulation of Rhodium(II) citrate coated superparamagnetic iron oxide nanoparticles in breast tumour: a promising platform for cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Silva Nunes, Eloiza da [Universidade Federal de Goias, Campus Samambaia, Instituto de Quimica (Brazil); Lemos Brettas Carneiro, Marcella; Guirelli Simoes de Oliveira, Ricardo; Nair Bao, Sonia [Universidade de Brasilia (UnB), Instituto de Ciencias Biologicas (Brazil); Ribeiro de Souza, Aparecido, E-mail: ardsouza@quimica.ufg.br [Universidade Federal de Goias, Campus Samambaia, Instituto de Quimica (Brazil)

    2013-06-15

    The colloidal stability of a rhodium(II) citrate, Rh{sub 2}(H{sub 2}cit){sub 4}, coating on the surface of maghemite ({gamma}-Fe{sub 2}O{sub 3}) nanoparticles was studied and compared in different dispersion media. The adsorption of Rh{sub 2}(H{sub 2}cit){sub 4} at the water-maghemite interface was evaluated as a function of pH and complex concentration. A slight pH-dependent adsorption of the complex was observed with a maximum at pH 3. The colloidal stability of the functionalised nanoparticles with different amounts of Rh{sub 2}(H{sub 2}cit){sub 4} as a function of pH was evaluated using dynamic light scattering measurements. The particles have a mean magnetic core size of 5.6 nm and the hydrodynamic diameters are approximately 60 nm, which remained unchanged in the pH range in which the samples were a stable sol. The tolerance to different dispersion media, which were deionised water, saline, phosphate-buffered saline (PBS), foetal bovine serum (FBS) and NaCl solutions with different concentrations, was investigated. At moderate ionic strength, the colloidal stability of the dispersions was similar in saline and in PBS compared to the stability of dispersions diluted in water. Moreover, the intracellular accumulation of nanoparticles in 4T1 breast tumour was examined by ultrastructural analysis performed by transmission electron microscopy. The rhodium(II) citrate-coated nanoparticles were found mostly in the cytoplasm and nucleus. Thus, we suggest that these SPIO nanoparticles functionalized with Rh{sub 2}(H{sub 2}Cit){sub 4} can be potential tools for anticancer therapy.

  11. Sputtering induced surface composition changes in copper-palladium alloys

    International Nuclear Information System (INIS)

    Sundararaman, M.; Sharma, S.K.; Kumar, L.; Krishnan, R.

    1981-01-01

    It has been observed that, in general, surface composition is different from bulk composition in multicomponent materials as a result of ion beam sputtering. This compositional difference arises from factors like preferential sputtering, radiation induced concentration gradients and the knock-in effect. In the present work, changes in the surface composition of copper-palladium alloys, brought about by argon ion sputtering, have been studied using Auger electron spectroscopy. Argon ion energy has been varied from 500 eV to 5 keV. Enrichment of palladium has been observed in the sputter-altered layer. The palladium enrichment at the surface has been found to be higher for 500 eV argon ion sputtering compared with argon ion sputtering at higher energies. Above 500 eV, the surface composition has been observed to remain the same irrespective of the sputter ion energy for each alloy composition. The bulk composition ratio of palladium to copper has been found to be linearly related to the sputter altered surface composition ratio of palladium to copper. These results are discussed on the basis of recent theories of alloy sputtering. (orig.)

  12. Ageing of palladium tritide: mechanical characterization, helium state and modelling

    International Nuclear Information System (INIS)

    Segard, M.

    2010-01-01

    Palladium is commonly used for the storage of tritium (the hydrogen radioactive isotope), since it forms a low-equilibrium-pressure and reversible tritide. Tritium decay into helium-3 is responsible for the ageing of the tritide, leading to the apparition of helium-3 bubbles for instance. Both experimental and theoretical aspects of this phenomenon are studied here.Previous works on ageing modelling led to two main models, dealing with:- Helium-3 bubbles nucleation (using a cellular automaton), - Bubbles growth (using continuum mechanics).These models were quite efficient, but their use was limited by the lack of input data and fitting experimental parameters.To get through these limitations, this work has consisted in studying the most relevant experimental data to improve the modelling of the palladium tritide ageing.The first part of this work was focused on the assessment of the mechanical properties of the palladium tritide (yield strength, ultimate strength, mechanical behaviour). They were deduced from the in situ tensile tests performed on palladium hydride and deuteride. In the second part, ageing characterization was undertaken, mainly focusing on: - Bubbles observations in palladium tritide using transmission electron microscopy, - Internal bubble pressure measurements using nuclear magnetic resonance, - Macroscopic swelling measurements using pycno-metry.The present work has led to significant progress in ageing understanding and has brought very valuable improvements to the modelling of such a phenomenon. (author) [fr

  13. Atomistic simulation of helium bubble nucleation in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Wang Liang [Department of Applied Physics, Hunan University, Changsha 410082 (China); Hu, Wangyu [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: wangyuhu2001cn@yahoo.com.cn; Xiao Shifang [Department of Applied Physics, Hunan University, Changsha 410082 (China)], E-mail: sfxiao@yahoo.com.cn; Yang Jianyu [Department of Maths and Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Deng Huiqiu [Department of Applied Physics, Hunan University, Changsha 410082 (China)

    2009-09-15

    A palladium crystal has been constructed with 11808 atoms. 55 helium atoms occupied the octahedral position of palladium crystal are introduced and retained in a spherical region. Molecular dynamic simulations are performed in a constant temperature and constant volume ensemble (NVT) with temperature controlled by Nose-Hoover thermostat. The interactions between palladium atoms are described with modified analytic embedded atom method (MAEAM), the interactions between palladium atom and helium atom are in the form of Morse potential, and the interactions between helium atoms are in the form of L-J potential function. With the analysis of the radial distribution function (RDF) and microstructure, it reveals that some of helium atoms form a series of clusters with different size, and the nucleation core is random at low temperature, and which is the embryo of helium bubble. Increasing temperature can accelerate the process of bubble nucleation, and the clusters will aggregate and coalesce into a bigger one in which there are no palladium atoms, and it is considered as a helium bubble.

  14. Metal allergen of the 21st century--a review on exposure, epidemiology and clinical manifestations of palladium allergy

    DEFF Research Database (Denmark)

    Faurschou, Annesofie; Menné, Torkil; Johansen, Jeanne D

    2011-01-01

    Consumers are mainly exposed to palladium from jewellery and dental restorations. Palladium contact allergy is nearly always seen together with nickel allergy, as palladium and nickel tend to cross-react. We aimed to analyse the available palladium patch test data and case reports to determine...

  15. Superparamagnetic iron oxides for MRI

    International Nuclear Information System (INIS)

    Weissleder, R.; Reimer, P.

    1993-01-01

    Pharmaceutical iron oxide preparations have been used as MRI contrast agents for a variety of purposes. These agents predominantly decrease T2 relaxation times and therefore cause a decrease in signal intensity of tissues that contain the agent. After intravenous administration, dextran-coated iron oxides typically accumulate in phagocytic cells in liver and spleen. Clinical trials have shown that iron oxide increases lesion/liver and lesion/spleen contrast, that more lesions can be depicted than on plain MRI or CT, and that the size threshold for lesion detection decreases. Decreased uptake of iron oxides in liver has been observed in hepatitis and cirrhosis, potentially allowing the assessment of organ function. More recently a variety of novel, target-specific monocrystalline iron oxides compounds have been used for receptor and immunospecific images. Future development of targeted MRI contrast agents is critical for organ- or tissue-specific quantitative and functional MRI. (orig.)

  16. Superparamagnetic iron oxides for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Weissleder, R [MGH-NMR Center, Dept. of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Reimer, P [MGH-NMR Center, Dept. of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); [Inst. fuer Klinische Radiologie, Zentrale Roentgendiagnostik, Westfaelische-Wilhelms-Univ., Muenster (Germany)

    1993-06-01

    Pharmaceutical iron oxide preparations have been used as MRI contrast agents for a variety of purposes. These agents predominantly decrease T2 relaxation times and therefore cause a decrease in signal intensity of tissues that contain the agent. After intravenous administration, dextran-coated iron oxides typically accumulate in phagocytic cells in liver and spleen. Clinical trials have shown that iron oxide increases lesion/liver and lesion/spleen contrast, that more lesions can be depicted than on plain MRI or CT, and that the size threshold for lesion detection decreases. Decreased uptake of iron oxides in liver has been observed in hepatitis and cirrhosis, potentially allowing the assessment of organ function. More recently a variety of novel, target-specific monocrystalline iron oxides compounds have been used for receptor and immunospecific images. Future development of targeted MRI contrast agents is critical for organ- or tissue-specific quantitative and functional MRI. (orig.)

  17. Cytotoxicity of Nanoliposomal Cisplatin Coated with Synthesized ...

    African Journals Online (AJOL)

    coating agent for the preparation of liposomal nanodrug formulation by reverse phase evaporation method. ..... Induced Ototoxicity: Effects, Mechanisms and Protection. Strategies. ... Kumar K, Jaikumar V. Gold and iron oxide nanoparticle-.

  18. Influences of the iron ion (Fe{sup 3+})-doping on structural and optical properties of nanocrystalline TiO{sub 2} thin films prepared by sol-gel spin coating

    Energy Technology Data Exchange (ETDEWEB)

    Ben Naceur, J. [Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Mechiakh, R., E-mail: raouf_mechiakh@yahoo.fr [Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia); Departement de Medecine, Faculte de Medecine, Universite Hadj Lakhdar, Batna (Algeria); Bousbih, F.; Chtourou, R. [Laboratoire de Photovoltaique de Semi-conducteurs et de Nanostructures, Centre de Recherche des Sciences et Technologies de l' Energie, BP.95, Hammam-Lif 2050 (Tunisia)

    2011-10-01

    Titanium dioxide (TiO{sub 2}) thin films doping of various iron ion (Fe{sup 3+}) concentrations were deposited on silicon (Si) (100) and quartz substrates by sol-gel Spin Coating technique followed by a thermal treatment at 600 deg. C. The structure, surface morphology and optical properties, as a function of the doping, have been studied by X-ray diffractometer (XRD), Raman, ultraviolet-visible (UV-vis) and Spectroscopic Ellipsometry (SE). XRD and Raman analyzes of our thin films show that the crystalline phase of TiO{sub 2} thin films comprised only the anatase TiO{sub 2}, but the crystallinity decreased when the Fe{sup 3+} content increased from 0% to 20%. During the Fe{sup 3+} addition to 20%, the phase of TiO{sub 2} thin film still maintained the amorphous state. The grain size calculated from XRD patterns varies from 29.3 to 22.6 nm. The complex index and the optical band gap (E{sub g}) of the films were determined by the spectroscopic ellipsometry analysis. We have found that the optical band gap decreased with an increasing Fe{sup 3+} content.

  19. Surface characteristics of the iron-oxyhydroxide layer formed during brick coatings by ESEM/EDS, {sup 23}Na and {sup 1}H MAS NMR, and ToF-SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Allahdin, O. [Chaire Unesco « Sur la gestion de l' eau », Laboratoire Hydrosciences Lavoisier, Université de Bangui, Faculté des Sciences, B.P. 908 (Central African Republic); Wartel, M. [Université Lille1, Laboratoire LASIR (UMR CNRS 8516), Equipe Physico-chimie de l' Environnement, Bât. C8, 2" è" m" e étage, 59655 Villeneuve d' Ascq cedex (France); Mabingui, J. [Chaire Unesco « Sur la gestion de l' eau », Laboratoire Hydrosciences Lavoisier, Université de Bangui, Faculté des Sciences, B.P. 908 (Central African Republic); Revel, B. [Université Lille1, Service RMN, Bât. C4, 59655 Villeneuve d' Ascq cedex (France); Nuns, N. [Université Lille1, Institut Chevreul, 59655 Villeneuve d' Ascq cedex (France); Boughriet, A., E-mail: abdel.boughriet@univ-lille1.fr [Université Lille1, Laboratoire LASIR (UMR CNRS 8516), Equipe Physico-chimie de l' Environnement, Bât. C8, 2" è" m" e étage, 59655 Villeneuve d' Ascq cedex (France)

    2015-09-01

    Brick made locally by craftsmen in Bangui (Central African Republic) was modified first by HCl activation and second by iron-oxyhydroxide impregnation through the precipitation of ferric ions by NaOH at various fixed pH values (ranging from 3 to 13). The elemental analyses of synthesized compounds were performed using ICP-AES, and their surface chemistry/properties were investigated by environmental scanning electron microscopy (ESEM/EDS), {sup 1}H and {sup 23}Na MAS NMR spectroscopy, and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The evidence of different {sup 23}Na chemical environments and the coexistence of Si and Al bound to ferrihydrite were made. The surface properties of this material which was found to be dependent upon synthesis pH, contributed to enhance metal uptake from water. - Highlights: • HCl-activated brick was coated at different Fe(III)-precipitation pH. • Surface properties were determined by ESEM, NMR and ToF-SIMS. • Al- and Si-bearing ferrihydrite and different Na environments were detected. • The pH used for modified-brick synthesis influenced metal uptake from water.

  20. Superconductivity and the structural phase transitions in palladium hydride and palladium deuteride

    International Nuclear Information System (INIS)

    Standley, R.W.

    1980-01-01

    The results of two experimental studies of the superconducting transition temperature, T/sub c/, of palladium hydride, PdH/sub x/, and palladium deuteride, PdD/sub x/, are presented. In the first study, the superconducting transition temperature of PdH/sub x/(D/sub x/) is studied as a function of H(D) concentration, x, in the temperature range from 0.2 K to 4K. The data join smoothly with those reported previously by Miller and Satterthwaite at higher temperatures, and the composite data are described by the empirical relation T/sub c/ = 150.8 (x-x/sub o/) 2 244 , where x/sub o/ = 0.715 for hydride samples and 0.668 for deuteride samples. The results, when compared with the theoretical predictions of Klein and Papaconstantopoulos, et al., raise questions about the validity of their explanation of the reverse isotope effect, which is based solely on a difference in force constants. In the second study, the effect of the order-disorder structural transition associated with the 50 K anomaly on the superconductivity of PdH/sub x/(D/sub x/) is investigated. Samples were quenched to low temperatures in the disordered state, and their transition temperatures measured. The samples were then annealed just below the anomaly temperature, and the ordering process followed by monitoring the change in sample resistance. The transition temperatures in the ordered state were then measured

  1. Superlattices of platinum and palladium nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    MARTIN,JAMES E.; WILCOXON,JESS P.; ODINEK,JUDY G.; PROVENCIO,PAULA P.

    2000-04-06

    The authors have used a nonionic inverse micelle synthesis technique to form nanoclusters of platinum and palladium. These nanoclusters can be rendered hydrophobic or hydrophilic by the appropriate choice of capping ligand. Unlike Au nanoclusters, Pt nanoclusters show great stability with thiol ligands in aqueous media. Alkane thiols, with alkane chains ranging from C{sub 6} to C{sub 18} were used as hydrophobic ligands, and with some of these they were able to form 2-D and/or 3-D superlattices of Pt nanoclusters as small as 2.7 nm in diameter. Image processing techniques were developed to reliably extract from transmission electron micrographs (TEMs) the particle size distribution, and information about the superlattice domains and their boundaries. The latter permits one to compute the intradomain vector pair correlation function of the particle centers, from which they can accurately determine the lattice spacing and the coherent domain size. From these data the gap between the particles in the coherent domains can be determined as a function of the thiol chain length. It is found that as the thiol chain length increases, the gaps between particles within superlattice domains increases, but more slowly than one might expect, possibly indicating thiol chain interdigitation.

  2. Palladium configuration dependence of hydrogen detection sensitivity based on graphene FET for breath analysis

    Science.gov (United States)

    Sakamoto, Yuri; Uemura, Kohei; Ikuta, Takashi; Maehashi, Kenzo

    2018-04-01

    We have succeeded in fabricating a hydrogen gas sensor based on palladium-modified graphene field-effect transistors (FETs). The negative-voltage shift in the transfer characteristics was observed with exposure to hydrogen gas, which was explained by the change in work function. The hydrogen concentration dependence of the voltage shift was investigated using graphene FETs with palladium deposited by three different evaporation processes. The results indicate that the hydrogen detection sensitivity of the palladium-modified graphene FETs is strongly dependent on the palladium configuration. Therefore, the palladium-modified graphene FET is a candidate for breath analysis.

  3. Wear mechanisms of coated hardmetals

    International Nuclear Information System (INIS)

    Richter, V.

    2001-01-01

    In the paper several aspects of the wear mechanisms of coated hardmetals, ceramics and super-hard materials (CBN) in machining cast iron are discussed, with particular attention being given to high-speed machining of different cast iron grades. The influence of machining parameters, microstructure, composition and mechanical and chemical properties of the cutting tool and the work-piece material on wear are considered. (author)

  4. Microwave-assisted synthesis of palladium nanocubes and nanobars

    International Nuclear Information System (INIS)

    Yu, Yanchun; Zhao, Yanxi; Huang, Tao; Liu, Hanfan

    2010-01-01

    Microwave was employed in the shape-controlled synthesis of palladium nanoparticles. Palladium nanocubes and nanobars with a mean size of about 23.8 nm were readily synthesized with H 2 PdCl 4 as a precursor, tetraethylene glycol (TEG) as both a solvent and a reducing agent in the presence of PVP and CTAB in 80 s under microwave irradiation. The structures of the as-prepared palladium nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and ultraviolet-visible (UV-vis) absorption spectroscopy. The formation of PdBr 4 2- due to the coordination replacement of the ligand Cl - ions in PdCl 4 2- ions by Br - ions in the presence of bromide was responsible for the synthesis of Pd nanocubes and nanobars. In addition, a milder reducing power, a higher viscosity and a stronger affinity of TEG were beneficial to the larger sizes of Pd nanocubes and nanobars.

  5. The solubility of palladium(II) bis-dimethylglyoximate

    International Nuclear Information System (INIS)

    Maghzian, R.

    1978-01-01

    The solubility of palladium(II) bis-dimethylglyoximate in different solutions has been determined. Values obtained for the solubility of the palladium complex are tabulated. The solubility is the lowest in water, ammonium acetate and a 25% acetone-water mixture. It is highest in dilute HCl and acetone but precipitation from aqueous acetone should be satisfactory for most purposes if the acetone content of the solvent is roughly less than 50% by volume. The solubility in dilute HCl reflects the concern by previous workers for losses in precipitation from mineral acid. In general, however, the losses are unlikely to be significant unless the quantity of palladium to be precipitated and weighed is small. (T.G.)

  6. Biodegradable surfactant stabilized nanoscale zero-valent iron for in situ treatment of vinyl chloride and 1,2-dichloroethane

    International Nuclear Information System (INIS)

    Wei, Yu-Ting; Wu, Shian-chee; Yang, Shi-Wei; Che, Choi-Hong; Lien, Hsing-Lung; Huang, De-Huang

    2012-01-01

    Highlights: ► Biodegradable surfactant stabilized nanoscale zero-valent iron (NZVI) is tested. ► Vinyl chloride and 1,2-dichloroethane are remediated by NZVI in the field. ► Multiple functions of biodegradable surfactants are confirmed. ► Biodegradable surfactants stabilize NZVI and facilitate the bioremediation. ► NZVI creates reducing conditions beneficial to an anaerobic bioremediation. - Abstract: Nanoscale zero-valent iron (NZVI) stabilized with dispersants is a promising technology for the remediation of contaminated groundwater. In this study, we demonstrated the use of biodegradable surfactant stabilized NZVI slurry for successful treatment of vinyl chloride (VC) and 1,2-dichloroethane (1,2-DCA) in a contaminated site in Taiwan. The biodegradable surfactant stabilized NZVI was coated with palladium and synthesized on-site. From monitoring the iron concentration breakthrough and distribution, it was found that the stabilized NZVI is capable of transporting in the aquifer at the test plot (200 m 2 ). VC was effectively degraded by NZVI while the 1,2-DCA degradation was relatively sluggish during the 3-month field test. Nevertheless, as 1,2-DCA is known to resist abiotic reduction by NZVI, the observation of 1,2-DCA degradation and hydrocarbon production suggested a bioremediation took place. ORP and pH results revealed that a reducing condition was achieved at the testing area facilitating the biodegradation of chlorinated organic hydrocarbons. The bioremediation may be attributed to the production of hydrogen gas as electron donor from the corrosion of NZVI in the presence of water or the added biodegradable surfactant serving as the carbon source as well as electron donor to stimulate microbial growth.

  7. Field and laboratory investigations of inactivation of viruses (PRD1 and MS2) attached to iron oxide-coated quartz san

    Science.gov (United States)

    Ryan, Joseph N.; Harvey, Ronald W.; Metge, David W.; Elimelech, Menachem; Navigato, Theresa; Pieper, Ann P.

    2002-01-01

    Field and laboratory experiments were conducted to investigate inactivation of viruses attached to mineral surfaces. In a natural gradient transport field experiment, bacteriophage PRD1, radiolabeled with 32P, was injected into a ferric oxyhydroxide-coated sand aquifer with bromide and linear alkylbenzene sulfonates. In a zone of the aquifer contaminated by secondary sewage infiltration, small fractions of infective and 32P-labeled PRD1 broke through with the bromide tracer, followed by the slow release of 84% of the 32P activity and only 0.011% of the infective PRD1. In the laboratory experiments, the inactivation of PRD1, labeled with 35S (protein capsid), and MS2, dual radiolabeled with 35S (protein capsid) and 32P (nucleic acid), was monitored in the presence of groundwater and sediment from the contaminated zone of the field site. Release of infective viruses decreased at a much faster rate than release of the radiolabels, indicating that attached viruses were undergoing surface inactivation. Disparities between 32P and35S release suggest that the inactivated viruses were released in a disintegrated state. Comparison of estimated solution and surface inactivation rates indicates solution inactivation is ∼3 times as fast as surface inactivation. The actual rate of surface inactivation may be substantially underestimated owing to slow release of inactivated viruses.

  8. Efficient one-pot sonochemical synthesis of thickness-controlled silica-coated superparamagnetic iron oxide (Fe3O4/SiO2) nanospheres

    Science.gov (United States)

    Abbas, Mohamed; Abdel-Hamed, M. O.; Chen, Jiangang

    2017-12-01

    A facile and eco-friendly efficient sonochemical approach was designed for the synthesis of highly crystalline Fe3O4 and Fe3O4/SiO2 core/shell nanospheres in single reaction. The generated physical properties (shock waves, microjets, and turbulent flows) from ultrasonication as a consequence of the collapse of microbubbles and polyvinylpyrrolidone (PVP) as a chemical linker were found to play a crucial role in the successful formation of the core/shell NPs within short time than the previously reported methods. Transmission electron microscopy revealed that a uniform SiO2 shell is successfully coated over Fe3O4 nanospheres, and the thickness of the silica shell could be easily controlled in the range from 5 to 15 nm by adjusting the reaction parameters. X-ray diffraction data were employed to confirm the formation of highly crystalline and pure phase of a cubic inverse spinel structure for magnetite (Fe3O4) nanospheres. The magnetic properties of the as-synthesized Fe3O4 and Fe3O4/SiO2 core/shell nanospheres were measured at room temperature using vibrating sample magnetometer, and the results demonstrated a high magnetic moment values with superparamagnetic properties.

  9. Investigation of radiation-chemical behaviour of divalent palladium in perchloric acid solutions

    International Nuclear Information System (INIS)

    Vladimirova, M.V.; Kalinina, S.V.

    1988-01-01

    Gamma-radiolysis of divalent palladium in perchloric acid solutions is studied. Absorption spectra of intermediate palladium compounds formed in the irradiated solution are taken. The analysis of literature data as well as comparative analysis of the absorption spectra obtained under irradiation of palladium (2) perchloric acid solutions with absorption spectra of palladium chlorocomplexes allows to suppose that the mentioned compounds are chlorocomplexes of palladium (2) of different composition depending on HClO 4 concentration in the initial solution and absorbed radiation dose. Radiation-chemical reduction of palladium (2) up to metal is stated to take place in the whole studied range of initial concentrations of components of the system and dose rates. Kinetic dependences of metallic palladium formation are obtained. Values of radiation-chemical yields of metallic palladium formation depending on the initial concentrations of palladium (2) and perchloric acid are given. A mechanism of radiolytic reduction of palladium (2) in the investigated system is suggested based on the experimental data, and a theoretical value of the radiation-chemical yield of palladium (2) reduction being in a good agreement with experimentally found values is calculated

  10. Ceramic wash-coat for catalyst support

    Science.gov (United States)

    Kulkarni, Anand A.; Subramanian, Ramesh; Sabol, Stephen M.

    2012-08-14

    A wash-coat (16) for use as a support for an active catalyst species (18) and a catalytic combustor component (10) incorporating such wash-coat. The wash-coat is a solid solution of alumina or alumina-based material (Al.sub.2O.sub.3-0-3 wt % La.sub.2O.sub.3) and a further oxide exhibiting a coefficient of thermal expansion that is lower than that exhibited by alumina. The further oxide may be silicon dioxide (2-30 wt % SiO.sub.2), zirconia silicate (2-30 wt % ZrSiO.sub.4), neodymium oxide (0-4 wt %), titania (Al.sub.2O.sub.3-3-40% TiO.sub.2) or alumina-based magnesium aluminate spinel (Al.sub.2O.sub.3-25 wt % MgO) in various embodiments. The active catalyst species may be palladium and a second metal in a concentration of 10-50% of the concentration of the palladium.

  11. Hydrogen Production via Steam Reforming of Ethyl Alcohol over Palladium/Indium Oxide Catalyst

    Directory of Open Access Journals (Sweden)

    Tetsuo Umegaki

    2009-01-01

    Full Text Available We report the synergetic effect between palladium and indium oxide on hydrogen production in the steam reforming reaction of ethyl alcohol. The palladium/indium oxide catalyst shows higher hydrogen production rate than indium oxide and palladium. Palladium/indium oxide affords ketonization of ethyl alcohol with negligible by-product carbon monoxide, while indium oxide mainly affords dehydration of ethyl alcohol, and palladium affords decomposition of ethyl alcohol with large amount of by-product carbon monoxide. The catalytic feature of palladium/indium oxide can be ascribed to the formation of palladium-indium intermetallic component during the reaction as confirmed by X-ray diffraction and X-ray photoelectron spectroscopic measurements.

  12. Morphological Study Of Palladium Thin Films Deposited By Sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Salcedo, K L; Rodriguez, C A [Grupo Plasma Laser y Aplicaciones, Ingenieria Fisica, Universidad Tecnologica de Pereira (Colombia); Perez, F A [WNANO, West Virginia University (United States); Riascos, H [Grupo Plasma Laser y Aplicaciones, Departamento de Fisica, Universidad Tecnologica de Pereira (Colombia)

    2011-01-01

    This paper presents a morphological analysis of thin films of palladium (Pd) deposited on a substrate of sapphire (Al{sub 2}O{sub 3}) at a constant pressure of 3.5 mbar at different substrate temperatures (473 K, 523 K and 573 K). The films were morphologically characterized by means of an Atomic Force Microscopy (AFM); finding a relation between the roughness and the temperature. A morphological analysis of the samples through AFM was carried out and the roughness was measured by simulating the X-ray reflectivity curve using GenX software. A direct relation between the experimental and simulation data of the Palladium thin films was found.

  13. Morphological Study Of Palladium Thin Films Deposited By Sputtering

    International Nuclear Information System (INIS)

    Salcedo, K L; Rodriguez, C A; Perez, F A; Riascos, H

    2011-01-01

    This paper presents a morphological analysis of thin films of palladium (Pd) deposited on a substrate of sapphire (Al 2 O 3 ) at a constant pressure of 3.5 mbar at different substrate temperatures (473 K, 523 K and 573 K). The films were morphologically characterized by means of an Atomic Force Microscopy (AFM); finding a relation between the roughness and the temperature. A morphological analysis of the samples through AFM was carried out and the roughness was measured by simulating the X-ray reflectivity curve using GenX software. A direct relation between the experimental and simulation data of the Palladium thin films was found.

  14. Chemical recovery of palladium-103 from irradiated silver target

    International Nuclear Information System (INIS)

    Lapshina, E.V.; Kokhanyuk, V.M.; Zhuikov, B.L.; Myasoedova, G.V.; Zakhartchenko, E.A.; Phillips, D.R.; Jamriska, D.J.

    2003-01-01

    The goal of this work is to develop an extraction method of no-carrier-added palladium-103 from silver. Metallic silver targets may be irradiated by protons with energy of 60-200 MeV or more to generate palladium-103 simultaneously with other radioactive isotopes of rhodium, ruthenium, technetium, palladium and silver. According to the dependence experimental production yield of Pd-103 and isotopes of other elements in thick silver target vs. Proton energy the most suitable energy for maximum yield of Pd-103 and minimum yield of other elements is from about 100 to about 140 MeV. Activity of radionuclides produced in silver target depends from many factors (target thickness, irradiation time, etc.). Two methods of Pd-103 recovering from irradiated silver target are considered in this work: (1) Silver target is dissolved in nitric acid followed by silver precipitation in the form of silver chloride by addition of HCl. The solution containing Pd, Rh and other radionuclides is passed through the layer of fibrous sorbent POLYORGS-15n. Then the sorbent is washed and Pd is desorbed by hot 12 M hydrochloric acid; (2) Silver target is dissolved in nitric acid followed by passing of the obtained solution (2 M HNO 3 ) through a disk set of complex forming sorbent POLYORGS-33n. Under these conditions palladium is sorbed by the sorbent while silver, rhodium, ruthenium and technetium are passed through the sorbent. Then the sorbent is washed with 2M nitric acid, and Pd is desorbed by 12 M hydrochloric acid. Extraction of palladium is occurred during the formation of palladium complex with a chelate sorbent specific to palladium in acidic solutions. Such a sorbent makes possible separation of palladium from accompanying radionuclides such as rhodium, ruthenium and technetium. The polymeric complex-forming sorbent of fibrous structure with the groups of 3(5)-methylpyrazole (POLYORGS-15) is used. The distinctive feature of the sorbents in the form of fibrous 'filled' material is

  15. In vivo tumor targeting and imaging with anti-vascular endothelial growth factor antibody-conjugated dextran-coated iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsieh WJ

    2012-06-01

    Full Text Available Wan-Ju Hsieh,1 Chan-Jung Liang,1 Jen-Jie Chieh,4 Shu-Huei Wang,1 I-Rue Lai,1 Jyh-Horng Chen,2 Fu-Hsiung Chang,3 Wei-Kung Tseng,4–6 Shieh-Yueh Yang,4 Chau-Chung Wu,7 Yuh-Lien Chen11Institute of Anatomy and Cell Biology, College of Medicine, 2Department of Electrical Engineering, 3Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei, Taiwan; 4Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei, Taiwan; 5Division of Cardiology, Department of Internal Medicine, E-Da Hospital, Taipei, Taiwan; 6Department of Medical Imaging and Radiological Sciences, I-Shou University, Taipei, Taiwan; 7Department of Internal Medicine and Primary Care Medicine, National Taiwan University Hospital, Taipei, TaiwanBackground: Active targeting by specific antibodies combined with nanoparticles is a promising technology for cancer imaging and detection by magnetic resonance imaging (MRI. The aim of the present study is to investigate whether the systemic delivery of antivascular endothelial growth factor antibodies conjugating to the surface of functionalized supermagnetic iron oxide nanoparticles (anti-VEGF-NPs led to target-specific accumulation in the tumor.Methods: The VEGF expression in human colon cancer and in Balb/c mice bearing colon cancers was examined by immunohistochemistry. The distribution of these anti-VEGF-NPs particles or NPs particles were evaluated by MRI at days 1, 2, or 9 after the injection into the jugular vein of Balb/c mice bearing colon cancers. Tumor and normal tissues (liver, spleen, lung, and kidney were collected and were examined by Prussian blue staining to determine the presence and distribution of NPs in the tissue sections.Results: VEGF is highly expressed in human and mouse colon cancer tissues. MRI showed significant changes in the T*2 signal and T2 relaxation in the anti-VEGF-NP- injected-mice, but not in mice injected with NP alone. Examination of paraffin

  16. FY05 HPCRM Annual Report: High-Performance Corrosion-Resistant Iron-Based Amorphous Metal Coatings Evaluation of Corrosion Resistance FY05 HPCRM Annual Report No. Rev. 1DOE-DARPA Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    Farmer, J C; Haslam, J J; Day, S D

    2007-01-01

    New corrosion-resistant, iron-based amorphous metals have been identified from published data or developed through combinatorial synthesis, and tested to determine their relative corrosion resistance. Many of these materials can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in some very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Two Fe-based amorphous metal formulations have been found that appear to have corrosion resistance comparable to, or better than that of Ni-based Alloy C-22, based on breakdown potential and corrosion rate. Both Cr and Mo provide corrosion resistance, B enables glass formation, and Y lowers critical cooling rate (CCR). SAM1651 has yttrium added, and has a nominal critical cooling rate of only 80 Kelvin per second, while SAM2X7 (similar to SAM2X5) has no yttrium, and a relatively high critical cooling rate of 610 Kelvin per second. Both amorphous metal formulations have strengths and weaknesses. SAM1651 (yttrium added) has a low critical cooling rate (CCR), which enables it to be rendered as a completely amorphous thermal spray coating. Unfortunately, it is relatively difficult to atomize, with powders being irregular in shape. This causes the powder to be difficult to pneumatically convey during thermal spray deposition. Gas atomized SAM1651 powder has required cryogenic milling to eliminate irregularities that make flow difficult. SAM2X5 (no yttrium) has a high critical cooling rate, which has caused problems associated with devitrification. SAM2X5 can be gas atomized to produce spherical powders of SAM2X5, which enable more facile thermal spray deposition. The reference material, nickel-based Alloy C-22, is an outstanding corrosion-resistant engineering material. Even so, crevice corrosion has been observed with C-22 in hot sodium chloride environments without buffer

  17. Microplasma synthesis on aluminum with additions of iron and nickel soluble complexes in electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rogov, A.B., E-mail: alex-lab@bk.ru [Nikolaev Institute of Inorganic Chemistry. 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation); Mironov, I.V.; Terleeva, O.P.; Slonova, A.I. [Nikolaev Institute of Inorganic Chemistry. 3, Acad. Lavrentiev Ave, Novosibirsk, 630090 (Russian Federation)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer Alkaline homogeneous electrolyte with transition metals complexes. Black-Right-Pointing-Pointer Coatings contain metallic iron, nickel and their oxides in alumina-silica matrix. Black-Right-Pointing-Pointer Effect of Fe/Ni ratio on coatings properties and process characteristics. - Abstract: The microplasma synthesis of coatings containing iron and nickel from homogeneous electrolytes has been studied. For stabilization of transition metals in solution, it is proposed to use chelation. It was found that the synthesis of coatings using alternating current leads to the formation of metallic iron and nickel particles in addition to oxide phases. The iron and nickel complexes concentrations ratio in the electrolyte correlates with the coatings composition. Obtained coatings have been studied by scanning electron microscopy with X-ray microanalyser and by X-ray diffraction with Cu and Mo radiation. The metal content in the coating was determined spectrophotometrically from the absorption of iron thiocyanate complexes and nickel dimethylglyoxime complex.

  18. Superparamagnetic iron oxide polyacrylic acid coated γ-Fe{sub 2}O{sub 3} nanoparticles do not affect kidney function but cause acute effect on the cardiovascular function in healthy mice

    Energy Technology Data Exchange (ETDEWEB)

    Iversen, Nina K., E-mail: nina.iversen@biology.au.dk [Zoophysiology, Department of Biological Sciences, Aarhus University (Denmark); Interdisciplinary Nanoscience Center, Aarhus University (Denmark); Frische, Sebastian [Department of Biomedicine, Aarhus University (Denmark); Thomsen, Karen [Interdisciplinary Nanoscience Center, Aarhus University (Denmark); Laustsen, Christoffer; Pedersen, Michael [MR Research Center, Aarhus University Hospital, Aarhus University (Denmark); Hansen, Pernille B.L.; Bie, Peter [Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark (Denmark); Fresnais, Jérome [Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques (PECSA) UMR 7195 CNRS-UPMC-ESPCI, 4 place Jussieu, 75252 Paris Cedex 05 (France); Berret, Jean-Francois [Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, 75205 Paris (France); Baatrup, Erik [Zoophysiology, Department of Biological Sciences, Aarhus University (Denmark); Interdisciplinary Nanoscience Center, Aarhus University (Denmark); Wang, Tobias [Zoophysiology, Department of Biological Sciences, Aarhus University (Denmark)

    2013-01-15

    This study describes the distribution of intravenously injected polyacrylic acid (PAA) coated γ-Fe{sub 2}O{sub 3} NPs (10 mg kg{sup −1}) at the organ, cellular and subcellular levels in healthy BALB/cJ mice and in parallel addresses the effects of NP injection on kidney function, blood pressure and vascular contractility. Magnetic resonance imaging (MRI) and transmission electron microscopy (TEM) showed accumulation of NPs in the liver within 1 h after intravenous infusion, accommodated by intracellular uptake in endothelial and Kupffer cells with subsequent intracellular uptake in renal cells, particularly the cytoplasm of the proximal tubule, in podocytes and mesangial cells. The renofunctional effects of NPs were evaluated by arterial acid–base status and measurements of glomerular filtration rate (GFR) after instrumentation with chronically indwelling catheters. Arterial pH was 7.46 ± 0.02 and 7.41 ± 0.02 in mice 0.5 h after injections of saline or NP, and did not change over the next 12 h. In addition, the injections of NP did not affect arterial PCO{sub 2} or [HCO{sub 3}{sup −}] either. Twenty-four and 96 h after NP injections, the GFR averaged 0.35 ± 0.04 and 0.35 ± 0.01 ml min{sup −1} g{sup −1}, respectively, values which were statistically comparable with controls (0.29 ± 0.02 and 0.33 ± 0.1 ml{sup –1} min{sup –1} 25 g{sup –1}). Mean arterial blood pressure (MAP) decreased 12–24 h after NP injections (111.1 ± 11.5 vs 123.0 ± 6.1 min{sup −1}) associated with a decreased contractility of small mesenteric arteries revealed by myography to characterize endothelial function. In conclusion, our study demonstrates that accumulation of superparamagnetic iron oxide nanoparticles does not affect kidney function in healthy mice but temporarily decreases blood pressure. -- Highlights: ► PAA coated γ-Fe{sub 2}O{sub 3} nanoparticles were injected intravenously into healthy mice. ► We examine the distribution and physiological effects of

  19. Hydrogen uptake causes molecular "avalanches" in palladium | Argonne

    Science.gov (United States)

    air cylinders for storing the gas. Palladium, a precious metal closely related to platinum, is that storage or purification, and this research gets us closer to making that a reality. In this study take up hydrogen from the environment. "The ultimate goal is hydrogen storage or purification, and

  20. XPS study of palladium sensitized nano porous silicon thin film

    Indian Academy of Sciences (India)

    Keywords. Porous silicon; passivation; palladium; oxidation; XPS. Abstract. Nano porous silicon (PS) was formed on -type monocrystalline silicon of 2–5 cm resistivity and (100) orientation by electrochemical anodization method using HF and ethanol as the electrolytes. High density of surface states, arising due to its ...

  1. Absorption of hydrogen by vanadium-palladium alloys

    International Nuclear Information System (INIS)

    Artman, D.; Lynch, J.F.; Flanagan, T.B.

    1976-01-01

    Pressure composition isotherms (273-373 K) have been determined for the absorption of hydrogen by a series of six palladium alloys (f.c.c) in the composition range from 1 to 8 at.% vanadium. At a given hydrogen content, the equilibrium hydrogen pressure progressively increases with vanadium content. Thermodynamic parameters for the absorption of hydrogen are reported at infinite dilution of hydrogen and for the formation of the nonstoichiometric hydride from the hydrogen-saturated alloy. The relative, partial molar enthalpy of solution of hydrogen at infinite dilution increases slightly with vanadium content. The presence of vanadium, which absorbs hydrogen itself in its normal b.c.c. structure, greatly inhibits the ability of palladium to absorb hydrogen. For example, the isobaric solubility of hydrogen (1 atm, 298K) decreases from H/Pd=0.7 (palladium) to 0.024 (V(6%)-Pd). The lattice expansion due to the presence of interstitial hydrogen has been determined by X-ray diffraction. From these data it can be concluded that the formation of two non-stoichiometric hydride phases does not occur at vanadium contents greater that 5 at.% (298 K). Electrical resistance has been measured as a function of the hydrogen content of the alloys. The electrical resistance increases more markedly with hydrogen content for these alloys than for any of the palladium alloys previously examined. (Auth.)

  2. Microscopic observations of palladium used for cold fusion

    International Nuclear Information System (INIS)

    Matsumoto, T.

    1991-01-01

    This paper examines the microscopic structures of palladium metals used for cold fusion experiments. Tiny spot defects suggesting cold fusion have been observed in grain boundaries as the Nattoh model predicts. The relationship between these defects and a series of neutron busts and an indirect loop of hydrogen chain reactions are discussed

  3. Palladium-based nanocatalysts for alcohol electrooxidation in alkaline media

    CSIR Research Space (South Africa)

    Modibedi, RM

    2013-01-01

    Full Text Available in the electrocatalytic oxidation of alcohols in alkaline media compared to platinum catalysts. Recent efforts have focused on the discovery of palladium-based electrocatalysts with little or no platinum for oxygen reduction reaction (ORR). This chapter is an overview...

  4. ERRATUM Study of microstructure in vanadium–palladium alloys by ...

    Indian Academy of Sciences (India)

    WINTEC

    ERRATUM. Study of microstructure in vanadium–palladium alloys by X-ray diffraction technique. J Ghosh, S K Chattopadhyay, A K Meikap, S K Chatterjee and P Chatterjee 2007 Bull. Mater. Sci. 30 447–454. In page 448, under §2.1 Warren–Averbach method, after equation (1), the sentence starting with “Then the domain ...

  5. Fractal analysis of electrolytically-deposited palladium hydride dendrites

    International Nuclear Information System (INIS)

    Bursill, L.A.; Julin, Peng; Xudong, Fan.

    1990-01-01

    The fractal scaling characteristics of the surface profile of electrolytically-deposited palladium hydride dendritic structures have been obtained using conventional and high resolution transmission electron microscopy. The results are in remarkable agreement with the modified diffusion-limited aggregation model. 19 refs., 3 tabs., 13 figs

  6. Palladium nanoparticles on InP for hydrogen detection

    Czech Academy of Sciences Publication Activity Database

    Černohorský, Ondřej; Žďánský, Karel; Zavadil, Jiří; Kacerovský, Pavel; Piksová, K.

    2011-01-01

    Roč. 6, č. 410 (2011), s. 4101-4104 ISSN 1931-7573 R&D Projects: GA AV ČR(CZ) KAN401220801; GA ČR GA102/09/1037 Institutional research plan: CEZ:AV0Z20670512 Keywords : palladium * indium phosphide Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.726, year: 2011

  7. Palladium-catalyzed allylation of tautomerizable heterocycles with alkynes.

    Science.gov (United States)

    Lu, Chuan-Jun; Chen, Dong-Kai; Chen, Hong; Wang, Hong; Jin, Hongwei; Huang, Xifu; Gao, Jianrong

    2017-07-21

    A method for the allylic amidation of tautomerizable heterocycles was developed by a palladium catalyzed allylation reaction with 100% atom economy. A series of structurally diverse N-allylic substituted heterocycles can be synthesized in good yields with high chemo-, regio-, and stereoselectivities under mild conditions.

  8. Supporting Information Palladium Complexes of a New Type of N ...

    Indian Academy of Sciences (India)

    Prasenjit Ghosh

    Palladium Complexes of a New Type of N-heterocyclic Carbene. Ligand Derived From a Tricyclic Triazolooxazine Framework. Manoj Kumar Gangwar, Alok Ch. Kalita and Prasenjit Ghosh*. Department of Chemistry,. Indian Institute of Technology Bombay, ... 2. Figure S1. 1. H NMR spectrum of the compound 1a in CDCl3.

  9. Electronic structure of palladium and its relation to uv spectroscopy

    DEFF Research Database (Denmark)

    Christensen, N.E.

    1976-01-01

    The electronic-energy-band structure of palladium has been calculated by means of the relativistic augmented-plane-wave method covering energies up to 30 eV above the Fermi level. The optical interband transitions producing structure in the dielectric function up to photon energies of 25 eV have ...

  10. Exposure to nickel and palladium from dental appliances

    NARCIS (Netherlands)

    Ventura Da Cruz Rodrigues Milheiro, A.M.

    2015-01-01

    The application of a dental material into the oral cavity is not free of biological implications, as deterioration of the material will undoubtedly occur. The adverse health effects of palladium and nickel are well known and their immunologic cross-reactivity is well established. The aim of this

  11. Mixed Hemi/Ad-Micelle Sodium Dodecyl Sulfate-Coated Magnetic Iron Oxide Nanoparticles for the Efficient Removal and Trace Determination of Rhodamine-B and Rhodamine-6G.

    Science.gov (United States)

    Ranjbari, Elias; Hadjmohammadi, Mohammad Reza; Kiekens, Filip; De Wael, Karolien

    2015-08-04

    Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g(-1), respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L(-1) of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL(-1). Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples.

  12. Growth and sedimentation of fine particles produced in aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Hatada, Motoyoshi; Jonah, C.D.

    1994-10-01

    It is known that palladium and palladium-silver fine particles were formed from deaerated aqueous solutions of palladium sulfate and palladium sulfate-silver sulfate induced by gamma-ray irradiation. Changes in particle size and with amount of particles in the solution with time during and after irradiation were studied using dynamic light scattering technique and UV spectrophotometer. The particles formed from palladium sulfate solution are found to be water-filled bulky particles of diameter of 200 nm, which grow by mutual coagulation even after irradiation was terminated. Average density depends on concentration of palladium ion in the solution and dose, and the lowest density was about 2 g/cm 3 for particles of 200 nm obtained from 0.06 mM solution by 2.4 kGy irradiation. The average density of the particles obtained from palladium sulfate-silver sulfate solutions was smaller than those obtained for the corresponding palladium sulfate solutions. Supersonic agitation destroyed coagulated precipitates to form fine particles, but did not form clusters of a few atoms. (author)

  13. Palladium-Catalyzed Atom-Transfer Radical Cyclization at Remote Unactivated C(sp3 )-H Sites: Hydrogen-Atom Transfer of Hybrid Vinyl Palladium Radical Intermediates.

    Science.gov (United States)

    Ratushnyy, Maxim; Parasram, Marvin; Wang, Yang; Gevorgyan, Vladimir

    2018-03-01

    A novel mild, visible-light-induced palladium-catalyzed hydrogen atom translocation/atom-transfer radical cyclization (HAT/ATRC) cascade has been developed. This protocol involves a 1,5-HAT process of previously unknown hybrid vinyl palladium radical intermediates, thus leading to iodomethyl carbo- and heterocyclic structures. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Evaluation of Moisture-Cure Urethane Coatings for Compliance with Industry Specifications

    Science.gov (United States)

    2011-12-01

    polyurethane coating with a thermoset binder and micaceous iron oxide pigment reinforcement. Since SSPC paint specifications are designed for zinc ...Outside Coating System No.2 (minimum AWWA OFT 7.5 mils) 1 ct. Corothane I GalvaPac Zinc Primer@ 3.0 mils dft 1 ct. Corothane Iron ox B@ 3.0 mils dft...Substrates Over properly prepared: Ferrous Metal Galvanized Metal Aluminium/Non-Ferrous Metal Ductile Iron Previously Existing Coatings

  15. Fexofenadine Suppresses Delayed-Type Hypersensitivity in the Murine Model of Palladium Allergy

    Directory of Open Access Journals (Sweden)

    Ryota Matsubara

    2017-06-01

    Full Text Available Palladium is frequently used in dental materials, and sometimes causes metal allergy. It has been suggested that the immune response by palladium-specific T cells may be responsible for the pathogenesis of delayed-type hypersensitivity in study of palladium allergic model mice. In the clinical setting, glucocorticoids and antihistamine drugs are commonly used for treatment of contact dermatitis. However, the precise mechanism of immune suppression in palladium allergy remains unknown. We investigated inhibition of the immune response in palladium allergic mice by administration of prednisolone as a glucocorticoid and fexofenadine hydrochloride as an antihistamine. Compared with glucocorticoids, fexofenadine hydrochloride significantly suppressed the number of T cells by interfering with the development of antigen-presenting cells from the sensitization phase. Our results suggest that antihistamine has a beneficial effect on the treatment of palladium allergy compared to glucocorticoids.

  16. Formation of palladium hydrides in low temperature Ar/H_2-plasma

    International Nuclear Information System (INIS)

    Wulff, H.; Quaas, M.; Deutsch, H.; Ahrens, H.; Fröhlich, M.; Helm, C.A.

    2015-01-01

    20 nm thick Pd coatings deposited on Si substrates with 800 nm SiO_2 and 1 nm Cr buffer layers were treated in a 2.45 GHz microwave plasma source at 700 W plasma power and 40 Pa working pressure without substrate heating. For obtaining information on the effect of energy influx due to ion energy on the palladium films the substrate potential was varied from U_s_u_b = 0 V to − 150 V at constant gas flow corresponding to mean ion energies E_i from 0.22 eV ∙ cm"−"2 ∙ s"−"1 to 1.28 eV ∙ cm"−"2 ∙ s"−"1. In contrast to high pressure reactions with metallic Pd, under plasma exposure we do not observe solid solutions over a wide range of hydrogen concentration. The hydrogen incorporation in Pd films takes place discontinuously. At 0 V substrate voltage palladium hydride is formed in two steps to PdH_0_._1_4 and PdH_0_._5_7. At − 50 V substrate voltage PdH_0_._5_7 is formed directly. However, substrate voltages of − 100 V and − 150 V cause shrinking of the unit cell. We postulate the formation of two fcc vacancy palladium hydride clusters PdH_V_a_c(I) and PdH_V_a_c(II). Under longtime plasma exposure the fcc PdH_V_a_c(II) phase forms cubic PdH_1_._3_3. The fcc PdH_0_._5_7 phase decomposes at temperatures > 300 °C to form metallic fcc Pd. The hydrogen removal causes a decrease of lattice defects. In situ high temperature diffractometry measurements also confirm the existence of PdH_V_a_c(II) as a palladium hydride phase. Stoichiometric relationship between cubic PdH_1_._3_3 and fcc PdH_V_a_c(II) becomes evident from XR measurements and structure considerations. We assume both phases have the chemical composition Pd_3H_4. Up to 700 °C we observe phase transformation between both the fcc PdH_V_a_c(II) and cubic PdH_1_._3_3 phases. These phase transformations could be explained analog to a Bain distortion by displacive solid state structural changes. - Highlights: • Thin Pd films were treated under low pressure conditions by an Ar/H_2-plasma. • The

  17. Formation of palladium hydrides in low temperature Ar/H{sub 2}-plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, H., E-mail: wulff@uni-greifswald.de [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Quaas, M. [LITEC-LP, Brandteichstraße 20, 17489 Greifswald (Germany); Deutsch, H.; Ahrens, H. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany); Fröhlich, M. [Leibniz Institute for Plasma Science and Technology e.V., Felix-Hausdorff-Straße 2 (Germany); Helm, C.A. [University of Greifswald, Institute of Physics, Felix-Hausdorff-Straße 6, 17487 Greifswald (Germany)

    2015-12-01

    20 nm thick Pd coatings deposited on Si substrates with 800 nm SiO{sub 2} and 1 nm Cr buffer layers were treated in a 2.45 GHz microwave plasma source at 700 W plasma power and 40 Pa working pressure without substrate heating. For obtaining information on the effect of energy influx due to ion energy on the palladium films the substrate potential was varied from U{sub sub} = 0 V to − 150 V at constant gas flow corresponding to mean ion energies E{sub i} from 0.22 eV ∙ cm{sup −2} ∙ s{sup −1} to 1.28 eV ∙ cm{sup −2} ∙ s{sup −1}. In contrast to high pressure reactions with metallic Pd, under plasma exposure we do not observe solid solutions over a wide range of hydrogen concentration. The hydrogen incorporation in Pd films takes place discontinuously. At 0 V substrate voltage palladium hydride is formed in two steps to PdH{sub 0.14} and PdH{sub 0.57}. At − 50 V substrate voltage PdH{sub 0.57} is formed directly. However, substrate voltages of − 100 V and − 150 V cause shrinking of the unit cell. We postulate the formation of two fcc vacancy palladium hydride clusters PdH{sub Vac}(I) and PdH{sub Vac}(II). Under longtime plasma exposure the fcc PdH{sub Vac}(II) phase forms cubic PdH{sub 1.33}. The fcc PdH{sub 0.57} phase decomposes at temperatures > 300 °C to form metallic fcc Pd. The hydrogen removal causes a decrease of lattice defects. In situ high temperature diffractometry measurements also confirm the existence of PdH{sub Vac}(II) as a palladium hydride phase. Stoichiometric relationship between cubic PdH{sub 1.33} and fcc PdH{sub Vac}(II) becomes evident from XR measurements and structure considerations. We assume both phases have the chemical composition Pd{sub 3}H{sub 4}. Up to 700 °C we observe phase transformation between both the fcc PdH{sub Vac}(II) and cubic PdH{sub 1.33} phases. These phase transformations could be explained analog to a Bain distortion by displacive solid state structural changes. - Highlights: • Thin Pd films

  18. Method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions

    Science.gov (United States)

    Horwitz, E. Philip; Delphin, Walter H.

    1979-07-24

    A method for recovering palladium and technetium values from nuclear fuel reprocessing waste solutions containing these and other values by contacting the waste solution with an extractant of tricaprylmethylammonium nitrate in an inert hydrocarbon diluent which extracts the palladium and technetium values from the waste solution. The palladium and technetium values are recovered from the extractant and from any other coextracted values with a strong nitric acid strip solution.

  19. Surface topography of a palladium cathode after electrolysis in heavy water

    International Nuclear Information System (INIS)

    Silver, D.S.; Dash, J.; Keefe, P.S.

    1993-01-01

    Electrolysis was performed with a palladium cathode and an electrolyte containing both hydrogen and deuterium ions. The cathode bends toward the anode during this process. Examination of both the concave and the convex surfaces with the scanning electron microscope, scanning tunneling microscope, and atomic force microscope shows unusual surface characteristics. Rimmed craters with faceted crystals inside and multitextural surfaces were observed on an electrolyzed palladium cathode but not on palladium that has not been electrolyzed. 9 refs., 9 figs

  20. Cast irons

    CERN Document Server

    1996-01-01

    Cast iron offers the design engineer a low-cost, high-strength material that can be easily melted and poured into a wide variety of useful, and sometimes complex, shapes. This latest handbook from ASM covers the entire spectrum of one of the most widely used and versatile of all engineered materials. The reader will find the basic, but vital, information on metallurgy, solidification characteristics, and properties. Extensive reviews are presented on the low-alloy gray, ductile, compacted graphite, and malleable irons. New and expanded material has been added covering high-alloy white irons used for abrasion resistance and high-alloy graphitic irons for heat and corrosion resistance. Also discussed are melting furnaces and foundry practices such as melting, inoculation, alloying, pouring, gating and rising, and molding. Heat treating practices including stress relieving, annealing, normalizing, hardening and tempering, autempering (of ductile irons), and surface-hardening treatments are covered, too. ASM Spec...

  1. Determination of the Debye-Waller Factor of hydrogen in Palladium and Palladium Silver alloy

    International Nuclear Information System (INIS)

    Khodabakhsh, R.

    1986-01-01

    The mean square amplitude of the vibrating hydrogen in metals can be determined by using coherent elastic neutron scattering experiments, inelastic one-phonon scattering measurements. To determine the D.W.F. Debye-Waller Factor from the coherent elastic scattering measurements, information about the positions of atoms within the unit is required, and vice versa. The main difficulty concerning the determination of the D.W.F. from the inelastic experiment is in elimination of multi-phonon contribution from the measured spectrum. However, the D.W.F. of hydrogen in palladium has been usually determined by the intensity of the quasi-elastic line. An integration of the measured scattering law S(Q,W) at constant Q, over a certain energy window ΔE, results in the quasi-elastic intensity. To obtain an accurate result, this window has to be chosen large enough to comprise most of the quasi-elastic line, but sufficiently small so that the phonon contributions are small. The MARX spectrometer is ideally constructed for this type of measurement where the window is about +-1 Mev for incident neutron wavelength, =4.115 A. Thus, the quasi-elastic scattering method was considered the best method of determining the D.W.F. of hydrogen in palladium using the MARX spectrometer. However, if the acoustic part overlaps with the quasi-elastic part, one has to obtain the D.W.F. by fitting the data to a quasi-elastic model. The work to be reported here is the investigation of variations of the D.W.F. of hydrogen in Pd and PdAgsub(0.085) with temperature and extension of the available data to as high a temperature as possible. Therefore the integrated intensity of incoherent quasi-elastic neutron scattering by proton in polycrystallin Pd/H and PdAgsub(0.085)/H was investigated as a function of the scattering vector Q. A quasi-harmonic D.W.F. behaviour was observed at elevated temperatures. The observed Debye-Waller Factor depends strongly on the form of the amplitude weighted frequency

  2. Noise temperature measurements for the determination of the thermodynamic temperature of the melting point of palladium

    Energy Technology Data Exchange (ETDEWEB)

    Edler, F.; Kuhne, M.; Tegeler, E. [Bundesanstalt Physikalisch-Technische, Berlin (Germany)

    2004-02-01

    The thermodynamic temperature of the melting point of palladium in air was measured by noise thermometric methods. The temperature measurement was based on noise comparison using a two-channel arrangement to eliminate parasitic noises of electronic components by cross correlation. Three miniature fixed points filled with pure palladium (purity: {approx}99.99%, mass: {approx}90 g) were used to realize the melts of the fixed point metal. The measured melting temperature of palladium in air amounted to 1552.95 deg C {+-} 0.21 K (k = 2). This temperature is 0.45 K lower than the temperature of the melting point of palladium measured by radiation thermometry. (authors)

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... risk for iron-deficiency anemia, including: Vegetarian or vegan eating patterns. Not eating enough iron-rich foods, ... iron-fortified foods that have iron added. Vegetarian diets can provide enough iron if you choose nonmeat ...

  4. A micromachined calorimetric gas sensor: an application of electrodeposited nanostructured palladium for the detection of combustible gases.

    Science.gov (United States)

    Bartlett, Philip N; Guerin, Samuel

    2003-01-01

    Palladium films with regular nanoarchitectures were electrochemically deposited from the hexagonal (H1) lyotropic liquid crystalline phase of the nonionic surfactant octaethyleneglycol monohexadecyl ether (C16EO8) onto micromachined silicon hotplate structures. The H1-e Pd films were shown to have high surface areas (approximately 28 m2 g(-1)) and to act as effective and stable catalysts for the detection of methane in air on heating to 500 degrees C. The response of the H1-e Pd-coated planar pellistors was found to be linearly proportional to the concentration of methane between 0 and 2.5% in air with a detection limit below 0.125%. Our results show that the electrochemical deposition of nanostructured metal films offers a promising approach to the fabrication of micromachined calorimetric gas sensors for combustible gases.

  5. Kinetic Characteristics of Hydrogen Transfer Through Palladium-Modified Membrane

    Science.gov (United States)

    Petriev, I. S.; Frolov, V. Yu.; Bolotin, S. N.; Baryshev, M. G.; Kopytov, G. F.

    2018-01-01

    The paper deals with hydrogen transfer through Pd-23%Ag alloy membrane, the surface of which is modified by the electrolytic deposition of highly dispersed palladium. The dependence between the density of hydrogen flow and its excess pressure on the input surface of membrane is well approximated by the first-order curve. This fact indicates that the process of hydrogen permeability is defined by its dissociation on the input surface. Activation energy of this process is 47.9 kJ/mol which considerably exceeds that of the process of hydrogen transfer through palladium (22-30 kJ/mol). This confirms the fact that the chemisorption is a rate-controlling step of the hydrogen transfer through membrane.

  6. Analysis of the anomalous hydrogen solubilities in deformed palladiums

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choong Nyeon; Lee, Ho Jong

    1987-02-01

    The anomalous hydrogen solubilities in the deformed palladiums were analyzed by empolying modified Kirchheim's model with considering the partially coherent strain energy which would induced during hydride precipitation around edge dislocations. The dislocation densities, obtained by this model, of the various cold worked and/or reversible US transformed palladium samples were the order of 10/sup 11/cm/sup -2/. The partially coherent strain energies were about 3 kJ/molH and nearly same in the various samples. This value could be compared with the incoherent strain energy, 0.4kJ/molH, which was obtained from the hysteresis on P-C isotherm, and the coherent strain energy calulated, 9.6kJ/molH.

  7. Hydrogenation of carbon monoxide over supported palladium catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, K.; Hashimoto, H.; Kunugi, T.

    1978-03-01

    An alumina-supported 2% palladium catalyst had higher activity for carbon monoxide hydrogenation than a silica-supported 2% palladium catalyst, at 250/sup 0/-400/sup 0/C and 1 atm. The addition of lanthanum oxide or thorium oxide, but not of potassium oxide, to the silica-supported catalyst increased the conversion at 350/sup 0/C from 1.1% to 81.0% with a selectivity of 56.1% for methane, 1.4% for C/sub 2/ compounds, 0.1% for C/sub 3/ compounds, and 42.5% for carbon dioxide. Temperature-programed desorption of carbon monoxide in a hydrogen stream showed that of two desorption peaks observed for carbon monoxide, the one at higher temperature corresponded to the carbon monoxide species which hydrogenates to methane and that the area of this peak increased with increasing thorium content of the catalyst. Graphs, tables, and 12 references.

  8. Adlayers of palladium particles and their aggregates on porous polypropylene hollow fiber membranes as hydrogenization contractors/reactors

    NARCIS (Netherlands)

    Volkov, V.V.; Lebedeva, V.I.; Petrova, I.V.; Bobyl, A.V.; Konnikov, S.G.; Roldughin, V.I.; Erkel, J. van; Tereshchenko, G.F.

    2011-01-01

    Principal approaches for the preparation of catalytic membrane reactors based on polymer membranes containing palladium nanoparticles and for the description of their characteristics are presented. The method for the development of adlayers composed of palladium nanoparticles and their aggregates on

  9. Co-deposition of palladium with hydrogen isotopes

    International Nuclear Information System (INIS)

    Dash, J.; Ambadkar, A.

    2006-01-01

    Palladium was co-deposited with hydrogen isotopes on a Pd cathode. This resulted in enhanced production of excess thermal power. After electrolysis the Pd Lβ/ Lα ratio was found to be increased in characteristic X-ray spectra from localized, microscopic areas on the surface of the Pd cathode. This suggests the possibility that appreciable amounts of silver are present in these areas. (authors)

  10. Unsupported palladium alloy membranes and methods of making same

    Science.gov (United States)

    Way, J. Douglas; Thoen, Paul; Gade, Sabina K.

    2015-06-02

    The invention provides support-free palladium membranes and methods of making these membranes. Single-gas testing of the unsupported foils produced hydrogen permeabilities equivalent to thicker membranes produced by cold-rolling. Defect-free films as thin as 7.2 microns can be fabricated, with ideal H.sub.2/N.sub.2 selectivities as high as 40,000. Homogeneous membrane compositions may also be produced using these methods.

  11. Interaction of CO with Palladium Supported on Oxidized Tungsten

    Czech Academy of Sciences Publication Activity Database

    Jirka, Ivan; Plšek, Jan; Šutara, F.; Matolín, V.; Cháb, Vladimír; Prince, K. C.

    2006-01-01

    Roč. 110, č. 47 (2006), s. 23837-23844 ISSN 1520-6106 R&D Projects: GA ČR GA202/05/0244; GA AV ČR IAA1010413 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100521 Keywords : palladium * WOx surfaces * TPD Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

  12. Application of Colloidal Palladium Nanoparticles for Labeling in Electron Microscopy

    Czech Academy of Sciences Publication Activity Database

    Vancová, Marie; Šlouf, Miroslav; Langhans, Jan; Pavlová, Eva; Nebesářová, Jana

    2011-01-01

    Roč. 17, č. 5 (2011), s. 810-816 ISSN 1431-9276 R&D Projects: GA AV ČR KAN200520704; GA AV ČR KJB600960906; GA ČR GAP205/10/0348 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40500505 Keywords : electron microscopy * colloidal palladium * nanoparticles * labeling * salivary glands * Ixodes ricinus Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.007, year: 2011

  13. HE3 outgassing from four working palladium and uranium beds

    International Nuclear Information System (INIS)

    Souers, P. C.; Coronado, P. R.; Fearon, F. M.; Garza, R. G.; Shaw , J. F.; Stump, R. K.; Tsugawa, R. T.

    1988-01-01

    The He 3 output from two palladium and two uranium beds storing T 2 and D-T was studied as a function of time. Three of the beds were started new and watched for a year; the fourth bed was twelve years old. All four were beds used in routine tritium handling. Initial stoichiometries were PdT/sub 0.3/ and UT/sub 0.7/ so that both operated at similar 1 to 130 kPa pressures. The He 3 from palladium ranged from the 0.002 mo1% lower level of sensitivity to 0.01% for PdT 2 at one year of age. The UT system showed 0.1% He 3 at 4 to 62 days and 0.1 to 10% at longer times, with the first cuts being high in He 3 . The palladium bed with 95 to 97% pure T 2 enriches the output to as high as 97 to 99%. 9 refs., 1 fig., 2 tabs

  14. Substoichiometric extraction of traces of gold and palladium

    International Nuclear Information System (INIS)

    Colonat, J.-F.

    1975-01-01

    Several systems for extracting palladium at concentrations ranging from 10 -4 to 10 -6 M/l were studied. Extraction by dithizone is limited by the transformation of the primary complex into a secondary complex which takes place at concentrations around 10 -6 M. This transformation has been demonstrated kinetically. Dimethylglyoxime is an interesting reagent in substoichiometry, in spite of its comparatively low extraction constant. Various complexes which are formed in a highly chlorinated medium have been proposed. Use of copper diethyldithiocarbamate is limited principally by its stability in presence of chlorine ions. The kinetic formation of palladium diethyldithiocarbamate has been studied with greater precision. A direct determination of 100μg of palladium in a copper matrix without preliminary separation has given results comparable in every way with those of other methods. In the case of gold (III) the constants of formation with the diethyldithiocarbamate ion have been determined by an iterative method of calculation, using the influence curves of interfering metals. Finally conditions for an automatization of the substoichiometric extraction, as well as its possibilities for gold determination in the range 200-20ppm, were proposed [fr

  15. Arsenic (III Adsorption Using Palladium Nanoparticles from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Farzaneh Arsiya

    2017-07-01

    Full Text Available The presence of Arsenic in drinking water is the greatest threat to health effects especially in water. The purpose of this study is application of green palladium nanoparticles for removal of trivalent Arsenic from aqueous solutions and also the impact of some factors such as retention time, pH, concentration of palladium nanoparticles and Arsenic concentrations was studied. The values for Arsenic removal from aqueous solutions were measured by furnace atomic adsorption spectrometry (Conter AA700. In the study, Langmuir and Freundlich isotherm models and pseudo-second order kinetic model were studied. The results of  optimization is shown that 0.5 g of nanoparticles can removed %99.8 of Arsenic with initial concentration of  0.5 g/l, in 5 minutes at pH=4. Langmuir model, Freundlich model (R2=0.94 and pseudo-second order kinetic model (R2=0.99 shown high correlation for removing of Arsenic from aqueous solutions. It was found, palladium nanoparticles can be used as an efficient method to remove Arsenic from aqueous solutions in a short time.

  16. Recovery of hydrogen from impurities using a palladium membrane reactor

    International Nuclear Information System (INIS)

    Willms, R.S.; Okuno, K.

    1993-01-01

    One of the important steps in processing the exhaust from a fusion reactor is recovering tritium which is incorporated into molecules such as water and methane. One device which may prove to be very effective for this purpose is a palladium membrane reactor. This is a reactor which incorporates a Pd/Ag membrane in the reactor geometry. Reactions such as water gas shift, steam reforming and methane cracking can be carried out over the reactor catalyst, and the product hydrogen can be simultaneously removed from the reacting mixture. Because product is removed, greater than usual conversions can be obtained. In addition ultrapure hydrogen is produced, eliminating the need for an additional processing step. A palladium membrane reactor has been built and tested with three different catalysts. Initial results with a Ni-based catalyst show that it is very effective at promoting all three reactions listed above. Under the proper conditions, hydrogen recoveries approaching 100% have been observed. This study serves to experimentally validate the palladium membrane reactor as potentially important tool for fusion fuel processing

  17. IRON DOME

    African Journals Online (AJOL)

    6 Israeli Navy 'First Arm of the Sea: The Successful Interception of the Iron Dome Rocket .... sky to destroy them whilst in flight to minimise civilian casualties. ..... Including The Moon and Celestial Bodies.53 Demeyere further emphasises the.

  18. Iron overdose

    Science.gov (United States)

    ... tracing) X-ray to detect and track iron tablets through the stomach and intestines Treatment may include: ... BF, St. Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; 2016: ...

  19. Degradation of polychlorinated biphenyls (PCBs) using palladized iron

    International Nuclear Information System (INIS)

    West, O.R.; Liang, L.; Holden, W.L.

    1996-06-01

    Contamination from polychlorinated biphenyls (PCBs) is a persistent problem within the Department of Energy complex, as well as in numerous industrial sites around the US. To date, commercially available technologies for destroying these highly stable compounds involve degradation at elevated temperatures either through incineration or base-catalyzed dehalogenation at 300 degrees C. Since the heating required with these processes substantially increases the costs for treatment of PCB-contaminated wastes, there is a need for finding an alternative approach where PCB can be degraded at ambient temperatures. This report describes the degradation of PCB's utilizing the bimetallic substrate of iron/palladium

  20. Nanophase hardfaced coatings

    Energy Technology Data Exchange (ETDEWEB)

    Reisgen, U.; Stein, L.; Balashov, B.; Geffers, C. [RWTH Aachen University (Germany). ISF - Welding and Joining Institute

    2009-08-15

    This paper demonstrates the possibility of producing iron or chromium-based nanophase hardfaced coatings by means of common arc welding methods (TIG, PTA). The appropriate composition of the alloys to be deposited allows to control the structural properties and thus also the coating properties of the weld metal. Specific variations of the alloying elements allow also the realisation of a nanostructured solidification of the carbides and borides with cooling rates that are common for arc surfacing processes. The hardfaced coatings, which had been thus produced, showed phase dimensions of approximately 100-300 nm. Based on the results it is established that the influence of the surfacing parameters and of the coating thickness and thus the influence of the heat control on the nanostructuring process is, compared with the influence of the alloy composition, of secondary importance. The generation of nanoscale structures in hardfaced coatings allows the improvement of mechanical properties, wear resistance and corrosion resistance. Potential applications for these types of hardfaced coatings lie, in particular, in the field of cutting tools that are exposed to corrosion and wear. (Abstract Copyright [2009], Wiley Periodicals, Inc.) [German] Diese Arbeit demonstriert die Moeglichkeit zur Herstellung Eisen- und Chrom-basierter nanophasiger Hartauftragschweissschichten mithilfe ueblicher Lichtbogenschweissverfahren (WIG-, Plasma-Pulver-Auftragschweissen - PPA). Eine geeignete Zusammensetzung der aufzutragenden Legierungen ermoeglicht es, die Gefuegeeigenschaften und damit die Schichteigenschaften des Schweissgutes zu kontrollieren. Gezielte Variationen der Legierungselemente erlauben die Realisierung einer nanostrukturierten Erstarrung der Karbide und Boride bei fuer Lichtbogen-Auftragschweissprozessen ueblichen Abkuehlgeschwindigkeiten. In den so erzeugten Hartschichten werden Phasengroessen von ca. 100-300 nm erreicht. Auf Basis der gewonnenen Ergebnisse kann

  1. Palladium alloy membrane process for the treatment of hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Hongsuk; Paek, Seungwoo; Lee, Minsoo; Kim, Kwangrag; Yim, Sungpaal; Ahn, Dohee [KAERI, Daejeon (Korea, Republic of); Shim, Myunghwa [Univ. of Science and Technology, Daejeon (Korea, Republic of)

    2005-11-15

    Tritium is a radioactive isotope of hydrogen and it has a half-life of 12.3 years; it decays to He-3 by emitting a low energy beta radiation with an average energy of 5.7 keV and a maximum energy of 18.6 keV. Transfer of environmentally tritiated water to humans takes place via an inhalation, diffusion through the skin and ingestion. Radioactive waste containing tritium is continuously generated by the nuclear industry in, for example, nuclear reactor operations and a radioisotope production, as well as in medical research. Methods for removing tritium from liquid waste provide an alternative to the control of tritium emissions and a personnel exposure. A combined electrolysis and catalytic exchange process is a very effective method to remove small quantities of tritium from light or heavy waste water streams. The process consists of three main steps: (a) A front end step that exchanges the tritium to a less toxic hydrogen phase. This can be performed either through a chemical exchange in the presence of a platinum supported catalyst or through the decomposition of water. (b) A back end process that purifies the tritiated hydrogen gas which evolved from the electrolysis. This can be performed through a palladium alloy membrane separator. (c) A means of storing the concentrated gas safely. Uranium is used if the storage is temporary; titanium is usually employed for long term storage. To gain a better understanding of the tritiated hydrogen gas purification process, a mathematical model of the palladium alloy membrane has been used. This model is described herein, and the representative results of the model calculations are presented. The authors selected the palladium alloy membrane for the hydrogen purification process by considering the membrane properties, such as a chemical resistance, mechanical stability, thermal stability, high permeability, and a stable operation. The solution-diffusion model can be a useful tool for designing a membrane permeator. The

  2. Palladium alloy membrane process for the treatment of hydrogen isotopes

    International Nuclear Information System (INIS)

    Chung, Hongsuk; Paek, Seungwoo; Lee, Minsoo; Kim, Kwangrag; Yim, Sungpaal; Ahn, Dohee; Shim, Myunghwa

    2005-01-01

    Tritium is a radioactive isotope of hydrogen and it has a half-life of 12.3 years; it decays to He-3 by emitting a low energy beta radiation with an average energy of 5.7 keV and a maximum energy of 18.6 keV. Transfer of environmentally tritiated water to humans takes place via an inhalation, diffusion through the skin and ingestion. Radioactive waste containing tritium is continuously generated by the nuclear industry in, for example, nuclear reactor operations and a radioisotope production, as well as in medical research. Methods for removing tritium from liquid waste provide an alternative to the control of tritium emissions and a personnel exposure. A combined electrolysis and catalytic exchange process is a very effective method to remove small quantities of tritium from light or heavy waste water streams. The process consists of three main steps: (a) A front end step that exchanges the tritium to a less toxic hydrogen phase. This can be performed either through a chemical exchange in the presence of a platinum supported catalyst or through the decomposition of water. (b) A back end process that purifies the tritiated hydrogen gas which evolved from the electrolysis. This can be performed through a palladium alloy membrane separator. (c) A means of storing the concentrated gas safely. Uranium is used if the storage is temporary; titanium is usually employed for long term storage. To gain a better understanding of the tritiated hydrogen gas purification process, a mathematical model of the palladium alloy membrane has been used. This model is described herein, and the representative results of the model calculations are presented. The authors selected the palladium alloy membrane for the hydrogen purification process by considering the membrane properties, such as a chemical resistance, mechanical stability, thermal stability, high permeability, and a stable operation. The solution-diffusion model can be a useful tool for designing a membrane permeator. The

  3. New Palladium-Catalyzed Approaches to Heterocycles and Carbocycles

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qinhua [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    The tert-butylimines of o-(1-alkynyl)benzaldehydes and analogous pyridinecarbaldehydes have been cyclized under very mild reaction conditions in the presence of I2, ICl, PhSeCl, PhSCl and p-O2NC6H4SCl to give the corresponding halogen-, selenium- and sulfur-containing disubstituted isoquinolines and naphthyridines, respectively. Monosubstituted isoquinolines and naphthyridines have been synthesized by the metal-catalyzed ring closure of these same iminoalkynes. This methodology accommodates a variety of iminoalkynes and affords the anticipated heterocycles in moderate to excellent yields. The Pd(II)-catalyzed cyclization of 2-(1-alkynyl)arylaldimines in the presence of various alkenes provides an efficient way to synthesize a variety of 4-(1-alkenyl)-3-arylisoquinolines in moderate to excellent yields. The introduction of an ortho-methoxy group on the arylaldimine promotes the Pd-catalyzed cyclization and stabilizes the resulting Pd(II) intermediate, improving the yields of the isoquinoline products. Highly substituted naphthalenes have been synthesized by the palladium-catalyzed annulation of a variety of internal alkynes, in which two new carbon-carbon bonds are formed in a single step under relatively mild reaction conditions. This method has also been used to synthesize carbazoles, although a higher reaction temperature is necessary. The process involves arylpalladation of the alkyne, followed by intramolecular Heck olefination and double bond isomerization. This method accommodates a variety of functional groups and affords the anticipated highly substituted naphthalenes and carbazoles in good to excellent yields. Novel palladium migratiodarylation methodology for the synthesis of complex fused polycycles has been developed, in which one or more sequential Pd-catalyzed intramolecular migration processes involving C-H activation are employed. The chemistry works best with electron-rich aromatics, which is in agreement

  4. Remediation of trichloroethylene by bio-precipitated and encapsulated palladium nanoparticles in a fixed bed reactor.

    Science.gov (United States)

    Hennebel, Tom; Verhagen, Pieter; Simoen, Henri; De Gusseme, Bart; Vlaeminck, Siegfried E; Boon, Nico; Verstraete, Willy

    2009-08-01

    Trichloroethylene is a toxic and recalcitrant groundwater pollutant. Palladium nanoparticles bio-precipitated on Shewanella oneidensis were encapsulated in polyurethane, polyacrylamide, alginate, silica or coated on zeolites. The reactivity of these bio-Pd beads and zeolites was tested in batch experiments and trichloroethylene dechlorination followed first order reaction kinetics. The calculated k-values of the encapsulated catalysts were a factor of six lower compared to non-encapsulated bio-Pd. Bio-Pd, used as a catalyst, was able to dechlorinate 100 mgL(-1) trichloroethylene within a time period of 1h. The main reaction product was ethane; yet small levels of chlorinated intermediates were detected. Subsequently polyurethane cubes empowered with bio-Pd were implemented in a fixed bed reactor for the treatment of water containing trichloroethylene. The influent recycle configuration resulted in a cumulative removal of 98% after 22 h. The same reactor in a flow through configuration achieved removal rates up to 1059 mg trichloroethylene g Pd(-1)d(-1). This work showed that fixed bed reactors with bio-Pd polyurethane cubes can be instrumental for remediation of water contaminated with trichloroethylene.

  5. Palladium emissions in the environment: analytical methods, environmental assessment and health effects

    National Research Council Canada - National Science Library

    Alt, Friedrich; Zereini, Fathi

    2006-01-01

    ... (Eds)). But there is a clear lack of information concerning palladium. It is very important to condense the present state of research findings from emission to potential health risks for the environment and humans. Very important is the chapter about analytical determination of palladium, which shows clearly the problems of several analytic...

  6. Carbon nanotubes decorated with palladium nanoparticles : Synthesis, characterization, and catalytic activity

    NARCIS (Netherlands)

    Karousis, Nikolaos; Tsotsou, Georgia-Eleni; Evangelista, Fabrizio; Rudolf, Petra; Ragoussis, Nikitas; Tagmatarchis, Nikos

    2008-01-01

    In this article, the in situ preparation of palladium nanoparticles, as mediated by the self-regulated reduction of palladium acetate with the aid of sodium dodecyl sulfate (SDS), followed by subsequent deposition onto single-walled carbon nanotubes and multimalled carbon nanotubes (MWCNTs), is

  7. Oxygen Activated, Palladium Nanoparticle Catalyzed, Ultrafast Cross-Coupling of Organolithium Reagents

    NARCIS (Netherlands)

    Heijnen, Dorus; Tosi, Filippo; Vila, Carlos; Stuart, Marc C. A.; Elsinga, Philip H.; Szymanski, Wiktor; Feringa, Ben L.

    2017-01-01

    The discovery of an ultrafast cross-coupling of alkyland aryllithium reagents with a range of aryl bromides is presented. The essential role of molecular oxygen to form the active palladium catalyst was established; palladium nanoparticles that are highly active in cross-coupling reactions with

  8. Palladium(II)-Stabilized Pyridine-2-Diazotates: Synthesis, Structural Characterization, and Cytotoxicity Studies.

    Science.gov (United States)

    Tskhovrebov, Alexander G; Vasileva, Anna A; Goddard, Richard; Riedel, Tina; Dyson, Paul J; Mikhaylov, Vladimir N; Serebryanskaya, Tatiyana V; Sorokoumov, Viktor N; Haukka, Matti

    2018-02-05

    Well-defined diazotates are scarce. Here we report the synthesis of unprecedented homoleptic palladium(II) diazotate complexes. The palladium(II)-mediated nitrosylation of 2-aminopyridines with NaNO 2 results in the formation of metal-stabilized diazotates, which were found to be cytotoxic to human ovarian cancer cells.

  9. A DFT study of arsine adsorption on palladium doped graphene: Effects of palladium cluster size

    International Nuclear Information System (INIS)

    Kunaseth, Manaschai; Mudchimo, Tanabat; Namuangruk, Supawadee; Kungwan, Nawee; Promarak, Vinich; Jungsuttiwong, Siriporn

    2016-01-01

    Graphical abstract: The relationship between charge difference and adsorption strength demonstrates that charge migration from Pd_n-SDG to AsH_x significantly enhanced adsorption strength, the Pd_6 clusters doped SDG with a steep slope is recommended as a superior adsorbent material for AsH_3 removal from gas stream. - Highlights: • Pd atom and Pd clusters bind strongly onto the defective graphene surface. • Larger size of Pd cluster adsorbs arsine and its hydrogenated products stronger. • Order of adsorption strength on Pd_n doped graphene: As > AsH > AsH_2 > > AsH_3. • Charge migration characterizes the strong adsorption of AsH_2, AsH, and As. • Pd cluster doped graphene is thermodynamically preferable for arsine removal. - Abstract: In this study, we have investigated the size effects of palladium (Pd) doped single-vacancy defective graphene (SDG) surface to the adsorption of AsH_3 and its dehydrogenated products on Pd using density functional theory calculations. Here, Pd cluster binding study revealed that Pd_6 nanocluster bound strongest to the SDG surface, while adsorption of AsH_x (x = 0–3) on the most stable Pd_n doped SDG showed that dehydrogenated arsine compounds adsorbed onto the surface stronger than the pristine AsH_3 molecule. Charge analysis revealed that considerable amount of charge migration from Pd to dehydrogenated arsine molecules after adsorption may constitute strong adsorption for dehydrogenated arsine. In addition, study of thermodynamic pathways of AsH_3 dehydrogenation on Pd_n doped SDG adsorbents indicated that Pd cluster doping on SDG adsorbent tends to be thermodynamically favorable for AsH_3 decomposition than the single-Pd atom doped SDG. Hence, our study has indicated that Pd_6 clusters doped SDG is more advantageous as adsorbent material for AsH_3 removal.

  10. MO-FG-BRA-03: A Monte-Carlo Study of Cellular Dosimetry of Radioactive Gold-Palladium Nanoparticles

    International Nuclear Information System (INIS)

    Ma, Y; Michaud, F; Fortin, M; Beaulieu, L

    2015-01-01

    Purpose: Radioactive gold-palladium nanoparticles ("1"0"3Pd:Pd@Au NPs) are being developed for prostate cancer brachytherapy. Photons emitted by the radioisotope palladium (photon energy: 20.1 and 23.0 keV), interacting with gold-coating of NPs, lead to enhanced energy distribution in nucleus. Here, a simple cellular model was studied using detailed track-structure method. Methods: Geant4-DNA was used with auger electrons enabled. Biological cell was modeled as a sphere of radius r=5 µm that were immersed in a fluid containing large number of NPs at different concentrations (S=1, 2.15, 5.1, 17.2 mg-Au/g-H2O). Nucleus was modeled as a concentric sphere (r=3µm). Thickness of gold-coating on "1"0"3Pd core was 15nm, 20nm and 25nm, respectively. A scenario of NP diffusion was investigated, where S=5.1 mg-Au/g-H2O outside cell and S=1 mg-Au/g-H2O in cytoplasm. 10"1"0 "1"0"3Pd decays were simulated for each combination of NP concentration and gold-coating. Results: A uniform increase in energy deposition (Edep) is observed in cell nucleus and the energy enhancement ratio (EER) is 1.16, 1.22 and 1.3 for 15nm, 20nm and 25nm of gold -coatings, respectively. Edep at the center of nucleus is increased by a factor of 1.47, 2.51 and 5.54 when the NP concentration in the cytoplasm increases from 1 mg-Au/g-H2O to 2.15, 5.10 and 17.2 mg-Au/g-H2O, respectively. When NPs diffuse into cytoplasm, the mean value of Edep in nucleus increases from 0.42 to 1.13 MeV per 10"9 decays (GBq-Second) of "1"0"3Pd and the maximum value increases from 0.54 to 2.5 MeV per GBq-Second. Conclusion: These results suggest that "1"0"3Pd:Pd@Au NPs constitute a promising nanotherapeutic agent. Ongoing studies use transmission electron microscopy (TEM) images of prostate cancer

  11. Development of anodic stripping voltametry for the determination of palladium in high level nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, T. K. [North Carolina State University, Raleigh (United States); Sharma, H. S.; Affarwal, S. K. [Bhabha Atomic Research Centre, Mumbai (India); Jain, P. C. [Meerut College, Meerut (India)

    2012-12-15

    Deposition potential, deposition time, square wave frequency, rotation speed of the rotating disc electrode, and palladium concentration were studied on a Glassy Carbon Electrode (GCE) in 0.01M HCl for the determination of palladium in High Level Nuclear Waste (HLNW) by anodic stripping voltammetry. Experimental conditions were optimized for the determination of palladium at two different, 10-8 and 10-7 M, levels. Error and standard deviation of this method were under 1% for all palladium standard solutions. The developed technique was successfully applied as a subsidiary method for the determination of palladium in simulated high level nuclear waste with very good precision and high accuracy (under 1 % error and standard deviation).

  12. Adsorptive removal of manganese, arsenic and iron from groundwater

    NARCIS (Netherlands)

    Buamah, R.

    2009-01-01

    Arsenic, manganese and iron in drinking water at concentrations exceeding recommended guideline values pose health risks and aesthetic defects. Batch and pilot experiments on manganese adsorption equilibrium and kinetics using iron-oxide coated sand (IOCS), Aquamandix and other media have been

  13. Iron oxyhydroxide mineralization on microbial extracellular polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Clara S.; Fakra, Sirine C.; Edwards, David C.; Emerson, David; Banfield, Jillian F.

    2010-06-22

    Iron biominerals can form in neutral pH microaerophilic environments where microbes both catalyze iron oxidation and create polymers that localize mineral precipitation. In order to classify the microbial polymers that influence FeOOH mineralogy, we studied the organic and mineral components of biominerals using scanning transmission X-ray microscopy (STXM), micro X-ray fluorescence ({mu}XRF) microscopy, and high-resolution transmission electron microscopy (HRTEM). We focused on iron microbial mat samples from a creek and abandoned mine; these samples are dominated by iron oxyhydroxide-coated structures with sheath, stalk, and filament morphologies. In addition, we characterized the mineralized products of an iron-oxidizing, stalk-forming bacterial culture isolated from the mine. In both natural and cultured samples, microbial polymers were found to be acidic polysaccharides with carboxyl functional groups, strongly spatially correlated with iron oxyhydroxide distribution patterns. Organic fibrils collect FeOOH and control its recrystallization, in some cases resulting in oriented crystals with high aspect ratios. The impact of polymers is particularly pronounced as the materials age. Synthesis experiments designed to mimic the biomineralization processes show that the polysaccharide carboxyl groups bind dissolved iron strongly but release it as mineralization proceeds. Our results suggest that carboxyl groups of acidic polysaccharides are produced by different microorganisms to create a wide range of iron oxyhydroxide biomineral structures. The intimate and potentially long-term association controls the crystal growth, phase, and reactivity of iron oxyhydroxide nanoparticles in natural systems.

  14. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron-rich foods, especially during certain stages of life when more iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  15. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... that are good sources of iron include dried beans, dried fruits, eggs, lean red meat, salmon, iron- ... of iron, including iron-fortified breads and cereals, beans, tofu, dried fruits, and spinach and other dark ...

  16. Iron in diet

    Science.gov (United States)

    ... Reasonable amounts of iron are also found in lamb, pork, and shellfish. Iron from vegetables, fruits, grains, ... strawberries, tomatoes, and potatoes) also increase iron absorption. Cooking foods in a cast-iron skillet can also ...

  17. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... from developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  18. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... you are diagnosed with iron-deficiency anemia. Risk Factors You may have an increased risk for iron- ... iron-deficiency anemia if you have certain risk factors , including pregnancy. To prevent iron-deficiency anemia, your ...

  19. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... for your body to absorb iron from the gastrointestinal tract (GI tract). Blood loss When you lose blood, ... iron deficiency. Endurance athletes lose iron through their gastrointestinal tracts. They also lose iron through the breakdown of ...

  20. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... iron in your body is low. For this reason, other iron tests are also done. Ferritin measure ... iron is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and ...

  1. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... develop new therapies for conditions that affect the balance of iron in the body and lead to ... Disease Control and Prevention) Iron - Health Professional Fact Sheet (NIH) Iron Dietary Supplement Fact Sheet (NIH) Iron- ...

  2. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... to moderate iron-deficiency anemia, or red blood cell transfusion for severe iron-deficiency anemia. You may ... body needs iron to make healthy red blood cells. Iron-deficiency anemia usually develops over time because ...

  3. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... enough iron-rich foods, such as meat and fish, may result in you getting less than the ... pregnancy. Good sources of iron are meat, poultry, fish, and iron-fortified foods that have iron added. ...

  4. Iron Dextran Injection

    Science.gov (United States)

    Iron dextran injection is used to treat iron-deficiency anemia (a lower than normal number of red blood cells ... treated with iron supplements taken by mouth. Iron dextran injection is in a class of medications called ...

  5. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... and severity. Treatments may include iron supplements, procedures, surgery, and dietary ... iron supplements, also called iron pills or oral iron, by mouth once or several times a ...

  6. Iron-Deficiency Anemia

    Medline Plus

    Full Text Available ... developing iron-deficiency anemia. Foods that are good sources of iron include dried beans, dried fruits, eggs, ... is needed, such as childhood and pregnancy. Good sources of iron are meat, poultry, fish, and iron- ...

  7. Iron deficiency

    DEFF Research Database (Denmark)

    Schou, Morten; Bosselmann, Helle; Gaborit, Freja

    2015-01-01

    BACKGROUND: Both iron deficiency (ID) and cardiovascular biomarkers are associated with a poor outcome in heart failure (HF). The relationship between different cardiovascular biomarkers and ID is unknown, and the true prevalence of ID in an outpatient HF clinic is probably overlooked. OBJECTIVES.......043). CONCLUSION: ID is frequent in an outpatient HF clinic. ID is not associated with cardiovascular biomarkers after adjustment for traditional confounders. Inflammation, but not neurohormonal activation is associated with ID in systolic HF. Further studies are needed to understand iron metabolism in elderly HF...