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Sample records for hydroxide carbonate nanorods

  1. Facile synthesis of zinc hydroxide carbonate flowers on zinc oxide nanorods with attractive luminescent and optochemical performance

    Energy Technology Data Exchange (ETDEWEB)

    Mao Jing; Li Jiajun; Ling Tao; Liu Hui; Yang Jing; Du Xiwen, E-mail: xwdu@tju.edu.cn [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2011-06-17

    A simple synthesis route was designed to fabricate a functional composite, zinc hydroxide carbonate (ZHC) flowers on zinc oxide (ZnO) nanorods. The hydrolysis of hexamethylenetetramine (HMT) can generate various species which are slowly released and gradually change reaction modes in a Zn(NO{sub 3}){sub 2}/HMT solution. As a result, ZnO nanorods and ZHC flowers can be sequentially synthesized and connect very well under constant experimental conditions. The obtained composite has the advantages of both components and exhibits attractive properties. For instance, ZHC flowers on ZnO nanorods exhibit strong blue emission under the excitation of ultraviolet light, and dye-sensitized solar cells with the annealed composite as photoanode achieve much higher conversion efficiency than pure nanorod arrays.

  2. PolyHIPE Derived Freestanding 3D Carbon Foam for Cobalt Hydroxide Nanorods Based High Performance Supercapacitor

    Science.gov (United States)

    Patil, Umakant M.; Ghorpade, Ravindra V.; Nam, Min Sik; Nalawade, Archana C.; Lee, Sangrae; Han, Haksoo; Jun, Seong Chan

    2016-10-01

    The current paper describes enhanced electrochemical capacitive performance of chemically grown Cobalt hydroxide (Co(OH)2) nanorods (NRs) decorated porous three dimensional graphitic carbon foam (Co(OH)2/3D GCF) as a supercapacitor electrode. Freestanding 3D porous GCF is prepared by carbonizing, high internal phase emulsion (HIPE) polymerized styrene and divinylbenzene. The PolyHIPE was sulfonated and carbonized at temperature up to 850 °C to obtain graphitic 3D carbon foam with high surface area (389 m2 g-1) having open voids (14 μm) interconnected by windows (4 μm) in monolithic form. Moreover, entangled Co(OH)2 NRs are anchored on 3D GCF electrodes by using a facile chemical bath deposition (CBD) method. The wide porous structure with high specific surface area (520 m2 g-1) access offered by the interconnected 3D GCF along with Co(OH)2 NRs morphology, displays ultrahigh specific capacitance, specific energy and power. The Co(OH)2/3D GCF electrode exhibits maximum specific capacitance about ~1235 F g-1 at ~1 A g-1 charge-discharge current density, in 1 M aqueous KOH solution. These results endorse potential applicability of Co(OH)2/3D GCF electrode in supercapacitors and signifies that, the porous GCF is a proficient 3D freestanding framework for loading pseudocapacitive nanostructured materials.

  3. PolyHIPE Derived Freestanding 3D Carbon Foam for Cobalt Hydroxide Nanorods Based High Performance Supercapacitor

    Science.gov (United States)

    Patil, Umakant M.; Ghorpade, Ravindra V.; Nam, Min Sik; Nalawade, Archana C.; Lee, Sangrae; Han, Haksoo; Jun, Seong Chan

    2016-01-01

    The current paper describes enhanced electrochemical capacitive performance of chemically grown Cobalt hydroxide (Co(OH)2) nanorods (NRs) decorated porous three dimensional graphitic carbon foam (Co(OH)2/3D GCF) as a supercapacitor electrode. Freestanding 3D porous GCF is prepared by carbonizing, high internal phase emulsion (HIPE) polymerized styrene and divinylbenzene. The PolyHIPE was sulfonated and carbonized at temperature up to 850 °C to obtain graphitic 3D carbon foam with high surface area (389 m2 g−1) having open voids (14 μm) interconnected by windows (4 μm) in monolithic form. Moreover, entangled Co(OH)2 NRs are anchored on 3D GCF electrodes by using a facile chemical bath deposition (CBD) method. The wide porous structure with high specific surface area (520 m2 g−1) access offered by the interconnected 3D GCF along with Co(OH)2 NRs morphology, displays ultrahigh specific capacitance, specific energy and power. The Co(OH)2/3D GCF electrode exhibits maximum specific capacitance about ~1235 F g−1 at ~1 A g−1 charge-discharge current density, in 1 M aqueous KOH solution. These results endorse potential applicability of Co(OH)2/3D GCF electrode in supercapacitors and signifies that, the porous GCF is a proficient 3D freestanding framework for loading pseudocapacitive nanostructured materials. PMID:27762284

  4. Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

    OpenAIRE

    Yun Zhao; Fenfei Xiao; Qingze Jiao

    2011-01-01

    Ni/Al layered double hydroxide (LDH) nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD). The morphology of the products was observed using transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al ...

  5. In vivo toxicity studies of europium hydroxide nanorods in mice.

    Science.gov (United States)

    Patra, Chitta Ranjan; Abdel Moneim, Soha S; Wang, Enfeng; Dutta, Shamit; Patra, Sujata; Eshed, Michal; Mukherjee, Priyabrata; Gedanken, Aharon; Shah, Vijay H; Mukhopadhyay, Debabrata

    2009-10-01

    Lanthanide nanoparticles and nanorods have been widely used for diagnostic and therapeutic applications in biomedical nanotechnology due to their fluorescence and pro-angiogenic properties to endothelial cells, respectively. Recently, we have demonstrated that europium (III) hydroxide [Eu(III)(OH)(3)] nanorods, synthesized by the microwave technique and characterized by several physico-chemical techniques, can be used as pro-angiogenic agents which introduce future therapeutic treatment strategies for severe ischemic heart/limb disease, and peripheral ischemic disease. The toxicity of these inorganic nanorods to endothelial cells was supported by several in vitro assays. To determine the in vivo toxicity, these nanorods were administered to mice through intraperitoneal injection (IP) everyday over a period of seven days in a dose dependent (1.25 to 125 mg kg(-1) day(-1)) and time dependent manner (8-60 days). Bio-distribution of europium elements in different organs was analyzed by inductively coupled plasma mass spectrometry (ICPMS). Short-term (S-T) and long-term (L-T) toxicity studies (mice euthanized on days 8 and 60 for S-T and L-T, respectively) show normal blood hematology and serum clinical chemistry with the exception of a slight elevation of liver enzymes. Histological examination of nanorod-treated vital organs (liver, kidney, spleen and lungs) showed no or only mild histological changes that indicate mild toxicity at the higher dose of nanorods.

  6. Hydrothermal Synthesis of Ni/Al Layered Double Hydroxide Nanorods

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    Yun Zhao

    2011-01-01

    Full Text Available Ni/Al layered double hydroxide (LDH nanorods were successfully synthesized by the hydrothermal reaction. The crystal structure of the products was characterized by X-ray diffraction (XRD. The morphology of the products was observed using transmission electron microscopy (TEM and field emission scanning electron microscopy (SEM. The influences of reaction time and pH value on the morphology of the Ni/Al LDHs were investigated. The result showed that the well-crystallized nanorods of Ni/Al LDHs could be obtained when the pH value was about 10.0 with a long reaction time (12–18 h at 180°C.

  7. Hydrothermal synthesis of lanthanide (hydr)oxide micro/nanorods in presence of tetrabutylammonium hydroxide

    Institute of Scientific and Technical Information of China (English)

    李银艳; 徐时清

    2016-01-01

    Uniform and well-defined lanthanide hydroxide and oxide micro/nanorods Ln(OH)3(Ln=La, Pr, Sm, Eu, Gd, Er) and Gd(OH)3:Eu3+, Gd2O3:Eu3+ were successfully synthesized through a green and facile hydrothermal method. Tetrabutylammonium hydroxide (TBAH) and lanthanide nitrides were used as the hydrothermal precursors without the addition of any templates/surfactants. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) spectra. The result demonstrated that lanthanide hydroxide micro/nanorods with 20–80 nm in diameter and 50–450 in length were obtained. The size of the Ln(OH)3 (Ln=La, Pr, Sm, Eu, Gd, Er) rods increased with the increase of the atomic number. The size of the Gd(OH)3:Eu3+ rods decreased with the increase of pH value by modulating the amount of the TBAH solution. The as-formed product via the hydrothermal process, Gd(OH)3:Eu3+, could be transformed to Gd2O3:Eu3+ with the same morphology and a slight shrinking in size after a post annealing process. It is a facial method to synthesize photoluminescent nanomaterial of Gd2O3:Eu3+. The Gd2O3:Eu3+ microrods exhibited strong red emission corresponding to5D0→7F2 transition (610 nm) of Eu3+ under UV light excitation (257 nm).

  8. Large-scale Hydrothermal Synthesis and Characterization of Size-controlled Lanthanum Hydroxide Nanorods

    Institute of Scientific and Technical Information of China (English)

    YI,Ran; ZHANG,Ning; SHI,Rongrong; LI,Yongbo; QIU Guanzhou; LIU Xiaohe

    2009-01-01

    Uniform lanthanum hydroxide nanorods were successfully synthesized in large quantities through a facile hydrothermal synthetic method, in which soluble lanthanum nitrate was used to supply the lanthanum source and triethylamine (TEA) was used as both alkaline agent and complexing agent. The influences of triethylamine amount, surfactant, reaction temperature and time on the size and shape of lanthanum hydroxide nanorods were investigated in detail. Trivalent rare earth ion doped lanthanum hydroxide nanorods were also obtained in this paper. The phase structures and morphologies of the as-prepared products were investigated in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high-resolution transmis-sion electron microscopy (HRTEM). The probable formation mechanism was proposed based on the experimental results.

  9. Analysis of barium hydroxide and calcium hydroxide slurry carbonation reactors

    Energy Technology Data Exchange (ETDEWEB)

    Patch, K.D.; Hart, R.P.; Schumacher, W.A.

    1980-05-01

    The removal of CO/sub 2/ from air was investigated by using a continuous-agitated-slurry carbonation reactor containing either barium hydroxide (Ba(OH)/sub 2/) or calcium hydroxide (Ca(OH)/sub 2/). Such a process would be applied to scrub /sup 14/CO/sub 2/ from stack gases at nuclear-fuel reprocessing plants. Decontamination factors were characterized for reactor conditions which could alter hydrodynamic behavior. An attempt was made to characterize reactor performance with models assuming both plug flow and various degrees of backmixing in the gas phase. The Ba(OH)/sub 2/ slurry enabled increased conversion, but apparently the process was controlled under some conditions by phenomena differing from those observed for carbonation by Ca(OH)/sub 2/. Overall reaction mechanisms are postulated.

  10. Physicochemical properties of praseodymium hydroxide and oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jun-Gill [Department of Chemistry, Chungnam National University, Daejeon 304-764 (Korea, Republic of); Min, Bong-Ki [Centre for Research Facility, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of); Sohn, Youngku, E-mail: youngkusohn@ynu.ac.kr [Department of Chemistry, Yeungnam University, Gyeongsan, Gyeongbuk 712-749 (Korea, Republic of)

    2015-01-15

    Highlights: • Pr(OH){sub 3} nanorods were synthesized by a hydrothermal method. • Pr{sub 6}O{sub 10} nanorods were obtained by a post-annealing method. • Pr(III) changed to Pr(IV) after annealing. • The physicochemical properties were fully examined. • Hydrogen reduction and CO oxidation profile were newly revealed. - Abstract: We synthesized hexagonal phase Pr(OH){sub 3} nanorods by a hydrothermal method and obtained cubic phase Pr{sub 6}O{sub 11} by post-thermal annealing at above 550 °C. Pr(OH){sub 3} nanorod growth was found to occur in the [0 0 1] direction. Upon thermal annealing, the oxidation state of Pr(III) was changed to Pr(III, IV). The physicochemical properties were fully examined by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) crystallography, UV–Visible–NIR absorption, differential scanning calorimetry/thermogravimetric analysis (DSC/TGA), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR) and CO oxidation activity tests.

  11. Accelerating the clearance of mutant huntingtin protein aggregates through autophagy induction by europium hydroxide nanorods.

    Science.gov (United States)

    Wei, Peng-Fei; Zhang, Li; Nethi, Susheel Kumar; Barui, Ayan Kumar; Lin, Jun; Zhou, Wei; Shen, Yi; Man, Na; Zhang, Yun-Jiao; Xu, Jing; Patra, Chitta Ranjan; Wen, Long-Ping

    2014-01-01

    Autophagy is one of the well-known pathways to accelerate the clearance of protein aggregates, which contributes to the therapy of neurodegenerative diseases. Although there are numerous reports that demonstrate the induction of autophagy with small molecules including rapamycin, trehalose and lithium, however, there are few reports mentioning the clearance of aggregate-prone proteins through autophagy induction by nanoparticles. In the present article, we have demonstrated that europium hydroxide [Eu(III)(OH)3] nanorods can reduce huntingtin protein aggregation (EGFP-tagged huntingtin protein with 74 polyQ repeats), responsible for neurodegenerative diseases. Again, we have found that these nanorods induce authentic autophagy flux in different cell lines (Neuro 2a, PC12 and HeLa cells) through the expression of higher levels of characteristic autophagy marker protein LC3-II and degradation of selective autophagy substrate/cargo receptor p62/SQSTM1. Furthermore, depression of protein aggregation clearance through the autophagy blockade has also been observed by using specific inhibitors (wortmannin and chloroquine), indicating that autophagy is involved in the degradation of huntingtin protein aggregation. Since [Eu(III)(OH)3] nanorods can enhance the degradation of huntingtin protein aggregation via autophagy induction, we strongly believe that these nanorods would be useful for the development of therapeutic treatment strategies for various neurodegenerative diseases in near future using nanomedicine approach. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. From layered double hydroxide to spinel nanostructures: facile synthesis and characterization of nanoplatelets and nanorods.

    Science.gov (United States)

    Sun, Genban; Sun, Lingna; Wen, He; Jia, Zhiqian; Huang, Kunlin; Hu, Changwen

    2006-07-13

    Mg-Al spinel (MgAl2O4) nanorods and nanoplatelets transformed from Mg-Al layered double hydroxide (Mg-Al-LDHs) were synthesized via a combined hydrothermal method and calcination route using Al(NO3).9H2O and Mg(NO3)2.6H2O as raw materials. The nanorods and nanoplatelets were characterized by means of physical techniques, including powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microcopy (HRTEM), selected-area electron diffraction (SAED), Fourier transform infrared spectra (FT-IR), thermogravimetric (TG), and nitrogen adsorption-desorption isotherms. XRD patterns reveal that the Mg-Al-LDHs nanostructures were obtained under a hydrothermal reaction temperature of 200 degrees C and Mg-Al spinel nanostructures were fabricated via calcination of the Mg-Al-LDHs nanostructures at 750 degrees C. It can be seen from TEM that the sizes of the Mg-Al-LDHs nanoplatelets were about 20-40 nm and the diameters of the MgAl2O4 nanorods were ca. 6 nm. The HRTEM images indicate that the crystal lattice spaces of the MgAl2O4 nanorods and nanoplatelets are 0.282 and 0.287 nm, respectively.

  13. Ion Exchange Processed CdS Nanorods in Powder Form Using Cadmium Hydroxide Nanowires By Wet Chemical Route

    Directory of Open Access Journals (Sweden)

    Savita L. Patil

    2010-06-01

    Full Text Available Simple, inexpensive and soft chemical route (wet chemical method was employed for the synthesis of bulk forms of cadmium hydroxide [Cd(OH2] nanowires bundles and their conversion to cadmium sulphide [CdS] nanorods at room temperature by simple anion exchange route. Due to difference in solubility product and diffusion rates of the Cd(OH2 and CdS, the anion exchange reaction was taken place and CdS nanorods were formed. CdS nanorods were characterized by X-ray diffraction (XRD, and scanning electron microscopy (SEM, energy-dispersive X-ray (EDX analysis. Since CdS is semi-conducting material, it has variety of potential applications, this work demonstrates a cost effective method for the synthesis of CdS nanorods in bulk form like CNT.

  14. Diamond-Like Carbon Nanorods and Fabrication Thereof

    Science.gov (United States)

    Varshney, Deepak (Inventor); Makarov, Vladimir (Inventor); Morell, Gerardo (Inventor); Saxena, Puja (Inventor); Weiner, Brad (Inventor)

    2017-01-01

    Novel sp. (sup 3) rich diamond-like carbon (DLC) nanorod films were fabricated by hot filament chemical vapor deposition technique. The results are indicative of a bottom-up self-assembly synthesis process, which results in a hierarchical structure that consists of microscale papillae comprising numerous nanorods. The papillae have diameters ranging from 2 to 4 microns and the nanorods have diameters in the 35-45 nanometer range. A growth mechanism based on the vapor liquid-solid mechanism is proposed that accounts for the morphological aspects in the micro- and nano-scales.

  15. Electrochemical Properties of Nanocomposite Nanoporous Carbon / Nickel Hydroxide

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    O.M. Hemiy

    2016-12-01

    Full Text Available The electrochemical properties of composite nanoporous carbon / nickel hydroxide as electrode material for hybrid supercapacitors were investigated. Fast reversible faradaic reactions flow was determined in connection with chemical makeup of the -Ni(OH2/С composite. It is shown that increase of nickel hydroxide concentration can intensify reactions. It is found that clean -Ni(OH2 has 238 F/g of specific capacity, but -Ni(OH2/С nanocomposite with 90 % nickel hydroxide has 292 F/g. Such capacity value can be considered as a maximum for these composites.

  16. Carbonate inhibits the crystallization of aluminum hydroxide in bauxite

    Energy Technology Data Exchange (ETDEWEB)

    Bardossy, G.; White, J.L.

    1979-01-01

    Although the role of anions such as nitrate, chloride, and sulfate in inhibiting the crystallization of aluminum hydroxide in soils and geological deposits is generally accepted, the dramatic effect of the carbonate ion in maintaining aluminum hydroxide gel in the amorphous form has been overlooked by most earth scientists. Examination of bauxite occurrences suggests that the inhibiting effect of carbonate is quite apparent in the smaller grain size of gibbsite in karstic bauxite deposits as compared to that in lateritic bauxite. Scarbroeite, a crystalline aluminum hydroxy carbonate, has been observed in rare instances. It is suggested that the highly reactive carbonate-containing aluminum hydroxide gells used as pharmaceutical antacids are amorphous or poorly crystalline forms of scarbroeite. The effect of the sulfate anion is also apparent in certain bauxite deposits where dissolution of gibbsite by sulfuric acid has resulted from the oxidation of pyrite, with subsequent reprecipitation of gibbsite.

  17. Hydrothermal Synthesis of Nanorods and Nanowires of Mg/Al Layered Double Hydroxides

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yun; JIAO Qing-ze; DING Xue-jia; ZHANG Li-qun; LIU Yuan-yuan

    2007-01-01

    @@ Layered double hydroxides (LDHs) are a class of synthetic anion clays, characterized by the formula[MⅡ1-xMⅢx (OH)2]x+ (An- )x/n·yH2O (where M =metal and A = anion, usually carbonate)[1-3]. A large number of LDHs with a wide variety of M Ⅱ-M Ⅲ cation pairs including M Ⅰ-M Ⅲ ( e. g. , Li-Al ) and M Ⅱ-MⅣ( e. g. , Co-Ti) have been reported. Thus the identities of the cations(MⅠ , MⅡ , MⅢ and MⅣ) and the interlayer anion (An-) together with the value of the stoichiometric coefficient (x) may vary widely, giving rise to a large class of isostructural materials.

  18. Preparation and characterization of gadolinium hydroxide single-crystalline nanorods by a hydrothermal process

    Institute of Scientific and Technical Information of China (English)

    Yi Dong Yin; Guang Yan Hong; Bai Fu Xin

    2007-01-01

    The Gd(OH)3 nanorods with diameters of ca. 40-60 nm and lengths of more than 400-550 nm have been prepared by a novel hydrothermal technique. The structural features and chemical composition of the nanorods were investigated by X-ray diffraction(XRD), transmission electron microscopy (TEM), and field emission scanning electron microscope (FESEM), selected area electron diffraction (SAED), and high resolution transmission electron microscopy (HRTEM). The possible mechanism for the formation of Gd(OH)3 nanorods was proposed.

  19. DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

    Energy Technology Data Exchange (ETDEWEB)

    OGDEN DM; KIRCH NW

    2007-10-31

    This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

  20. Electrodeposition of Pd Nanowires and Nanorods on Carbon Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bliznakov, S.; Vukmirovic, M.; Sutter, E.; Adzic, R.

    2011-06-01

    We report on the method for synthesizing palladium nanowires and nanorods involving the electrodeposition on oxidized amorphous carbon nanoparticles from chloride containing solutions. The effect of the deposition overpotential and the concentration of palladium ions on the morphology of the Pd electrodeposits have been established. Palladium grows predominately in the shape of nanowires if electrodeposited at potentials in the H underpotential deposition potential (UPD) range, where chloride ions are adsorbed only at the edges of nucleated monolayer-thick clusters on the carbon surface. The effect of the concentration of palladium ions on deposits morphology is also discussed. The mechanism of electrodeposition of Pd nanowires and nanorods in the H UPD potential range has been proposed.

  1. Growth of Carbon Encapsulated Long Nickel Nanorods on Bulk Nickel Substrate

    Institute of Scientific and Technical Information of China (English)

    BIN Xiaobei; CHEN Jiazang; XUE Jun; WANG Xuehua; TU Wenmao; CAO Hong

    2011-01-01

    Carbon nanotube encapsulated nickel nanorods were catalytic grown via pyrolysis of oil on a bulk nickel wire substrate. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy were employed to characterize the as-prepared sample. The results show that, carbon nanotubes possess several microns in length, the filled metallic nickel nanorods with a uniform diameter of 35 nm were tightly encapsulated by the carbon capsules. The detailed formation mechanism for the carbon nanotubes encapsulated nickel nanorods were discussed briefly.

  2. Semiconductor nanorod-carbon nanotube biomimetic films for wire-free photostimulation of blind retinas.

    Science.gov (United States)

    Bareket, Lilach; Waiskopf, Nir; Rand, David; Lubin, Gur; David-Pur, Moshe; Ben-Dov, Jacob; Roy, Soumyendu; Eleftheriou, Cyril; Sernagor, Evelyne; Cheshnovsky, Ori; Banin, Uri; Hanein, Yael

    2014-11-12

    We report the development of a semiconductor nanorod-carbon nanotube based platform for wire-free, light induced retina stimulation. A plasma polymerized acrylic acid midlayer was used to achieve covalent conjugation of semiconductor nanorods directly onto neuro-adhesive, three-dimensional carbon nanotube surfaces. Photocurrent, photovoltage, and fluorescence lifetime measurements validate efficient charge transfer between the nanorods and the carbon nanotube films. Successful stimulation of a light-insensitive chick retina suggests the potential use of this novel platform in future artificial retina applications.

  3. Effects of aluminum hydroxide and calcium carbonate antacids on the bioavailability of ciprofloxacin.

    OpenAIRE

    Frost, R W; Lasseter, K C; Noe, A J; Shamblen, E C; Lettieri, J T

    1992-01-01

    This study was designed to determine the effects of an aluminum hydroxide antacid and a calcium carbonate antacid on the bioavailability of ciprofloxacin (Cipro). Cipro (750 mg) was administered orally to 12 healthy volunteers in a three-way randomized crossover design. The three treatments included Cipro alone, four 850-mg calcium carbonate tablets taken 5 min before Cipro, and three 600-mg aluminum hydroxide tablets taken 5 min before Cipro. The relative bioavailability of Cipro when given ...

  4. Parametric Effect of Sodium Hydroxide and Sodium Carbonate on the Potency of a Degreaser

    Directory of Open Access Journals (Sweden)

    Babatope Abimbola Olufemi

    2016-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Experimental and statistical analysis was carried out on the comparative effect of sodium hydroxide and sodium carbonate on the potency of a laboratory produced degreaser in this work. The materials used include; octadecyl benzene sulphonic acid, sodium hydroxide, sodium carbonate, sodium metasilicate, carboxyl methyl cellulose (C.M.C, formadelhyde, perfume, colourant and distilled water. Different samples of degreaser were produced with varying composition of sodium hydroxide and sodium carbonate respectively. Statistical significance through methods like analysis of variance (ANOVA of some parameters on various concentrations of sodium hydroxide and sodium carbonate was investigated. The effect of the varying compositions of sodium hydroxide and sodium carbonate was also determined by using a gray scale (GS test, and also subjecting surfaces heavily stained with crude oil to determine and characterize the cleansing action of the degreaser. It was found that as the concentration of sodium hydroxide increases, the cleansing ability also increases, whereas the increase in concentration of sodium carbonate had no effect on the cleansing ability. The work would enable production of effective, useful and property controlled degreasers at moderate cost.

  5. Synthesis of Nanorods of Crystalline Co304 Using Carbon Nanotubes as Templates

    Institute of Scientific and Technical Information of China (English)

    WU,Hua-Qiang(吴华强); SHAO,Ming-Wang(邵明望); WEI,Xian-Wen(魏先文); GU,Jia-Shan(顾家山); QU,Mei-Zhen(瞿美臻)

    2002-01-01

    Synthesis of cobalt oxide (Co3O4) nanorods was achieved by templating against carbon nanotubes via wet chemical technique. The products with crystalline structure were mainly composed of Co3O4 nanorods with diameters in the range of ca. 75-100 mn and lengths in the range of 0.12-1μm, and were characterized by XRD, TEM, SAED and HRTEM.

  6. Synthesis of Dimethyl Carbonate from Methanol and Carbon Dioxide Catalyzed by Potassium Hydroxide under Mild Conditions

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide using potassium hydroxide as catalyst in the presence of CH3I and the effect of ionic liquid on the reaction were investigated. The results showed that KOH is an effective catalyst; the high selectivity and raised yield of DMC formation under mild conditions were achieved. However,the addition of the ionic liquid, 1-ethyl-3-methylimidazolium bromide (emimBr), can evidently accelerate the conversion of methanol and yield of the product.

  7. A Ni-Fe Layered Double Hydroxide-Carbon Nanotube Complex for Water Oxidation

    CERN Document Server

    Gong, Ming; Wang, Hailiang; Liang, Yongye; Wu, Justin Zachary; Zhou, Jigang; Wang, Jian; Regier, Tom; Wei, Fei; Dai, Hongjie

    2013-01-01

    Highly active, durable and cost-effective electrocatalysts for water oxidation to evolve oxygen gas hold a key to a range of renewable energy solutions including water splitting and rechargeable metal-air batteries. Here, we report the synthesis of ultrathin nickel iron layered double hydroxide nanoplates on mildly oxidized multi-walled carbon nanotubes. Incorporation of Fe into the nickel hydroxide induced the formation of NiFe-layered double hydroxide. The nanoplates were covalently attached to a network of nanotubes, affording excellent electrical wiring to the nanoplates. The ultra-thin Ni-Fe layered double hydroxide nanoplates/carbon nanotube complex was found to exhibit unusually high electro-catalytic activity and stability for oxygen evolution and outperformed commercial precious metal Ir catalysts.

  8. Self-lubricated Array Film of Amorphous Carbon Nanorods on an Aluminum Substrate

    Institute of Scientific and Technical Information of China (English)

    JIANGChun-xi; TUJiang-ping; GUOShao-yi; FUMing-fu; ZHAOXin-bing

    2004-01-01

    A self-lubricated array film of amorphous carbon nanorods was prepared by chemical catalytic pyrolysis of acetylene on the anodic aluminum oxide membrane fabricated by two-step anodization of aluminum. The tribological properties of the array film of amorphous carbon nanorods in ambient air were investigated using a ball-on-disk tester at applied loads range from 245 mN to 1960 mN at a sliding velocity of 0.2 m/s. The self-lubricated array film exhibited a small value of the friction coefficient as well as good wear resistance. The friction coefficient of array film of amorphous carbon nanorods decreased gradually with increasing the applied load. The approach proposed demonstrated a new efficient route towards enhanced the friction and wear performances of aluminum.

  9. The determination of hydroxide and carbonate in concentrated sodium chloride solutions

    NARCIS (Netherlands)

    Roolvink, W.B.; Bos, M.

    1980-01-01

    A computer method for the determination of carbonate and hydroxide in concentrated (2.89 M) sodium chloride solutions is described. The method is based on multiparametric curve-fitting and can also be applied to salts of dibasic acids with unknown equilibrium constants. The systematic error is not m

  10. Mechanochemical Reaction of Lanthanum Carbonate with Sodium Hydroxide and Preparation of Lanthanum Oxide Nanoparticle

    Institute of Scientific and Technical Information of China (English)

    李永绣; 周雪珍; 王志强

    2002-01-01

    The preparation of nano sized La2O3 powder by mechanochemical reaction of lanthanum carbonate with sodium hydroxide and subsequent heat treatment was studied using X-ray diffraction, differential thermal and thermo gravimetric analysis and transmission electron microscopy. It was found that the mechanochemical reaction process can be divided into two steps: the first step is the multi-phases mechanochemical reaction of lanthanum carbonate with NaOH to form amorphous lanthanum basic carbonate and lanthanum hydroxide, and the second step is the crystallization of basic lanthanum carbonate with the formula of La2(OH)2(CO3)2*H2O under a quasi-hydrothermal synthesis condition caused by the mechanical ball-milling. The synthesized La2O3 powder appears clearly separated spherical-like monodisperse nano-size particles in which particle size ranges from 30 to 50 nm.

  11. Effect of hydroxide and carbonate alkaline media on anion exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Vega, Jose A.; Chartier, Casey; Mustain, William E. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 191 Auditorium Rd., Unit 3222, Storrs, CT 06269 (United States)

    2010-11-01

    The effect of hydroxide and carbonate alkaline environments on the chemical stability and ionic conductivity of five commercially available anion exchange membranes was investigated. Exposure of the membranes to concentrated hydroxide environments (1 M) had a detrimental effect on ionic conductivity with time. Over a 30-day period, decreases in conductivity ranged from 27% to 6%, depending on the membrane. The decrease in ionic conductivity is attributed to the loss of stationary cationic sites due to the Hofmann elimination and nucleophilic displacement mechanisms. Exposure of the membranes to low concentration hydroxide (10{sup -4} M) or carbonate/bicarbonate (0.5 M Na{sub 2}CO{sub 3}/0.5 M NaHCO{sub 3}) environments had no measurable effect on the ionic conductivity over a 30-day period. ATR-FTIR spectroscopy confirmed degradation of membranes soaked in 1 M KOH. Apparition of a doublet peak in the region between 1600 cm{sup -1} and 1675 cm{sup -1} confirms formation of carbon-carbon double bonds due to Hofmann elimination. Membranes soaked in mild alkaline environments did not show formation of carbon-carbon double bonds. (author)

  12. Fabrication of Vertically Aligned Carbon Nanotube or Zinc Oxide Nanorod Arrays for Optical Diffraction Gratings.

    Science.gov (United States)

    Kim, Jeong; Kim, Sun Il; Cho, Seong-Ho; Hwang, Sungwoo; Lee, Young Hee; Hur, Jaehyun

    2015-11-01

    We report on new fabrication methods for a transparent, hierarchical, and patterned electrode comprised of either carbon nanotubes or zinc oxide nanorods. Vertically aligned carbon nanotubes or zinc oxide nanorod arrays were fabricated by either chemical vapor deposition or hydrothermal growth, in combination with photolithography. A transparent conductive graphene layer or zinc oxide seed layer was employed as the transparent electrode. On the patterned surface defined using photoresist, the vertically grown carbon nanotubes or zinc oxides could produce a concentrated electric field under applied DC voltage. This periodic electric field was used to align liquid crystal molecules in localized areas within the optical cell, effectively modulating the refractive index. Depending on the material and morphology of these patterned electrodes, the diffraction efficiency presented different behavior. From this study, we established the relationship between the hierarchical structure of the different electrodes and their efficiency for modulating the refractive index. We believe that this study will pave a new path for future optoelectronic applications.

  13. Potassium hydroxide catalyst supported on palm shell activated carbon for transesterification of palm oil

    Energy Technology Data Exchange (ETDEWEB)

    Baroutian, Saeid; Aroua, Mohamed Kheireddine; Raman, Abdul Aziz Abdul; Sulaiman, Nik Meriam Nik [Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2010-11-15

    In this study, potassium hydroxide catalyst supported on palm shell activated carbon was developed for transesterification of palm oil. The Central Composite Design (CCD) of the Response Surface Methodology (RSM) was employed to investigate the effects of reaction temperature, catalyst loading and methanol to oil molar ratio on the production of biodiesel using activated carbon supported catalyst. The highest yield was obtained at 64.1 C reaction temperature, 30.3 wt.% catalyst loading and 24:1 methanol to oil molar ratio. The physical and chemical properties of the produced biodiesel met the standard specifications. This study proves that activated carbon supported potassium hydroxide is an effective catalyst for transesterification of palm oil. (author)

  14. Synthesis and carbon dioxide sorption of layered double hydroxide/silica foam nanocomposites with hierarchical mesostructure

    KAUST Repository

    Fu, Liling

    2014-03-05

    Layered double hydroxides (LDHs) with a hierarchical mesostructure are successfully synthesized on mesoporous silica foams by simple impregnation and hydrothermal treatment. The as-synthesized LDH/silica foam nanocomposites show well-defined mesostructures with high surface areas, large pore volumes, and mesopores of 6-7 nm. The nanocomposites act as carbon dioxide (CO2) sorbents under simulated flue gas conditions. They also exhibit significantly enhanced CO2 capacities under high-pressure conditions and high CO2/N2 and CO2/CH4 selectivities. Respect the hierarchy: Hierarchical mesoporous layered double hydroxide (LDH) nanocomposites with high surface areas and large pore volumes are synthesized by controlled hydrothermal growth of LDH precursors on a mesoporous silica foam. The as-synthesized nanocomposites exhibit a significantly enhanced capacity and selectivity towards carbon dioxide, making them very promising candidates for carbon dioxide (CO2) separation applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Production of activated carbons from pyrolysis of waste tires impregnated with potassium hydroxide.

    Science.gov (United States)

    Teng, H; Lin, Y C; Hsu, L Y

    2000-11-01

    Activated carbons were produced from waste tires using a chemical activation method. The carbon production process consisted of potassium hydroxide (KOH) impregnation followed by pyrolysis in N2 at 600-900 degrees C for 0-2 hr. The activation method can produce carbons with a surface area (SA) and total pore volume as high as 470 m2/g and 0.57 cm3/g, respectively. The influence of different parameters during chemical activation, such as pyrolysis temperature, holding time, and KOH/tire ratio, on the carbon yield and the surface characteristics was explored, and the optimum preparation conditions were recommended. The pore volume of the resulting carbons generally increases with the extent of carbon gasified by KOH and its derivatives, whereas the SA increases with degree of gasification to reach a maximum value, and then decreases upon further gasification.

  16. Catalytic Studies of Sodium Hydroxide and Carbon Monoxide Reaction

    Directory of Open Access Journals (Sweden)

    Surendra K. Saxena

    2012-11-01

    Full Text Available We have studied the effect of ball milling on alumina mixed nickel, magnetite and Raney nickel on the reaction: 2NaOH(s + CO (g = Na2CO3 (s + H2 (g and determined the optimum particle size for the catalysts. The best performance was shown by a 2 h ball milled Raney nickel with average crystallite size of 209 Å. This reaction serves the dual purpose of carbon sequestration and yielding hydrogen gas.

  17. Adsorption of pharmaceuticals to microporous activated carbon treated with potassium hydroxide, carbon dioxide, and steam.

    Science.gov (United States)

    Fu, Heyun; Yang, Liuyan; Wan, Yuqiu; Xu, Zhaoyi; Zhu, Dongqiang

    2011-01-01

    Adsorption of sulfapyridine, tetracycline, and tylosin to a commercial microporous activated carbon (AC) and its potassium hydroxide (KOH)-, CO-, and steam-treated counterparts (prepared by heating at 850°C) was studied to explore efficient adsorbents for the removal of selected pharmaceuticals from water. Phenol and nitrobenzene were included as additional adsorbates, and nonporous graphite was included as a model adsorbent. The activation treatments markedly increased the specific surface area and enlarged the pore sizes of the mesopores of AC (with the strongest effects shown on the KOH-treated AC). Adsorption of large-size tetracycline and tylosin was greatly enhanced, especially for the KOH-treated AC (more than one order of magnitude), probably due to the alleviated size-exclusion effect. However, the treatments had little effect on adsorption of low-size phenol and nitrobenzene due to the predominance of micropore-filling effect in adsorption and the nearly unaffected content of small micropores causative to such effect. These hypothesized mechanisms on pore-size dependent adsorption were further tested by comparing surface area-normalized adsorption data and adsorbent pore size distributions with and without the presence of adsorbed antibiotics. The findings indicate that efficient adsorption of bulky pharmaceuticals to AC can be achieved by enlarging the adsorbent pore size through suitable activation treatments.

  18. Carbonation acceleration of calcium hydroxide nanoparticles: induced by yeast fermentation

    Science.gov (United States)

    Lopez-Arce, Paula; Zornoza-Indart, Ainara

    2015-09-01

    Carbonation of Ca(OH)2 nanoparticles and consolidation of limestone are accelerated by high humidity and a yeast fermentation system that supplies a saturated atmosphere on CO2, H2O vapor and ethanol during 28 days. Nanoparticles were analyzed by X-ray diffraction and differential thermal analyses with thermogravimetry. Spectrophotometry, scanning electron microscopy analyses, and hydric and mechanical tests were also performed in stones specimens. Samples exposed to the yeast environment achieve 100 % relative CaCO3 yield, whereas at high humidity but without the yeast and under laboratory environment, relative yields of 95 % CaCO3 and 15 % CaCO3 are, respectively, reached, with white crusts and glazing left on the stone surfaces when the nanoparticles are applied at a concentration of 25 g/l. The largest increase in the drilling resistance and surface hardness values with slight increase in the capillarity absorption and desorption coefficients and with lesser stone color changes are produced at a concentration of 5 g/l, in the yeast system environment. This especially happens in stone specimens initially with bimodal pore size distributions, more amounts of pores with diameters between 0.1 and 1 µm, higher open porosity values and faster capillary coefficients. An inexpensive and reliable method based on water and yeast-sugar solution is presented to speed up carbonation of Ca(OH)2 nanoparticles used as a consolidating product to improve the mechanical properties of decayed limestone from archaeological and architectural heritage.

  19. Flexible solid-state supercapacitors based on carbon nanoparticles/MnO2 nanorods hybrid structure.

    Science.gov (United States)

    Yuan, Longyan; Lu, Xi-Hong; Xiao, Xu; Zhai, Teng; Dai, Junjie; Zhang, Fengchao; Hu, Bin; Wang, Xue; Gong, Li; Chen, Jian; Hu, Chenguo; Tong, Yexiang; Zhou, Jun; Wang, Zhong Lin

    2012-01-24

    A highly flexible solid-state supercapacitor was fabricated through a simple flame synthesis method and electrochemical deposition process based on a carbon nanoparticles/MnO(2) nanorods hybrid structure using polyvinyl alcohol/H(3)PO(4) electrolyte. Carbon fabric is used as a current collector and electrode (mechanical support), leading to a simplified, highly flexible, and lightweight architecture. The device exhibited good electrochemical performance with an energy density of 4.8 Wh/kg at a power density of 14 kW/kg, and a demonstration of a practical device is also presented, highlighting the path for its enormous potential in energy management.

  20. Carbon-Coated SnO2 Nanorod Array for Lithium-Ion Battery Anode Material

    Directory of Open Access Journals (Sweden)

    Ji Xiaoxu

    2010-01-01

    Full Text Available Abstract Carbon-coated SnO2 nanorod array directly grown on the substrate has been prepared by a two-step hydrothermal method for anode material of lithium-ion batteries (LIBs. The structural, morphological and electrochemical properties were investigated by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM and electrochemical measurement. When used as anodes for LIBs with high current density, as-obtained array reveals excellent cycling stability and rate capability. This straightforward approach can be extended to the synthesis of other carbon-coated metal oxides for application of LIBs.

  1. Carbon dioxide capture capacity of sodium hydroxide aqueous solution.

    Science.gov (United States)

    Yoo, Miran; Han, Sang-Jun; Wee, Jung-Ho

    2013-01-15

    The present paper investigates the various features of NaOH aqueous solution when applied as an absorbent to capture carbon dioxide (CO(2)) emitted with relatively high concentration in the flue gas. The overall CO(2) absorption reaction was carried out according to consecutive reaction steps that are generated in the order of Na(2)CO(3) and NaHCO(3). The reaction rate and capture efficiency were strongly dependent on the NaOH concentration in the Na(2)CO(3) production range, but were constant in the NaHCO(3) production step, irrespective of the NaOH concentration. The amount of CO(2) absorbed in the solution was slightly less than the theoretical value, which was ascribed to the low trona production during the reaction and the consequent decrease in CO(2) absorption in the NaOH solution. The mass ratio of absorbed CO(2) that participated in the Na(2)CO(3), NaHCO(3), and trona production reactions was calculated to be 20:17:1, respectively.

  2. High photocatalytic activity of immobilized TiO{sub 2} nanorods on carbonized cotton fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bin, E-mail: bwang23@cityu.edu.hk [Ability R and D Energy Research Center, School of Energy and Environment, City University of Hong Kong, Hong Kong (China); Karthikeyan, Rengasamy; Lu, Xiao-Ying [Ability R and D Energy Research Center, School of Energy and Environment, City University of Hong Kong, Hong Kong (China); Xuan, Jin [Ability R and D Energy Research Center, School of Energy and Environment, City University of Hong Kong, Hong Kong (China); State-Key Laboratory of Chemical Engineering, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China); Leung, Michael K.H., E-mail: mkh.leung@cityu.edu.hk [Ability R and D Energy Research Center, School of Energy and Environment, City University of Hong Kong, Hong Kong (China)

    2013-12-15

    Highlights: • Hollow carbon fibers derived from natural cotton was successfully prepared by pyrolysis method. • TiO{sub 2} nanorods immobilized on carbon fibers by a facile hydrothermal method showed high photocatalytic activity. • The enhancement was due to the reduced band gap, improved dye adsorption capacity and effective electron–hole separation. -- Abstract: In this study, TiO{sub 2} nanorods were successfully immobilized on carbon fibers by a facile pyrolysis of natural cotton in nitrogen atmosphere followed by a one-pot hydrothermal method. Carbonized cotton fibers (CCFs) and TiO{sub 2}-CCFs composites were characterized using field-emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, X-ray diffractometer (XRD), diffuse reflectance UV–vis spectroscopy (DRS) and photoluminescence (PL) spectroscopy. Results implied that the band gap narrowing of TiO{sub 2} was achieved after integration of CCFs. Dye adsorption isotherm indicated that the maximum dye adsorption capacity (q{sub m}) of CCFs-1000 (13.4 mg/g) was 2 times higher than that of cotton fibers and q{sub m} of TiO{sub 2}-CCFs-1000 (9.0 mg/g) was 6–7 times higher than that of TiO{sub 2} nanorods. Photocatalytic activity of TiO{sub 2} nanorods prepared with 3 mL Ti(OBu){sub 4} showed the highest photocatalytic activity. TiO{sub 2}-CCFs-1000 exhibited higher activity than TiO{sub 2} immobilized on CCFs-400, CCFs-600 and CCFs-800. Good photostability of TiO{sub 2}-CCFs-1000 was found for dye degradation under visible light irradiation. The enhancement of photocatalytic dye degradation was due to the high adsorptivity of dye molecules, enhanced light adsorption and effective separation of electron–hole pairs. This work provides a low-cost and sustainable approach to immobilize nanostructured TiO{sub 2} on carbon fibers for environmental remediation.

  3. From spent Mg/Al layered double hydroxide to porous carbon materials.

    Science.gov (United States)

    Laipan, Minwang; Zhu, Runliang; Chen, Qingze; Zhu, Jianxi; Xi, Yunfei; Ayoko, Godwin A; He, Hongping

    2015-12-30

    Adsorption has been considered as an efficient method for the treatment of dye effluents, but proper disposal of the spent adsorbents is still a challenge. This work attempts to provide a facile method to reutilize the spent Mg/Al layered double hydroxide (Mg/Al-LDH) after the adsorption of orange II (OII). Herein, the spent hybrid was carbonized under the protection of nitrogen, and then washed with acid to obtain porous carbon materials. Thermogravimetric analysis results suggested that the carbonization could be well achieved above 600°C, as mass loss of the spent hybrid gradually stabilized. Therefore, the carbonization process was carried out at 600, 800, and 1000°C, respectively. Scanning electron microscope showed that the obtained carbon materials possessed a crooked flaky morphology. Nitrogen adsorption-desorption results showed that the carbon materials had large BET surface area and pore volume, e.g., 1426 m(2)/g and 1.67 cm(3)/g for the sample carbonized at 800°C. Moreover, the pore structure and surface chemistry compositions were tunable, as they were sensitive to the temperature. Toluene adsorption results demonstrated that the carbon materials had high efficiency in toluene removal. This work provided a facile approach for synthesizing porous carbon materials using spent Mg/Al-LDH.

  4. A novel method to encapsulate a Au nanorod array in 15 nm radius multiwalled carbon nanotubes

    Science.gov (United States)

    Liao, Gaomin; Pan, Yuanyuan; Wu, Qiang; Li, Shaoyun; Weng, Yuyan; Zhang, Xiaohua; Yang, Zhaohui; Guo, Jun; Chen, Muzi; Tang, Minghua; Tsui, Ophelia K. C.

    2014-11-01

    In this paper we demonstrate a novel complex array structure comprising well-aligned Au nanorods (10 nm in diameter) encapsulated inside 15 nm radius multiwalled carbon nanotubes (MWCNTs). A pre-aligned and open-ended nanoporous MWCNT membrane is used as the starting material. Au nanorods are precisely deposited and aligned inside the hollow channels of CNTs by inter-diffusing the HAuCl4 precursor and the reductant solution. Ultra-long Au nanowires and spherical Au nanoparticles are also observed in the CNT cavity with the same diameter in special cases. Using high-resolution TEM (HRTEM), scanning transmission electron microscopy (STEM), 3-dimensional TEM (3D-TEM) and energy dispersive X-ray spectroscopy (EDX), the precise location and composition of the encapsulated Au components with various structures are confirmed. This aligned Au@CNT endohedral material has important potential applications in nanocatalysis, waveguides, as well as in novel plasmonic devices.In this paper we demonstrate a novel complex array structure comprising well-aligned Au nanorods (10 nm in diameter) encapsulated inside 15 nm radius multiwalled carbon nanotubes (MWCNTs). A pre-aligned and open-ended nanoporous MWCNT membrane is used as the starting material. Au nanorods are precisely deposited and aligned inside the hollow channels of CNTs by inter-diffusing the HAuCl4 precursor and the reductant solution. Ultra-long Au nanowires and spherical Au nanoparticles are also observed in the CNT cavity with the same diameter in special cases. Using high-resolution TEM (HRTEM), scanning transmission electron microscopy (STEM), 3-dimensional TEM (3D-TEM) and energy dispersive X-ray spectroscopy (EDX), the precise location and composition of the encapsulated Au components with various structures are confirmed. This aligned Au@CNT endohedral material has important potential applications in nanocatalysis, waveguides, as well as in novel plasmonic devices. Electronic supplementary information (ESI

  5. Sunlight-Induced Photochemical Degradation of Methylene Blue by Water-Soluble Carbon Nanorods

    Directory of Open Access Journals (Sweden)

    Anshu Bhati

    2016-01-01

    Full Text Available Water-soluble graphitic hollow carbon nanorods (wsCNRs are exploited for their light-driven photochemical activities under outdoor sunlight. wsCNRs were synthesized by a simple pyrolysis method from castor seed oil, without using any metal catalyst or template. wsCNRs exhibited the light-induced photochemical degradation of methylene blue used as a model pollutant by the generation of singlet oxygen species. Herein, we described a possible degradation mechanism of methylene blue under the irradiation of visible photons via the singlet oxygen-superoxide anion pathway.

  6. Formation of silicon carbide nanorods from wood-based carbons

    NARCIS (Netherlands)

    Hata, T; Castro, [No Value; Fujisawa, M; Imamura, Y; Bonnamy, S; Bronsveld, P; Kikuchi, H

    2005-01-01

    Man-made ceramic wood similar to petrified wood found in nature can be used at high temperature as the high oxidation rate of carbon above 500 degrees C is suppressed by a mu m thin SiC coating similar to the shuttle's heat shield. Possible applications are in the field of energy production, e.g., g

  7. Rapid exchange between atmospheric CO2 and carbonate anion intercalated within magnesium rich layered double hydroxide.

    Science.gov (United States)

    Sahoo, Pathik; Ishihara, Shinsuke; Yamada, Kazuhiko; Deguchi, Kenzo; Ohki, Shinobu; Tansho, Masataka; Shimizu, Tadashi; Eisaku, Nii; Sasai, Ryo; Labuta, Jan; Ishikawa, Daisuke; Hill, Jonathan P; Ariga, Katsuhiko; Bastakoti, Bishnu Prasad; Yamauchi, Yusuke; Iyi, Nobuo

    2014-10-22

    The carbon cycle, by which carbon atoms circulate between atmosphere, oceans, lithosphere, and the biosphere of Earth, is a current hot research topic. The carbon cycle occurring in the lithosphere (e.g., sedimentary carbonates) is based on weathering and metamorphic events so that its processes are considered to occur on the geological time scale (i.e., over millions of years). In contrast, we have recently reported that carbonate anions intercalated within a hydrotalcite (Mg0.75Al0.25(OH)2(CO3)0.125·yH2O), a class of a layered double hydroxide (LDH), are dynamically exchanging on time scale of hours with atmospheric CO2 under ambient conditions. (Ishihara et al., J. Am. Chem. Soc. 2013, 135, 18040-18043). The use of (13)C-labeling enabled monitoring by infrared spectroscopy of the dynamic exchange between the initially intercalated (13)C-labeled carbonate anions and carbonate anions derived from atmospheric CO2. In this article, we report the significant influence of Mg/Al ratio of LDH on the carbonate anion exchange dynamics. Of three LDHs of various Mg/Al ratios of 2, 3, or 4, magnesium-rich LDH (i.e., Mg/Al ratio = 4) underwent extremely rapid exchange of carbonate anions, and most of the initially intercalated carbonate anions were replaced with carbonate anions derived from atmospheric CO2 within 30 min. Detailed investigations by using infrared spectroscopy, scanning electron microscopy, powder X-ray diffraction, elemental analysis, adsorption, thermogravimetric analysis, and solid-state NMR revealed that magnesium rich LDH has chemical and structural features that promote the exchange of carbonate anions. Our results indicate that the unique interactions between LDH and CO2 can be optimized simply by varying the chemical composition of LDH, implying that LDH is a promising material for CO2 storage and/or separation.

  8. Sodium hydroxide-mediated hydrogel of citrus pectin for preparation of fluorescent carbon dots for bioimaging.

    Science.gov (United States)

    Zhao, Xi Juan; Zhang, Wen Lin; Zhou, Zhi Qin

    2014-11-01

    The citrus process industry produces annually a huge amount of pomace, which is a rich source of citrus pectin. Here, we report the hydrogel of citrus pectin mediated by sodium hydroxide can be used to prepare fluorescent carbon dots (CDs). The introduction of hydrogel can not only make the temperature of the hydrothermal reaction down to 100 °C, but also avoid visually carbonized precipitates in the synthesis process even up to 180 °C. The as-synthesized CDs are well dispersed in water with an average size of 2.7 nm and show cyan fluorescence with high photostability, good biocompatibility. Furthermore, the CDs can act as a potential fluorescent probe for cell imaging. Citrus pectin as a non-toxic carbonaceous precursor for preparation of fluorescent CDs provides a new approach for the efficient utilization of citrus germplasm in future.

  9. Effects of potassium hydroxide post-treatments on the field-emission properties of thermal chemical vapor deposited carbon nanotubes.

    Science.gov (United States)

    Lee, Li-Ying; Lee, Shih-Fong; Chang, Yung-Ping; Hsiao, Wei-Shao

    2011-12-01

    In this study, a simple potassium hydroxide treatment was applied to functionalize the surface and to modify the structure of multi-walled carbon nanotubes grown on silicon substrates by thermal chemical vapor deposition. Scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and energy dispersive spectrometry were employed to investigate the mechanism causing the modified field-emission properties of carbon nanotubes. From our experimental data, the emitted currents of carbon nanotubes after potassium hydroxide treatment are enhanced by more than one order of magnitude compared with those of untreated carbon nanotubes. The emitted current density of carbon nanotubes increases from 0.44 mA/cm2 to 7.92 mA/cm2 after 30 minutes KOH treatment. This technique provides a simple, economical, and effective way to enhance the field-emission properties of carbon nanotubes.

  10. Removal of oxyanions from synthetic wastewater via carbonation process of calcium hydroxide: applied and fundamental aspects.

    Science.gov (United States)

    Montes-Hernandez, G; Concha-Lozano, N; Renard, F; Quirico, E

    2009-07-30

    Removal of oxyanions (selenite, selenate, arsenate, phosphate and nitrate) during calcite formation was experimentally studied using aqueous carbonation of calcium hydroxide under moderate pressure (P(CO2) congruent with 20 bar) and temperature (30 degrees C). The effects of Ca(OH)(2) dose (10 and 20 g), Ca(OH)(2) source (commercial pure material or alkaline paper mill waste) and oxyanion initial concentration (from 0 to 70 mg atom/L) were investigated for this anisobaric gas-liquid-solid system. The Ca(OH)(2) carbonation reaction allowed successfully the removal of selenite (>90%), arsenate (>78%) and phosphate (congruent with 100%) from synthetic solutions. Conversely, nitrate and selenate had not any physicochemical affinity/effect during calcite formation. The rate of CO(2) transfer during calcite formation in presence of oxyanions was equal or slower than for an oxyanion-free system, allowing to define a retarding kinetic factor RF that can vary between 0 (no retarding effect) to 1 (total inhibition). For selenite and phosphate RF was quite high, close to 0.3. A small retarding effect was detected for arsenate (RF approximately 0.05) and no retarding effect was detected for selenate and nitrate (RF approximately 0). In general, RF depends on the oxyanion initial concentration, oxyanion nature and Ca(OH)(2) dose. The presence of oxyanions could also influence the crystal morphology and aggregation/agglomeration process. For example, a c-axis elongation of calcite crystals was clearly observed at the equilibrium, for calcite formation in presence of selenite and phosphate. The oxyanions removal process proposed herein was inspired on the common physicochemical treatment of wastewater using calcium hydroxide (Ca(OH)(2)). The particularity, for this novel method is the simultaneous calcium hydroxide carbonation with compressed carbon dioxide in order to stabilise the solid matter. This economical and ecological method could allow the removal of various oxyanions

  11. Nano-porous architecture of N-doped carbon nanorods grown on graphene to enable synergetic effects of supercapacitance

    Science.gov (United States)

    Fan, H. S.; Wang, H.; Zhao, N.; Xu, J.; Pan, F.

    2014-01-01

    A novel nano-porous 3D architecture of N-doped carbon nanorods arrays grown on the surface of graphene has been prepared by carbonizing polyaniline/graphene oxide (PANI-GO) composite with PANI nanorod arrays on both sides of GO nanosheets. The obtained carbon materials are entirely composed of regularly grown carbon nanorods on graphene with height of about 100 nm and width about 30 nm, showing porous property due to the decomposition of PANI chains. The morphology of PANI grown on GO at the different growth stages was investigated to demonstrate the mechanism of the finally hierarchical architecture formation. Due to its large specific surface area and incorporation of the nitrogen groups into the carbon matrix, the obtained 3D carbon material enhances the ionic transport and the super-capacitance by synergetic effect of both double-layer and faradaic capacitances. This study provides a controllable approach to fabricate hierarchical carbon material based on conducting polymers and graphene oxide with promising applications in the high-rate electrode material of supercapacitors. PMID:25519206

  12. Nano-porous architecture of N-doped carbon nanorods grown on graphene to enable synergetic effects of supercapacitance.

    Science.gov (United States)

    Fan, H S; Wang, H; Zhao, N; Xu, J; Pan, F

    2014-12-18

    A novel nano-porous 3D architecture of N-doped carbon nanorods arrays grown on the surface of graphene has been prepared by carbonizing polyaniline/graphene oxide (PANI-GO) composite with PANI nanorod arrays on both sides of GO nanosheets. The obtained carbon materials are entirely composed of regularly grown carbon nanorods on graphene with height of about 100 nm and width about 30 nm, showing porous property due to the decomposition of PANI chains. The morphology of PANI grown on GO at the different growth stages was investigated to demonstrate the mechanism of the finally hierarchical architecture formation. Due to its large specific surface area and incorporation of the nitrogen groups into the carbon matrix, the obtained 3D carbon material enhances the ionic transport and the super-capacitance by synergetic effect of both double-layer and faradaic capacitances. This study provides a controllable approach to fabricate hierarchical carbon material based on conducting polymers and graphene oxide with promising applications in the high-rate electrode material of supercapacitors.

  13. A new one-step synthesis method for coating multi-walled carbon nanotubes with iron oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Song Haojie, E-mail: songhj@ujs.edu.cn; Qian Jing [Jiangsu University, School of Material Science and Engineering (China); Jia Xiaohua [Jiangsu University, School of the Environment (China); Yang Xiaofei; Tang Hua; Min Chunying [Jiangsu University, School of Material Science and Engineering (China)

    2012-01-15

    A facile solution-chemical method has been developed to be capable of covering a multiwalled carbon nanotube (MWNTs) with iron oxide nanorods without using any bridging species. MWNTs in this composite were decorated randomly by {alpha}-Fe{sub 2}O{sub 3} nanorods with diameters in the range of 3-5 nm and lengths of 15-30 nm. The formation route to anchor {alpha}-Fe{sub 2}O{sub 3} nanorods onto MWNTs was proposed as the intercalation and adsorption of iron ions onto the wall of MWNTs, followed by the nucleation and growth of {alpha}-Fe{sub 2}O{sub 3} nanorods. {alpha}-Fe{sub 2}O{sub 3}/MWNTs nanocomposites show specific high Brunauer-Emmett-Teller surface areas. The photocatalytic activity experiment indicated that the prepared {alpha}-Fe{sub 2}O{sub 3}/MWNTs nanocomposites exhibited a higher photocatalytic activity for the photocatalytic decolorization of rhodamine B aqueous solution under the visible-light illumination than the single phase {alpha}-Fe{sub 2}O{sub 3} samples. This methodology made the synthesis of MWNTs-nanorods composites possible and may be further extended to prepare more complicated nanocomposites based on MWNTs for technological applications.

  14. Core-Shell Structure of a Silicon Nanorod/Carbon Nanotube Field Emission Cathode

    Directory of Open Access Journals (Sweden)

    Bohr-Ran Huang

    2012-01-01

    Full Text Available A novel core-shell structure of silicon nanorods/carbon nanotubes (SiNRs/CNTs is developed for use in field emission cathodes. The CNTs were synthesized on SiNRs, using the Ag-assisted electroless etching technique to form the SiNRs/CNT core-shell structure. This resulting SiNRs/CNT field emission cathode demonstrated improved field emission properties including a lower turn-on electric field on (1.3 V/μm, 1 μA/cm2, a lower threshold electric field th (1.8 V/μm, 1 mA/cm2, and a higher enhancement factor (2347. These superior properties indicate that this core-shell structure of SiNRs/CNTs has good potential in field emission cathode applications.

  15. Layered double hydroxide materials coated carbon electrode: New challenge to future electrochemical power devices

    Science.gov (United States)

    Djebbi, Mohamed Amine; Braiek, Mohamed; Namour, Philippe; Ben Haj Amara, Abdesslem; Jaffrezic-Renault, Nicole

    2016-11-01

    Layered double hydroxides (LDHs) have been widely used in the past years due to their unique physicochemical properties and promising applications in electroanalytical chemistry. The present paper is going to focus exclusively on magnesium-aluminum and zinc-aluminum layered double hydroxides (MgAl & ZnAl LDHs) in order to investigate the property and structure of active cation sites located within the layer structure. The MgAl and ZnAl LDH nanosheets were prepared by the constant pH co-precipitation method and uniformly supported on carbon-based electrode materials to fabricate an LDH electrode. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy revealed the LDH form and well-crystallized materials. Wetting surface properties (hydrophilicity and hydrophobicity) of both prepared LDHs were recorded by contact angle measurement show hydrophilic character and basic property. The electrochemical performance of these hybrid materials was investigated by mainly cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques to identify the oxidation/reduction processes at the electrode/electrolyte interface and the effect of the divalent metal cations in total reactivity. The hierarchy of the modified electrode proves that the electronic conductivity of the bulk material is considerably dependent on the divalent cation and affects the limiting parameter of the overall redox process. However, MgAl LDH shows better performance than ZnAl LDH, due to the presence of magnesium cations in the layers. Following the structural, morphological and electrochemical behavior studies of both synthesized LDHs, the prepared LDH modified electrodes were tested through microbial fuel cell configuration, revealing a remarkable, potential new pathway for high-performance and cost-effective electrode use in electrochemical power devices.

  16. Endothelialization of TiO2 Nanorods Coated with Ultrathin Amorphous Carbon Films

    Science.gov (United States)

    Chen, Hongpeng; Tang, Nan; Chen, Min; Chen, Dihu

    2016-03-01

    Carbon plasma nanocoatings with controlled fraction of sp3-C bonding were deposited on TiO2 nanorod arrays (TNAs) by DC magnetic-filtered cathodic vacuum arc deposition (FCVAD). The cytocompatibility of TNA/carbon nanocomposites was systematically investigated. Human umbilical vein endothelial cells (HUVECs) were cultured on the nanocomposites for 4, 24, and 72 h in vitro. It was found that plasma-treated TNAs exhibited excellent cell viability as compared to the untreated. Importantly, our results show that cellular responses positively correlate with the sp3-C content. The cells cultured on high sp3-C-contented substrates exhibit better attachment, shape configuration, and proliferation. These findings indicate that the nanocomposites with high sp3-C content possessed superior cytocompatibility. Notably, the nanocomposites drastically reduced platelet adhesion and activation in our previous studies. Taken together, these findings suggest the TNA/carbon scaffold may serve as a guide for the design of multi-functionality devices that promotes endothelialization and improves hemocompatibility.

  17. Layered double hydroxide materials coated carbon electrode: New challenge to future electrochemical power devices

    Energy Technology Data Exchange (ETDEWEB)

    Djebbi, Mohamed Amine, E-mail: mohamed.djebbi@etu.univ-lyon1.fr [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Braiek, Mohamed [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Namour, Philippe [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France); Irstea, 5 rue de la Doua, 69100 Villeurbanne (France); Ben Haj Amara, Abdesslem [Laboratoire de Physique des Matériaux Lamellaires et Nano-Matériaux Hybrides, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Bizerte (Tunisia); Jaffrezic-Renault, Nicole [Institut des Sciences Analytiques UMR CNRS 5280, Université Claude Bernard-Lyon 1, 5 rue de la Doua, 69100 Villeurbanne (France)

    2016-11-15

    Highlights: • MgAl and ZnAl LDH nanosheets were chemically synthesized and deposited over carbon electrode materials. • Catalytic performance of both LDHs was investigated for Fe(II) reduction reaction. • Satisfactory results have been achieved with the MgAl LDH material. • MgAl and ZnAl LDH modified carbon felt were applied in MFC as an efficient anode catalyst. • The LDH-modified anode significantly increased power performance of MFC. - Abstract: Layered double hydroxides (LDHs) have been widely used in the past years due to their unique physicochemical properties and promising applications in electroanalytical chemistry. The present paper is going to focus exclusively on magnesium-aluminum and zinc-aluminum layered double hydroxides (MgAl & ZnAl LDHs) in order to investigate the property and structure of active cation sites located within the layer structure. The MgAl and ZnAl LDH nanosheets were prepared by the constant pH co-precipitation method and uniformly supported on carbon-based electrode materials to fabricate an LDH electrode. Characterization by powder x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy revealed the LDH form and well-crystallized materials. Wetting surface properties (hydrophilicity and hydrophobicity) of both prepared LDHs were recorded by contact angle measurement show hydrophilic character and basic property. The electrochemical performance of these hybrid materials was investigated by mainly cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry techniques to identify the oxidation/reduction processes at the electrode/electrolyte interface and the effect of the divalent metal cations in total reactivity. The hierarchy of the modified electrode proves that the electronic conductivity of the bulk material is considerably dependent on the divalent cation and affects the limiting parameter of the overall redox process. However

  18. Arsenic transformation and adsorption by iron hydroxide/manganese dioxide doped straw activated carbon

    Science.gov (United States)

    Xiong, Ying; Tong, Qiang; Shan, Weijun; Xing, Zhiqiang; Wang, Yuejiao; Wen, Siqi; Lou, Zhenning

    2017-09-01

    Iron hydroxide/manganese dioxide doped straw activated carbon was synthesized for As(III) adsorption. The Fe-Mn-SAc adsorbent has two advantages, on the one hand, the straw active carbon has a large surface area (1360.99 m2 g-1) for FeOOH and MnO2 deposition, on the other hand, the manganese dioxide has oxidative property as a redox potential of (MnO2 + H+)/Mn2+, which could convert As(III) into As(V). Combined with the arsenic species after reacting with Fe-Mn-SAc, the As(III) transformation and adsorption mechanism was discussed. H2AsO4-oxidized from As(III) reacts with the Fe-Mn-SAc by electrostatic interaction, and unoxidized As(III) as H3AsO3 reacts with SAc and/or iron oxide surface by chelation effect. The adsorption was well-described by Langmuir isotherms model, and the adsorption capacity of As(III) was 75.82 mg g-1 at pH 3. Therefore, considering the straw as waste biomass material, the biosorbent (Fe-Mn-SAc) is promising to be exploited for applications in the treatment of industrial wastewaters containing a certain ratio of arsenic and germanium.

  19. Glycolysis of carbon fiber-epoxy unidirectional mat catalysed by sodium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Zaini, Mariana Binti Mohd [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Badri, Khairiah Haji [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia and Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43 (Malaysia)

    2014-09-03

    This study was conducted to recycle carbon fibre-epoxy (CFRP) composite in woven sheet/ mat form. The CFRP was recycled through glycolysis with polyethlyene glycol (PEG 200) as the solvent. The CFRP was loaded into the solvent at a ratio of 4:1 (w/w). PEG200 was diluted with water to a ratio of 80:20 (v/v). This reaction was catalysed by sodium hydroxide (NaOH) solution with varying concentrations at 1.5, 1.7 and 1.9% (w/v). The glycolysis was conducted at 180-190 °C. The recovered CF (rCF) was analysed using Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray (EDX) while the degraded solution was analysed using FTIR and the epoxy content was determined. The FTIR spectrum of the rCF exhibited the disappearance of the COC peak belonged to epoxy and supported by the SEM micrographs that showed clear rCF. On the other hand, the analysed filtrate detected the disappearance of oxygen peak element in the EDX spectrum for all rCF samples. This gave an indication that the epoxy resin has been removed from the surface of the carbon fiber.

  20. Highly selective electrodeposition of sub-10 nm crystalline noble metallic nanorods inside vertically aligned multiwall carbon nanotubes

    Science.gov (United States)

    Wang, Xuyang; Wang, Ranran; Wu, Qiang; Zhang, Xiaohua; Yang, Zhaohui; Guo, Jun; Chen, Muzi; Tang, Minghua; Cheng, Yajun; Chu, Haibin

    2016-07-01

    In this paper crystalline noble metallic nanorods including Au and Ag with sub-10 nm diameter, are encapsulated within prealigned and open-ended multiwall carbon nanotubes (MWCNTs) through an electrodeposition method. As the external surface of CNTs has been insulated by the epoxy the CNT channel becomes the only path for the mass transport as well as the nanoreactor for the metal deposition. Highly crystallized Au and Ag2O nanorods parallel to the radial direction of CNTs are confirmed by high-resolution transmission electron microscopy, energy dispersive x-ray spectroscopy and x-ray powder diffraction spectroscopy. The Ag2O nanorods are formed by air oxidation on the Ag metals and show a single crystalline structure with (111) planes. The Au nanorods exhibit a complex crystalline structure including twin-crystal and lattice dislocation with (111) and (200) planes. These crystalline noble metallic nanostructures may have important applications for nanocatalysts for fuel cells as well as nanoelectronic and nanophotonic devices. This method is deemed to benefit the precise deposition of other crystalline nanostructures inside CNTs with a small diameter.

  1. Fabrication and Corrosion Resistance of Superhydrophobic Hydroxide Zinc Carbonate Film on Aluminum Substrates

    Directory of Open Access Journals (Sweden)

    Jin Liang

    2013-01-01

    Full Text Available Superhydrophobic hydroxide zinc carbonate (HZC films were fabricated on aluminum substrate through a convenient in situ deposition process. Firstly, HZC films with different morphologies were deposited on aluminum substrates through immersing the aluminum substrates perpendicularly into aqueous solution containing zinc nitrate hexahydrate and urea. Secondly, the films were then modified with fluoroalkylsilane (FAS: CH3(CF26(CH23Si(OCH33 molecules by immersing in absolute ethanol solution containing FAS. The morphologies, hydrophobicity, chemical compositions, and bonding states of the films were analyzed by scanning electron microscopy (SEM, water contact angle measurement (CA, Fourier transform infrared spectrometer (FTIR, and X-ray photoelectron spectroscopy (XPS, respectively. It was shown by surface morphological observation that HZC films displayed different microstructures such as microporous structure, rose petal-like structure, block-shaped structure, and pinecone-like structure by altering the deposition condition. A highest water contact angle of 156.2° was obtained after FAS modification. Moreover, the corrosion resistance of the superhydrophobic surface on aluminum substrate was investigated using electrochemical impedance spectroscopy (EIS measurements. The EIS measurements’ results revealed that the superhydrophobic surface considerably improved the corrosion resistance of aluminum.

  2. Cadmium hydroxide nanowire loaded on activated carbon as efficient adsorbent for removal of Bromocresol Green.

    Science.gov (United States)

    Ghaedi, Mehrorang; Khajesharifi, Habibollah; Hemmati Yadkuri, Amin; Roosta, Mostafa; Sahraei, Reza; Daneshfar, Ali

    2012-02-01

    In the present research, cadmium hydroxide nanowire loaded on activated carbon (Cd(OH)(2)-NW-AC) was synthesized and characterized. This new adsorbent was applied for the removal of Bromocresol Green (BCG) molecules from aqueous solutions. The influence of effective variables such as solution pH, contact time, initial BCG concentration, amount of Cd(OH)(2)-NW-AC and temperature on the adsorption efficiency of BCG in batch system was examined. During all experiments BCG contents were determined by UV-Vis spectrophotometer. Fitting the experimental data to different kinetic models including pseudo-first-order, pseudo-second-order, Elovich and intra-particle diffusion kinetic models show the suitability of the pseudo-second-order kinetic model to interpret in the experimental data. Equilibrium isotherm studies were examined by application of different conventional models such as Langmuir, Freundlich and Tempkin models to explain the experimental data. Based on considering R(2) value as criterion the adsorption data well fitted to Langmuir model with maximum adsorption capacity of 108.7 mg g(-1). Thermodynamic parameters (Gibb's free energy, entropy and enthalpy) of adsorption were calculated according to general procedure to take some information about the on-going adsorption process. The high negative value of Gibb's free energy and positive value of enthalpy show the feasibility and endothermic nature of adsorption process.

  3. Metal-Organic Framework Derived Iron Sulfide-Carbon Core-Shell Nanorods as a Conversion-Type Battery Material

    DEFF Research Database (Denmark)

    Huang, Wei; Li, Shuo; Cao, Xianyi

    2017-01-01

    to prepare carbon-encapsulated ploy iron sulfide through solid-state chemical sulfurizing. The resulting core-shell nanorods consisting of approximately 13% carbon and 87% Fe7S8 have a hierarchically porous structure and a very high specific surface area of 277 m2g-1. When tested for use in fabrication...... of systematic structural analysis and microscopic mapping, we discuss the charge-discharge mechanisms and the crucial factors associated with the stability and structural changes upon charge-discharge cycling....

  4. Rectangular bunched rutile TiO2 nanorod arrays grown on carbon fiber for dye-sensitized solar cells.

    Science.gov (United States)

    Guo, Wenxi; Xu, Chen; Wang, Xue; Wang, Sihong; Pan, Caofeng; Lin, Changjian; Wang, Zhong Lin

    2012-03-07

    Because of their special application in photovoltaics, the growth of one-dimensional single-crystalline TiO(2) nanostructures on a flexible substrate is receiving intensive attention. Here we present a study of rectangular bunched TiO(2) nanorod (NR) arrays grown on carbon fibers (CFs) from titanium by a "dissolve and grow" method. After a corrosion process in a strong acid solution, every single nanorod is etched into a number of small nanowires. Tube-shaped dye-sensitized solar cells are fabricated by using etched TiO(2) NRs-coated CFs as the photoanode. An absolute energy conversion efficiency of 1.28% has been demonstrated under 100 mW cm(-2) AM 1.5 illumination. This work demonstrates an innovative method for growing bunched TiO(2) NRs on flexible substrates that can be applied in flexible devices for energy harvesting and storage.

  5. Connecting the Morphological and Crystal Structural Changes during the Conversion of Lithium Hydroxide Monohydrate to Lithium Carbonate Using Multi-Scale X-ray Scattering Measurements

    Directory of Open Access Journals (Sweden)

    Greeshma Gadikota

    2017-09-01

    Full Text Available While CO2 storage technologies via carbon mineralization have focused on the use of earth-abundant calcium- and magnesium-bearing minerals, there is an emerging interest in the scalable synthesis of alternative carbonates such as lithium carbonate. Lithium carbonate is the carbonated end-product of lithium hydroxide, a highly reactive sorbent for CO2 capture in spacecraft and submarines. Other emerging applications include tuning the morphology of lithium carbonates synthesized from the effluent of treated Li-bearing batteries, which can then be reused in ceramics, glasses, and batteries. In this study, in operando Ultra-Small-Angle, Small-Angle, and Wide-Angle X-ray Scattering (USAXS/SAXS/WAXS measurements were used to link the morphological and crystal structural changes as lithium hydroxide monohydrate is converted to lithium carbonate. The experiments were performed in a flow-through reactor at PCO2 of 1 atm and at temperatures in the range of 25–500 °C. The dehydration of lithium hydroxide monohydrate to form lithium hydroxide occurs in the temperature range of 25–150 °C, while the onset of carbonate formation is evident at around 70 °C. A reduction in the nanoparticle size and an increase in the surface area were noted during the dehydration of lithium hydroxide monohydrate. Lithium carbonate formation increases the nanoparticle size and reduces the surface area.

  6. Formation of Silicon/Carbon Core-Shell Nanowires Using Carbon Nitride Nanorods Template and Gold Catalyst

    Directory of Open Access Journals (Sweden)

    Ilyani Putri Jamal

    2013-01-01

    Full Text Available In this experiment, silicon/carbon (Si/C core-shell nanowires (NWs were synthesized using gold nanoparticles (Au NPs coated carbon nitride nanorods (CN NRs as a template. To begin with, the Au NPs coated CN NRs were prepared by using plasma-enhanced chemical vapor deposition assisted with hot-wire evaporation technique. Fourier transform infrared spectrum confirms the C–N bonding of the CN NRs, while X-ray diffraction pattern indicates the crystalline structure of the Au NPs and amorphous structure of the CN NRs. The Au NPs coated CN NRs were thermally annealed at temperature of 800°C in nitrogen ambient for one hour to induce the growth of Si/C core-shell NWs. The growth mechanism for the Si/C core-shell NWs is related to the nitrogen evolution and solid-liquid-solid growth process which is a result of the thermal annealing. The formation of Si/C core-shell NWs is confirmed by electron spectroscopic imaging analysis.

  7. Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

    OpenAIRE

    Hang, To Thi Xuan; Truc, Trinh Anh; Duong, Nguyen Thuy; Pébère, Nadine; Olivier, Marie-Georges

    2012-01-01

    International audience; The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by U...

  8. Study of Activated Carbons by Pyrolysis of Mangifera Indica Seed (Mango in Presence of Sodium and Potassium Hydroxide

    Directory of Open Access Journals (Sweden)

    J. C. Moreno-Piraján

    2012-01-01

    Full Text Available Activated carbons (ACs were prepared by pyrolysis of seeds mango in presence of sodium and potassium hydroxide (chemical activities. Seeds mango from Colombian Mango cultives were impregnated with aqueous solutions of NaOH and KOH following a variant of the incipient wetness method. Different concentrations were used to produce impregnation ratios of 3:1 (weight terms. Activation was carried out under argon flow by heating to 823 K with 1 h soaking time. The porous texture of the obtained ACs was characterized by physical adsorptions of N2 at 77 K and CO2 at 273 K. The impregnation ration and hydroxide type had a strong influence on the pore structure of these ACs, which could be easily controlled by simply varying the proportion of the hydroxides used in the activation. Thus, the development of porosity for precursors with low structural order (high reactivity is better with NaOH than KOH, whereas the opposite is observed for the highly ordered ones. Variable adsorption capacities and porosity distributions can be achieved depending on the activating agent selected. In general, KOH produces activated carbons with narrower micropore distributions than those prepared by NaOH.

  9. Influence of carbonate intercalation in the surface-charging behavior of Zn-Cr layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, R., E-mail: rrojas@mail.fcq.unc.edu.ar [INFIQC, Departamento de Fisicoquimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Barriga, C. [Departamento de Quimica Inorganica e Ingenieria Quimica, Edificio Marie Curie, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain); De Pauli, C.P. [INFIQC, Departamento de Fisicoquimica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina); Avena, M.J. [Departamento de Quimica, Universidad Nacional del Sur, Avenida Alem 1253, 8000 Bahia Blanca (Argentina)

    2010-01-15

    The influence of interlayer composition in the surface charge and reactivity of layered double hydroxides (LDHs) has been explored. With this purpose, a chloride-intercalated Zn-Cr-LDH has been synthesized by the constant pH coprecipitation method and afterwards exchanged with carbonate to obtain solids with different Cl{sup -}/CO{sub 3}{sup 2-} ratios. The solids structure has been characterized by elemental chemical analysis, powder X-ray diffraction and infrared spectroscopy, while its surface-charging behavior and reactivity have been studied by acid-base potentiometric titrations and electrophoretic mobility determinations. The chloride-intercalated sample shows an increasing hydroxyl adsorption with increasing pH and decreasing support electrolyte concentration and the particles present positive electrophoretic mobility in the measured pH range. As carbonate content increases in the samples, the total OH{sup -} uptake diminishes and the samples show an isoelectric point at pH around 10. When the gallery is totally occupied by carbonate anions, the OH uptake vs. pH curves registered at different electrolyte concentrations merge at around pH 10. A LDH-water interface model has been used to give an interpretation to the experimental data. The model indicates that as carbonate content increases, the sample behavior becomes similar to that of a metal (hydr)oxide and that surface (bi)carbonate anions undergo acid-base reactions.

  10. Kinetic Study of the Electro-Catalytic Oxidation of Hydrazine on Cobalt Hydroxide Modified Glassy Carbon Electrode

    Institute of Scientific and Technical Information of China (English)

    HASANZADEH,Mohammad; KARIM-NEZHAD,Ghasem; SHADJOU,Nasrin; KHALILZADEH,Balal; SAGHATFOROUSH,Lotali; ERSHAD,Sohrab; KAZEMAN,Isa

    2009-01-01

    Electrocatalytic oxidation of hydrazine was investigated on a cobalt hydroxide modified glassy carbon (CHM-GC) electrode in alkaline solution.The process of oxidation involved and its kinetics were established by using cyclic voltammetry,chronoamperometry techniques as well as steady state polarization measurements.In cyclic voltammetry (CV) studies,in the presence of hydrazine the peak current increase of the oxidation of cobalt hydroxide is followed by a decrease in the corresponding cathodic current.This indicates that hydrazine is oxidized on the redox mediator that is immobilized on the electrode surface via an electrocatalytic mechanism.A mechanism based on the electrochemical generation of Co(IV) active sites and their subsequent consumption by the hydrazine in question was also investigated.

  11. Arsenic Adsorption Equilibrium Concentration and Adsorption Rate of Activated Carbon Coated with Ferric-Aluminum Hydroxides

    Science.gov (United States)

    Zhang, M.; Sugita, H.; Oguma, T.; Hara, J.; Takahashi, S.

    2015-12-01

    In some areas of developing countries, ground or well water contaminated with arsenic has been reluctantly used as drinking water. It is highly desirable that effective and inexpensive arsenic removal agents should be developed and provided to reduce the potential health risk. Previous studies demonstrated that activated carbon coated with ferric-aluminum hydroxides (Fe-Al-C) has high adsorptive potential for removal of arsenic. In this study, a series of experiments using Fe-Al-C were carried to discuss adsorption equilibrium time, adsorption equilibrium concentration and adsorption rate of arsenic for Fe-Al-C. Fe-Al-C used in this study was provided by Astec Co., Ltd. Powder reagent of disodium hydrogen arsenate heptahydrate was dissolved into ion-exchanged water. The solution was then further diluted with ion-exchanged water to be 1 and 10 mg/L as arsenic concentration. The pH of the solution was adjusted to be around 7 by adding HCl and/or NaOH. The solution was used as artificial arsenic contaminated water in two types of experiments (arsenic adsorption equilibrium and arsenic adsorption rate tests). The results of the arsenic equilibrium tests were showed that a time period of about 3 days to reach apparent adsorption equilibrium for arsenic. The apparent adsorption equilibrium concentration and adsorbed amount of arsenic on Fe-Al-C adsorbent could be estimated by application of various adsorption isotherms, but the distribution coefficient of arsenic between solid and liquid varies with experimental conditions such as initial concentration of arsenic and addition concentration of adsorbent. An adsorption rate equation that takes into account the reduction in the number of effective adsorption sites on the adsorbent caused by the arsenic adsorption reaction was derived based on the data obtained from the arsenic adsorption rate tests.

  12. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O’Hare, Dermot; Wang, Qiang

    2016-01-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH–oxidized carbon nanotube (AMO-LDH–OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH–OCNT hybrids. For PP mixed with AMO-LDH–OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH–OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively). PMID:27752096

  13. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O'Hare, Dermot; Wang, Qiang

    2016-10-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH-oxidized carbon nanotube (AMO-LDH-OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH-OCNT hybrids. For PP mixed with AMO-LDH-OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH-OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively).

  14. Direct growth of MnOOH nanorod arrays on a carbon cloth for high-performance non-enzymatic hydrogen peroxide sensing.

    Science.gov (United States)

    Xu, Weina; Liu, Jianlin; Wang, Mingjun; Chen, Lin; Wang, Xue; Hu, Chenguo

    2016-03-24

    Novel MnOOH nanorod arrays directly growing on a flexible carbon cloth substrate (MnOOH/CC) is first synthesized through a facile hydrothermal technique and utilized as an electrocatalyst for non-enzymatic detection of hydrogen peroxide. The as-prepared MnOOH nanorods are uniformly distributed on the carbon cloth with a 3D porous network structure, which provides a high specific surface area and numerous electroactive sites. The electrode based on the carbon cloth-supported MnOOH nanorod arrays exhibits a higher sensitivity (692.42 μA mM(-1) cm(-2)) and a wider linear range (20 μm-9.67 mM) with a detection limit of 3.2 μM (S/N = 3) compared with the electrode based on the rigid graphite substrate supported the random distributed MnOOH nanorods. Further, the MnOOH/CC possesses an outstanding flexibility and can conveniently be assembled into the required shape for a specific use, thus the arc-shaped MnOOH/CC electrodes are fabricated whose electrocatalytic activity toward the hydrogen peroxide reduction remains nearly unchanged in comparison with the unbent state. Due to its excellent sensitivity, reproducibility, anti-interference and stability, the electrode based on the carbon cloth-supported MnOOH nanorod arrays is believed to be promising for applications in high efficiency flexible hydrogen peroxide sensing.

  15. Synthetic Applications and Mechanistic Studies of the Hydroxide-Mediated Cleavage of Carbon-Carbon Bonds in Ketones

    DEFF Research Database (Denmark)

    Mazziotta, Andrea; Makarov, Ilya S.; Fristrup, Peter

    2017-01-01

    The hydroxide-mediated cleavage of ketones into alkanes and carboxylic acids has been reinvestigated and the substrate scope extended to benzyl carbonyl compounds. The transformation is performed with a 0.05 M ketone solution in refluxing xylene in the presence of 10 equiv of potassium hydroxide....... The studies were complemented by a theoretical investigation where two possible pathways were characterized by DFT/M06-2X. The calculations showed that the scission takes place by nucleophilic attack of hydroxide on the ketone followed by fragmentation of the resulting oxyanion into the carboxylic acid...

  16. Electrochemical characterization of carbon coated bundle-type silicon nanorod for anode material in lithium ion secondary batteries

    Energy Technology Data Exchange (ETDEWEB)

    Halim, Martin [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Energy and Environmental Engineering, Korea University of Science and Technology, Gwahangno, Yuseong-gu, Daejeon, 305-333 (Korea, Republic of); Kim, Jung Sub [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Department of Material Science & Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Choi, Jeong-Gil [Department of Chemical Engineering, Hannam University, 461-1 Junmin-dong, Yusung-gu, Taejon 305-811 (Korea, Republic of); Lee, Joong Kee, E-mail: leejk@kist.re.kr [Center for Energy Convergence, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Energy and Environmental Engineering, Korea University of Science and Technology, Gwahangno, Yuseong-gu, Daejeon, 305-333 (Korea, Republic of)

    2015-04-15

    Highlights: • Bundle-type silicon nanorods (BSNR) were synthesized by metal assisted chemical etching. • Novel bundle-type nanorods electrode showed self-relaxant characteristics. • The self-relaxant property was enhanced by increasing the silver concentration. • PAA binder enhanced the self-relaxant property of the silicon material. • Carbon coated BSNR (BSNR@C) has evidently provided better cycle performance. - Abstract: Nanostructured silicon synthesis by surface modification of commercial micro-powder silicon was investigated in order to reduce the maximum volume change over cycle. The surface of micro-powder silicon was modified using an Ag metal-assisted chemical etching technique to produce nanostructured material in the form of bundle-type silicon nanorods. The volume change of the electrode using the nanostructured silicon during cycle was investigated using an in-situ dilatometer. Our result shows that nanostructured silicon synthesized using this method showed a self-relaxant characteristic as an anode material for lithium ion battery application. Moreover, binder selection plays a role in enhancing self-relaxant properties during delithiation via strong hydrogen interaction on the surface of the silicon material. The nanostructured silicon was then coated with carbon from propylene gas and showed higher capacity retention with the use of polyacrylic acid (PAA) binder. While the nano-size of the pore diameter control may significantly affect the capacity fading of nanostructured silicon, it can be mitigated via carbon coating, probably due to the prevention of Li ion penetration into 10 nano-meter sized pores.

  17. Prussian Blue Modified Solid Carbon Nanorod Whisker Paste Composite Electrodes: Evaluation towards the Electroanalytical Sensing of H2O2

    Directory of Open Access Journals (Sweden)

    Carolin Siimenson

    2012-01-01

    Full Text Available Metallic impurity free solid carbon nanorod “Whiskers” (SCNR Whiskers, a derivative of carbon nanotubes, are explored in the fabrication of a Prussian Blue composite electrode and critically evaluated towards the mediated electroanalytical sensing of H2O2. The sensitivity and detection limits for H2O2 on the paste electrodes containing 20% (w/w Prussian Blue, mineral oil, and carbon nanorod whiskers were explored and found to be 120 mA/(M cm2 and 4.1 μM, respectively, over the concentration range 0.01 to 0.10 mM. Charge transfer constant for the 20% Prussian Blue containing SCNR Whiskers paste electrode was calculated, for the reduction of Prussian Blue to Prussian White, to reveal a value of 1.8±0.2 1/s (α=0.43, N=3. Surprisingly, our studies indicate that these metallic impurity-free SCNR Whiskers, in this configuration, behave electrochemically similar to that of an electrode constructed from graphite.

  18. Separation of Tetramethyl Ammonium Hydroxide in Waste Water with Ion Exchange Using Activated Carbon Prepared by Bamboo

    Science.gov (United States)

    Yamaguchi, Ayako; Nishihama, Syouhei; Yoshizuka, Kazuharu

    Activated carbon is prepared by bamboo for the selective recovery of tetramethyl ammonium hydroxide (TMAH), contained in waste water from semiconductive industry, at the end of pipe of the plant. The adsorption ability of the activated carbon from bamboo (BAC) is comparable to the commercial activated carbons. The adsorption of TMAH with BAC in batchwise system increases with increase in pH value of the aqueous solution, and the effective adsorption and elution yield is also obtained in column system. Quantitative adsorption-elution processing can be achieved with the present BAC, and thus indicating the BAC is effective material as the adsorbent of TMAH at the end of pipe of the plant.

  19. Ecological comparison of calcium hydroxide and sodium hydrogen carbonate as sorbents; Oekologischer Vergleich der Sorptionsmittel Calciumhydroxid und Natriumhydrogencarbonat

    Energy Technology Data Exchange (ETDEWEB)

    Pacher, Christian; Weber-Blaschke, Gabriele [Technische Univ. Muenchen, Freising (Germany). Lehrstuhl fuer Rohstoff- und Energietechnologie; Mocker, Mario [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany); Faulstich, Martin [Technische Univ. Muenchen, Straubing (Germany). Wissenschaftszentrum Straubing

    2009-07-01

    Lime products have long been used with success for flue gas purification in waste incineration plants, where they serve to eliminate acid gas pollutants such as sulphur dioxide, hydrogen chloride and hydrogen fluoride. This article presents excerpts of a study commissioned by the German lime industry association for the purpose of obtaining an unbiased well-founded comparison of the environmental impact of the two sorbents calcium hydroxide and sodium hydrogen carbonate. The following questions were addressed by the study: Which of the two flue gas additives provides greater environmental benefit under specified conditions? What parameters influence the outcome? How can the results be viewed in regard to different plant configurations?.

  20. Improved electrochemical performance of α-Fe{sub 2}O{sub 3} nanorods and nanotubes confined in carbon nanoshells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shan; Sun, Yan-Hui, E-mail: sunyanhui0102@163.com; Zhou, Feng-Chen; Nan, Jun-Min

    2016-07-01

    Highlights: • Core-shell Fe{sub 2}O{sub 3}@C nanorods & nanotubes are prepared by a simple hydrothermal method. • Carbon shell enhances conductivity of anode and buffers the volume change of Fe{sub 2}O{sub 3}. • Fe{sub 2}O{sub 3}@C nanotube anode shows super lithium storage performance than that of nanorods. • Fe{sub 2}O{sub 3}@C nanotube anode shows high capacity of 1350 mAh g{sup −1} (100 mA g{sup −1}, 50 cycles). • Fe{sub 2}O{sub 3}@C nanotube anode shows super rate capability of 765 mAh g{sup −1} (2 Ag{sup −1}, 300 cycles). - Abstract: Core-shell α-Fe{sub 2}O{sub 3}@C nanorods (FC1) and nanotubes (FC2) are synthesized via a hydrothermal method with further annealing. The structure, morphology and lithium storage performance are investigated by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, thermogravimetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The electrode based on the core-shell nanotubes (FC2) delivers the reversible capacity of 1350 mAh g{sup −1} cycled at 100 mA g{sup −1} after 50 cycles, 1186 mAh g{sup −1} at 500 mA g{sup −1} after 100 cycles, and 765 mAh g{sup −1} at 2 A g{sup −1} after 300 cycles, much higher than those of pure α-Fe{sub 2}O{sub 3} nanotubes and the core-shell nanorods (FC1). Electrochemical measurements show that the tubular morphology and the carbon shell play an important role in affecting both the cycle life and the rate capability of the electrodes. These insights will be of benefits in designing of other anode materials for lithium-ion batteries.

  1. Magnesium Hydroxide

    Science.gov (United States)

    Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

  2. Synthesis of Nitrogen-Doped Carbon Nanocoils with Adjustable Morphology using Ni–Fe Layered Double Hydroxides as Catalyst Precursors

    Directory of Open Access Journals (Sweden)

    Tomohiro Iwasaki

    2015-01-01

    Full Text Available Nitrogen-doped carbon nanocoils (CNCs with adjusted morphologies were synthesized in a one-step catalytic chemical vapour deposition (CVD process using acetoni‐ trile as the carbon and nitrogen source. The nickel iron oxide/nickel oxide nanocomposites, which were derived from nickel–iron layered double hydroxide (LDH precur‐ sors, were employed as catalysts for the synthesis of CNCs. In this method, precursor-to-catalyst transformation, catalyst activation, formation of CNCs, and nitrogen doping were all performed in situ in a single process. The morphology (coil diameter, coil pitch, and fibre diameter and nitrogen content of the synthesized CNCs was indi‐ vidually adjusted by modulation of the catalyst composi‐ tion and CVD reaction temperature, respectively. The adjustable ranges of the coil diameter, coil pitch, fibre diameter, and nitrogen content were confirmed to be approximately 500±100 nm, 600±100 nm, 100±20 nm, and 1.1±0.3 atom%, respectively.

  3. Nitrogen-enriched, double-shelled carbon/layered double hydroxide hollow microspheres for excellent electrochemical performance

    Science.gov (United States)

    Xu, Jie; He, Fei; Gai, Shili; Zhang, Shenghuan; Li, Lei; Yang, Piaoping

    2014-08-01

    A unique, double-shelled, hollow, carbon-based composite with enriched nitrogen has been prepared through a facile and versatile synthetic strategy. The hierarchical composite employs the nitrogen-enriched carbon hollow sphere as an interior shell and intercrossed Ni/Al layered double hydroxide (LDH) nanosheets as an exterior shell. The obtained N-C@LDH hollow microspheres (HMS) have high nitrogen enrichment, large specific surface area (337 m2 g-1), and uniform and open mesoporous structure. Taking advantage of these characteristics, the composite exhibits obviously superior capacitive behavior, including high specific capacitance, excellent rate capability and good cycling stability, compared with nitrogen-free carbon@LDH composite and hollow LDH without carbon shell. The composite displays high specific capacitance of 1711.51 F g-1 at a current density of 1 A g-1. In particular, the high specific capacitance can be kept to 997.3 F g-1 at a high current density of 10 A g-1, which still retains 94.97% of the initial specific capacitance after 500 cycles at this high current density. This N-enriched, hollow carbon/LDH composite can be expected to be a promising electrode material for electrochemical capacitors due to its high electrochemical performance.A unique, double-shelled, hollow, carbon-based composite with enriched nitrogen has been prepared through a facile and versatile synthetic strategy. The hierarchical composite employs the nitrogen-enriched carbon hollow sphere as an interior shell and intercrossed Ni/Al layered double hydroxide (LDH) nanosheets as an exterior shell. The obtained N-C@LDH hollow microspheres (HMS) have high nitrogen enrichment, large specific surface area (337 m2 g-1), and uniform and open mesoporous structure. Taking advantage of these characteristics, the composite exhibits obviously superior capacitive behavior, including high specific capacitance, excellent rate capability and good cycling stability, compared with nitrogen

  4. Kinetic analysis of anionic surfactant adsorption from aqueous solution onto activated carbon and layered double hydroxide with the zero length column method

    NARCIS (Netherlands)

    Schouten, Natasja; Ham, Louis G.J. van der; Euverink, Gert-Jan W.; Haan, André B. de

    2009-01-01

    Low cost adsorption technology offers high potential to clean-up laundry rinsing water. From an earlier selection of adsorbents, layered double hydroxide (LDH) and granular activated carbon (GAC) proved to be interesting materials for the removal of anionic surfactant, linear alkyl benzene sulfonate

  5. Comparisons of kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide adsorption in aqueous solution with graphene oxide, zeolite and activated carbon

    Science.gov (United States)

    Chang, Shenteng; Lu, Chungsying; Lin, Kun-Yi Andrew

    2015-01-01

    Graphene oxide (GO), sodium Y-type zeolite (NaY) and granular activated carbon (GAC) are selected as adsorbents to study their kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide (TMAH) adsorption from water. The adsorption kinetics follows the pseudo-second-order rate law while the adsorption thermodynamics shows an exothermic reaction with GO and GAC but displays an endothermic reaction with NaY. The adsorbed TMAH can be readily desorbed from the surface of GO and NaY by 0.05 M NaCl solution. A comparative study on the cyclic TMAH adsorption with GO, NaY and GAC is also conducted and the results reveal that GO exhibits the greatest TMAH adsorption capacity as well as superior reversibility of TMAH adsorption over 10 cycles of adsorption and desorption process. These features indicate that GO is a promising and efficient adsorbent for TMAH removal in wastewater treatment.

  6. The preparation of layered double hydroxide wrapped carbon nanotubes and their application as a flame retardant for polypropylene

    Science.gov (United States)

    Du, Baoxian; Fang, Zhengping

    2010-08-01

    Carbon nanotubes (CNTs) wrapped with layered double hydroxide (LDH-w-CNTs) were facilely obtained through in situ introduction of CNTs into the hydrothermal reaction system of LDH, with the goal of combining their unique physical and chemical characteristics to meet new advanced applications. Morphological observations indicated that LDH lamellae enwrapped the surface of CNTs and the wrapping degree was dependent on the functionalization of CNTs. ζ-potential measurements showed that the interaction between the positive charge of LDH and the negative charge of CNTs was the main driving force of the wrapping process. Both hybrids led to a reduction in the peak heat release rate (PHRR) of polypropylene, indicating that they could confer better flame retardancy on polypropylene with respect to LDH and CNTs.

  7. Electrochemical oxidation of 4-chloro phenol over a carbon paste electrode modified with Zn Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez F, D.; Palomar P, M.; Licona S, T. de J.; Romero R, M. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Departamento de Materiales, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D. F. (Mexico); Valente, Jaime S., E-mail: mepp@correo.azc.uam.mx [Instituto Mexicano del Petroleo, Eje Central No. 152, 07730 Mexico D. F. (Mexico)

    2014-07-01

    A study is presented on the electrochemical oxidation of 4-chloro phenol (4cp) in aqueous solution using a bare carbon paste electrode, Cpe, and another one that was modified with Zn Al layered double hydroxides (Cpe/Zn Al-LDH). The electro-oxidation was effected at ph values ranging from 3 up to 11. It was found through cyclic voltammetry that this process was irreversible, namely, there were no reduction peaks, and that depending on the nature of the electrode, the anodic current was limited either by adsorption (Cpe) or diffusion (Cpe/Zn Al-LDH). The energy required and the oxidation reaction rate depended on the ph and on the nature of the electrode, such that the greater rates were obtained when the Cpe/Zn Al-LDH electrode and acid ph were used. The Zn Al-LDH was characterized by means of X-ray diffraction. (Author)

  8. From Zn-Al layered double hydroxide to ZnO nanostructure:Gradually etching by sodium hydroxide

    Institute of Scientific and Technical Information of China (English)

    Gang Qiang Wan; Dong Xiang Li; Chun Fang Li; Jie Xu; Wan Guo Hou

    2012-01-01

    Zn-Al layered double hydroxide (LDH) was used as precursor to produce ZnO nanostructures through dissolution of aluminum hydroxide in caustic soda.The Zn-Al LDH could transform into different nanostructures of ZnO on LDH nanosheets and even pure ZnO nanorods under various NaOH concentration.The formed ZnO nanorods vertically aligned on both LDH sides.UV-vis diverse reflectance spectra show that the obtained ZnO nanorods have a band gap of approximately 3.05 eV.Such ZnO/LDH nanostructures might be used as photocatalyst in the organic pollutant decomposition.

  9. Structural and surface functionality changes in reticulated vitreous carbon produced from poly(furfuryl alcohol) with sodium hydroxide additions

    Science.gov (United States)

    Oishi, Silvia Sizuka; Botelho, Edson Cocchieri; Rezende, Mirabel Cerqueira; Ferreira, Neidenêi Gomes

    2017-02-01

    The use of sodium hydroxide to neutralize the acid catalyst increases the storage life of poly(furfuryl alcohol) (PFA) resin avoiding its continuous polymerization. In this work, a concentrated sodium hydroxide solution (NaOH) was added directly to the PFA resin in order to minimize the production of wastes generated when PFA is washed with diluted basic solution. Thus, different amounts of this concentrated basic solution were added to the resin up to reaching pH values of around 3, 5, 7, and 9. From these four types of modified PFA two sample sets of reticulated vitreous carbon (RVC) were processed and heat treated at two different temperatures (1000 and 1700 °C). A correlation among cross-link density of PFA and RVC morphology, structural ordering and surface functionalities was systematically studied using Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy techniques. The PFA neutralization (pH 7) led to its higher polymerization degree, promoting a crystallinity decrease on RVC treated at 1000 °C as well as its highest percentages of carboxylic groups on surface. A NaOH excess (pH 9) substantially increased the RVC oxygen content, but its crystallinity remained similar to those for samples from pH 3 and 5 treated at 1000 °C, probably due to the reduced presence of carboxylic group and the lower polymerization degree of its cured resin. Samples with pH 3 and 5 heat treated at 1000 and 1700 °C can be considered the most ordered which indicated that small quantities of NaOH may be advantageous to minimize continuous polymerization of PFA resin increasing its storage life and improving RVC microstructure.

  10. Microwave-assisted synthesis and prototype oxygen reduction electrocatalyst application of N-doped carbon-coated Fe3O4 nanorods

    Science.gov (United States)

    Hadidi, Lida; Davari, Elaheh; Ivey, Douglas G.; Veinot, Jonathan G. C.

    2017-03-01

    Fe3O4 nanorods coated with nitrogen-doped mesoporous carbon (ND-Fe3O4@mC) shells of defined thicknesses have been prepared via a new microwave-assisted approach. Microstructural characterization of these ND-Fe3O4@mC structures was performed using x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy. Following identification, the electrochemical performance of the catalysts was evaluated using linear sweep voltammetry with a rotating disc electrode system. The present investigation reveals enhanced oxygen reduction reaction catalytic activity and the carbon layer thickness influences oxygen diffusion to the active Fe3O4 nanorod core.

  11. Horseradish peroxidase immobilization on carbon nanodots/CoFe layered double hydroxides: direct electrochemistry and hydrogen peroxide sensing.

    Science.gov (United States)

    Wang, Yinling; Wang, Zhangcui; Rui, Yeping; Li, Maoguo

    2015-02-15

    Carbon nanodots and CoFe layered double hydroxide composites (C-Dots/LDHs) were prepared via simply mixing C-Dots and CoFe-LDHs. The as-prepared composites were used for the immobilization of horseradish peroxidase (HRP) on the glass carbon (GC) electrode. The electrochemical behavior of the HRP/C-Dots/LDHs/GC electrode and its application as a H2O2 biosensor were investigated. The results indicated that HRP immobilized by C-Dots/LDHs retained the activity of enzyme and displayed quasi-reversible redox behavior and fast electron transfer with an electron transfer rate constant ks of 8.46 s(-1). Under optimum experimental conditions, the HRP/C-Dots/LDHs/GC electrode displayed good electrocatalytic reduction activity and excellent analytic performance toward H2O2. The H2O2 biosensor showed a linear range of 0.1-23.1 μM (R(2) = 0.9942) with a calculated detection limit of 0.04 μM (S/N = 3). In addition, the biosensor exhibited high sensitivity, good selectivity, acceptable reproducibility and stability. The superior properties of this biosensor are attributed to the synergistic effect of HRP, C-Dots and CoFe-LDHs, which has been proved by investigating their electrochemical response to H2O2. Thus the C-Dots and LDHs composites provide a promising platform for the immobilization of redox enzymes and construction of sensitive biosensors.

  12. Ammonium hydroxide modulated synthesis of high-quality fluorescent carbon dots for white LEDs with excellent color rendering properties

    Science.gov (United States)

    Wang, Shengda; Zhu, Zhifeng; Chang, Yajing; Wang, Hui; Yuan, Nan; Li, Guopeng; Yu, Dabin; Jiang, Yang

    2016-07-01

    A novel type of aqueous fluorescent carbon dot (CD) was synthesized using citric acid as the only carbon source via an ammonium hydroxide modulated method, providing a blue color gamut. The amino group is considered to be the key factor in the high fluorescence of CDs and a model is established to investigate the mechanism of fluorescence. In addition, white light-emitting diodes (WLEDs) are fabricated by utilizing the prepared CDs and rare earth luminescent materials (SrSi2O2N2:Eu and Sr2Si5N8:Eu) as color conversion layers and UV-LED chips as the excitation light source. The WLEDs produce bright white light with attractive color rendering properties including a color rendering index of up to 95.1, a CIE coordinate of (0.33, 0.37), and a T c of 5447 K under a 100 mA driven current, indicating that the CDs are promising in the field of optoelectronic devices.

  13. Mechanistic Study of Magnesium Carbonate Semibatch Reactive Crystallization with Magnesium Hydroxide and CO2

    DEFF Research Database (Denmark)

    Han, B.; Qu, H. Y.; Niemi, H.;

    2014-01-01

    This work investigates semibatch precipitation of magnesium carbonate at ambient temperature and pressure using Mg(OH)(2) and CO2 as starting materials. A thermal analysis method was developed that reflects the dissolution rate of Mg(OH)(2) and the formation of magnesium carbonate. The method...... the liquid and solid phases. A stirring rate of 650 rpm was found to be the optimum speed as the flow rate of CO2 was 1 L/min. Precipitation rate increased with gas flow rate, which indicates that mass transfer of CO2 plays a critical role in this precipitation case. Magnesium carbonate trihydrate...

  14. Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

    Energy Technology Data Exchange (ETDEWEB)

    Hlaing, Nwe Ni, E-mail: nwenihlaing76@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Vignesh, K., E-mail: vignesh134@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Anano Sphere Sdn Bhd, Lorong Industri 11, Kawasan Industri Bukit Panchor, 14300 Nibong Tebal, Penang (Malaysia); Sreekantan, Srimala, E-mail: srimala@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Pung, Swee-Yong [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hinode, Hirofumi; Kurniawan, Winarto [Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Othman, Radzali [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Malacca (Malaysia); Thant, Aye Aye [Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Mohamed, Abdul Rahman [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Salim, Chris [Department of Environmental Engineering, Surya University, Tangerang 15810, Banten (Indonesia)

    2016-02-15

    Graphical abstract: Carbonation conversions of (a) CC, (b) CH-2, (c) CH-4, (d) CH-6, (e) CH-8 precursor adsorbents for 10 cycles. - Highlights: • Ca(OH){sub 2} precursor was synthesized using precipitation method. • The effect of CTAB concentration on the synthesis of Ca(OH){sub 2} was studied. • The sorbent synthesized using 0.8 M of CTAB showed good CO{sub 2} adsorption capacity. • The cyclic stability of Ca(OH){sub 2} was increased with increase of CTAB concentration. - Abstract: Calcium hydroxide (Ca(OH){sub 2}) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH){sub 2} based adsorbents for carbon dioxide (CO{sub 2}) capture. The effect of CTAB concentration (0.2–0.8 M) on the structure, morphology and CO{sub 2} adsorption performance of Ca(OH){sub 2} was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG–DTA) techniques. The phase purity, crystallite size, Brunauer–Emmett–Teller (BET) surface area and CO{sub 2} adsorption performance of Ca(OH){sub 2} precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH){sub 2} phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH){sub 2} precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

  15. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    OpenAIRE

    2014-01-01

    This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been e...

  16. Large pore volume mesoporous copper particles and scaffold microporous carbon material obtained from an inorganic-organic nanohybrid material, copper-succinate-layered hydroxide.

    Science.gov (United States)

    Ghotbi, Mohammad Yeganeh; Bagheri, Narjes; Sadrnezhaad, S K

    2011-10-01

    Copper-succinate-layered hydroxide (CSLH), a new nanohybrid material, was synthesized as an inorganic-organic nanohybrid, in which organic moiety was intercalated between the layers of a single cation layered material, copper hydroxide nitrate. Microporous scaffold carbon material was obtained by thermal decomposition of the nanohybrid at 500 °C under argon atmosphere followed by acid washing process. Furthermore, the heat-treated product of the nanohybrid at 600 °C was ultrafine mesoporous metallic copper particles. The results of this study confirmed the great potential of CSLH to produce the carbon material with large surface area (580 m(2)/g) and high pore volume copper powder (2.04 cm(3)/g).

  17. Synthesis of carbon nanotube/layered double hydroxide nanocomposite as a novel fiber coating for the headspace solid-phase microextraction of phenols from water samples.

    Science.gov (United States)

    Abolghasemi, Mir Mahdi; Yousefi, Vahid; Piryaei, Marzieh

    2015-05-01

    In this research, a carbon nanotube/layered double hydroxide nanocomposite was synthesized by an in situ growth route by electrostatic force. The prepared carbon nanotube/layered double hydroxide nanocomposite was successfully prepared and deposited on a stainless-steel wire for the fabrication of the solid-phase microextraction fiber. The fiber was evaluated for the extraction of phenolic compounds from water samples. Analytical merits of the method, under optimum conditions (extraction temperature: 75°C, extraction time: 30 min, desorption time: 2 min, desorption temperature 260°C, salt concentration: 10% w/v) are 0.01-300 ng/mL for the linear dynamic range and 0.005-0.08 for the limit of detection. In optimum conditions, the repeatability for one fiber (n = 3), expressed as relative standard deviation, was between 6.5 and 9.9% for the phenolic compounds.

  18. Removal of fluoride from drinking water using aluminum hydroxide coated activated carbon prepared from bark of Morinda tinctoria

    Science.gov (United States)

    Amalraj, Augustine; Pius, Anitha

    2016-10-01

    The aim of this study is to design and develop a novel cost effective method for fluoride removal, applicable to rural areas of developing countries. Adsorption is widely considered as one of the appropriate technologies for water defluoridation. This study investigates the feasibility of using low-cost biomass based activated carbon from the bark of Morinda tinctoria coated with aluminum hydroxide (AHAC) for water defluoridation, at neutral pH range. Characterization of AHAC was done through IR, SEM with EDAX studies before and after fluoride treatment. The fluoride adsorption capacity of AHAC as a function of contact time, pH and initial fluoride concentration was investigated. The role of co-existing interfering ions also was studied. The isotherm and kinetic models were used to understand the nature of the fluoride adsorption onto AHAC. Freundlich isotherm and intra-particle diffusion were the best-fitting models for the adsorption of fluoride on AHAC. Fluoride adsorption kinetics well fitted with pseudo-second order model. The results showed excellent fluoride adsorption capacity was found to be 26.03 mg g-1 at neutral pH.

  19. Flexible Fiber-Shaped Supercapacitor Based on Nickel-Cobalt Double Hydroxide and Pen Ink Electrodes on Metallized Carbon Fiber.

    Science.gov (United States)

    Gao, Libo; Surjadi, James Utama; Cao, Ke; Zhang, Hongti; Li, Peifeng; Xu, Shang; Jiang, Chenchen; Song, Jian; Sun, Dong; Lu, Yang

    2017-02-15

    Flexible fiber-shaped supercapacitors (FSSCs) are recently of extensive interest for portable and wearable electronic gadgets. Yet the lack of industrial-scale flexible fibers with high conductivity and capacitance and low cost greatly limits its practical engineering applications. To this end, we here present pristine twisted carbon fibers (CFs) coated with a thin metallic layer via electroless deposition route, which exhibits exceptional conductivity with ∼300% enhancement and superior mechanical strength (∼1.8 GPa). Subsequently, the commercially available conductive pen ink modified high conductive composite fibers, on which uniformly covered ultrathin nickel-cobalt double hydroxides (Ni-Co DHs) were introduced to fabricate flexible FSSCs. The synthesized functionalized hierarchical flexible fibers exhibit high specific capacitance up to 1.39 F·cm(-2) in KOH aqueous electrolyte. The asymmetric solid-state FSSCs show maximum specific capacitance of 28.67 mF·cm(-2) and energy density of 9.57 μWh·cm(-2) at corresponding power density as high as 492.17 μW·cm(-2) in PVA/KOH gel electrolyte, with demonstrated high flexibility during stretching, demonstrating their potential in flexible electronic devices and wearable energy systems.

  20. Catalytic synthesis of nitrogen-doped multi-walled carbon nanotubes using layered double hydroxides as catalyst precursors

    Indian Academy of Sciences (India)

    Yong Cao; Yun Zhao; Qingxia Li; Qingze Jiao

    2009-03-01

    The nitrogen (N)-doped carbon (CN) nanotubes were synthesized by pyrolysis of ethylenediamine with Ni1.07Mg1.01AlO3.58, Ni1.99Mg0.29AlO3.78, and Ni2.31Mg0.08AlO3.89 mixed oxides as catalysts at 650°C. Those mixed oxides were obtained by calcination of corresponding layered double hydroxide precursors (LDHs). Structure and composition of LDHs and mixed oxides were characterized by X-ray diffraction (XRD) and Inductively coupled plasma spectrum. X-ray photoelectron spectroscopy and transmission electron microscope were used to characterize the N content, proportion of pyridine-like N structure and morphology of CN nanotubes. The results showed that the tubes grown with Ni2.31Mg0.08AlO3.89 as catalysts had more obvious bamboo-like structure, larger diameter than those grown with Ni1.07Mg1.01AlO3.58 and Ni1.99Mg0.29AlO3.78. The N content and proportion of graphitic-like N structures increased with the content of Ni2+ increasing in LDH precursors. The morphology, N content and pyridine-like N structures for CN nanotubes can be controlled to a certain extent by varying the content of Ni2+ in LDH precursors.

  1. Comparisons of kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide adsorption in aqueous solution with graphene oxide, zeolite and activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shenteng; Lu, Chungsying, E-mail: clu@nchu.edu.tw; Lin, Kun-Yi Andrew

    2015-01-30

    Graphical abstract: A comparison of TMAH adsorption capacity with GO, NaY and GAC is conducted and the result reveals that the magnitude of qe follows the order of GO > NaY > GAC. The adsorption capacity of GO is significantly higher than those of zeolite and activated carbon in this and reported studies, showing its encouraging potential. GO also exhibits good reversibility of TMAH adsorption through 10 cycles of adsorption and desorption process. This reflects that GO is a promising and efficient adsorbent for TMAH removal in wastewater treatment. - Highlights: • Adsorption kinetics and isotherms of TMAH to GO, NaY and GAC are compared. • Thermodynamics of TMAH adsorption to GO, NaY and GAC is determined. • GO exhibits the highest TMAH adsorption capacity, followed by NaY and GAC. • Recyclabilities of NaY and GO remain above 95% but that of GAC dropped to 70%. - Abstract: Graphene oxide (GO), sodium Y-type zeolite (NaY) and granular activated carbon (GAC) are selected as adsorbents to study their kinetics, thermodynamics and regeneration of tetramethylammonium hydroxide (TMAH) adsorption from water. The adsorption kinetics follows the pseudo-second-order rate law while the adsorption thermodynamics shows an exothermic reaction with GO and GAC but displays an endothermic reaction with NaY. The adsorbed TMAH can be readily desorbed from the surface of GO and NaY by 0.05 M NaCl solution. A comparative study on the cyclic TMAH adsorption with GO, NaY and GAC is also conducted and the results reveal that GO exhibits the greatest TMAH adsorption capacity as well as superior reversibility of TMAH adsorption over 10 cycles of adsorption and desorption process. These features indicate that GO is a promising and efficient adsorbent for TMAH removal in wastewater treatment.

  2. Electrochemical determination of dopamine in the presence of ascorbic acid based on the gold nanorods/carbon nanotubes composite film

    Energy Technology Data Exchange (ETDEWEB)

    Deng Chunyan, E-mail: dengchunyan81@126.com [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China); Chen Jinzhuo; Yang Minghui [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China); Nie Zhou [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082 (China); Si Shihui [Key Laboratory of Resources Chemistry of Nonferrous Metals, Central South University, Changsha, 410083 (China)

    2011-10-01

    Highlights: > The GNR/CNT/GC electrode was fabricated simply. It has higher catalytic activity towards the oxidation of DA and ascorbic acid (AA). The selective determination of DA was carried out with low detection limit (0.8 nM, S/N = 3). The proposed method was feasible to detect the concentration of DA in human blood serum. - Abstract: In this paper, the gold nanorods (GNRs)/multiwalled carbon nanotubes (CNT) composite film-modified glassy carbon (GC) electrode was fabricated simply by the electrostatic interaction between the positively charged GNRs and the negatively charged CNT. And the GNRs/CNT/GC electrode was used for the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA). It was found that the GNRs/CNT/GC electrode had higher catalytic activity towards the oxidation of DA and ascorbic acid (AA) comparing with the bare GC and CNT/GC electrodes. It may be due to the synergic effect of GNRs and CNT, because the surface area of the GNRs/CNT/GC electrode increased, the edge plan sites presented on the CNT surface can improve the electron transfer between the modified electrode and DA, and the rod-shaped gold may be served as the mediator for the oxidation of dopamine and provided the electrocatalytic ability. Moreover, the voltammetric peaks of AA and DA were separated enough at the GNRs/CNT/GC electrode, which was sufficiently enough for the selective determination of DA. Thus, the selective determination of DA was carried out with low detection limit (0.8 nM, S/N = 3). Also it was obtained that the proposed method was feasible to detect the concentration of DA in human blood serum. Therefore, it can be concluded that the GNRs/CNT modified electrode may be advantageous for the DA determination.

  3. The effect of carbon type on arsenic and trichloroethylene removal capabilities of iron (hydr)oxide nanoparticle-impregnated granulated activated carbons.

    Science.gov (United States)

    Cooper, Anne Marie; Hristovski, Kiril D; Möller, Teresia; Westerhoff, Paul; Sylvester, Paul

    2010-11-15

    This study investigates the impact of the type of virgin granular activated carbon (GAC) media used to synthesize iron (hydr)oxide nanoparticle-impregnated granular activated carbon (Fe-GAC) on its properties and its ability to remove arsenate and organic trichloroethylene (TCE) from water. Two Fe-GAC media were synthesized via a permanganate/ferrous ion synthesis method using bituminous and lignite-based virgin GAC. Data obtained from an array of characterization techniques (pore size distribution, surface charge, etc.) in correlation with batch equilibrium tests, and continuous flow modeling suggested that GAC type and pore size distribution control the iron (nanoparticle) contents, Fe-GAC synthesis mechanisms, and contaminant removal performances. Pore surface diffusion model calculations predicted that lignite Fe-GAC could remove ∼6.3 L g(-1) dry media and ∼4 L g(-1) dry media of water contaminated with 30 μg L(-1) TCE and arsenic, respectively. In contrast, the bituminous Fe-GAC could remove only ∼0.2 L/g dry media for TCE and ∼2.8 L/g dry media for As of the same contaminated water. The results show that arsenic removal capability is increased while TCE removal is decreased as a result of Fe nanoparticle impregnation. This tradeoff is related to several factors, of which changes in surface properties and pore size distributions appeared to be the most dominant.

  4. Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

    Science.gov (United States)

    Ahmed, Nesreen S.; Menzel, Robert; Wang, Yifan; Garcia-Gallastegui, Ainara; Bawaked, Salem M.; Obaid, Abdullah Y.; Basahel, Sulaiman N.; Mokhtar, Mohamed

    2017-02-01

    Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterisation by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements and X-ray photoelectron spectroscopy (XPS). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl- and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

  5. A Novel Gas Sensor Based on MgSb2O6 Nanorods to Indicate Variations in Carbon Monoxide and Propane Concentrations

    Science.gov (United States)

    Guillén-Bonilla, Héctor; Flores-Martínez, Martín; Rodríguez-Betancourtt, Verónica-María; Guillen-Bonilla, Alex; Reyes-Gómez, Juan; Gildo-Ortiz, Lorenzo; de la Luz Olvera Amador, María; Santoyo-Salazar, Jaime

    2016-01-01

    Bystromite (MgSb2O6) nanorods were prepared using a colloidal method in the presence of ethylenediamine, after a calcination step at 800 °C in static air. From X-ray powder diffraction analyses, a trirutile-type structure with lattice parameters a = 4.64 Å and c = 9.25 Å and space group P42/mnm was identified. Using scanning electron microscopy (SEM), microrods with sizes from 0.2 to 1.6 μm were observed. Transmission electron microscopy (TEM) analyses revealed that the nanorods had a length of ~86 nm and a diameter ~23.8 nm. The gas-sensing properties of these nanostructures were tested using pellets elaborated with powders of the MgSb2O6 oxide (calcined at 800 °C) at temperatures 23, 150, 200, 250 and 300 °C. The pellets were exposed to different concentrations of carbon monoxide (CO) and propane (C3H8) at these temperatures. The results showed that the MgSb2O6 nanorods possess excellent stability and high sensitivity in these atmospheres. PMID:26840318

  6. High-performance aqueous asymmetric supercapacitor based on K0.3WO3 nanorods and nitrogen-doped porous carbon

    Science.gov (United States)

    Ma, Guofu; Zhang, Zhiguo; Sun, Kanjun; Feng, Enke; Peng, Hui; Zhou, Xiaozhong; Lei, Ziqiang

    2016-10-01

    A novel asymmetric supercapacitor device for energy storage is fabricated using K0.3WO3 nanorods as negative electrode and nitrogen-doped porous carbon (CBC-1) based on agricultural wastes corn bract as positive electrode. The K0.3WO3 nanorods are composed of some thinner needle-shaped nanorods which are parallel to each other, and the CBC-1 reveals rough surface of coral-like frameworks with abundant nanopores. The structures can provide high surface area, low diffusion paths and intercalation/de-intercalation of electrolyte ions between the electrode/electrolyte interfaces. Thus, the asymmetric supercapacitor exhibits high energy density about 26.3 Wh kg-1 at power density of 404.2 W kg-1 in the wide voltage region of 0-1.6 V, as well as a good electrochemical stability (80% capacitance retention after 1000 cycles). Such outstanding electrochemical behaviors imply the CBC-1//K0.3WO3 asymmetric supercapacitor is a promising practical energy-storage system.

  7. Zn–Al layered double hydroxides intercalated with carbonate, nitrate, chloride and sulphate ions: Synthesis, characterisation and dye removal properties

    Directory of Open Access Journals (Sweden)

    Fatima Zahra Mahjoubi

    2017-01-01

    Full Text Available In this work, Zn–Al layered double hydroxides intercalated with carbonate, nitrate, chloride and sulphate ions were synthesised via a co-precipitation method at a constant solution pH. The as-synthesised samples were characterised by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and simultaneous thermogravimetric/differential thermal analysis (TGA-DTA. The XRD patterns showed that Zn-Al-SO4 had the greatest interlayer spacing, followed by Zn-Al-Cl, Zn-Al-NO3 and Zn-Al-CO3. The FTIR spectra clearly confirmed the presence of intercalated anions in the structure of the LDHs. Batch experiments for methyl orange (MO adsorption onto synthesised samples were investigated under various conditions such as contact time, initial dye concentration and solution pH. The experimental results show that pH is the most influencing factor. The effective pH range for the MO removal was found to be 3.5–4.5. The kinetics data can be described accurately by a pseudo-second-order kinetic model instead of a pseudo-first-order model. The equilibrium data were analysed using the Langmuir, Freundlich and Dubinin–Radushkevich models. The results showed that the Langmuir and Dubinin–Radushkevich isotherm models fit well to the experimental data. The Zn-Al-LDH samples exhibited exceptional Langmuir maximum adsorption capacities of 2758, 2455, 2270 and 1684 mg/g for Zn-Al-SO4, Zn-Al-Cl, Zn-Al-NO3 and Zn-Al-CO3, respectively.

  8. Removal of arsenate and 17alpha-ethinyl estradiol (EE2) by iron (hydr)oxide modified activated carbon fibers.

    Science.gov (United States)

    Hristovski, Kiril D; Nguyen, Hanhphuc; Westerhoff, Paul K

    2009-03-01

    Activated carbon fibers (ACF) were modified with iron (hydr)oxide and studied to determine their suitability to remove arsenate and 17alpha -ethinyl estradiol (EE2) from water. Two synthesis methods, one involving aqueous KMnO(4) pretreatment followed by Fe(II) treatment, and the other involving reaction with Fe(III) in an organic solvent followed by NaOH treatment, were used to produce modified ACF media containing 5.9% and 8.4% iron by dry weight, respectively. Scanning electron microscopy (SEM) and Electron dispersion X-ray (EDX) techniques indicated slightly higher iron content near the outer edges of the fibers. Pseudo-equilibrium batch test experimental data at pH = 7.0 +/- 0.1 in 5 mM NaHCO(3) buffered ultrapure water containing approximately 100 micro g(As)/L and approximately 500 micro gEE2/L were fitted with the Freundlich isotherm model (q = K x C(E)(1/n)). The adsorption capacity parameters (K) were approximately 2586 (micro gAs/gFe)(L/micro gAs)(1/n) and approximately 425 (micro gAs/gFe)(L/micro gAs)(1/n)), respectively, for the KMnO(4)/Fe(II) and Fe(III)/NaOH treated media. The KMnO(4)/Fe(II) media exhibited a lower adsorption capacity at 99% EE2 removal than did the Fe(III)/NaOH treated media (1.3 mgEE2/g -dry -media vs. 1.8 mgEE2/g -dry -media). The arsenate adsorption intensity parameters (1/n) for both modified ACF media were < 0.29, implying very favorable adsorption, which suggests that this type of media may be suitable for single point -of -use applications in which arsenic and organic co-contaminants require simultaneous removal and the depth of the packed bed is the key factor.

  9. Hierarchical Assembly of α-Fe2O3 Nanorods on Multiwall Carbon Nanotubes as a High-Performance Sensing Material for Gas Sensors.

    Science.gov (United States)

    Dai, Mingjun; Zhao, Liupeng; Gao, Hongyu; Sun, Peng; Liu, Fengmin; Zhang, Sean; Shimanoe, Kengo; Yamazoe, Noboru; Lu, Geyu

    2017-03-15

    This paper presents a facile hydrolysis reaction and annealing for preparing a novel hierarchical nanoheterostructure via assembly of α-Fe2O3 nanorods onto multiwall carbon nanotubes (MWCNTs) backbones. The as-synthesized nanocomposites were characterized using XRD (X-ray diffraction), FESEM (Field emission scanning electron microscopy), TEM (Transmission electron microscopy), XPS (X-ray photoelectron spectroscopy) and BET (Surface Area and Porosity System). The observations showed uniform α-Fe2O3 nanorods approximately 100-200 nm in length and 50-100 nm in diameter that were hierarchically assembled onto the surface of the MWCNTs. The formation of the heterostructure was investigated by observing the evolution of the microstructure of the products at different reaction times. The X-ray photoelectron spectra (XPS) showed that the ability of the absorbing oxygen was enhanced by the formation of the heterostructure composites. Moreover, as a proof-of-concept presentation, the novel CNTs@α-Fe2O3 hierarchical heterostructure acted as a gas sensitive material. Significantly, the composites exhibited excellent sensing properties for acetone with high sensitivity, exceptional selectivity and good reproducibility. The response of the CNTs@α-Fe2O3 sensor to 100 ppm acetones at 225 °C was nearly 35, which was superior to the single α-Fe2O3 nanorods with a response of 16, and the detection limit of the sensor was 500 ppb. The enhanced properties were mainly attributed to the unique structure and p-n heterojunction between the CNTs and the α-Fe2O3 nanorods.

  10. Clay minerals, metallic oxides and oxy-hydroxides and soil organic carbon distribution within soil aggregates in temperate forest soils

    Science.gov (United States)

    Gartzia-Bengoetxea, Nahia; Fernández-Ugalde, Oihane; Virto, Iñigo; Arias-González, Ander

    2017-04-01

    Soil mineralogy is of primary importance for key environmental services provided by soils like carbon sequestration. However, current knowledge on the effects of clay mineralogy on soil organic carbon (SOC) stabilization is based on limited and conflicting data. In this study, we investigated the relationship between clay minerals, metallic oxides and oxy-hydroxides and SOC distribution within soil aggregates in mature Pinus radiata D.Don forest plantations. Nine forest stands located in the same geographical area of the Basque Country (North of Spain) were selected. These stands were planted on different parent material (3 on each of the following: sandstone, basalt and trachyte). There were no significant differences in climate and forest management among them. Moreover, soils under these plantations presented similar content of clay particles. We determined bulk SOC storage, clay mineralogy, the content of Fe-Si-Al-oxides and oxyhydroxides and the distribution of organic C in different soil aggregate sizes at different soil depths (0-5 cm and 5-20 cm). The relationship between SOC and abiotic factors was investigated using a factor analysis (PCA) followed by stepwise regression analysis. Soils developed on sandstone showed significantly lower concentration of SOC (29 g C kg-1) than soils developed on basalts (97 g C kg-1) and trachytes (119 g C kg-1). The soils on sandstone presented a mixed clay mineralogy dominated by illite, with lesser amounts of hydroxivermiculite, hydrobiotite and kaolinite, and a total absence of interstratified chlorite/vermiculite. In contrast, the major crystalline clay mineral identified in the soils developed on volcanic rocks was interstratified chlorite/vermiculite. Nevertheless, no major differences were observed between basaltic and trachytic soils in the clay mineralogy. The selective extraction of Fe showed that the oxalate extractable iron was significantly lower in soils on sandstone (3.7%) than on basalts (11.2%) and

  11. Facile synthesis of nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite with enhanced photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiangpeng; Li, Changqing; Cong, Jingkun; Liu, Ziwei; Zhang, Hanzhuo; Liang, Mei [The Key laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Gao, Junkuo, E-mail: jkgao@zstu.edu.cn [The Key laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Wang, Shunli [Department of Physics, Center for Optoelectronic Materials and Devices, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Yao, Juming, E-mail: yaoj@zstu.edu.cn [The Key laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, National Engineering Lab for Textile Fiber Materials and Processing Technology (Zhejiang), College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2016-06-15

    Here we report a facile synthesis of nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) by using Fe-melamine supramolecular framework as precursor. The chemical and optical properties of the nanocomposites are well-characterized. The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities under visible light due to the efficient utilization of sunlight and the construction of Z-scheme electron transfer pathway. The results indicated that it could be a promising approach for the preparation of efficient g-C{sub 3}N{sub 4} nanocomposites photocatalysts by using metal-melamine supramolecular framework as precursors. - Graphical abstract: Nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) was synthesized by using Fe-melamine supramolecular framework as precursor. The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities under visible light. Display Omitted - Highlights: • Nanorod-type graphitic carbon nitride/Fe{sub 2}O{sub 3} composite (Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4}) was synthesized. • Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} showed strong optical absorption in the visible-light region. • The Fe{sub 2}O{sub 3}-g-C{sub 3}N{sub 4} nanocomposite demonstrated excellent photocatalytic activities.

  12. Functionalization effects of single-walled carbon nanotubes as templates for the synthesis of silica nanorods and study of growing mechanism of silica.

    Science.gov (United States)

    Lee, Kyoung G; Wi, Rinbok; Imran, Muhammad; Park, Tae Jung; Lee, Jaebeom; Lee, Sang Yup; Kim, Do Hyun

    2010-07-27

    Silica nanorods were successfully prepared through a sol-gel process in the presence of carboxylic-functionalized single-walled carbon nanotubes (C-SWCNTs). The effect of chemical functionalization of single-walled carbon nanotubes (SWCNTs) on the growth of the silica layer was investigated using pristine SWCNTs (P-SWCNTs) and C-SWCNTS. The C-SWCNTs served as a unique template to fabricate silica hybrid composite materials. The crystalline formation and growing mechanism of the silica layer on C-SWCNTs were explained by the hydrolysis and chemical bonding between silica precursors and carboxylated SWCNTs. The C-SWCNTs, as templates, were successfully encapsulated using silica, and used templates were removed by oxidation at high temperature. Finally, silica nanorods/nanowires were synthesized in forms of mold, and this silica fabrication mechanism could be applied for large-scale production of silica nanomaterials and highly flexible nanocomposites. The sequence of a silica encapsulation process of C-SWCNTs and removed C-SWCNTs was characterized using SEM, TEM, EDX, FT-IR and Raman spectroscopy, XRD, and electrical analysis.

  13. RGD-conjugated silica-coated gold nanorods on the surface of carbon nanotubes for targeted photoacoustic imaging of gastric cancer

    Science.gov (United States)

    Wang, Can; Bao, Chenchen; Liang, Shujing; Fu, Hualin; Wang, Kan; Deng, Min; Liao, Qiande; Cui, Daxiang

    2014-05-01

    Herein, we reported for the first time that RGD-conjugated silica-coated gold nanorods on the surface of multiwalled carbon nanotubes were successfully used for targeted photoacoustic imaging of in vivo gastric cancer cells. A simple strategy was used to attach covalently silica-coated gold nanorods (sGNRs) onto the surface of multiwalled carbon nanotubes (MWNTs) to fabricate a hybrid nanostructure. The cross-linked reaction occurred through the combination of carboxyl groups on the MWNTs and the amino group on the surface of sGNRs modified with a silane coupling agent. RGD peptides were conjugated with the sGNR/MWNT nanostructure; resultant RGD-conjugated sGNR/MWNT probes were investigated for their influences on viability of MGC803 and GES-1 cells. The nude mice models loaded with gastric cancer cells were prepared, the RGD-conjugated sGNR/MWNT probes were injected into gastric cancer-bearing nude mice models via the tail vein, and the nude mice were observed by an optoacoustic imaging system. Results showed that RGD-conjugated sGNR/MWNT probes showed good water solubility and low cellular toxicity, could target in vivo gastric cancer cells, and obtained strong photoacoustic imaging in the nude model. RGD-conjugated sGNR/MWNT probes will own great potential in applications such as targeted photoacoustic imaging and photothermal therapy in the near future.

  14. Scientific Opinion on the safety assessment of the active substances, sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulphate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, for use as active system in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-02-01

    Full Text Available This scientific opinion of EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the active substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water, used in mixture which is packed into sachets for absorbing oxygen/carbon dioxide emitting from/into the headspace surrounding packed food. All substances of this formulation have been evaluated and approved for use as additives in plastic food contact materials or as food additives. No migration of calcium, iron and sodium ions was detected. No volatile organic compounds other than carbon dioxide were detected at the limit of detection of 0.5 μg/l. The CEF Panel concluded that the use of the substances sodium erythorbate, sodium carbonate, sodium bicarbonate, iron sulfate, activated carbon, cellulose, calcium hydroxide, calcium chloride and water does not raise a safety concern when used in oxygen absorber/carbon dioxide emitter systems, in sachets that prevent the physical release of their contents into the food. The sachets are to be placed in the headspace of the packaging and as such may come into occasional contact with the food, e.g. during handling. The sachet should not come into direct contact with liquid foods or foods that have and external aqueous liquid phase on the surface (liquid or exudates.

  15. TiO2 nanorods grown on carbon fiber cloth as binder-free electrode for sodium-ion batteries and flexible sodium-ion capacitors

    Science.gov (United States)

    Liu, Sainan; Luo, Zhigao; Tian, Gengyu; Zhu, Mengnan; Cai, Zhenyang; Pan, Anqiang; Liang, Shuquan

    2017-09-01

    Na-ion batteries (NIBs) and Na-ion capacitors (NICs) have tremendous potential in many large-scale energy storage applications. Here, NIBs based on TiO2 nanorods/carbon fiber cloth (TiO2/CFC) flexible anode materials are introduced. The as-prepared flexible anode exhibited a notable rate performance and high specific capacity of 148.7 mAh g-1 after 2000 cycles at 1 A g-1. Furthermore, we demonstrate a highly flexible NIC system employing the TiO2/CFC anode and carbon fibers (CFs) as the cathode material. The flexible TiO2/CFC//CFs NIC device achieved a high energy density of 73.8 Wh kg-1 and high power density of 13,750 W kg-1, as well as long-term cycling stability over 4000 cycles with a capacity retention of ∼90%.

  16. Simultaneous tracking of drug molecules and carriers using aptamer-functionalized fluorescent superstable gold nanorod-carbon nanocapsules during thermo-chemotherapy

    Science.gov (United States)

    Wang, Xue-Wei; Gao, Wei; Fan, Huanhuan; Ding, Ding; Lai, Xiao-Fang; Zou, Yu-Xiu; Chen, Long; Chen, Zhuo; Tan, Weihong

    2016-04-01

    Controlling and monitoring the drug delivery process is critical to its intended therapeutic function. Many nanocarrier systems for drug delivery have been successfully developed. However, biocompatibility, stability, and simultaneously tracing drugs and nanocarriers present significant limitations. Herein, we have fabricated a multifunctional nanocomposite by coating the gold nanorod (AuNR) with a biocompatible, superstable and fluorescent carbon layer, obtaining the AuNR@carbon core-shell nanocapsule. In this system, the carbon shell, originally obtained in aqueous glucose solutions and, therefore, biocompatible in physiological environments, could be simply loaded with cell-specific aptamers and therapeutic molecules through π-π interactions, a useful tool for cancer-targeted cellular imaging and therapy. Moreover, such a stable and intrinsic fluorescence effect of the AuNR@carbon enabled simultaneous tracking of released therapeutic molecules and nanocarriers under thermo-chemotherapy. The AuNR@carbons had high surface areas and stable shells, as well as unique optical and photothermal properties, making them promising nanostructures for biomedical applications.Controlling and monitoring the drug delivery process is critical to its intended therapeutic function. Many nanocarrier systems for drug delivery have been successfully developed. However, biocompatibility, stability, and simultaneously tracing drugs and nanocarriers present significant limitations. Herein, we have fabricated a multifunctional nanocomposite by coating the gold nanorod (AuNR) with a biocompatible, superstable and fluorescent carbon layer, obtaining the AuNR@carbon core-shell nanocapsule. In this system, the carbon shell, originally obtained in aqueous glucose solutions and, therefore, biocompatible in physiological environments, could be simply loaded with cell-specific aptamers and therapeutic molecules through π-π interactions, a useful tool for cancer-targeted cellular imaging and

  17. Enhanced Oxygen and Hydroxide Transport in a Cathode Interface by Efficient Antibacterial Property of a Silver Nanoparticle-Modified, Activated Carbon Cathode in Microbial Fuel Cells.

    Science.gov (United States)

    Li, Da; Qu, Youpeng; Liu, Jia; Liu, Guohong; Zhang, Jie; Feng, Yujie

    2016-08-17

    A biofilm growing on an air cathode is responsible for the decreased performance of microbial fuel cells (MFCs). For the undesired biofilm to be minimized, silver nanoparticles were synthesized on activated carbon as the cathodic catalyst (Ag/AC) in MFCs. Ag/AC enhanced maximum power density by 14.6% compared to that of a bare activated carbon cathode (AC) due to the additional silver catalysis. After operating MFCs over five months, protein content on the Ag/AC cathode was only 38.3% of that on the AC cathode, which resulted in a higher oxygen concentration diffusing through the Ag/AC cathode. In addition, a lower pH increment (0.2 units) was obtained near the Ag/AC catalyst surface after biofouling compared to 0.8 units of the AC cathode, indicating that less biofilm on the Ag/AC cathode had a minor resistance on hydroxide transported from the catalyst layer interfaces to the bulk solution. Therefore, less decrements of the Ag/AC activity and MFC performance were obtained. This result indicated that accelerated transport of oxygen and hydroxide, benefitting from the antibacterial property of the cathode, could efficiently maintain higher cathode stability during long-term operation.

  18. Synthesis and characterization of metal oxide nanorod brushes

    Indian Academy of Sciences (India)

    Kalyan Raidongia; M Eswaramoorthy

    2008-02-01

    Nanorod brushes of -Al2O3, MoO3 and ZnO have been synthesized using amorphous carbon nanotube (-CNT) brushes as the starting material. The brushes of -Al2O3 and MoO3 are made up of single crystalline nanorods. In the case of ZnO brushes, the nanorod bristles are made by the fusion of 15–25 nm size nanoparticles and are porous in nature. Metal oxide nanorod brushes thus obtained have been characterized by XRD, FESEM, TEM and Raman spectroscopy. Single crystalline ruby nanorods were obtained by introducing chromium ions during the synthesis of alumina rods.

  19. Synthesis of Ni/Mg/Al Layered Double Hydroxides and Their Use as Catalyst Precursors in the Preparation of Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yun; JIAO Qing-ze; LIANG Ji; LI Chun-hua

    2005-01-01

    Ni/Mg/Al layered double hydroxides(LDHs) with different n(Ni):n(Mg):n(Al) ratio values were prepared via a coprecipitation reaction. Then Ni/Mg/Al mixed oxides were obtained by calcination of these LDHs precursors. Carbon nanotubes were produced in the catalytic decomposition of propane over the Ni/Mg/Al mixed oxide catalysts. The quality of as-made nanotubes was investigated by SEM and TEM. The nanotubes were multiwall with a high length-diameter ratio and appeared to be flexible. The catalytic activities of these mixed oxides increased with increasing the Ni content. The Ni/Mg/Al mixed oxide with the highest Ni content [n(Ni)/n(Mg)/n(Al)=1/1/1] showed the highest activity and the carbon nanotubes grown on its surface had the best quality.

  20. High-performance and ultra-stable lithium-ion batteries based on MOF-derived ZnO@ZnO quantum dots/C core-shell nanorod arrays on a carbon cloth anode.

    Science.gov (United States)

    Zhang, Guanhua; Hou, Sucheng; Zhang, Hang; Zeng, Wei; Yan, Feilong; Li, Cheng Chao; Duan, Huigao

    2015-04-08

    MOF-derived ZnO@ZnO Quantum Dots/C core-shell nanorod arrays grown on flexible carbon cloth are successfully fabricated as a binder-free anode for Li-ion storage. In combination with the advantages from the ZnO/C core-shell architecture and the 3D nanorod arrays, this material satisfies both efficient ion and fast electron transport, and thus shows superior rate capability and excellent cycling stability. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Structural and optical properties of ZnO nanorods by electrochemical growth using multi-walled carbon nanotube-composed seed layers.

    Science.gov (United States)

    Ko, Yeong Hwan; Kim, Myung Sub; Yu, Jae Su

    2012-01-05

    We reported the enhancement of the structural and optical properties of electrochemically synthesized zinc oxide [ZnO] nanorod arrays [NRAs] using the multi-walled carbon nanotube [MWCNT]-composed seed layers, which were formed by spin-coating the aqueous seed solution containing MWCNTs on the indium tin oxide-coated glass substrate. The MWCNT-composed seed layer served as the efficient nucleation surface as well as the film with better electrical conductivity, thus leading to a more uniform high-density ZnO NRAs with an improved crystal quality during the electrochemical deposition process. For ZnO NRAs grown on the seed layer containing MWCNTs (2 wt.%), the photoluminescence peak intensity of the near-band-edge emission at a wavelength of approximately 375 nm was enhanced by 2.8 times compared with that of the ZnO nanorods grown without the seed layer due to the high crystallinity of ZnO NRAs and the surface plasmon-meditated emission enhancement by MWCNTs. The effect of the MWCNT-composed seed layer on the surface wettability was also investigated.PACS: 81.07.-b; 81.16.-c; 81.07.Pr; 61.48.De.

  2. 碳酸镁和碳酸锌的比热容及分解吸热效应研究%On the specific heat capacity and decomposition heat of the basic magnesium carbonate and zinc carbonate hydroxide

    Institute of Scientific and Technical Information of China (English)

    高云升; 杜志明; 王春迎

    2013-01-01

    This paper aims to bring about our experimental results on the study of the specific heat capacity and decomposition heat of the basic magnesium carbonate and zinc carbonate hydroxide. As is known, most of carbonates are prone to decompose by absorbing heat, which accounts for their being used as a coolant. Basic magnesium carbonate and zinc carbonate hydroxide have good environmental performance and chemical stability, which accounts for their popular use in the condensed aerosol fire extinguishing device as a coolant for high-temperature gases. Thermal analysis experiments tell us that the specific heat capacities of basic magnesium carbonate and zinc carbonate hydroxide are 1.249 - 2.099 J/(g·℃) and 1.022 - 1.420 J/(g·℃) respectively in the range of 45 - 150℃ . We have also found the relation curve about the specific heat capacity and the temperature of the two compounds. And, next, we have worked out the decomposition reaction of heat absorption capacities of basic magnesium carbonate and zinc carbonate hydroxide to the differential scanning calorimetry curve s peak area by means of the integral method. The experimental facts state that the basic magnesium carbonate has two endothermic peaks: one is near the 250 ℃ , whose decomposition caloric receptivity is about 266.91 J/g, whereas the other is near the 400 ℃ , whose decomposition caloric receptivity is about 1 512.27 J/g. However, zinc carbonate hydroxide has only one endothermic peak, which is bound to be reached near the 250℃ . Its decomposition caloric receptivity is about 283.91 J/g. Hence, the cooling effect of the basic magnesium carbonate has been found preliminary through testing and measurement, which accounts for its application as a coolant in the condensed aerosol fire extinguishing device. The above results prove that basic magnesium carbonate can serve as an excellent chemical coolant suitable for such a device.%碱式碳酸镁和碱式碳酸锌常用作热气溶胶灭火装置

  3. Palladium on Layered Double Hydroxide: A Heterogeneous System for the Enol Phosphate Carbon-Oxygen Bond Activation in Aqueous Media

    Directory of Open Access Journals (Sweden)

    Jaqueline D. Senra

    2017-01-01

    Full Text Available In this work, a new catalytic approach for the C-O activation of enol phosphates based on a palladium supported on layered double hydroxide was developed. In this case, two different ketene aminal phosphates were used as models to study the synthesis of α-phenyl enecarbamates N-Boc/CBz under the Suzuki-Miyaura conditions. The use of an ortho-bromoaniline as precursor allowed the synthesis of the 2-phenyl indole through an arylation/Heck cyclization. Catalyst reusability enabled the synthesis of the heterocycle in moderate yields for four consecutive runs.

  4. Preparation of Nd2O3 nanorods in SDBS micelle system

    Institute of Scientific and Technical Information of China (English)

    吴萍萍; 张之魁; 宋根萍

    2014-01-01

    Well-crystallized Nd2O3 nanorods were prepared in the aqueous solution containing neodymium nitrate, sodium hydroxide (dissolved in ethanol) and sodium dodecyl benzene sulfonate (SDBS). One dimensional nanorods of neodymium hydroxide were synthesized first, which was then placed at different temperatures (600 and 800 °C) in a calcar for 10 h to form Nd2O3 nanorods. The morphology and crystal structure of the products were investigated by X-ray diffraction, transmission electron microscopy, field emission transmission electron microscopy, Fourier transform infrared spectroscopy and fluorescence spectrometry. By using SDBS micelles as a template, this method manufactured uniform morphology of hexagonal one-dimensional neodymium oxide nanorods with a diameter ranging from 20 to 70 nm. The length of the nanorods increased with prolonged reaction time.

  5. Central composite design and genetic algorithm applied for the optimization of ultrasonic-assisted removal of malachite green by ZnO Nanorod-loaded activated carbon

    Science.gov (United States)

    Ghaedi, M.; Azad, F. Nasiri; Dashtian, K.; Hajati, S.; Goudarzi, A.; Soylak, M.

    2016-10-01

    Maximum malachite green (MG) adsorption onto ZnO Nanorod-loaded activated carbon (ZnO-NR-AC) was achieved following the optimization of conditions, while the mass transfer was accelerated by ultrasonic. The central composite design (CCD) and genetic algorithm (GA) were used to estimate the effect of individual variables and their mutual interactions on the MG adsorption as response and to optimize the adsorption process. The ZnO-NR-AC surface morphology and its properties were identified via FESEM, XRD and FTIR. The adsorption equilibrium isotherm and kinetic models investigation revealed the well fit of the experimental data to Langmuir isotherm and pseudo-second-order kinetic model, respectively. It was shown that a small amount of ZnO-NR-AC (with adsorption capacity of 20 mg g- 1) is sufficient for the rapid removal of high amount of MG dye in short time (3.99 min).

  6. Gold nanorod@silica-carbon dots as multifunctional phototheranostics for fluorescence and photoacoustic imaging-guided synergistic photodynamic/photothermal therapy

    Science.gov (United States)

    Jia, Qingyan; Ge, Jiechao; Liu, Weimin; Liu, Sha; Niu, Guangle; Guo, Liang; Zhang, Hongyan; Wang, Pengfei

    2016-06-01

    Phototheranostics, which is the application of light in the diagnostic imaging and therapy of cancer, has shown great promise for multimodal cancer imaging and effective therapy. Herein, we developed multifunctional gold nanorod@silica-carbon dots (GNR@SiO2-CDs) as a phototheranostic agent by incorporating carbon dots (CDs) with gold nanorods (GNRs), using SiO2 as a scaffold. In GNR@SiO2-CDs, the GNRs act as both photoacoustic (PA) imaging and photothermal therapy (PTT) agents, and the CDs serve as fluorescence (FL) imaging and photodynamic therapy (PDT) agents. The introduction of SiO2 not only improves the chemical stability of the GNRs and CDs in the physiological environment but also prevents the absolute quenching of the fluorescence of the CDs by GNRs. These collective properties make GNR@SiO2-CDs a novel phototheranostic agent, in which high sensitivity and good spatial resolution of FL/PA imaging can be achieved to guide PDT/PTT treatments through i.v. administration. The combination of PDT and PTT proved to be more efficient in killing cancer cells compared to PDT or PTT alone under a low dose of laser irradiation (low toxicity of this phototheranostic agent. Our work highlights the potential of using GNRs and CDs as novel phototheranostic agents for multifunctional cancer therapies.Phototheranostics, which is the application of light in the diagnostic imaging and therapy of cancer, has shown great promise for multimodal cancer imaging and effective therapy. Herein, we developed multifunctional gold nanorod@silica-carbon dots (GNR@SiO2-CDs) as a phototheranostic agent by incorporating carbon dots (CDs) with gold nanorods (GNRs), using SiO2 as a scaffold. In GNR@SiO2-CDs, the GNRs act as both photoacoustic (PA) imaging and photothermal therapy (PTT) agents, and the CDs serve as fluorescence (FL) imaging and photodynamic therapy (PDT) agents. The introduction of SiO2 not only improves the chemical stability of the GNRs and CDs in the physiological

  7. Peapod-like V2O3 nanorods encapsulated into carbon as binder-free and flexible electrodes in lithium-ion batteries

    Science.gov (United States)

    Li, Xingxing; Fu, Jijiang; Pan, Zhiguo; Su, Jianjun; Xu, Jiangwen; Gao, Biao; Peng, Xiang; Wang, Lei; Zhang, Xuming; Chu, Paul K.

    2016-11-01

    Designing and fabricating electrodes with excellent mechanical flexibility and superior electrochemical performance for high-performance lithium ion battery (LIBs) is challenging. Herein, ultralong peapod-like nanowires (NWs) composed of short vanadium sesquioxide nanorods (V2O3 NRs) encapsulated with carbon are produced as high-performance anode materials. The freestanding and flexible film has a high capacity of 210 mAh g-1 at a current density of 0.1 C, and exhibits appreciable rate capability with 68% capacitance retention when the current density is increased from 0.1 to 1 C, and excellent long-term cycling stability without apparent capacity fading after 125 cycles, which is better then that of the active carbon mixed V2O3 NRs and bare V2O3 NRs. The outstanding electrochemical performance is attributed to proper accommodation of the volume expansion of the vanadium oxide in the carbon in the lithiation/delithiation process as well as the outer conductive three-dimensional (3D) carbon network. The formation mechanism of the peapod-like structure is investigated by thermogravimetric analysis connected to a mass spectrometer (MS). The ultralong peapod-like nanostructure overcomes the physical and chemical drawbacks of vanadium oxide and has large potential applicability for flexible energy-storage devices.

  8. Novel bamboo leaf shaped CuO nanorod@hollow carbon fibers derived from plant biomass for efficient and nonenzymatic glucose detection.

    Science.gov (United States)

    Li, Mian; Zhao, Zheng; Liu, Xiaotian; Xiong, Yueping; Han, Ce; Zhang, Yufan; Bo, Xiangjie; Guo, Liping

    2015-09-21

    The present paper reports on the preparation of novel bamboo leaf shaped CuO nanorod dispersed hollow carbon fibers (denoted as CuO NR@PCFs). Specially, the new-type hollow carbon fibers (containing abundant micro/meso/macropores and a large specific surface area) were prepared only by simple and fast pyrolysis of the natural product catkins without using any template or surfactant. Meanwhile, a facile method was used to prepare the bamboo leaf shaped CuO nanorod covered PCFs. Thanks to the abundant micro/meso/macropores, large specific surface area, and excellent electrical conduction efficiency of the PCF matrix, the as-prepared CuO NR@PCFs could also afford more catalytic sites, show more excellent reactant transport efficiency, and display more excellent electron transport rates compared with those for the pure CuO balls. Above all, these advantages will result in the excellent oxidation and detection efficiency of the CuO NR@PCF sample to glucose. Electrochemical measurements reveal that the CuO NR@PCF modified electrode can directly catalyze glucose oxidation and display an enhanced current response compared with the pure CuO balls (such as a response time within 4 s, wide linear ranges of 5 × 10(-3)-0.8 mM and 0.8-8.5 mM, good reproducibility, considerable stability, and excellent anti-interference to electroactive molecules and Cl(-)). The superior catalytic activity and selectivity make the CuO NR@PCF catalyst very promising for application in direct detection of glucose.

  9. Conformal Coating of Cobalt-Nickel Layered Double Hydroxides Nanoflakes on Carbon Fibers for High-performance Electrochemical Energy Storage Supercapacitor Devices

    KAUST Repository

    Warsi, Muhammad Farooq

    2014-07-01

    High specific capacitance coupled with the ease of large scale production is two desirable characteristics of a potential pseudo-supercapacitor material. In the current study, the uniform and conformal coating of nickel-cobalt layered double hydroxides (CoNi0.5LDH,) nanoflakes on fibrous carbon (FC) cloth has been achieved through cost-effective and scalable chemical precipitation method, followed by a simple heat treatment step. The conformally coated CoNi0.5LDH/FC electrode showed 1.5 times greater specific capacitance compared to the electrodes prepared by conventional non-conformal (drop casting) method of depositing CoNi0.5LDH powder on the carbon microfibers (1938 Fg-1 vs 1292 Fg-1). Further comparison of conformally and non-conformally coated CoNi0.5LDH electrodes showed the rate capability of 79%: 43% capacity retention at 50 Ag-1 and cycling stability 4.6%: 27.9% loss after 3000 cycles respectively. The superior performance of the conformally coated CoNi0.5LDH is mainly due to the reduced internal resistance and fast ionic mobility between electrodes as compared to non-conformally coated electrodes which is evidenced by EIS and CV studies. © 2014 Elsevier Ltd.

  10. Ultrathin nickel hydroxide nanosheet arrays grafted biomass-derived honeycomb-like porous carbon with improved electrochemical performance as a supercapacitive material

    Science.gov (United States)

    Nagaraju, Goli; Cha, Sung Min; Yu, Jae Su

    2017-03-01

    Three-dimensional hierarchical honeycomb-like activated porous carbon pillared ultrathin Ni(OH)2 nanosheets (Ni(OH)2 NSs@HAPC) for use as supercapacitor materials were facilely synthesized. With an aid of pine cone flowers as a biomass source, HAPC conducting scaffolds were prepared by the alkali treatment and pyrolysis methods under an inert gas atmosphere. Subsequently, the Ni(OH)2 NSs were synthesized evenly on the surface of HAPC via a solvothermal method. The resulting HAPC and Ni(OH)2 NSs@HAPC composite materials offered free pathways for effective diffusion of electrolyte ions and fast transportation of electrons when employed as an electrode material. The Ni(OH)2 NSs@HAPC composite electrode exhibited excellent electrochemical properties including a relatively high specific capacitance (Csp) value of ~ 916.4 F/g at 1 A/g with good cycling stability compared to the pristine HAPC and Ni(OH)2 NSs electrodes. Such bio-friendly derived carbon-based materials with transition metal hydroxide/oxide composite materials could be a promising approach for high-performance energy storage devices because of their advantageous properties of cost effectiveness and easy availability.

  11. Carbon nanotubes incorporated with sol-gel derived La(OH)3 nanorods as platform to simultaneously determine ascorbic acid, dopamine, uric acid and nitrite.

    Science.gov (United States)

    Zhang, Yu; Yuan, Ruo; Chai, Yaqin; Zhong, Xia; Zhong, Huaan

    2012-12-01

    A novel material, sol-gel derived La(OH)(3) nanorods (La(OH)(3)NRs) with excellent film forming ability was prepared, and it was first designed to incorporate with carbon nanotubes (CNTs) to modify glassy carbon electrode (GCE) to simultaneously voltammetric determine ascorbic acid (AA), dopamine (DA), uric acid (UA), and nitrite (NO(2)(-)). Cyclic voltammetry (CV), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were employed to characterize the sensor. Under optimal conditions, the linear response range for AA, DA, UA, and NO(2)(-) were 0.5 μmol L(-1) to 1.46 mmol L(-1), 50 nmol L(-1) to 35.36 μmol L(-1), 50 nmol L(-1) to 0.79 mmol L(-1), and 0.55 μmol L(-1) to 0.72 mmol L(-1), respectively and the detection limits were 1.67 μmol L(-1), 1.67 nmol L(-1), 1.67 nmol L(-1), and 0.18 μmol L(-1). The sensor demonstrated well stability, high selectivity and sensitivity. More importance, this material can be extended to construct other electrochemical sensors by the immobilization of enzymes and antibodies.

  12. Straight SiO_x nanorod Yjunctions

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Novel straight silicon oxide [SiOx (1nanorod Y junctions have been synthesized on Si plate by thermal evaporation of mixed powders of silica and carbon nanofibers at 1300℃ and condensation on a Si substrate without assistance of any catalyst. The synthesized samples were characterized by means of scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The results suggested that the straight nanorod Y junctions are amorphous and consist only of elements Si and O, and these rods with diameters about 50―200 nm have a neat smooth surface. The growth of such silicon oxide nanorods may be a result of the second nucleation on the surface of rods causing a change in the growth direc- tion of silicon oxide nanorods developed.

  13. Acrylic acid-allylpolyethoxy carboxylate copolymer dispersant for calcium carbonate and iron(III) hydroxide scales in cooling water systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guangqing; Huang, Jingyi; Zhou, Yuming; Yao, Qingzhao; Ling, Lei; Zhang, Peixin; Fu, Change [Southeast Univ., Nanjing (China). School of Chemistry and Chemical Engineering; Wu, Wendao; Sun, Wei; Hu, Zhengjun [Jianghai Chemical Co., Ltd., Changzhou (China)

    2012-05-15

    A novel environmentally friendly type of calcium carbonate and iron(III) scale inhibitor (ALn) was synthesized. The anti-scale property of the Acrylic acid-allylpolyethoxy carboxylate copolymer (AA-APELn or ALn) towards CaCO{sub 3} and iron(III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate and iron(III) inhibition increase with increasing the degree of polymerization of ALn from 5 to 15, and the dosage of ALn plays an important role on calcium carbonate and iron(III)-inhibition. The effect on formation of CaCO{sub 3} was investigated with a combination of scanning electronic microscopy (SEM), Transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and Fourier transform infrared spectrometer, respectively. The results showed that the ALn copolymer not only influences calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO{sub 3} in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the ALn copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems. (orig.)

  14. Mesoporous-activated carbon prepared from chitosan flakes via single-step sodium hydroxide activation for the adsorption of methylene blue.

    Science.gov (United States)

    Marrakchi, F; Ahmed, M J; Khanday, W A; Asif, M; Hameed, B H

    2017-05-01

    In this work, mesoporous-activated carbon (CSAC) was prepared from chitosan flakes (CS) via single-step sodium hydroxide activation for the adsorption of methylene blue (MB). CSAC was prepared using different impregnation ratios of NaOH:CS (1:1, 2:1, 3:1, and 4:1) at 800°C for 90min. The adsorption performance of CSAC was evaluated for MB at different adsorption variables, such MB initial concentrations (25-400mg/L), solution pH (3-11), and temperature (30-50°C). The adsorption isotherm data of CSAC-MB were well fitted to Langmuir model with a maximum adsorption capacity 143.53mg/g at 50°C. Best representation of kinetic data was obtained by the pseudo-second order model. CSAC exhibited excellent adsorption uptake for MB and can potentially be used for other cationic dyes. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Nickel-cobalt layered double hydroxide anchored zinc oxide nanowires grown on carbon fiber cloth for high-performance flexible pseudocapacitive energy storage devices

    KAUST Repository

    Shakir, Imran

    2014-05-01

    Nickel-cobalt layered double hydroxide (Ni-Co LDH) nanoflakes-ZnO nanowires hybrid array has been directly synthesized on a carbon cloth substrate by a facile cost-effective two-step hydrothermal route. As electrode materials for flexible pseudocapacitors, Ni-Co LDH nanoflakes-ZnO nanowires hybrid array exhibits a significantly enhanced specific capacitance of 1927 Fg-1, which is a ∼1.8 time greater than pristine Ni-Co LDH nanoflakes. The synthesized Ni-Co LDH nanoflakes-ZnO nanowires hybrid array shows a maximum energy density of 45.55 Whkg-1 at a power density of 46.15 kWkg -1, which is 35% higher than the pristine Ni-Co LDH nanoflakes electrode. Moreover, Ni-Co LDH nanoflakes-ZnO nanowires hybrid array exhibit excellent excellent rate capability (80.3% capacity retention at 30 Ag -1) and cycling stability (only 3.98% loss after 3000 cycles), due to the significantly improved faradaic redox reaction. © 2014 Elsevier Ltd.

  16. ZnO-Layered Double Hydroxide@Graphitic Carbon Nitride Composite for Consecutive Adsorption and Photodegradation of Dyes under UV and Visible Lights.

    Science.gov (United States)

    Zhang, Luhong; Li, Li; Sun, Xiaoming; Liu, Peng; Yang, Dongfang; Zhao, Xiusong

    2016-11-15

    In this work, a ZnO-layered double hydroxide@graphitic carbon nitride composite (ZnO-LDH@C₃N₄) was synthesized via co-precipitation method with solvothermal treatment. The structure and morphology of ZnO-LDH@C₃N₄ composite were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopes/transmission electron microscopes (SEM/TEM), N₂ adsorption/desorption, ultraviolet visible diffuse reflectance spectroscopy (UV-Vis-DRS), photoluminescence spectrometer (PL) and electrochemical impedance spectroscopy (EIS). The adsorption and photocatalytic properties of ZnO-LDH@C₃N₄ composite towards the organic dyes: Orange II sodium salt (OrgII, an anionic azo dye) and methylene blue (MB, a cationic azo dye) were investigated. Compared to ZnO-LDH and g-C₃N₄, the ZnO-LDH@C₃N₄ composite displayed an excellent performance in both adsorption and photocatalytic degradation of the organic dyes. Moreover, a combination of ZnO-LDH and g-C₃N₄ significantly improved the photocatalytic performance of ZnO-LDH and g-C₃N₄ under visible-light irradiation. The adsorption and photocatalytic mechanism were also investigated.

  17. ZnO-Layered Double Hydroxide@Graphitic Carbon Nitride Composite for Consecutive Adsorption and Photodegradation of Dyes under UV and Visible Lights

    Directory of Open Access Journals (Sweden)

    Luhong Zhang

    2016-11-01

    Full Text Available In this work, a ZnO-layered double hydroxide@graphitic carbon nitride composite (ZnO-LDH@C3N4 was synthesized via co-precipitation method with solvothermal treatment. The structure and morphology of ZnO-LDH@C3N4 composite were characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopes/transmission electron microscopes (SEM/TEM, N2 adsorption/desorption, ultraviolet visible diffuse reflectance spectroscopy (UV-Vis-DRS, photoluminescence spectrometer (PL and electrochemical impedance spectroscopy (EIS. The adsorption and photocatalytic properties of ZnO-LDH@C3N4 composite towards the organic dyes: Orange II sodium salt (OrgII, an anionic azo dye and methylene blue (MB, a cationic azo dye were investigated. Compared to ZnO-LDH and g-C3N4, the ZnO-LDH@C3N4 composite displayed an excellent performance in both adsorption and photocatalytic degradation of the organic dyes. Moreover, a combination of ZnO-LDH and g-C3N4 significantly improved the photocatalytic performance of ZnO-LDH and g-C3N4 under visible-light irradiation. The adsorption and photocatalytic mechanism were also investigated.

  18. Nickel-cobalt hydroxide nanosheets coated on NiCo2O4 nanowires grown on carbon fiber paper for high-performance pseudocapacitors.

    Science.gov (United States)

    Huang, Liang; Chen, Dongchang; Ding, Yong; Feng, Shi; Wang, Zhong Lin; Liu, Meilin

    2013-07-10

    A series of flexible nanocomposite electrodes were fabricated by facile electro-deposition of cobalt and nickel double hydroxide (DH) nanosheets on porous NiCo2O4 nanowires grown radially on carbon fiber paper (CFP) for high capacity, high energy, and power density supercapacitors. Among different stoichiometries of CoxNi1-xDH nanosheets studied, Co0.67Ni0.33 DHs/NiCo2O4/CFP hybrid nanoarchitecture showed the best cycling stability while maintaining high capacitance of ∼1.64 F/cm(2) at 2 mA/cm(2). This hybrid composite electrode also exhibited excellent rate capability; the areal capacitance decreased less than 33% as the current density was increased from 2 to 90 mA/cm(2), offering excellent specific energy density (∼33 Wh/kg) and power density (∼41.25 kW/kg) at high cycling rates (up to150 mA/cm(2)).

  19. Comparison of calcium carbonate and aluminium hydroxide as phosphate binders on biochemical bone markers, PTH(1-84), and bone mineral content in dialysis patients

    DEFF Research Database (Denmark)

    Jespersen, B; Jensen, J D; Nielsen, H K;

    1991-01-01

    Bone mineral content, estimated by single-photon absorptiometry of the forearm, serum values of intact parathyroid hormone (PTH(1-84], osteocalcin, alkaline phosphatase, 1,25-dihydroxycholecalciferol (1,25(OH)2D3), and aluminium were determined during treatment with calcium carbonate (CaCO3...... 0.05), osteocalcin decreased (89% versus 117%, P less than 0.01), alkaline phosphatase decreased (92% versus 116%, P less than 0.05), and aluminium decreased (56% versus 189%, P less than 0.05). 1,25(OH)2D3 remained unchanged in both periods. No increase in soft-tissue calcification was demonstrated......) or aluminium hydroxide (Al(OH)3) in 11 dialysis patients participating in a randomised cross-over study. Each treatment period lasted 6 months. Serum phosphorus was maintained in the range 1.5-2.0 mmol/l. During Al(OH)3 treatment bone mineral content (BMC) decreased by 11% per half-year (mean), but only by 3...

  20. Vertically aligned cobalt hydroxide nano-flake coated electro-etched carbon fiber cloth electrodes for supercapacitors

    Science.gov (United States)

    Cheng, Qian; Tang, Jie; Zhang, Han; Qin, Lu-Chang

    2014-11-01

    We describe preparation and characterization of nanostructured electrodes using Co(OH)2 nano-flakes and carbon fiber cloth for supercapacitors. Nanostructured Co(OH)2 flakes are produced by electrodeposition and they are coated onto the electro-etched carbon fiber cloth. A highest specific capacitance of 3404.8 F g-1 and an area-normalized specific capacitance of 3.3 F cm-2 have been obtained from such electrodes. Morphology and structure of the nanostructured electrodes have been characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties have been studied by cyclic voltammetry (CV), constant-current charge and discharge, electrochemical impedance spectroscopy (EIS), and long-time cycling.

  1. Low temperature synthesis and characterization of carbonated hydroxyapatite nanocrystals

    Science.gov (United States)

    Anwar, Aneela; Asghar, Muhammad Nadeem; Kanwal, Qudsia; Kazmi, Mohsin; Sadiqa, Ayesha

    2016-08-01

    Carbonate substituted hydroxyapatite (CHA) nanorods were synthesized via coprecipitation method from aqueous solution of calcium nitrate tetrahydrate and diammonium hydrogen phosphate (with urea as carbonate ion source) in the presence of ammonium hydroxide solution at 70 °C at the conditions of pH 11. The obtained powders were physically characterized using transmission electron microscopy (TEM), X-ray powder diffraction analysis (XRD), and FTIR and Raman spectroscopy. The particle size was evaluated by Dynamic light scattering (DLS). The chemical structural analysis of as prepared sample was performed using X-ray photoelectron spectroscopy (XPS). After ageing for 12 h, and heat treatment at 1000 °C for 1 h, the product was obtained as highly crystalline nanorods of CHA.

  2. Study on the Synthesis of Nano Ammonium Aluminum Carbonate Hydroxide (AACH)%纳米碳酸铝铵前驱体制备的研究

    Institute of Scientific and Technical Information of China (English)

    王伟礼; 毕见强; 邢政

    2008-01-01

    以硫酸铝铵(NH4Al(SO4)2)和碳酸氢铵(NH4HCO3)为主要原料,采用沉淀法制备纳米碳酸铝铵(AACH)前驱体,并利用X射线衍射(XRD),透射电镜(TEM)对前驱体的物相和形貌进行表征.研究表明,滴定速度和陈化时间对前驱体的形貌略有影响,而滴定方式和pH值对其影响较大.将硫酸铝铵溶液滴入碳酸氢铵溶液中,调节体系的pH值9-10,并将其陈化12小时,可以得到较好的前驱体.%Ammonium aluminum carbonate hydroxide (AACH) nanopowder was prepared via a precipitation reaction between ammonium aluminum sulphate (NH4 Al(SO4)2) and ammonium hydrogen carbonate (NH4 HCO3) in different conditions.The precursors were characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM).The results show that titration rate and aging time affected the morphology of precursors a bit,and titration mode and pH value affected the composition of precursors greatly.The optimum process was that NH4 Al(SO4)2 solution was added into NH4 HCO3 solution at pH 9-10 with aging time of 12h.

  3. Synthesis of binary bismuth-cadmium oxide nanorods with sensitive electrochemical sensing performance

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Yong [Xinjiang Univ., Xinjiang (China). School of Civil Engineering and Architecture; Pei, Lizhai; Wei, Tian [Anhui Univ. of Technology, Anhui (China). School of Materials Science and Engineering

    2017-07-15

    Binary bismuth-cadmium oxide nanorods have been synthesized by a simple hydrothermal process without templates and additives. X-ray diffraction and high-resolution transmission electron microscopy reveal that the nanorods possess single crystalline tetragonal Bi{sub 2}CdO{sub 4} phase. Scanning electron microscopy and transmission electron microscopy images show that the length and diameter of the nanorods are 20-300 nm and 5-10 μm, respectively. The formation of the binary bismuth-cadmium oxide nanorods is closely related to the hydrothermal parameters. The electrochemical sensing performance of the binary bismuth-cadmium oxide nanorods has been investigated using the nanorods as glassy carbon electrode modifiers. The detection limit is 0.19 μM with a linear range of 0.0005-2 mM. The nanorod-modified glassy carbon electrode exhibits good electrocatalytic activity toward L-cysteine and great application potential for electrochemical sensors.

  4. 废碳酸锶制备八水氢氧化锶联产硝酸钠研究%STUDY ON PREPARATION OF STRONTIUM HYDROXIDE AND SODIUM NITRATE FROM WASTE STRONTIUM CARBONATE.

    Institute of Scientific and Technical Information of China (English)

    郭志余

    2001-01-01

    The process for preparation of strontium hydroxide and sodium nitrate from waste strontium, which comes from industrial strontium carbonate production, is introduced. It provides a new way for utilizing waste strontium carbonate.%介绍了利用工业SCO3生产过程中产生的废次碳酸锶生产八水氢氧化锶及硝酸钠的工艺,为废锶的综合利用提出了一条新的途径。

  5. Drastically Enhanced High-Rate Performance of Carbon-Coated LiFePO4 Nanorods Using a Green Chemical Vapor Deposition (CVD) Method for Lithium Ion Battery: A Selective Carbon Coating Process.

    Science.gov (United States)

    Tian, Ruiyuan; Liu, Haiqiang; Jiang, Yi; Chen, Jiankun; Tan, Xinghua; Liu, Guangyao; Zhang, Lina; Gu, Xiaohua; Guo, Yanjun; Wang, Hanfu; Sun, Lianfeng; Chu, Weiguo

    2015-06-03

    Application of LiFePO4 (LFP) to large current power supplies is greatly hindered by its poor electrical conductivity (10(-9) S cm(-1)) and sluggish Li+ transport. Carbon coating is considered to be necessary for improving its interparticle electronic conductivity and thus electrochemical performance. Here, we proposed a novel, green, low cost and controllable CVD approach using solid glucose as carbon source which can be extended to most cathode and anode materials in need of carbon coating. Hydrothermally synthesized LFP nanorods with optimized thickness of carbon coated by this recipe are shown to have superb high-rate performance, high energy, and power densities, as well as long high-rate cycle lifetime. For 200 C (18s) charge and discharge, the discharge capacity and voltage are 89.69 mAh g(-1) and 3.030 V, respectively, and the energy and power densities are 271.80 Wh kg(-1) and 54.36 kW kg(-1), respectively. The capacity retention of 93.0%, and the energy and power density retention of 93.6% after 500 cycles at 100 C were achieved. Compared to the conventional carbon coating through direct mixing with glucose (or other organic substances) followed by annealing (DMGA), the carbon phase coated using this CVD recipe is of higher quality and better uniformity. Undoubtedly, this approach enhances significantly the electrochemical performance of high power LFP and thus broadens greatly the prospect of its applications to large current power supplies such as electric and hybrid electric vehicles.

  6. Hydroxide depletion in dilute supernates stored in waste tanks

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.T.

    1985-10-10

    Free hydroxide ion in dilute supernates are depleted by reaction with atmospheric carbon dioxide to form bicarbonate and carbonate species and by reaction with acidic compounds formed by the radiolytic decomposition of tetraphenylborate salts. A model of the kinetics and thermodynamics of absorption of carbon dioxide in the waste tanks has been developed. Forecasts of the rate of hydroxide depletion and the requirements for sodium hydroxide to maintain technical standards have been made for the washed sludge and washed precipitate storage tanks. Hydroxide depletion is predicted to have a minimal impact on sludge processing operations. However, in-tank precipitation and downstream DWPF operations are predicted to be significantly affected by hydroxide depletion in Tank 49H. The installation of a carbon dioxide scrubber on Tank 49H may be justified in view of the decrease in alkali content and variation in the melter feed.

  7. Influence of Sodium Carbonate, Sodium Hydroxide and Sodium Silicate on Dispersion of Ultrafine Hematite%3种调整剂对微细粒赤铁矿分散行为的影响

    Institute of Scientific and Technical Information of China (English)

    左倩; 张芹; 邓冰; 王飞

    2011-01-01

    The influence of sodium carbonate, sodium hydroxide and sodium silicate on dispersion of hematite fines were studied. The results showed that hematite was better dispersed by sodium hydroxide and sodium silicate, compared with sodium carbonate; Tbere is a synergistic action between the sodium hydroxide and sodium silicate on the dispersion of ultra - fine hematite. The hematite can be better dispersed with the increase of stirring speed in a range, but the dispersion becomes worse when the stirring speed exceed a critical value.%通过单矿物沉降试验,研究了碳酸钠,氧氧化钠和硅酸钠对微细粒赤铁矿分散行为的影响.试验结果表明:与碳酸钠相比,氢氧化钠和硅酸钠对徽细粒赤铁矿有更好的分散效果;氢氧化钠和硅酸钠对微细粒赤铁矿的分散具有协同作用;在一定范围内增强搅拌强度有利于微细粒赤铁矿的分散,但搅拌强度超过某一临界值后分散效果变差.

  8. Application of ZnO nanorods loaded on activated carbon for ultrasonic assisted dyes removal: Experimental design and derivative spectrophotometry method.

    Science.gov (United States)

    Ansari, Fatemeh; Ghaedi, Mehrorang; Taghdiri, Mehdi; Asfaram, Arash

    2016-11-01

    A method based on application of ZnO nanorods loaded on activated carbon (ZnO-NRs-AC) for adsorption of Bromocresol Green (BCG) and Eosin Y (EY) accelerated by ultrasound was described. The present material was synthesized under ultrasound assisted wet-chemical method and subsequently was characterized by FE-SEM, TEM, BET and XRD analysis. The extent of contribution of conventional variables like pH (2.0-10.0), BCG concentration (4-20mgL(-1)), EY concentration (3-23mgL(-1)), adsorbent dosage (0.01-0.03g), sonication time (1-5min) and centrifuge time (2-6min) as main and interaction part were investigated by central composite design under response surface methodology. Analysis of variance (ANOVA) was adapted to experimental data and guide the best operational conditions mass by set at 6.0, 9mgL(-1), 10mgL(-1), 0.02g, 4 and 4min for pH, BCG concentration, EY concentration, adsorbent dosage, sonication and centrifuge time, respectively. At these specified conditions dye adsorption efficiency was higher than 99.5%. The suitability and well prediction of optimum point was tested by conducting five experiments and respective results revel that RSD% was lower than 3% and high quality of fitting was confirmed by t-test. The experimental data were best fitted in Langmuir isotherm equation and the removal followed pseudo second order kinetics. The experimentally obtained maximum adsorption capacities were estimated as 57.80 and 61.73mgg(-1) of ZnO-NRs-AC for BCG and EY respectively from binary dye solutions. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion.

  9. Using carbon nanotubes-gold nanocomposites to quench energy from pinnate titanium dioxide nanorods array for signal-on photoelectrochemical aptasensing.

    Science.gov (United States)

    Deng, Wenping; Shen, Lei; Wang, Xiu; Yang, Chunlei; Yu, Jinghua; Yan, Mei; Song, Xianrang

    2016-08-15

    On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between carbon nanotubes-gold nanoparticles (CNTs-Au) and pinnate titanium dioxide nanorods array (P-TiO2 NA) was obtained. Three-dimensional single crystalline P-TiO2 were prepared successfully on fluorine-doped tin oxide conducting glass (FTO glass), and its optical absorption properties and photoelectrochemical (PEC) properties were investigated. With the synergy of CNTs-Au as energy acceptor, it resulted in the enhancement of energy transfer between excited P-TiO2 NA and CNTs-Au. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in P-TiO2 NA was annihilated and a damped photocurrent was obtained. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under the optimal conditions, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.5ngmL(-1) with a detection limit of 0.39pgmL(-1) and was satisfactory for clinical sample detection. Furthermore, the proposed aptasensor shows satisfying performance, such as easy preparation, rapid detection and so on. Moreover, since different aptamer can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.

  10. Photoelectrochemical sensitive detection of insulin based on CdS/polydopamine co-sensitized WO3 nanorod and signal amplification of carbon nanotubes@polydopamine.

    Science.gov (United States)

    Wang, Rongyu; Ma, Hongmin; Zhang, Yong; Wang, Qi; Yang, Zhongping; Du, Bin; Wu, Dan; Wei, Qin

    2017-10-15

    An ultrasensitive photoelectrochemical sandwich immunosensor was designed for detection of insulin based on WO3/CdS/polydopamine (WO3/CdS/PDA) co-sensitized and PDA@carbon nanotubes (PDA@CNT) conjugates for signal amplification. The CdS nanoparticles were first deposited on the WO3 nanorods via sequential chemical bath deposition to form the WO3/CdS structure to enhance photocurrent. Then equipped with PDA to form the WO3/CdS/PDA photosensitive structure. The PDA was used not only to reduce the toxicity of CdS but also adsorb insulin primary antibodies (Ab1). Meanwhile, insulin secondary antibodies (Ab2) were decorated by PDA@CNT conjugates for signal amplification and further enhance photocurrent. Different photocurrent intensities were obtained by the photoelectrochemical workstation at applied bias of 0V due to the different amount of the PDA@CNT conjugates introduced by the different concentrations of insulin. A good linear relationship was obtained between the increased photocurrent and insulin concentrations range from 0.01ngmL(-1) to 50ngmL(-1). And a detection limit of 2.8pgmL(-1) was obtained. The proposed sensor was applied to the determination of the insulin in human serum sample, and satisfactory results were obtained. The sensor presented good specificity, reproducibility and stability, thus it might find application in the clinical diagnosis of insulin or other biomarkers in the near future. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Graded core/shell semiconductor nanorods and nanorod barcodes

    Science.gov (United States)

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2010-12-14

    Graded core/shell semiconductor nanorods and shaped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

  12. The Effect of Single, Binary and Ternary Anions of Chloride, Carbonate and Phosphate on the Release of 2,4-Dichlorophenoxyacetate Intercalated into the Zn–Al-layered Double Hydroxide Nanohybrid

    Directory of Open Access Journals (Sweden)

    Zainal Zulkarnain

    2009-01-01

    Full Text Available Abstract Intercalation of beneficial anion into inorganic host has lead to an opportunity to synthesize various combinations of new organic–inorganic nanohybrids with various potential applications; especially, for the controlled release formulation and storage purposes. Investigation on the release behavior of 2,4-dichlorophenoxyacetate (2,4-D intercalated into the interlayer of Zn–Al-layered double hydroxide (ZAN have been carried out using single, binary and ternary aqueous systems of chloride, carbonate and phosphate. The release behavior of the active agent 2,4-D from its double-layered hydroxide nanohybrid ZANDI was found to be of controlled manner governed by pseudo-second order kinetics. It was found that carbonate medium yielded the highest accumulated release of 2,4-D, while phosphate in combination with carbonate and/or nitrate speeds up the release rate of 2,4-D. These results indicate that it is possible to design and develop new delivery system of latex stimulant compound with controlled release property based on 2,4-D that is known as a substance to increase latex production of rubber tree,Hevea brasiliensis.

  13. Influence of Arsenic on the Reduction of Lepidocrocite and Hydroxycarbonate Green Rust 1 Into Ferrous-Carbonate Hydroxide by Shewanella putrefaciens

    Science.gov (United States)

    Ona-Nguema, G.; Morin, G.; Wang, Y.; Juillot, F.; Abdelmoula, M.; Ruby, C.; Guyot, F.; Calas, G.; Brown, G.

    2007-12-01

    Shewanella putrefaciens, an iron-respiring bacterium, is capable of reducing As(V) to As(III) when HAs(V)O42- is the sole electron acceptor, or when it is adsorbed on the surface of lepidocrocite (γ-FeOOH), a common well-crystallized hydromorphic soil mineral. Cultures in which lepidocrocite was used as the sole electron acceptor (i.e., pure lepidocrocite and As(III)-adsorbed lepidocrocite) led to the formation of biogenic hydroxycarbonate green rust 1 (GR1) prior to precipitation of ferrous-carbonate hydroxide (FCH). However, the presence of As(III) slowed down the biotransformation of hydroxycarbonate GR1 into FCH, leading to the co-occurrence of both phases after 22-month of aging. In contrast, when the electron acceptor was As(V)- bearing lepidocrocite, XRD analysis revealed FCH to be the dominant reaction product; no green rust formation was observed in this case. Arsenic K-edge XANES spectroscopy indicated that all As(V) (K-edge(max) = 11875.0eV) was reduced to As(III) (K-edge(max) = 11871.3eV), suggesting the presence of As(III) either on the surface of FCH, and/or in another ferrous-containing solid phase. Mössbauer analysis of the 22-month aged biogenic sample obtained from the bioreduction of As(III)-adsorbed lepidocrocite revealed the presence of FCH (80%) and GR (20%). In contrast, Mössbauer spectra of white biogenic solid phases resulting from the bioreduction of As(V)-adsorbed lepidocrocite and of pure lepidocrocite were characterized by ferrous iron doublets. These spectra indicate that the white biogenic sample without arsenic contains 100% Fe(II) assigned to FCH, while the white biogenic As(III)-Fe(II)-containing reaction products consists of 87% FCH and of 13% of another ferrous phase, probably an As(III)-Fe(II)-containing compound. These results show for the first time bacterial reduction of stoichiometric hydroxycarbonate green rust 1.

  14. Role of oxidative stress, mitochondrial membrane potential, and calcium homeostasis in human lymphocyte death induced by nickel carbonate hydroxide in vitro

    Energy Technology Data Exchange (ETDEWEB)

    M' Bemba-Meka, Prosper [Faculty of Medicine, Universite de Montreal, QC (Canada); University of Louisville, Department of Pharmacology and Toxicology, Center for Genetics and Molecular Medicine, Louisville, KY (United States); Lemieux, Nicole [Universite de Montreal, Department of Pathology and Cellular Biology, Main Station, P.O. Box 6128, Montreal, QC (Canada); Chakrabarti, Saroj K. [Faculty of Medicine, Universite de Montreal, QC (Canada)

    2006-07-15

    When isolated human lymphocytes were treated in vitro with various concentrations of soluble form of nickel carbonate hydroxide (NiCH) (0-1 mM), at 37 C for 4 h, both concentration- and time-dependent effects of NiCH on lymphocyte death were observed. Increased generation of hydrogen peroxide (H{sub 2}O{sub 2}), superoxide anion (O{sub 2} {sup -}), depletion of both no protein (NP-) and protein (P-) sulfhydryl (SH) contents and lipid peroxidation (LPO) were induced by NiCH. Pretreatment of lymphocytes with either catalase (H{sub 2}O{sub 2} scavenger), or deferoxamine (DFO) (iron chelator), or excess glutathione (GSH) (an antioxidant) not only significantly reduced the NiCH-induced generation of H{sub 2}O{sub 2} and LPO, but also increased the NP-SH and P-SH contents initially reduced by NiCH. NiCH-induced generation of excess O{sub 2} {sup -} but not excess LPO was significantly reduced by pretreatment with superoxide dismutase (SOD). NiCH-induced lymphocyte death was significantly prevented by pre-treatment with either catalase, or dimethylthiourea/mannitol (hydroxyl radical scavengers), or DFO, or excess GSH/N-acetylcysteine. NiCH-induced lymphocyte death was also significantly prevented by pretreatment with excess SOD. Thus, various types of oxidative stresses play an important role in NiCH-induced lymphocyte death. Cotreatment with cyclosporin A, a specific inhibitor of alteration in mitochondrial membrane potential ({delta}{psi}{sub m}), not only inhibited NiCH-induced alteration in {delta}{psi}{sub m}, but also significantly prevented Ni-compound-induced lymphocyte death. Furthermore, NiCH-induced destabilization of cellular calcium homeostasis. As such, NiCH-induced lymphocyte death was significantly prevented by modulating intracellular calcium fluxes such as Ca{sup 2+} channel blockers and intracellular Ca{sup 2+} antagonist. Thus, the mechanism of NiCH (soluble form)-induced activation of lymphocyte death signalling pathways involves not only the excess

  15. Rapid Synthesis of Lead Oxide Nanorods by One-step Solid-state Chemical Reaction at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    CAO, Ya-Li(曹亚丽); JIA, Dian-Zeng(贾殿赠); LIU, Lang(刘浪); LUO, Jian-Min(骆建敏)

    2004-01-01

    A simple and facile method was reported to synthesize lead oxide nanorods. Nanorods of lead oxide were obtained directly from grinding solid metal salt and sodium hydroxide in agate mortar with the assistance of a suitable nonionic surfactant in only one step, which is different from the result of hydroxide in solution. The product has been characterized by XRD, TEM and SEM. The formation mechanism of rod-like morphology is discussed and the surfactant plays an important soft-template role in modifying the interface of solid-state reaction and according process of rod-formation.

  16. Effects of Sodium hydroxide, Sodium Carbonate and Sodium Silicate on the Dispersion Behavior of Ultrafine Collophanite%3种调整剂对微细粒胶磷矿分散行为的影响

    Institute of Scientific and Technical Information of China (English)

    王飞; 张芹; 邓冰; 左倩

    2011-01-01

    The effects of sodium carbonate, sodium hydroxide, and sodium silicate on the dispersion behavior of ultrafine collophanite were investigated by adopting the sedimentation and liquid removal method. The results showed that comparing with sodium carbonate, sodium silicate and sodium hydroxide had no obvious effects on dispersion of ultrafine collophanite; The dispersion of collophanite was effective at a higher pH value; And the collophanite was better dispersed by improving the stirring speed to be a certain extent, but more stirring had no benefit on the dispersion.%采用沉降抽液法研究了碳酸钠、氧氧化钠和硅酸钠对微细粒胶磷矿分散行为的影响.研究结果表明:相对于碳酸钠,氢氧化钠和硅酸钠对提高微细粒胶磷矿分散效果的作用不明显;在较高的pH条件下,胶磷矿的分散效果较好;在一定程度上提高搅拌速度有利于胶磷矿的分散,但过分提高则无益.

  17. One-pot synthesis of carbon supported calcined-Mg/Al layered double hydroxides for antibiotic removal by slow pyrolysis of biomass waste

    Science.gov (United States)

    Tan, Xiaofei; Liu, Shaobo; Liu, Yunguo; Gu, Yanling; Zeng, Guangming; Cai, Xiaoxi; Yan, Zhili; Yang, Chunping; Hu, Xinjiang; Chen, Bo

    2016-12-01

    A biochar supported calcined-Mg/Al layered double hydroxides composite (CLDHs/BC) was synthesized by a one-pot slow pyrolysis of LDHs preloaded bagasse biomass. Multiple characterizations of the product illustrated that the calcined-Mg/Al layered double hydroxides (CLDHs) were successfully coated onto the biochar in slow pyrolysis of pre-treated biomass. The as-synthesized CLDHs/BC could efficiently remove antibiotic tetracycline from aqueous solutions. The coating of CLDHs significantly increased the adsorption ability of biochar, and CLDHs/BC exhibited more than 2 times higher adsorption capacity than that of the pristine biochar (BC) in the tested pH range. The maximum adsorption capacity of CLDHs/BC for tetracycline was 1118.12 mg/g at 318 K. The experimental results suggested that the interaction with LDHs on biochar played a dominant role in tetracycline adsorption, accompanied with π-π interaction and hydrogen bond. This study provides a feasible and simple approach for the preparation of high-performance material for antibiotics contaminated wastewater treatment in a cost-effective way.

  18. Physical properties of nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Krahne, Roman; George, Chandramohan [Istituto Italiano di Tecnologia, Genoa (Italy). Nanostructures; Manna, Liberato [Istituto Italiano di Tecnologia, Genoa (Italy). Nanochemistry; Morello, Giovanni [CNR, Lecce (Italy). Nanoscience Institute; Figuerola, Albert [Barcelona Univ. (Spain). Inst. de Nanociencia i Nanotecnologia; Deka, Sasanka [Delhi Univ. (India). Dept. of Chemistry

    2013-06-01

    Inorganic nanoparticles are among the most investigated objects nowadays, both in fundamental science and in various technical applications. In this book the physical properties of nanowires formed by nanoparticles with elongated shape, i.e. rod-like or wire-like, are described. The transition in the physical properties is analyzed for nanorods and nanowires consisting of spherical and rod-like nanoparticles. The physical properties of nanowires and elongated inorganic nanoparticles are reviewed too. The optical, electrical, magnetic, mechanical and catalytic properties of nanowires consisting of semiconductors, noble and various other metals, metal oxides properties and metal alloys are presented. The applications of nanorods and nanowires are discussed in the book.

  19. Biomass-Derived Nitrogen-Doped Carbon Nanofiber Network: A Facile Template for Decoration of Ultrathin Nickel-Cobalt Layered Double Hydroxide Nanosheets as High-Performance Asymmetric Supercapacitor Electrode.

    Science.gov (United States)

    Lai, Feili; Miao, Yue-E; Zuo, Lizeng; Lu, Hengyi; Huang, Yunpeng; Liu, Tianxi

    2016-06-01

    The development of biomass-based energy storage devices is an emerging trend to reduce the ever-increasing consumption of non-renewable resources. Here, nitrogen-doped carbonized bacterial cellulose (CBC-N) nanofibers are obtained by one-step carbonization of polyaniline coated bacterial cellulose (BC) nanofibers, which not only display excellent capacitive performance as the supercapacitor electrode, but also act as 3D bio-template for further deposition of ultrathin nickel-cobalt layered double hydroxide (Ni-Co LDH) nanosheets. The as-obtained CBC-N@LDH composite electrodes exhibit significantly enhanced specific capacitance (1949.5 F g(-1) at a discharge current density of 1 A g(-1) , based on active materials), high capacitance retention of 54.7% even at a high discharge current density of 10 A g(-1) and excellent cycling stability of 74.4% retention after 5000 cycles. Furthermore, asymmetric supercapacitors (ASCs) are constructed using CBC-N@LDH composites as positive electrode materials and CBC-N nanofibers as negative electrode materials. By virtue of the intrinsic pseudocapacitive characteristics of CBC-N@LDH composites and 3D nitrogen-doped carbon nanofiber networks, the developed ASC exhibits high energy density of 36.3 Wh kg(-1) at the power density of 800.2 W kg(-1) . Therefore, this work presents a novel protocol for the large-scale production of biomass-derived high-performance electrode materials in practical supercapacitor applications.

  20. A controllable hydrothermal method to prepare La(OH)3 nanorods using new precursors

    Institute of Scientific and Technical Information of China (English)

    Mehdi Mousavi-Kamazani; Sakineh Alizadeh; Fateme Ansari; Masoud Salavati-Niasari

    2015-01-01

    Using the hydrothermal method, lanthanum hydroxide nanorods were synthesized by the reaction of LaCl3·7H2O, ethyl-enediamine, and hydrazine. According to SEM results, ethylenediamine and hydrazine with pH management could control the parti-cle growth and played an important role in formation of lanthanum hydroxide nanorods. The morphology and microstructure of the obtained products were characterized by X-ray diffraction (XRD) spectra, energy-dispersive X-ray spectroscopy (EDX), Fourier transformed infrared (FTIR) spectrum, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Further-more, the effects of the molar ratio of the precursors as well as the reaction temperature and time on the morphology and particle size of the products were investigated.

  1. Cobalt oxide acicular nanorods with high sensitivity for the non-enzymatic detection of glucose.

    Science.gov (United States)

    Kung, Chung-Wei; Lin, Chia-Yu; Lai, Yi-Hsuan; Vittal, R; Ho, Kuo-Chuan

    2011-09-15

    Acicular cobalt oxide nanorods (CoONRs) were prepared for the non-enzymatic detection of glucose, first by directly growing layered cobalt carbonate hydroxide (LCCH) on a conducting fluorine-doped tin oxide (FTO) substrate using a simple chemical bath deposition (CBD) technique and then by transforming the LCCH into CoONRs through pyrolysis. The composition and grain size of the films of LCCH and CoONRs were verified by X-ray diffraction (XRD); their morphologies were examined by scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images. CoONRs showed high electrocatalytic activity for the electro-oxidation of glucose in alkaline media, and the activity was strongly influenced by NaOH concentration, annealing temperature of CoONRs, and thickness of CoONRs film. The pertinent sensor could be successfully used for the quantification of glucose by amperometric method. The sensing parameters include wide linear range up to 3.5 mM, a high sensitivity of 571.8 μA/(cm(2) mM), and a remarkable low detection limit of 0.058 μM. The CoONRs modified electrode exhibited a high selectivity for glucose in human serum, against ascorbic acid, uric acid, and acetaminophen.

  2. A seedless approach to continuous flow synthesis of gold nanorods.

    Science.gov (United States)

    Bullen, Craig; Latter, Melissa J; D'Alonzo, Nicholas J; Willis, Glen J; Raston, Colin L

    2011-04-14

    A direct seedless method for the continuous synthesis of gold nanorods has been developed using a sequential rotating tube-narrow channel processing microfluidic configuration, with the stock feed solutions (HAuCl(4)/CTAB/acetylacetone and AgNO(3)/CTAB/carbonate buffer) being stable for weeks.

  3. Fabrication of ZnO nanorods in ionic liquids and their photoluminescent properties

    Institute of Scientific and Technical Information of China (English)

    WANG Li; ZHAO Bin; CHANG LiXian; ZHENG WenJun

    2007-01-01

    A novel and simple approach is reported to fabricate uniform single-crystal ZnO nanorods in ionic liquids. The as-obtained ZnO nanorods have been characterized by XRD, TEM, HRTEM, SAED, XPS, EDXA,PL and UV-vis absorption spectra. The rod diameters of the nanostructures can be controlled by tuning the amount of sodium hydroxide in the synthesis. Photoluminescence results show that the nanostructural ZnO exhibits better optical properties than bulk ZnO does and interestingly, the smaller the rod diameters are, the better optical property 1D nanostructural ZnO exhibits. The possible growth mechanism of ZnO nanorods is also investigated.

  4. Fabrication of ZnO nanorods in ionic liquids and their photoluminescent properties

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel and simple approach is reported to fabricate uniform single-crystal ZnO nanorods in ionic liq-uids. The as-obtained ZnO nanorods have been characterized by XRD,TEM,HRTEM,SAED,XPS,EDXA,PL and UV-vis absorption spectra. The rod diameters of the nanostructures can be controlled by tuning the amount of sodium hydroxide in the synthesis. Photoluminescence results show that the nanos-tructural ZnO exhibits better optical properties than bulk ZnO does and interestingly,the smaller the rod diameters are,the better optical property 1D nanostructural ZnO exhibits. The possible growth mechanism of ZnO nanorods is also investigated.

  5. Material and gas-sensing properties of tungsten oxide nanorod thin-films.

    Science.gov (United States)

    Kim, Yong Shin; Lee, Kwangyeol

    2009-04-01

    Tungsten oxide thin-films were deposited simply by drop-casting a solution containing single-crystalline and monodispersed W18O49 nanorods prepared by a large-scale colloidal synthesis route. They were verified to be highly porous, nonstoichiometric, and monoclinic crystal structure only with little carbon impurities. These material properties heavily reflect relevant nanostructural characteristics of the nanorods acting as a basic building block. It could be comprehended by the observed structure of randomly arranged tungsten oxide agglomerates formed by favorable parallel alignment of individual nanorod units. Tungsten oxide nanorod sensors exhibit sensitive detection capability even at room temperature to various reducing volatile organic compounds (VOCs). This anomalous performance seems to result from unique nanostructural features of the thin-films, allowing a high surface-to-volume ratio and a considerable amount of active sensing sites due to the highly anisotropic, nonstoichiometric structure of W18O49 nanorods.

  6. Microporous-mesoporous carbons for energy storage synthesized by activation of carbonaceous material by zinc chloride, potassium hydroxide or mixture of them

    Science.gov (United States)

    Härmas, M.; Thomberg, T.; Kurig, H.; Romann, T.; Jänes, A.; Lust, E.

    2016-09-01

    Various electrochemical methods have been applied to establish the electrochemical characteristics of the electrical double layer capacitor (EDLC) consisting of the 1 M triethylmethylammonium tetrafluoroborate solution in acetonitrile and activated carbon based electrodes. Activated microporous carbon materials used for the preparation of electrodes have been synthesized from the hydrothermal carbonization product (HTC) prepared via hydrothermal carbonization process of D-(+)-glucose solution in H2O, followed by activation with ZnCl2, KOH or their mixture. Highest porosity and Brunauer-Emmett-Teller specific surface area (SBET = 2150 m2 g-1), micropore surface area (Smicro = 2140 m2 g-1) and total pore volume (Vtot = 1.01 cm3 g-1) have been achieved for HTC activated using KOH with a mass ratio of 1:4 at 700 °C. The correlations between SBET, Smicro, Vtot and electrochemical characteristics have been studied to investigate the reasons for strong dependence of electrochemical characteristics on the synthesis conditions of carbon materials studied. Wide region of ideal polarizability (ΔV ≤ 3.0 V), very short characteristic relaxation time (0.66 s), and high specific series capacitance (134 F g-1) have been calculated for the mentioned activated carbon material, demonstrating that this system can be used for completing the EDLC with high energy- and power densities.

  7. Novel synthesis of layered double hydroxides (LDHs) from zinc hydroxide

    Science.gov (United States)

    Meng, Zilin; Zhang, Yihe; Zhang, Qian; Chen, Xue; Liu, Leipeng; Komarneni, Sridhar; Lv, Fengzhu

    2017-02-01

    The most common synthesis methods for layered double hydroxides (LDHs) are co-precipitation and reconstruction, which can have some limitations for application. Here, we report a novel synthesis method for LDHs. We use zinc hydroxide as the precursor to synthesize LDHs phase through a simple transformation process of zinc hydroxide phase. For this transformation process, aluminum can enter into zinc hydroxide and replace zinc quickly to transform it into LDH by creating positive charges in the zinc hydroxide solid phase. The mechanism of LDH formation was through Al3+ reaction first with zinc hydroxide followed by recrystallization of the original structure of zinc hydroxide. Thus, the new process of LDH formation involves a reaction of Al to substitute for Zn and recrystallization leading to LDH and the final pH influences the crystallization of LDHs by this process. In addition, Cr3+ was employed as a trivalent cation for LDH formation to react with zinc hydroxide, which also led to LDH structure.

  8. Photocatalytic Conversion of Carbon Dioxide Using Zn–Cu–Ga Layered Double Hydroxides Assembled with Cu Phthalocyanine: Cu in Contact with Gaseous Reactant is Needed for Methanol Generation

    Directory of Open Access Journals (Sweden)

    Kawamura Shogo

    2015-09-01

    Full Text Available Photocatalytic conversion of CO2 into fuels is an attractive option in terms of both reducing the increased concentration of atmospheric CO2 as well as generating renewable hydrocarbon fuels. It is necessary to investigate good catalysts for CO2 conversion and to clarify the mechanism irradiated by natural light. Layered Double Hydroxides (LDH have been attracting attention for CO2 photoreduction with the expectation of sorption capacity for CO2 in the layered space and tunable semiconductor properties as a result of the choice of metal cations. This study first clarifies the effects of Cu doping to LDH comprising Zn and Al or Ga. Cu could be incorporated in the cationic layers of LDH as divalent metal cations and/or interlayer anions as Cu(OH42−. The formation rates of methanol and CO were optimized for [Zn1.5Cu1.5Ga(OH8]+2Cu(OH42−·mH2O at a total rate of 560 nmol h−1 gcat−1 irradiated by UV–visible light. Cu phthalocyanine tetrasulfonate hydrate (CuPcTs4− and silver were effective as promoters of LDH for CO2 photoreduction. Especially, the total formation rate using CuPcTs-[Zn3Ga(OH8]+2CO32−·mH2O irradiated by visible light was 73% of that irradiated by UV–visible light. The promotion was based on HOMO–LUMO excitation of CuPcTs4− by visible light. The LUMO was distributed on N atoms of pyrrole rings bound to central Cu2+ ions. The photogenerated electrons diffused to the Cu site would photoreduce CO2 progressively in a similar way to inlayer and interlayer Cu sites in the LDH in this study.

  9. Effect of additives on magnesium carbonate and aluminium hydroxide compound with flame-retardant polyethylene system%添加剂对阻燃聚乙烯体系性能的影响

    Institute of Scientific and Technical Information of China (English)

    李建新; 吴洁

    2011-01-01

    为提高碳酸镁/氢氧化铝复配阻燃聚乙烯体系的性能,将几种常用协效剂和两种偶联剂添加到阻燃体系中,测量其阻燃性能及力学性能.实验表明:几种添加剂对提高体系的氧指数贡献相当;白炭黑可以明显提高体系的拉伸强度,硼酸锌对体系的断裂伸长率影响最小.对于拉伸强度、使用铝酸酯偶联剂效果优于硅烷偶联剂.%To improve the property of magnesium carbonate and aluminium hydroxide compound with flame-retardant PE sys tem,several synergistic agents and two kind of eoupling agents were added into the flame-retardant PE system. The fire retard ant property and mechanical property were tested. It indicates that several synergistic agents have similar contribution to oxy gen index of the system, silica white can improve the tenslle strength evidently, and zinc borate has little influence on the e longation at break of the system. As far as the tensile strength is concerned , aluminate coupling agent is better than silane cou pling agent.

  10. Effect of Additives on Properties of Flame Retardant LLDPE with Magnesium Carbonate/Aluminium Hydroxide Compound%助剂对氢氧化铝和碳酸镁复配阻燃LLDPE性能的影响

    Institute of Scientific and Technical Information of China (English)

    李建新; 吴洁

    2011-01-01

    将协效剂白炭黑、硼酸锌、低熔点玻璃和硅烷偶联剂、铝酸脂偶联剂分别添加到碳酸镁/氢氧化铝复配阻燃的线型低密度聚乙烯(LLDPE)体系中,考察了这些助剂对体系阻燃性能和力学性能的影响.结果表明:几种助剂对体系的氧指数影响较小;白炭黑可以明显提高体系的拉伸强度,硼酸锌对体系的断裂伸长率影响最小;对拉伸强度而言,使用铝酸脂偶联剂优于硅烷偶联剂.%Several synergistic agents and two kind of coupling agents were added into the fame-retardant LLDPE system with magnesium carbonate and aluminium hydroxide compound, and the effects of additives on the flame retardant and mechanical properties of LLDPE system were studied.The results show that several synergistic agents have slight effect on oxygen index of the system, silica can improve the tensile strength evidently, and zinc borate has little influence on the elongation at break of the system. As far as the tensille strength is concerned, aluminate coupling agent is better than silane coupling agent.

  11. 有机硅和EVA对阻燃聚乙烯体系的影响%Effect of organic silicon and EVA on magnesium carbonate and aluminium hydroxide compound with flame-retardant polyethylene system

    Institute of Scientific and Technical Information of China (English)

    吴洁; 李建新

    2011-01-01

    为提高碳酸镁/氢氧化铝复配阻燃聚乙烯体系的性能,将有机硅和EVA添加到阻燃体系中,测量其氧指数、拉伸强度和断裂伸长率.实验表明:有机硅是该体系很好的阻燃协效剂,而用EVA改性基础树脂,不但可以提高体系的阻燃性能,还可以提高体系的断裂伸长率.%To improve the property of Magnesium Carbonate and Aluminium Hydroxide compound with flame-retardant PE system.Organic silicon and EVA were added into the flame-retardant PE system.The Oxygen index, the tensile strength and the elongation at break were tested.The results indicate that organic silicon is the efficient synergistic agent for the flame-retardant system, and base resin modified by EVA has better flame-retardant performance , meanwhile the elongation at break of the system is improved too.

  12. Mesocarbon Microbead Carbon-Supported Magnesium Hydroxide Nanoparticles: Turning Spent Li-ion Battery Anode into a Highly Efficient Phosphate Adsorbent for Wastewater Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan; Guo, Xingming; Wu, Feng; Yao, Ying; Yuan, Yifei; Bi, Xuanxuan; Luo, Xiangyi; Shahbazian-Yassar, Reza; Zhang, Cunzhong; Amine, Khalil

    2016-08-24

    Phosphorus in water eutrophication has become a serious problem threatening the environment. However, the development of efficient adsorbents for phosphate removal from water is lagging. In this work, we recovered the waste material, graphitized carbon, from spent lithium ion batteries and modified it with nanostructured Mg(OH)2 on the surface to treat excess phosphate. This phosphate adsorbent shows one of the highest phosphate adsorption capacities to date, 588.4 mg/g (1 order of magnitude higher than previously reported carbon-based adsorbents), and exhibits decent stability. A heterogeneous multilayer adsorption mechanism was proposed on the basis of multiple adsorption results. This highly efficient adsorbent from spent Li-ion batteries displays great potential to be utilized in industry, and the mechanism study paved a way for further design of the adsorbent for phosphate adsorption.

  13. Selective Oxidation of Glycerol to Glyceric Acid in Base-Free Aqueous Solution at Room Temperature Catalyzed by Platinum Supported on Carbon Activated with Potassium Hydroxide

    KAUST Repository

    Tan, Hua

    2016-04-18

    Pt supported on KOH-activated mesoporous carbon (K-AMC) was used to catalyze glycerol oxidation under base-free conditions at room temperature. To study the relationship between the carbon surface chemistry and the catalytic performance of the K-AMC-based Pt catalysts, different levels of surface oxygen functional groups (SOFGs) on the AMC supports were induced by thermal treatment at different temperatures under inert or H2 gas. A strong effect of the surface chemistry was observed on AMC-supported Pt catalysts for glycerol oxidation. The presence of carboxylic acid groups impedes the adsorption of glycerol, which leads to the reduction of catalytic activity, whereas the presence of high-desorption-temperature SOFGs, such as phenol, ether, and carbonyl/quinone groups, provide hydrophilicity to the carbon surface that improves the adsorption of glycerol molecules on Pt metal surface, which is beneficial for the catalytic activity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Preparation and magnetic properties of nickel nanorods by thermal decomposition reducing methods

    Institute of Scientific and Technical Information of China (English)

    LUO Yu; ZHANG Jian-cheng; SHEN Yue; JIANG Shu-tao; LIU Guo-yong; WANG Lin-jun

    2006-01-01

    The single-crystalline nickel nanorods with narrow size distribution and better magnetic properties were synthesized by thermal decomposition of nickel hydroxide nanorods precursor powders,which were produced by soft template method using nickel oxalic acid as raw material. The influences of hydrothermal reaction temperature and time on morphology of the products were investigated. The structure,morphology and magnetic properties of the products were characterized by X-ray powder diffraction (XRD),transmission electron microscopy (TEM),thermogravimetric differential scanning calorimetry (TGA-DSC) and vibrating sample magnetometer (VSM). The as-prepared nickel nanorods are uniform with a diameter of 10-15 nm and length 70-120 nm. The results of magnetic measurements show that the specific saturation magnetization(ós) and coercivity values(Hc) of the nickel nanorods are 50.649 A·m2/kg and 190.0×(103/4π)A/m,respectively. Finally,a possible mechanism for the formation of nickel nanorods was discussed briefly.

  15. Effect of Different Seed Solutions on the Morphology and Electrooptical Properties of ZnO Nanorods

    Directory of Open Access Journals (Sweden)

    M. Kashif

    2012-01-01

    Full Text Available The morphology and electrooptical properties of ZnO nanorods synthesized on monoethanolamine-based seed layer and KOH-based seed layer were compared. The seed solutions were prepared in monoethanolamine in 2-methoxyethanol and potassium hydroxide in methanol, respectively. Zinc acetate dihydrate was as a common precursor in both solutions. The nanorod-ZnOs were synthesized via the spin coating of two different seed solutions on silicon substrates followed by their hydrothermal growth. The scanning electron microscopy (SEM, X-ray diffraction (XRD, photoluminescence (PL, and Raman studies revealed that the ZnO nanorods obtained from monoethanolamine-based seed layer had fewer defects, better crystals, and better alignment than those realized via KOH-based seed layer. However, the current-voltage (I-V characteristics demonstrated better conductivity of the ZnO nanorods obtained via KOH-based seed layer. The current measured in forward bias was 4 mA and 40 μA for ZnO-nanorods grown on KOH-based seed layer and monoethanolamine-based with the turn on voltage of approximately 1.5 V and 2.5 V, respectively, showing the feasibility of using both structures in optoelectric devices.

  16. Arsenite sequestration at the surface of nano-Fe(OH) 2, ferrous-carbonate hydroxide, and green-rust after bioreduction of arsenic-sorbed lepidocrocite by Shewanella putrefaciens

    Science.gov (United States)

    Ona-Nguema, Georges; Morin, Guillaume; Wang, Yuheng; Menguy, Nicolas; Juillot, Farid; Olivi, Luca; Aquilanti, Giuliana; Abdelmoula, Mustapha; Ruby, Christian; Bargar, John R.; Guyot, François; Calas, Georges; Brown, Gordon E., Jr.

    2009-03-01

    X-ray Absorption Fine Structure (XAFS) spectroscopy was used in combination with high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), X-ray energy dispersive spectroscopy (XEDS), X-ray powder diffraction, and Mössbauer spectroscopy to obtain detailed information on arsenic and iron speciation in the products of anaerobic reduction of pure and As(V)- or As(III)-adsorbed lepidocrocite (γ-FeOOH) by Shewanella putrefaciens ATCC 12099. We found that this strain of S. putrefaciens is capable of using Fe(III) in lepidocrocite and As(V) in solution or adsorbed on lepidocrocite surfaces as electron acceptors. Bioreduction of lepidocrocite in the absence of arsenic resulted in the formation of hydroxycarbonate green rust 1 [Fe II4Fe III2(OH) 12CO 3: GR1(CO 3)], which completely converted into ferrous-carbonate hydroxide (Fe II2(OH) 2CO 3: FCH) over nine months. This study thus provides the first evidence of bacterial reduction of stoichiometric GR1(CO 3) into FCH. Bioreduction of As(III)-adsorbed lepidocrocite also led to the formation of GR1(CO 3) prior to formation of FCH, but the presence of As(III) slows down this transformation, leading to the co-occurrence of both phases after 22-month of aging. At the end of this experiment, As(III) was found to be adsorbed on the surfaces of GR1(CO 3) and FCH. After five months, bioreduction of As(V)-bearing lepidocrocite led directly to the formation of FCH in association with nanometer-sized particles of a minor As-rich Fe(OH) 2 phase, with no evidence for green rust formation. In this five-month experiment, As(V) was fully converted to As(III), which was dominantly sorbed at the surface of the Fe(OH) 2 nanoparticles as oligomers binding to the edges of Fe(OH) 6 octahedra at the edges of the octahedral layers of Fe(OH) 2. These multinuclear As(III) surface complexes are characterized by As-As pairs at a distance of 3.32 ± 0.02 Å and by As-Fe pairs at a distance of 3.50 ± 0.02

  17. Electrostatic-Induced Assembly of Graphene-Encapsulated Carbon@Nickel-Aluminum Layered Double Hydroxide Core-Shell Spheres Hybrid Structure for High-Energy and High-Power-Density Asymmetric Supercapacitor.

    Science.gov (United States)

    Wu, Shuxing; Hui, Kwan San; Hui, Kwun Nam; Kim, Kwang Ho

    2017-01-18

    Achieving high energy density while retaining high power density is difficult in electrical double-layer capacitors and in pseudocapacitors considering the origin of different charge storage mechanisms. Rational structural design became an appealing strategy in circumventing these trade-offs between energy and power densities. A hybrid structure consists of chemically converted graphene-encapsulated carbon@nickel-aluminum layered double hydroxide core-shell spheres as spacers among graphene layers (G-CLS) used as an advanced electrode to achieve high energy density while retaining high power density for high-performance supercapacitors. The merits of the proposed architecture are as follows: (1) CLS act as spacers to avoid the close restacking of graphene; (2) highly conductive carbon sphere and graphene preserve the mechanical integrity and improve the electrical conductivity of LDHs hybrid. Thus, the proposed hybrid structure can simultaneously achieve high electrical double-layer capacitance and pseudocapacitance resulting in the overall highly active electrode. The G-CLS electrode exhibited high specific capacitance (1710.5 F g(-1) at 1 A g(-1)) under three-electrode tests. An ASC fabricated using the G-CLS as positive electrode and reduced graphite oxide as negative electrode demonstrated remarkable electrochemical performance. The ASC device operated at 1.4 V and delivered a high energy density of 35.5 Wh kg(-1) at a 670.7 W kg(-1) power density at 1 A g(-1) with an excellent rate capability as well as a robust long-term cycling stability of up to 10 000 cycles.

  18. 氧化锌碳纤维复合结构制备及其紫外光响应性能研究%Hybrid Structures of ZnO Nanorods/Carbon Fiber and Their Application on Ultraviolet Photodetector

    Institute of Scientific and Technical Information of China (English)

    李朝辉; 戴俊; 吴春霞; 卢俊峰; 石增良; 徐春祥

    2016-01-01

    利用预处理的碳纤维为模板,在其表面磁控溅射氧化锌种子层,再通过水热法生长出氧化锌纳米棒,形成刷子状复合结构。轴心的碳纤维增强了材料的导电性能,同时该结构又具有较高的比表面积。将单根氧化锌/碳纤维转移到间距为180μm的金叉指电极上构建紫外光探测器,在325 nm激光照射下,该器件显示出约200倍的光电流增益,且具有良好的稳定性和光谱选择性。文中同时对响应机理进行了讨论。%Brush-like hierarchical ZnO nanostructures on carbon fiber was fabricated by RF magnetic sputtering method and hydrothermal growth. The hybrid structures showed high surface-to-volume ratio and better electrical conductivity. An individual carbon fiber coated ZnO nanorods was transferred to the Au interdigital electrodes to form an ultraviolet photodetector, and the spacing of the electrodes is 180μm. Under the illumination of 325 nm UV light, the device shows a high photocurrent gain of 200, a good stability and the spectral responsivities. Furthermore, the mechanism for UV response is discussed.

  19. Studies on ZnO Nanorods Synthesized by Hydrothermal Method and their Characterization

    Directory of Open Access Journals (Sweden)

    B.H. Soni

    2014-01-01

    Full Text Available ZnO nanorods, with a wide band gap of 3.37 eV have been attracting much attention due to its wide range of applications. Looking to this aspect in the present paper, ZnO nanorods were synthesized by hydrothermal method at 120 C for 2 hrs in an autoclave by using zinc acetate and sodium hydroxide as the starting materials. The final product obtained was then characterized by Energy Dispersive analysis of X-rays (EDAX, X-ray powder diffraction (XRD, transmission electron microscopy (TEM, selected area electron diffraction (SAED and Raman Spectroscopy. X-ray diffraction and Raman spectra showed that ZnO nanorods are belonging to wurtzite structure without any impurity phases. The ZnO nanorods shows polycrystalline behaviour as observed from SAED pattern and the calculated lattice parameters from this pattern which matches with the XRD results.The optical properties of the ZnO nanorods were then further studied with the help of absorption, photoluminescence (PL and FTIR spectra. The optical energy band gap determined from the absorption spectra comes about 3.33 eV. In the photoluminescence spectra of ZnO nanorods the UV emission appears at 380 nm and strong blue emission appears at 445 nm. FTIR spectra indicate the existence of distinct characteristic absorption peak at 520 cm – 1 for ZnO stretching modes. The potential toxicity of nanosized ZnO nanorods were investigated using Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Serratia marceseus and Proteus vulgaris bacteria as test organism.

  20. from Anatase to Rutile Nanorods

    African Journals Online (AJOL)

    NJD

    a Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, P.O. ... powder diffraction and scanning electron microscopy. ... converted the remaining anatase material into rutile titania nanorod clusters.

  1. Cathodoluminescence spectra of gallium nitride nanorods.

    Science.gov (United States)

    Tsai, Chia-Chang; Li, Guan-Hua; Lin, Yuan-Ting; Chang, Ching-Wen; Wadekar, Paritosh; Chen, Quark Yung-Sung; Rigutti, Lorenzo; Tchernycheva, Maria; Julien, François Henri; Tu, Li-Wei

    2011-12-14

    Gallium nitride [GaN] nanorods grown on a Si(111) substrate at 720°C via plasma-assisted molecular beam epitaxy were studied by field-emission electron microscopy and cathodoluminescence [CL]. The surface topography and optical properties of the GaN nanorod cluster and single GaN nanorod were measured and discussed. The defect-related CL spectra of GaN nanorods and their dependence on temperature were investigated. The CL spectra along the length of the individual GaN nanorod were also studied. The results reveal that the 3.2-eV peak comes from the structural defect at the interface between the GaN nanorod and Si substrate. The surface state emission of the single GaN nanorod is stronger as the diameter of the GaN nanorod becomes smaller due to an increased surface-to-volume ratio.

  2. Aluminium bismuthate nanorods and the electrochemical performance for detection of tartaric acid

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Wei, T.; Lin, N.; Fan, C.G. [Key Lab of Materials Science and Processing of Anhui Province, School of Materials Science and Engineering, Anhui University of Technology, Ma' anshan, Anhui 243002 (China); Yang, Zao, E-mail: yangzao888@tom.com [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610064 (China)

    2016-09-15

    Aluminium bismuthate nanorods had been synthesized by a facile hydrothemral method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations showed that the lengh and diameter were 2–10 μm and 50–200 nm, respectively. X-ray diffraction (XRD) and high-resolution TEM (HRTEM) showed that the nanorods were composed of single crystalline orthorhombic Al{sub 4}Bi{sub 2}O{sub 9} phase. The aluminium bismuthate nanorods could be explained by the nucleation and crystalline growth process based on the products obtained from different hydrothermal conditions. Aluminium bismuthate nanorods modified glassy carbon electrode (GCE) was fabricated for the electrochemical detection of tartaric acid (TA) in neutral solution. A pair of semi-reversible redox peaks located at −0.08 V and −0.53 V, respectively were observed. The current intensity of the cyclic voltammogram (CV) peak increased linearly obviously with increasing the scan rate and TA concentration. The detection limit and linear range were 0.64 μM and 0.001–2 mM, respectively with the correlation coefficient of 0.995. The aluminium bismuthate nanorods modified GCE had good reproducibility and stability for the detection of TA. - Highlights: • Aluminium bismuthate nanorods were synthesized by a facile hydrothermal process. • The size of aluminium bismuthate nanorods could be controlled by growth conditions. • Aluminium bismuthate nanorods showed good electrochemical performance for the detection of tartaric acid. • Aluminium bismuthate nanorods modified GCE had good reproducibility and stability.

  3. Synthesis of iron oxide nanorods via chemical scavenging and phase transformations of intermediates at ambient conditions

    Science.gov (United States)

    Deshmukh, Ruchi; Mehra, Anurag; Thaokar, Rochish

    2017-01-01

    Chemically induced shape transformations of isotropic seeds, comprised of iron oxyhydroxides and iron oxide borate into nanorods, is reported. Transient growth studies show that the nanorods are formed via phase transformation and aggregation of various metastable species. Addition of tetra- methyl-ammonium hydroxide (TMAH) to the in situ synthesized seeds ensures a typical reaction pathway that favors formation of magnetite (Fe 3 O 4) via the steps of chemical etching, phase transformation of intermediates, and crystal consolidation. Whereas, with addition of sodium hydroxide (NaOH), either magnetite (Fe 3 O 4) or a mixture of ( γ-Fe 2 O 3 + α-FeOOH) is obtained. The shape with both the additives is always that of nanorods. When the seeds treated with TMAH were aged in an ultrasonication bath, rods with almost twice the length and diameter (length = 2800 nm, diameter = 345 nm) are obtained as compared to the sample aged without ultrasonication (length = 1535 nm, diameter = 172 nm). The morphology of nanostructures depending upon other experimental conditions such as, aging the sample at 60 ∘C, seeds synthesized under ultrasonication/ stirring or externally added are also examined and discussed in detail. All the samples show high coercivity and strong ferromagnetic behavior at room temperature and should be promising candidates as ferro-fluids for various applications.

  4. Synthesis and structure refinement of layered double hydroxides of Co, Mg and Ni with Ga

    Indian Academy of Sciences (India)

    G V Manohara; P Vishnu Kamath

    2010-06-01

    Homogeneous precipitation by urea hydrolysis results in the formation of highly ordered layered double hydroxides of divalent metal ions (Co, Mg, Ni) and Ga. Structure refinement shows that these carbonate containing layered hydroxides crystallize with rhombohedral symmetry (space group -3) in the structure of the 31 polytype. An analysis of the structure shows that, coulombic attraction between the layer and interlayer remains invariant in different layered hydroxides, whereas the strength of hydrogen bonding varies. The Ni–Ga LDH has the weakest hydrogen bonding and Co–Ga, the strongest, as reflected by the layer–interlayer oxygen–oxygen distances. The poor polarity of the OH bond in the Ni–Ga hydroxide points to the greater covalency of the (2+}/′3+)-oxygen bond in this compound as opposed to the Co–Ga hydroxide. These observations are supported by IR spectra.

  5. Oxidative desulfurization of diesel by potato based-carbon as green support for H5PMo10V2O40: Efficient composite nanorod catalyst

    OpenAIRE

    Ezzat Rafiee; Mohammad Joshaghani; Parvaneh Ghaderi-Shekhi Abadi

    2017-01-01

    The C@POM (carbon@polyoxometalate) containing H3PMo12O40 (PMo12), H5PMo10V2O40 (PMo10V2), H6PMo9V3O40 (PMo9V3), H7PMo8V4O40 (PMo8V4), H3PW12O40 (PW), and H4SiW12O40 (SiW) were prepared from natural potato as green, and cheap catalyst support source. The C@PMo10V2 was found to be a unique, effective, and eco-friendly catalyst for selective oxidation of sulfides, using 30% aq. H2O2. C@PMo10V2 composite was characterized by X-ray diffraction spectroscopy (XRD), energy dispersive X-ray spectrosco...

  6. Morfologia e cristalinidade de hidroxicarbonato de zinco obtido via precipitação homogênea: influência dos ânions cloreto e nitrato Morphology and crystallinity of zinc hydroxide carbonate obtained from homogeneous precipitation: influence of chloride and nitrate anions

    Directory of Open Access Journals (Sweden)

    Fernando Aparecido Sigoli

    2000-10-01

    Full Text Available The effects of chloride and nitrate anions and their respective concentrations, as well as urea presence, on solid phase morphologies were investigated. Zinc hydroxide carbonate was prepared by aging diluted zinc salt solution in presence of urea at 90ºC. Samples were identified by X-ray powder diffractograms showing the characteristic patterns of hydrozincite. The crystallinity was correlated with the concentrations of reagents. Spherulitic-type aggregates and single acicular particles were obtained from diluted chloride and nitrate solutions while porous aggregates of uniform size were formed from solutions with high chloride and urea concentrations.

  7. Role of oxidative stress and intracellular calcium in nickel carbonate hydroxide-induced sister-chromatid exchange, and alterations in replication index and mitotic index in cultured human peripheral blood lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    M' Bemba-Meka, Prosper [Universite de Montreal, Human Toxicology Research Group (TOXHUM), Department of Environmental and Occupational Health, Main Station, P.O. Box 6128, Montreal, QC (Canada); University of Louisville, Department of Pharmacology and Toxicology, Center for Genetics and Molecular Medicine, Louisville, KY (United States); Lemieux, Nicole [Universite de Montreal, Department of Pathology and Cellular Biology, Faculty of Medicine, Main Station, P.O. Box 6128, Montreal, QC (Canada); Chakrabarti, Saroj K. [Universite de Montreal, Human Toxicology Research Group (TOXHUM), Department of Environmental and Occupational Health, Main Station, P.O. Box 6128, Montreal, QC (Canada)

    2007-02-15

    Human peripheral lymphocytes from whole blood cultures were exposed to either soluble form of nickel carbonate hydroxide (NiCH) (0-60 {mu}M), or of nickel subsulfide (Ni{sub 3}S{sub 2}) (0-120 {mu}M), or of nickel oxide (NiO) (0-120 {mu}M), or nickel sulfate (NiSO{sub 4}) (0-120 {mu}M) for a short duration of 2 h. The treatments occurred 46 h after the beginning of the cultures. The cultures were harvested after a total incubation of 72 h, and sister-chromatid exchange (SCE), replication index (RI), and mitotic index (MI) were measured for each nickel compound. The soluble form of NiCH at 30 {mu}M but those of Ni{sub 3}S{sub 2} and NiO at 120 {mu}M produced significant increase in the SCE per cell compared to the control value, whereas NiSO{sub 4} failed to produce any such significant increase. Except NiSO{sub 4}, the soluble forms of NiCH, Ni{sub 3}S{sub 2}, and NiO produced significant cell-cycle delay (as measured by the inhibition of RI) as well as significant inhibition of the MI at respective similar concentrations as mentioned above. Pretreatment of human blood lymphocytes with catalase (H{sub 2}O{sub 2} scavenger), or superoxide dismutase (superoxide anion scavenger), or dimethylthiourea (hydroxyl radical scavenger), or deferoxamine (iron chelator), or N-acetylcysteine (general antioxidant) inhibited NiCH-induced SCE, and changes in RI and MI. This suggests the participation of oxidative stress involving H{sub 2}O{sub 2}, the superoxide anion radical, the hydroxyl radical, and iron in the NiCH-induced genotoxic responses. Cotreatment of NiCH with either verapamil (inhibitor of intracellular calcium ion ([Ca{sup 2+}]{sub i}) movement through plasma membranes), or dantrolene (inhibitor of [Ca{sup 2+}]{sub i} release from sarcoplasmic reticulum), or BAPTA (Ca{sup 2+} chelator) also inhibited the NiCH-induced responses. These results suggest that [Ca{sup 2+}]{sub i} is also implicated in the genotoxicity of NiCH. Overall these data indicate that various types

  8. Synthesis and characterization of Nb2O5@C core-shell nanorods and Nb2O5nanorods by reacting Nb(OEt5via RAPET (reaction under autogenic pressure at elevated temperatures technique

    Directory of Open Access Journals (Sweden)

    George PP

    2006-01-01

    Full Text Available AbstractThe reaction of pentaethoxy niobate, Nb(OEt5, at elevated temperature (800 °C under autogenic pressure provides a chemical route to niobium oxide nanorods coated with amorphous carbon. This synthetic approach yielded nanocrystalline particles of Nb2O5@C. As prepared Nb2O5@C core-shell nanorods is annealed under air at 500 °C for 3 h (removing the carbon coating results in neat Nb2O5nanorods. According to the TEM measurements, the Nb2O5crystals exhibit particle sizes between 25 nm and 100 nm, and the Nb2O5crystals display rod-like shapes without any indication of an amorphous character. The optical band gap of the Nb2O5nanorods was determined by diffuse reflectance spectroscopy (DRS and was found to be 3.8 eV.

  9. 21 CFR 184.1428 - Magnesium hydroxide.

    Science.gov (United States)

    2010-04-01

    ... hydration of reactive grades of magnesium oxide. (b) The ingredient meets the specifications of the Food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium hydroxide. 184.1428 Section 184.1428 Food... Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide (Mg(OH)2,...

  10. Contribution to the knowledge of nickel hydroxide electrodes. 5. Analysis and electrochemical behavior of cadmium nickel hydroxides

    Science.gov (United States)

    Bode, H.; Dennstedt, W.

    1981-01-01

    Electrochemical experiments performed at sintered and bulk electrodes show that beta nickel hydroxide contains an electrochemically inactive proportion of cadmium hydroxide of up to 10%. The electrochemically ineffective cadmium hydroxide is homogeneously dissolved in beta nickel hydroxide.

  11. Artificial neural network (ANN) method for modeling of sunset yellow dye adsorption using zinc oxide nanorods loaded on activated carbon: Kinetic and isotherm study.

    Science.gov (United States)

    Maghsoudi, M; Ghaedi, M; Zinali, A; Ghaedi, A M; Habibi, M H

    2015-01-05

    In this research, ZnO nanoparticle loaded on activated carbon (ZnO-NPs-AC) was synthesized simply by a low cost and nontoxic procedure. The characterization and identification have been completed by different techniques such as SEM and XRD analysis. A three layer artificial neural network (ANN) model is applicable for accurate prediction of dye removal percentage from aqueous solution by ZnO-NRs-AC following conduction of 270 experimental data. The network was trained using the obtained experimental data at optimum pH with different ZnO-NRs-AC amount (0.005-0.015 g) and 5-40 mg/L of sunset yellow dye over contact time of 0.5-30 min. The ANN model was applied for prediction of the removal percentage of present systems with Levenberg-Marquardt algorithm (LMA), a linear transfer function (purelin) at output layer and a tangent sigmoid transfer function (tansig) in the hidden layer with 6 neurons. The minimum mean squared error (MSE) of 0.0008 and coefficient of determination (R(2)) of 0.998 were found for prediction and modeling of SY removal. The influence of parameters including adsorbent amount, initial dye concentration, pH and contact time on sunset yellow (SY) removal percentage were investigated and optimal experimental conditions were ascertained. Optimal conditions were set as follows: pH, 2.0; 10 min contact time; an adsorbent dose of 0.015 g. Equilibrium data fitted truly with the Langmuir model with maximum adsorption capacity of 142.85 mg/g for 0.005 g adsorbent. The adsorption of sunset yellow followed the pseudo-second-order rate equation.

  12. Reactive transport modeling at uranium in situ recovery sites: uncertainties in uranium sorption on iron hydroxides

    Science.gov (United States)

    Johnson, Raymond H.; Tutu, Hlanganani; Brown, Adrian; Figueroa, Linda; Wolkersdorfer, Christian

    2013-01-01

    Geochemical changes that can occur down gradient from uranium in situ recovery (ISR) sites are important for various stakeholders to understand when evaluating potential effects on surrounding groundwater quality. If down gradient solid-phase material consists of sandstone with iron hydroxide coatings (no pyrite or organic carbon), sorption of uranium on iron hydroxides can control uranium mobility. Using one-dimensional reactive transport models with PHREEQC, two different geochemical databases, and various geochemical parameters, the uncertainties in uranium sorption on iron hydroxides are evaluated, because these oxidized zones create a greater risk for future uranium transport than fully reduced zones where uranium generally precipitates.

  13. Light scattering of interacting gold nanorods

    Energy Technology Data Exchange (ETDEWEB)

    McGuirt, Baxter; Kielbasa, Jerry; Park, Jung-Ho; Zhang, Junping; Peterson, Eric; Williams, Richard; Carroll, David [Center for Nanotechnology and Molecular Materials and Department of Physics, Wake Forest University, Winston-Salem, NC (United States); Sisco, Patrick; Murphy, Catherine; Adams, Richard D. [Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC (United States)

    2009-12-15

    The optical field intensity of light scattering from nanorods of gold has been imaged at distances that are intermediate between the near-field and far-field regimes using a near-field scanning optical microscope (NSOM). For scattering from isolated nanorods the Fraunhofer diffractive behaviour is modified slightly by the dipolar nature of metal nanoantannae as would be expected at these imaging distances. However, when the nanorods are brought into close proximity, interactions between the nanorods alter the scattering behaviour substantially creating large field intensities between the structures. By sampling the field with the near-field microscope tip scanned at different heights, detailed maps of the scattering profile can be generated. The NSOM image of far-field scattered light from an isolated gold nanorod. The nanorod was imaged at a distance of roughly 8 {mu}m above the support substrate using a scanning near-field microscope operated at constant height mode. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  14. Supermolecular layered dou- ble hydroxides

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Research progresses in the layered double hydroxides ·mH2O intercalated with metal coordinate ions or oxometalates in the last ten years are reviewed. These layered double hydroxides are mainly intercalated with polyoxometalate (POM) ions, a LiAl-LDH photochemical assembly containing TiO2 and CH3(CH2)12COO- anions, together with Zn(TPPC) (porphy-rin derivate) and macrocyclic ligand-containing porphyrin derivate anions. Emphasis is put on the synthesis methods for intercalation of the anions into the interlayer regions, the characterization techniques and structures for the layered compounds and the newest research progress in the fields such as catalysis. The review also forecasts the prospects of the field.

  15. Silver nanorod arrays for photocathode applications

    Energy Technology Data Exchange (ETDEWEB)

    Vilayurganapathy, Subramanian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Nandasiri, Manjula I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Western Michigan Univ., Kalamazoo MI (United States); Joly, Alan G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); El-Khoury, Patrick Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Varga, Tamas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Coffey, Greg W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schwenzer, Birgit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pandey, Archana [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kayani, Asghar N. [Western Michigan Univ., Kalamazoo MI (United States); Hess, Wayne P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thevuthasan, Suntharampillai [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-10-16

    In this study, we explore the possibility of using plasmonic Ag nanorod arrays featuring enhanced photoemission as high-brightness photocathode material. Silver nanorod arrays are synthesized by the DC electrodeposition method and their dimensionality, uniformity, crystallinity and oxide/impurity content are characterized. These Ag nanorod arrays exhibit greatly enhanced two-photon photoemission under 400 nm femtosecond pulsed laser excitation. Plasmonic field enhancement in the array produces photoemission hot spots that are mapped using photoemission electron microscopy (PEEM). The relative photoemission enhancement of nanorod array hot spots relative to that of a flat Ag thin film is found to range between 102 and 3 x 103.

  16. Graded core/shell semiconductor nanorods and nanorod barcodes

    Science.gov (United States)

    Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

    2009-05-19

    Disclosed herein is a graded core/shell semiconductor nanorod having at least a first segment of a core of a Group II-VI, Group III-V or a Group IV semiconductor, a graded shell overlying the core, wherein the graded shell comprises at least two monolayers, wherein the at least two monolayers each independently comprise a Group II-VI, Group III-V or a Group IV semiconductor.

  17. Chemical modification of zinc hydroxide nitrate and Zn-Al-layered double hydroxide with dicarboxylic acids.

    Science.gov (United States)

    Arizaga, Gregorio Guadalupe Carbajal; Mangrich, Antonio Salvio; da Costa Gardolinski, José Eduardo Ferreira; Wypych, Fernando

    2008-04-01

    A zinc hydroxide nitrate (ZHN), Zn5(OH)8(NO3)2.2H2O, and a layered double hydroxide (LDH), Zn/Al-NO3 were doped with 0.2 mol% of Cu2+ during alkaline chemical precipitation. Both compounds were intercalated with adipate ((-)OOC(CH2)4COO(-)), azelate ((-)OOC(CH2)7COO(-)), and benzoate (C6H5COO(-)) ions through ion exchange reactions. Solid state 13C nuclear magnetic resonance spectroscopy showed only one signal of carboxylic carbon for adipate and azelate intercalated into LDH, indicating that the carboxylic ends of both acids were equivalent, whereas the signal split when the intercalation was into the ZHN matrix. The electron paramagnetic resonance (EPR) spectrum of copper in octahedral cation sites of LDH layers showed a Hamiltonian parameter ratio g ||/A ||=170 cm and, after intercalation of adipate, the change was not significant: g ||/A ||=174 cm. This result indicates that the carboxylate ions did not coordinate with copper centers. Nonetheless, the intercalation of azelate increased the ratio to g ||/A ||=194 cm, similar to the spectra of ZHN modified with adipate, g ||/A ||=199 cm, and azelate, g ||/A ||=183 and 190 cm, which are associated with the coordination of copper by weak carboxylate anion ligands. Copper occupies octahedral or tetrahedral sites in ZHN layers, and the EPR spectra indicate that the dicarboxylate anions reacted preferentially with octahedral sites, whereas benzoate reacted with both sites.

  18. Biaxially Oriented CdSe Nanorod

    DEFF Research Database (Denmark)

    Breiby, Dag W.; Chin, Patrick T.K.; Andreasen, Jens Wenzel

    2009-01-01

    The shape, structure, and orientation of rubbing-aligned cadmium selenide (CdSe) nanorods on polymer coated glass substrates have been studied using transmission electron microscopy (TEM) and grazing incidence X-ray scattering combined with computer simulations. The nanorods are found to be of wu...

  19. Synthesis, characterization and catalytic activity of birnessite type potassium manganese oxide nanotubes and nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Khalid Abdelazez Mohamed, E-mail: khalidgnad@hotmail.com [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Chemistry, School of Chemistry and Chemical Technology, Faculty of Science and Technology, Al-Neelain University, P.O. Box 12702, Khartoum (Sudan); Huang Kaixun, E-mail: hxxzrf@mail.hust.edu.cn [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Birnessite type manganese oxides nanotubes and nanorods were prepared by calcination route. Black-Right-Pointing-Pointer The transition from tube to rod structure is described by an oriented attachment-thermodynamical (OA-TD) process. Black-Right-Pointing-Pointer The catalytic degradation efficiency of safranin O by as-prepared products was compared. - Abstract: Birnessite-type manganese oxide nanotubes and nanorods were synthesized via a calcination process using manganese acetate and potassium hydroxide as precursors in presence of polyethylene glycol-melamine-formaldehyde. As-prepared products were characterized by XRD, FT-IR, FE-SEM, TEM, SA-ED, HR-TEM, Brunauer-Emmett-Teller (BET) and TGA analyses. The influences of reaction temperature and time on the morphology of manganese oxide nanocrystals were investigated. The oriented attachment-thermodynamical (OA-TD) process is suggested to describe the transition from tube to rod structure. Their capability of catalytic degradation of safranin O was compared. The results indicate that birnessite-type manganese oxide nanotube has higher catalytic activity for than nanorod crystal in aqueous solution, because it has a larger surface area. The decomposition of safranin O follows pseudo-first order kinetics and is markedly affected by pH.

  20. Synthesis of gold nanorods with a longitudinal surface plasmon resonance peak of around 1250 nm

    Science.gov (United States)

    Nguyen, Thi Nhat Hang; Le Trinh Nguyen, Thi; Thanh Tuyen Luong, Thi; Thang Nguyen, Canh Minh; Nguyen, Thi Phuong Phong

    2016-03-01

    We prepared gold nanorods and joined them to chemicals such as tetrachloauric (III) acid trihydrate, silver nitrate, hydroquinone, hexadecyltrimethylammonium bromide, sodium hydroxide and sodium borohydride using the seed-mediated method. The combination of hydroquinone, with or without salicylic acid, influences the size of the gold nanorods, and this is demonstrated by the results of TEM images, UV-vis spectra and the value of the longitudinal surface plasmon resonance peak with respect to the UV-vis spectra. By changing the Ag+ ion and hydroquinone concentration and the combination of hydroquinone and salicylic acid, the size of the gold nanorods can be controlled and this is manifested by longitudinal surface plasmon resonance peaks forming between 875 and 1278 nm. In particular, sample E2 achieved a longitudinal surface plasmon peak at 1273 nm and an aspect ratio of more than 10 by modifying the hydroquinone to 2.5 mM and salicylic acid to 0.5 mM concentration in the growth solution.

  1. Nanorod dynamics in ac electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Ruda, H E; Shik, A [Centre for Advanced Nanotechnology, University of Toronto, Toronto, M5S 3E3 (Canada)

    2010-06-11

    Metal and semiconductor nanorods polarized by an external electric field tend to align parallel to this field. We derived the equation of motion for this alignment, taking into account electrostatic forces, thermal fluctuations and viscous resistance of the liquid the nanorods are suspended in. It was solved for a strong ac electric field, as well as for the combination of strong dc and weak ac fields. The results were used for calculations of the capacity of the nanorod solution, its frequency dispersion and dependence on the field strength. Modification of the nanorod absorption spectra under the influence of an electric field was also considered. It was shown that metal nanorods in laser radiation, with the frequency belonging to the interval between longitudinal and transverse plasmon modes, tend to align perpendicular, rather than parallel, to the optical electric field.

  2. 21 CFR 184.1191 - Calcium carbonate.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of... soda process”; (2) By precipitation of calcium carbonate from calcium hydroxide in the...

  3. PVA基碱性聚合物电解质Ni(OH)2/AC超级电容器的电化学性能%Electrochemical Performance of Nickel Hydroxide/Activated Carbon Supercapacitors Using a Modified Polyvinyl Alcohol Based Alkaline Polymer Electrolyte

    Institute of Scientific and Technical Information of China (English)

    孙紫红; 袁安保

    2009-01-01

    Polyvinyl alcohol (PVA)-sodium polyacrylate (PAAS)-KOH-H2O alkaline polymer electrolyte film with high ionic conductivity was prepared by a solution-casting method. Polymer Ni(OH)2/activated carbon (AC) hybrid supercapacitors with different electrode active material mass ratios (positive to negative) were fabricated using this alkaline polymer electrolyte, nickel hydroxide positive electrodes, and AC negative electrodes. Galvanostatic charge/ discharge and electrochemical impedance spectroscopy (EIS) methods were used to study the electrochemical per-formance of the capacitors, such as charge/discharge specific capacitance, rate charge/discharge ability, and charge/discharge cyclic stability. Experimental results showed that with the decreasing of active material mass ratio m(Ni(OH)2)/m(AC), the charge/discharge specific capacitance increases, but the rate charge/discharge ability and the charge/discharge cyclic stability decrease.

  4. Pharmacokinetic Profile of Oral Magnesium Hydroxide

    DEFF Research Database (Denmark)

    Dolberg, Mette Konow Bøgebjerg; Nielsen, Lars Peter; Dahl, Ronald

    2016-01-01

    Despite the presumption of a beneficial effect of magnesium (Mg) supplementation on various diseases, little is known concerning the pharmacokinetics of Mg hydroxide. This study was designed to provide a pharmacokinetic profile of Mg hydroxide after a single oral dose. Ten healthy male adults...

  5. Neutral and anionic superhalogen hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Swierszcz, Iwona [Department of Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Anusiewicz, Iwona, E-mail: iwonaa@chem.univ.gda.pl [Department of Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)

    2011-05-26

    Graphical abstract: The energy profile for the Na(OH){sub 2}{sup -} anionic hydroxide formation according to the NaOH+OH{sup -}{yields}Na(OH){sub 2}{sup -} reaction. Display Omitted Highlights: {yields} The superhalogen hydroxides and their anions were studied at the CCSD(T)/6-311++G(3df,3pd) level. {yields} All anionic superhalogen hydroxides were found to be thermodynamically stable. {yields} The VDE values calculated for the M(OH){sub k+1}{sup -} anions exceed 4 eV in all cases. {yields} The largest VDEs were found for the Al(OH){sub 4}{sup -} (6.07 eV) and Ga(OH){sub 4}{sup -} (6.21 eV). - Abstract: The properties of superhalogen M(OH){sub k+1}{sup -} anions and their M(OH){sub k+1} neutral parents (where M = Li, Na, K, Be, Mg, Ca, B, Al, Ga) were investigated at the ab initio CCSD(T)/6-311++G(3df,3pd)//MP2/6-311++G(d,p) level of theory. All the M(OH){sub k+1}{sup -} anions and some of their M(OH){sub k+1} neutral parents (k is the maximal formal valence of M) were found to be thermodynamically stable against the fragmentations (OH, OH{sup -}, O{sub 2} or H{sub 2}O loss). The vertical electron detachment energies (VDE) of the M(OH){sub k+1}{sup -} anions were calculated with the OVGF method and using the 6-311++G(3df,3pd) basis sets. The VDE values calculated for the anions studied exceed 4 eV in all cases, whereas the largest values of the electron binding energies were found for the Al(OH){sub 4}{sup -} (6.07 eV) and Ga(OH){sub 4}{sup -} anions (6.21 eV). Finally, formation of most of the species considered was predicted to be spontaneous due to the lack of kinetic barriers for these processes and their thermodynamic favorability.

  6. Preparation of Pinewood- and Wheat Straw-based Activated Carbon via a Microwave-assisted Potassium Hydroxide Treatment and an Analysis of the Effects of the Microwave Activation Conditions

    Directory of Open Access Journals (Sweden)

    Haiyan Mao

    2014-12-01

    Full Text Available This study explored the effect of activated carbon preparation conditions on their adsorption performance. Pinewood and wheat straw were used as source materials to prepare activated carbon via a fast activation process using KOH and microwave heating. The iodine numbers and carbon yields were determined to evaluate the adsorption properties of the activated carbon. The effects of various KOH/char mass ratios, particle sizes, humidity levels, and microwave heating times on the physical characteristics of the activated carbon were investigated. The iodine number and yield and SEM images were used to characterize the activated carbon. Small particle sizes, the presence of humidity in the purge gas, and high KOH/char ratios resulted in higher iodine numbers. The best activated carbons were obtained using a KOH/char ratio of 3.0, a microwave power of 600 W, a radiation time of 30 min, and a particle size of 0.1 to 0.42 mm in a humid environment; these carbons showed iodine numbers of 2208 mg/g (pinewood activated carbon and 1420 mg/g (wheat straw activated carbon, with carbon yields of 73% and 52%, respectively. Longer microwave heating times increased the iodine number. The iodine numbers and yields of the pinewood activated carbons were much higher than those of their wheat straw counterparts.

  7. Ag nanoparticle/polymer composite barcode nanorods

    Institute of Scientific and Technical Information of China (English)

    Hongxu Chen[1; Tieqiang Wang[2; Huaizhong Shen[1; Wendong Liu[1; Shuli Wang[1; Kun Liu[1; Junhu Zhang[1; Bai Yang[1

    2015-01-01

    We demonstrate a facile method combining colloidal lithography, selective ion-exchange, and the in situ reduction of Ag ions (Ag+) for the fabrication of multi-segmented barcode nanorods. First, polymer multilayer films were prepared by spin-coating alternating thin films of polystyrene and polyacrylic acid (PAA), and then multi-segmented polymer nanorods were fabricated via reactive ion etching with colloidal masks. Second, Ag nanoparticles (Ag NPs) were incorporated into the PAA segments by an ion exchange and the in situ reduction of the Ag~. The selective incorporation of the Ag NPs permitted the modification of the specific bars of the nanorods. Lastly, the Ag NP/polymer composite nanorods were released from the substrate to form suspensions for further coding applications. By increasing the number of segments and changing the length of each segment in the nanorods, the coding capacity of nanorods was improved. More importantly, this method can easily realize the density tuning of Ag NPs in different segments of a single nanorod by varying the composition of the PAA segments. We believe that numerous other coded materials can also be obtained, which introduces new approaches for fabricating barcoded nanomaterials.

  8. Scalable Synthesis of Defect Abundant Si Nanorods for High-Performance Li-Ion Battery Anodes.

    Science.gov (United States)

    Wang, Jing; Meng, Xiangcai; Fan, Xiulin; Zhang, Wenbo; Zhang, Hongyong; Wang, Chunsheng

    2015-06-23

    Microsized nanostructured silicon-carbon composite is a promising anode material for high energy Li-ion batteries. However, large-scale synthesis of high-performance nano-Si materials at a low cost still remains a significant challenge. We report a scalable low cost method to synthesize Al/Na-doped and defect-abundant Si nanorods that have excellent electrochemical performance with high first-cycle Coulombic efficiency (90%). The unique Si nanorods are synthesized by acid etching the refined and rapidly solidified eutectic Al-Si ingot. To maintain the high electronic conductivity, a thin layer of carbon is then coated on the Si nanorods by carbonization of self-polymerized polydopamine (PDA) at 800 °C. The carbon coated Si nanorods (Si@C) electrode at 0.9 mg cm(-2) loading (corresponding to area-specific-capacity of ∼2.0 mAh cm(-2)) exhibits a reversible capacity of ∼2200 mAh g(-1) at 100 mA g(-1) current, and maintains ∼700 mAh g(-1) over 1000 cycles at 1000 mA g(-1) with a capacity decay rate of 0.02% per cycle. High Coulombic efficiencies of 87% in the first cycle and ∼99.7% after 5 cycles are achieved due to the formation of an artificial Al2O3 solid electrolyte interphase (SEI) on the Si surface, and the low surface area (31 m(2) g(-1)), which has never been reported before for nano-Si anodes. The excellent electrochemical performance results from the massive defects (twins, stacking faults, dislocations) and Al/Na doping in Si nanorods induced by rapid solidification and Na salt modifications; this greatly enhances the robustness of Si from the volume changes and alleviates the mechanical stress/strain of the Si nanorods during the lithium insertion/extraction process. Introducing massive defects and Al/Na doping in eutectic Si nanorods for Li-ion battery anodes is unexplored territory. We venture this uncharted territory to commercialize this nanostructured Si anode for the next generation of Li-ion batteries.

  9. Functionalized gold nanorod solution via reverse micelle based polyacrylate coating.

    Science.gov (United States)

    Basiruddin, S K; Saha, Arindam; Pradhan, Narayan; Jana, Nikhil R

    2010-05-18

    Functionalization of gold nanorods is a key issue for their biomedical application, and currently it is performed via either electrostatic interaction or thiol based strategy. We have developed a polyacrylate based coating chemistry for gold nanorods that can be used in deriving a variety of functional nanorods with high colloidal stability. The coating processes can introduce primary amines, fluorescein, or poly(ethylene glycol) (PEG) on the nanorod surface in one step process. While fluorescein incorporation can produce fluorescent nanorods, primary amine groups can be used for further functionalization. Various functional nanorods have been successfully synthesized from these coated nanorods and used in different applications. Glucose and biotin functionalized nanorods are used for protein detection, and oleyl functionalized nanorods with fluorescein incorporated in the polymer shell are used for fluorescence based cell labeling.

  10. Photocatalytic reduction of CO2 by CuxO nanocluster loaded SrTiO3 nanorod thin film

    Science.gov (United States)

    Shoji, Shusaku; Yin, Ge; Nishikawa, Masami; Atarashi, Daiki; Sakai, Etsuo; Miyauchi, Masahiro

    2016-08-01

    Photocatalytic carbon dioxide (CO2) conversion into carbon monoxide (CO) using H2O as an electron donor was achieved by the strontium titanate (SrTiO3: STO) nanorod thin films loaded with amorphous copper oxide (CuxO) nanoclusters. The loading of the CuxO-cocatalysts onto STO nanorods clearly improved the photocatalytic activity compared to bare STO nanorods. The CuxO-cocatalysts are composed of abundant and non-toxic elements, and can be loaded by using a simple and economical method. Our findings demonstrate that CuxO nanoclusters function as a general cocatalyst and can be used in combination with various semiconductors to construct low-cost and efficient photocatalytic CO2 reduction systems.

  11. Thermodynamics of Volatile Silicon Hydroxides Studied

    Science.gov (United States)

    Copland, Evan H.; Opila, Elizabeth J.; Jacobson, Nathan S.

    2001-01-01

    Silicon-based ceramics are promising candidate structural materials for heat engines. The long-term stability of these materials to environmental degradation is dependent on the formation and retention of a protective SiO2 layer. It is well known that SiO2 forms stable volatile hydroxides in the presence of water vapor at elevated temperatures. Combustion conditions, which characteristically are at high velocities, contain significant water vapor pressures, and high temperatures tend to promote continuous formation of these hydroxides with resulting material degradation. For the degradation of silicon-based ceramics to be predicted, accurate thermodynamic data on the formation of silicon hydroxides are needed.

  12. Properties of oxide-hydroxide sintered ceramics

    Science.gov (United States)

    Levkov, R. V.; Kulkov, S. N.

    2017-02-01

    In this paper the study of porous ceramics obtained from aluminum hydroxide with gibbsite modification is presented. It was shown that aluminum hydroxide may be used for pore formation and pore volume in the sintered ceramics can be controlled by varying the aluminum hydroxide concentration and sintering temperature. It was shown that compressive strength of alumina ceramics increases by 40 times with decreasing the pore volume from 65 to 15%. Based on these results one can conclude that the obtained structure is very close to inorganic bone matrix and can be used as promising material for bone implants production.

  13. Lasing action in gallium nitride quasicrystal nanorod arrays.

    Science.gov (United States)

    Chang, Shih-Pang; Sou, Kuok-Pan; Chen, Chieh-Han; Cheng, Yuh-Jen; Huang, Ji-Kai; Lin, Chung-Hsiang; Kuo, Hao-Chung; Chang, Chun-Yen; Hsieh, Wen-Feng

    2012-05-21

    We report the observation of lasing action from an optically pumped gallium nitride quasicrystal nanorod arrays. The nanorods were fabricated from a GaN substrate by patterned etching, followed by epitaxial regrowth. The nanorods were arranged in a 12-fold symmetric quasicrystal pattern. The regrowth grew hexagonal crystalline facets and core-shell multiple quantum wells (MQWs) on nanorods. Under optical pumping, multiple lasing peaks resembling random lasing were observed. The lasing was identified to be from the emission of MQWs on the nanorod sidewalls. The resonant spectrum and mode field of the 12-fold symmetric photonic quasicrystal nanorod arrays is discussed.

  14. Zinc Oxide Nanorods and Their Photoluminescence Property

    Institute of Scientific and Technical Information of China (English)

    DAI Ying; ZHANG Yue; PEI Xin-mei; CHEN Wen

    2003-01-01

    Large-quantity growth of ZnO nanorods is achieved by oxidation of Zn powders with catalyst-free method.The products are characterized using X-ray diffraction,scanning electron microscopy,transmission electron microscopy and photoluminescence spectroscopy.The as-grown nanorods are structurally uniform with diameter ranging from 60 to 150nm and lengths of up to 5-8μm,and they are single crystalline in nature with growth direction parallel to [0001].Room-temperature photoluminescence spectrum of the nanorods shows a strong and sharp UV emission band at 385 nm and a weak and broad green emission band at 495 nm.The vapor-solid model is also proposed to explain the growth behavior of ZnO nanorods in our synthesis process.

  15. Hybrid nanorod-polymer solar cells.

    Science.gov (United States)

    Huynh, Wendy U; Dittmer, Janke J; Alivisatos, A Paul

    2002-03-29

    We demonstrate that semiconductor nanorods can be used to fabricate readily processed and efficient hybrid solar cells together with polymers. By controlling nanorod length, we can change the distance on which electrons are transported directly through the thin film device. Tuning the band gap by altering the nanorod radius enabled us to optimize the overlap between the absorption spectrum of the cell and the solar emission spectrum. A photovoltaic device consisting of 7-nanometer by 60-nanometer CdSe nanorods and the conjugated polymer poly-3(hexylthiophene) was assembled from solution with an external quantum efficiency of over 54% and a monochromatic power conversion efficiency of 6.9% under 0.1 milliwatt per square centimeter illumination at 515 nanometers. Under Air Mass (A.M.) 1.5 Global solar conditions, we obtained a power conversion efficiency of 1.7%.

  16. Can Nanorods Emulsify Immiscible Polymer Blends?

    Science.gov (United States)

    Hore, Michael J. A.

    2005-03-01

    The addition of nanoscale rods to immiscible binary polymer blends has a pronounced effect on the dynamics of phase separation. The results of computer simulations of the Dissipative Particle Dynamics (DPD) model in three dimensions (3D) indicate that when nanorods prefer one of two components in an immiscible binary polymer blend, the rate of phase separation decreases when the volume fraction of nanorods is increased, or as the aspect ratio (L/D) of the rods is increased. Interestingly, anisotropic nanoparticles have a much more pronounced effect on phase separation dynamics in the system when compared to the effects of spherical nanoparticles, which, generically, do not alter the characteristics of the kinetics in the system. In particular, it may be the case that at high volume fractions -- or alternatively, low volume fractions and large aspect ratio of nanorods -- the system may undergo micro-phase separation only, indicating that the nanorods may be excellent emulsifying agents.

  17. Nickel hydroxide precipitation from aqueous sulfate media

    Science.gov (United States)

    Sist, Cinziana; Demopoulos, George P.

    2003-08-01

    Hydrometallurgical processing of laterite ores constitutes a major industrial and R&D activity in extractive metallurgy. In some of the process flowsheets, nickel hydroxide precipitation is incorporated. For these operations, the optimization of nickel hydroxide precipitation is important to assure efficiency and product quality. The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulfate system using supersaturation controlled precipitation.

  18. Optical forces in nanorod metamaterial

    CERN Document Server

    Bogdanov, Andrey A; Ginzburg, Pavel

    2015-01-01

    Optomechanical manipulation of micro and nano-scale objects with laser beams finds use in a large span of multidisciplinary applications. Auxiliary nanostructuring could substantially improve performances of classical optical tweezers by means of spatial localization of objects and intensity required for trapping. Here we investigate a three-dimensional nanorod metamaterial platform, serving as an auxiliary tool for the optical manipulation, able to support and control near-field interactions and generate both steep and flat optical potential profiles. It was shown that the 'topological transition' from the elliptic to hyperbolic dispersion regime of the metamaterial, usually having a significant impact on various light-matter interaction processes, does not strongly affect the distribution of optical forces in the metamaterial. This effect is explained by the predominant near-fields contributions of the nanostructure to optomechanical interactions. Semi-analytical model, approximating the finite size nanopar...

  19. Plasmon spectra in two-dimensional nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Z H; Fava, D; Kumacheva, E [Department of Chemistry, University of Toronto, Toronto, Ontario, M5S 3H6 (Canada); Ruda, H E; Shik, A [Centre for Advanced Nanotechnology, University of Toronto, Toronto, Ontario, M5S 3E4 (Canada)

    2009-07-22

    For various types of ensembles of metal nanorods, the frequencies of longitudinal and transverse plasmons were calculated and correlations between the plasmon frequency shifts and the topology of nanorod arrays were found. The theoretical predictions were compared with the experimentally determined optical absorption in arrays of polymer-terminated Au nanorods obtained by self-assembly in selective solvents.

  20. Nickel titanates hollow shells: nanosphere, nanorod, and their photocatalytic properties.

    Science.gov (United States)

    Li, Qiuye; Xing, Yangyang; Zong, Lanlan; Li, Rui; Yang, Jianjun

    2013-01-01

    Two kinds of hollow shell structured nickel titanates (nanosphere, nanorod) were prepared by the microwave-assisted hydrothermal method using carbon material as the template. Their phase structure, morphology, and optical properties were well characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS). Comparing with the template-free NiTiO3 (NiTiO3-TF), the two kinds of hollow shell structured NiTiO3 have larger Brunauer-Emmet-Teller (BET) surface areas. Both NiTiO3 nanosphere (NiTiO3-NS) and nanorod (NiTiO3-NR) showed remarkably photocatalytic H2 evolution from the methanol aqueous solution under full-arc lamp and visible light. Additional, their photocatalytic activities were also determined by photo-degradation of methyl blue (MB), and the degradation yield reached nearly 100% within 100 min on NiTiO3-NR under visible light. Whatever in photocatalytic H2 evolution or MB degradation, their photocatalytic activities all followed the order: NiTiO3-NR > NiTiO3-NS > NiTiO3-TF. The higher photocatalytic activities of the hollow shelled NiTiO3 should be due to their larger BET surface areas and more utilization of the incident light.

  1. Effects of Sodium Sulfate and Sodium Chloride on Ca2+ , Mg2+ Removal from Glauber Type Brine by Sodium Hydroxide and Sodium Carbonate%芒硝型卤水中盐硝组分对碱法脱除钙镁的影响

    Institute of Scientific and Technical Information of China (English)

    董泽亮; 张琦; 王俐聪; 蔡荣华; 马来波; 黄西平

    2013-01-01

    Ca2+ 、Mg2+ removal from Glauber type brine by sodium hydroxide and sodium carbonate has been studied.The effects of sodium sulfate and sodium chloride on removal efficiency of Ca2+,Mg2+ at room temperature were investigated in detail when addition amount of sodium hydroxide and sodium carbonate was theoretical value,reaction time was 30 min,aging time was 60 min.The experimental results show that the presence of sodium sulfate has large effect on removal efficiency of Ca2+.The removal rate of Ca2+ is more than 90% when the concentration of sodium sulfate is below 30 g/L.The presence of sodium sulfate has good but little effect on removal efficiency of Mg2+.The presence of sodium chloride has small effect on removal efficiency of Ca2+ and Mg2+.When the concentration of sodium chloride increases,the removal rate of Ca2+ increases significantly,but the removal rate of Mg2+ declines slightly.%采用“烧碱-纯碱”法,对芒硝型卤水中Ca2+和Mg2+的脱除进行了研究,在常温、两碱用量为理论用量、反应时间为30 min和陈化时间为60 min的条件下详细考察了卤水中氯化钠和硫酸钠含量的变化对Ca2+和Mg2脱除效果的影响.结果表明,硫酸钠组分对Ca2+的脱除效果影响较大,当硫酸钠含量在30 g/L以下时,Ca2+脱除率在90%以上,硫酸钠浓度增加有利于Mg2+的脱除,但影响不大.氯化钠组分对Ca2、Mg2+脱除效果的影响相对较小,氯化钠含量增加,Ca2+脱除率明显增加,而Mg2+脱除率略有下降.

  2. Optimum size of nanorods for heating application

    Energy Technology Data Exchange (ETDEWEB)

    Seshadri, G., E-mail: seshg@stanford.edu; Thaokar, Rochish; Mehra, Anurag

    2014-08-01

    Magnetic nanoparticles (MNP's) have become increasingly important in heating applications such as hyperthermia treatment of cancer due to their ability to release heat when a remote external alternating magnetic field is applied. It has been shown that the heating capability of such particles varies significantly with the size of particles used. In this paper, we theoretically evaluate the heating capability of rod-shaped MNP's and identify conditions under which these particles display highest efficiency. For optimally sized monodisperse particles, the power generated by rod-shaped particles is found to be equal to that generated by spherical particles. However, for particles which are not mono dispersed, rod-shaped particles are found to be more effective in heating as a result of the greater spread in the power density distribution curve. Additionally, for rod-shaped particles, a dispersion in the radius of the particle contributes more to the reduction in loss power when compared to a dispersion in the length. We further identify the optimum size, i.e the radius and length of nanorods, given a bi-variate log-normal distribution of particle size in two dimensions. - Highlights: • Theoretically estimated loss power of magnetic nanorods. • Compared the heat generation by nanorods and nano-spheres. • Incorporated size distribution of particles into calculations. • Nanorods are more efficient than nano-spheres for heating. • 2D heat maps for optimizing size of nanorods for heating.

  3. Hydroquinone Based Synthesis of Gold Nanorods.

    Science.gov (United States)

    Picciolini, Silvia; Mehn, Dora; Ojea-Jiménez, Isaac; Gramatica, Furio; Morasso, Carlo

    2016-08-10

    Gold nanorods are an important kind of nanoparticles characterized by peculiar plasmonic properties. Despite their widespread use in nanotechnology, the synthetic methods for the preparation of gold nanorods are still not fully optimized. In this paper we describe a new, highly efficient, two-step protocol based on the use of hydroquinone as a mild reducing agent. Our approach allows the preparation of nanorods with a good control of size and aspect ratio (AR) simply by varying the amount of hexadecyl trimethylammonium bromide (CTAB) and silver ions (Ag(+)) present in the "growth solution". By using this method, it is possible to markedly reduce the amount of CTAB, an expensive and cytotoxic reagent, necessary to obtain the elongated shape. Gold nanorods with an aspect ratio of about 3 can be obtained in the presence of just 50 mM of CTAB (versus 100 mM used in the standard protocol based on the use of ascorbic acid), while shorter gold nanorods are obtained using a concentration as low as 10 mM.

  4. Synthesis of layered double hydroxides from eggshells

    Energy Technology Data Exchange (ETDEWEB)

    Li Songnan [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, 150001 (China); Wang Fangyong [College of Engineering and Technology, Northeast Forestry University, 150001 (China); Jing Xiaoyan [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, 150001 (China); Wang Jun, E-mail: zhqw1888@sohu.com [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, 150001 (China); Saba, Jamil; Liu Qi; Ge Lan; Song Dalei; Zhang Milin [Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, 150001 (China)

    2012-01-16

    Graphical abstract: This is the XRD pattern and TEM image of 4Ca-Al layered double hydroxide, which is obtained from eggshells. It can be seen that the sample is of layered double hydroxide and shows the plate-like agglomerations with an average size of 20-100 nm. Highlights: Black-Right-Pointing-Pointer We synthesize layered double hydroxides from eggshells. Black-Right-Pointing-Pointer Eggshells are the mainly material in this method. Black-Right-Pointing-Pointer The additional alkaline solution is not required. - Abstract: Ca-Al and Ca-Fe layered double hydroxides (LDHs) were successfully synthesized from chicken eggshells by an ultrasonic wave assistant method. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) techniques. XRD and TEM analyses showed that the 4Ca-Al LDHs were of high purity but other samples were not. The present study provides a simple, efficient and environmental friendly method to obtain LDHs from biowaste eggshells, in which additional alkaline solution is not required for synthesis. Moreover, eggshells provide all the requisite bivalent metal ions, which are needed to form layered double hydroxides.

  5. Propriedades mecânicas e de inflamabilidade de composições de borracha EPDM carregadas com negro de fumo e hidróxido de alumínio Mechanical and flammability properties of EPDM (ethylene-propylene terpolymer rubber compositions filled with carbon black and aluminum hydroxide

    Directory of Open Access Journals (Sweden)

    Cristine Canaud

    2001-03-01

    Full Text Available Composições de EPDM (terpolímero de etileno-propileno-dieno contendo misturas de negro de fumo e hidróxido de alumínio (ATH foram preparadas com o objetivo de se avaliar seu potencial de utilização em aplicações elétricas. O hidróxido de alumínio, conhecido por suas características de retardante de chama, é uma carga semi-reforçante e, portanto, incapaz de fornecer o nível de reforço necessário para diversas aplicações. Dessa forma, para aliar ao artefato propriedades de não inflamabilidade e alto desempenho mecânico, foi também adicionado o negro de fumo (que é a carga reforçante mais largamente empregada. A escolha do EPDM se justifica pela facilidade de ser encontrado no mercado brasileiro, por sua característica em aceitar grandes quantidades de carga e por ser um elastômero apolar, o que é um requisito básico para aplicação em isolamento elétrico. Os materiais foram submetidos a testes mecânicos e de inflamabilidade, para se determinar aqueles que se ajustavam às normas estabelecidas pela Associação Brasileira de Normas Técnicas - ABNT. Verificou-se que pelo menos 160 phr de hidróxido de alumínio são necessários nessas composições para que a resistência à chama seja alcançada.EPDM composition filled with mixtures of aluminum hydroxide (ATH and carbon black were evaluated for electrical applications. Aluminum hydroxide, known for its characteristics of flame retardancy, is a semi-reinforcing filler and, in this sense, it is unable to impart the reinforcement level necessary to several applications. Thus, to have in the same artifact the non-flammability properties together with a high mechanical performance, carbon black, the most widely used reinforcing filler, has also been used. The choice of EPDM can be justified by the availability of this polymer in the brazilian market, allied to its characteristics to accept large amounts of filler and its apolar chemical character, which is a basic

  6. Surface Acidity of Amorphous Aluminum Hydroxide

    Institute of Scientific and Technical Information of China (English)

    K. FUKUSHI; K. TSUKIMURA; H. YAMADA

    2006-01-01

    The surface acidity of synthetic amorphous Al hydroxide was determined by acid/base titration with several complementary methods including solution analyses of the reacted solutions and XRD characterization of the reacted solids. The synthetic specimen was characterized to be the amorphous material showing four broad peaks in XRD pattern. XRD analyses of reacted solids after the titration experiments showed that amorphous Al hydroxide rapidly transformed to crystalline bayerite at the alkaline condition (pH>10). The solution analyses after and during the titration experiments showed that the solubility of amorphous aluminum hydroxide, Ksp =aAl3+/a3H+,was 1010.3,The amount of consumption of added acid or base during the titration experiment was attributed to both the protonation/deprotonation of dissolved Al species and surface hydroxyl group. The surface acidity constants, surface hydroxyl density and specific surface area were estimated by FITEQL 4.0.

  7. Aluminium hydroxide-induced granulomas in pigs

    DEFF Research Database (Denmark)

    Valtulini, S; Macchi, C; Ballanti, P

    2005-01-01

    The effect of intramuscular injection of 40 mg/2 ml aluminium hydroxide in the neck of pigs was examined in a number of ways. The investigation followed repeated slaughterhouse reports, according to which 64.8% of pigs from one particular farm were found at slaughter to have one or more nodules...... in the muscles of the neck (group slaughtered). The pigs had been injected with a vaccine containing 40 mg/2 ml dose of aluminium hydroxide as adjuvant. Research consisted of two phases: first, an epidemiological study was carried out, aimed at determining the risk factors for the granulomas. The results...... and adjuvant) to pigs inoculated twice with apyrogenic bi-distilled water (group water) and to pigs inoculated once with the adjuvant and once with apyrogenic bi-distilled water (group adjuvant/water). Both studies agreed in their conclusions, which indicate that the high amount of aluminium hydroxide...

  8. Impedance spectroscopy and investigation of conduction mechanism in BaMnO{sub 3} nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Khizar [Nanostructured Materials and Devices Group, Department of Chemicals and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad 45650 (Pakistan); Rafiq, M.A., E-mail: fac221@pieas.edu.p [Nanostructured Materials and Devices Group, Department of Chemicals and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad 45650 (Pakistan); Durrani, S.K. [Material Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad 45650 (Pakistan); Hasan, M.M. [Nanostructured Materials and Devices Group, Department of Chemicals and Materials Engineering, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad 45650 (Pakistan)

    2011-02-01

    BaMnO{sub 3} nanorods were synthesized at 200 {sup o}C and atmospheric pressure using the composite-hydroxide mediated method. X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy were used to investigate the structure, size, morphology, phase purity and elemental composition of BaMnO{sub 3} nanorods. Electrical characterization of BaMnO{sub 3} pellet was performed at 300-400 K and in the frequency range 200 Hz-2 MHz. Temperature dependence of AC conductivity suggests that the BaMnO{sub 3} pellet behaves as a semiconducting material and conduction across the pellet can be explained by the correlated barrier hopping model. Impedance analysis was performed using the equivalent circuit model (R{sub 1}Q{sub 1}C{sub 1})(R{sub 2}C{sub 2}) and it suggests a single relaxation process in the BaMnO{sub 3} pellet at a particular temperature. The analysis reveals that the BaMnO{sub 3} pellet behaves like an n-type semiconductor material due to the presence of oxygen vacancies and some disorder. Modulus spectroscopy also supports the impedance results.

  9. ADSORPTION OF PITCH AND STICKIES ON MAGNESIUM ALUMINUM HYDROXIDES TREATED AT DIFFERENT TEMPERAURES

    Directory of Open Access Journals (Sweden)

    Guodong Li

    2011-04-01

    Full Text Available Magnesium aluminum hydroxides (MAH of nitrate and carbonate forms were prepared by co-precipitation, dried at different temperatures, and employed as an adsorbent for pitch and stickies in papermaking. Results indicated that MAH that had been heat-treated had higher adsorption capacity to model pitch and stickies at neutral pH. Low-temperature-dried magnesium aluminum hydroxides of nitrate form (MAH-NO3 had higher adsorption capacity to model pitch and model stickies than those of the carbonate form (MAH-CO3. Increasing the drying temperature of MAH reduced the difference of adsorption capacity between MAH-NO3 and MAH-CO3. Higher-temperature-dried magnesium aluminum hydroxides also showed higher adsorption capacity to model pitch and stickies when the drying temperature was lower than 550 oC. MAH displayed higher adsorption capacity while a lower initial adsorption rate of model stickies than of model pitch. The model pitch and stickies were adsorbed on MAH significantly by charge neutralization and distributed mainly on the surface of the platelets of magnesium aluminum hydroxides. The experimental isothermal adsorption data of model pitch and stickies on MAH dried at 500 oC fit well to the Freundlich and Dubinin–Radushkevich isotherm equations.

  10. Nanorod optical antennas for dipolar transitions

    CERN Document Server

    Taminiau, Tim H; van Hulst, Niek F

    2009-01-01

    Optical antennas link objects to light. Here, we analyze metal nanorod antennas as cavities with variable reflection coefficients to derive the interaction of dipolar transitions with radiation through the antenna modes. The presented analytical model accurately describes the complete emission process, and is summarized in a phase-matching equation. We show how antenna modes evolve as they become increasingly more bound, i.e. plasmonic. The results illustrate why efficient antennas should not be too plasmonic, and how subradiant even modes can evolve into weakly-interacting dark modes. Our description is valid for the interaction of nanorods with light in general, and is thus widely applicable.

  11. Cation ordering and superstructures in natural layered double hydroxides.

    Science.gov (United States)

    Krivovichev, Sergey V; Yakovenchuk, Victor N; Zolotarev, Andrey A; Ivanyuk, Gregory N; Pakhomovsky, Yakov A

    2010-01-01

    Layered double hydroxides (LDHs) constitute an important group of materials with many applications ranging from catalysis and absorption to carriers for drug delivery, DNA intercalation and carbon dioxide sequestration. The structures of LDHs are based upon double brucite-like hydroxide layers [M(2+)(n)M(3+)(m)(OH)(2(m+n)](m+), where M(2+) = Mg(2+), Fe(2+), Mn(2+), Zn(2+), etc.; M(3+) = Al(3+), Fe(3+), Cr(3+), Mn(3+), etc. Structural features of LDHs such as cation ordering, charge distribution and polytypism have an immediate influence upon their properties. However, all the structural studies on synthetic LDHs deal with powder samples that prevent elucidation of such fine details of structure architecture as formation of superstructures due to cation ordering. In contrast to synthetic materials, natural LDHs are known to form single crystals accessible to single-crystal X-ray diffraction analysis, which provides a unique possibility to investigate 3D cation ordering in LDHs that results in formation of complex superstructures, where 2D cation order is combined with a specific order of layer stacking (polytypism). Therefore LDH minerals provide an indispensable source of structural information for modeling of structures and processes happening in LDHs at the molecular and nanoscale levels.

  12. Layered double hydroxide stability. 1. Relative stabilities of layered double hydroxides and their simple counterparts

    Science.gov (United States)

    Boclair, J. W.; Braterman, P. S.

    1999-01-01

    Solutions containing di- and trivalent metal chlorides [M(II) = Mg2+, Zn2+, Co2+, Ni2+, Mn2+; M(III) = Al3+, Fe3+] were titrated with NaOH to yield hydrotalcite-like layered double hydroxides (LDH), [[M(II)]1-x[M(III)]x(OH)2][Cl]x yH2O, by way of M(III) hydroxide/hydrous oxide intermediates. Analysis of the resultant titration curves yields nominal solubility constants for the LDH. The corresponding LDH stabilities are in the order Mg hydroxides/hydrous oxides is discussed.

  13. Acid mine water neutralisation with ammonium hydroxide and ...

    African Journals Online (AJOL)

    2013-05-30

    May 30, 2013 ... Keywords: acid mine water, ammonium hydroxide, barium hydroxide, sulphate removal ... oxygen becomes oxidised to soluble iron and sulphuric acid, .... The effects of the following parameters on the Fe (II) oxidation.

  14. Monolithic porous carbon prepared by Na2CO3 templating as a substrate for a nickel hydroxide electrode%以Na2CO3为模板制备多孔炭片作为Ni(OH)2电极基体

    Institute of Scientific and Technical Information of China (English)

    陈冬; 程杰; 文越华; 潘军青; 杨裕生

    2013-01-01

    Monolithic porous carbon (MPC) was synthesized by a templating method using Na2CO3 as template, novolac-type phenolic resin as carbon precursor and hexamethylenetetramine as hardening agent. The template, carbon precursor and hardening a-gent were mechanically mixed in a grinding machine, hardened at 150 ℃, crushed into fine particles, compacted into a disc, carbonized at 800 ℃ and finally washed with deionized water to form MPC. MPC-Ni(OH)2 electrodes were prepared by loading Ni (OH)2 into the MPC by cathodic deposition. The MPC is hierarchically porous, has an electric conductivity of 20.40 S·cm-1 and a specific surface area of 576 m2· g-1. Charge-discharge characterization of the MPC-Ni ( OH) 2 electrodes shows that the specific capacities based on active material and the whole electrode are 230 mAh·g-1 and 131 mAh·g-1, respectively. This suggests that the MPC is a promising lightweight matrix to host nickel hydroxide to achieve a high specific energy in nickel-based alkaline batteries.%以Na2CO3为模板、线性酚醛树脂为碳源,经粉末压制成型、炭化、除去模板制备MPC.制备的MPC电导率为20.4 S·cm-1,比表面积约576 m2·g-1,具有无序的分级孔结构.将所制MPC作为Ni(OH)2电极基体,以电化学浸渍的方式填充Ni(OH)2,得到MPC-Ni (OH)2电极,测得Ni(OH)2比容量可达230 mAh·g-1,电极比容量为131 mAh·g-1.研究表明,多孔炭片材料作为一种轻质电极基体,可提高氧化镍电极的性能.

  15. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, R.W.; Muller, R.H.

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 {endash} 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  16. Structural transformation of nickel hydroxide films during anodic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States)

    1992-05-01

    The transformation of anodically formed nickel hydroxide/oxy-hydroxide electrodes has been investigated. A mechanism is proposed for the anodic oxidation reaction, in which the reaction interface between the reduced and oxidized phases of the electrode evolves in a nodular topography that leads to inefficient utilization of the active electrode material. In the proposed nodular transformation model for the anodic oxidation reaction, nickel hydroxide is oxidized to nickel oxy-hydroxide in the region near the metal substrate. Since the nickel oxy-hydroxide is considerably more conductive than the surrounding nickel hydroxide, as further oxidation occurs, nodular features grow rapidly to the film/electrolyte interface. Upon emerging at the electrolyte interface, the reaction boundary between the nickel hydroxide and oxy-hydroxide phases spreads laterally across the film/electrolyte interface, creating an overlayer of nickel oxy-hydroxide and trapping uncharged regions of nickel hydroxide within the film. The nickel oxy-hydroxide overlayer surface facilitates the oxygen evolution side reaction. Scanning tunneling microscopy of the electrode in its charged state revealed evidence of 80 - 100 Angstrom nickel oxy-hydroxide nodules in the nickel hydroxide film. In situ spectroscopic ellipsometer measurements of films held at various constant potentials agree quantitatively with optical models appropriate to the nodular growth and subsequent overgrowth of the nickel oxy-hydroxide phase. A two-dimensional, numerical finite difference model was developed to simulate the current distribution along the phase boundary between the charged and uncharged material. The model was used to explore the effects of the physical parameters that govern the electrode behavior. The ratio of the conductivities of the nickel hydroxide and oxy-hydroxide phases was found to be the dominant parameter in the system.

  17. Hydroxide catalysis bonding of silicon carbide

    NARCIS (Netherlands)

    Veggel, A.A. van; Ende, D.A. van den; Bogenstahl, J.; Rowan, S.; Cunningham, W.; Gubbels, G.H.M.; Nijmeijer, H.

    2008-01-01

    For bonding silicon carbide optics, which require extreme stability, hydroxide catalysis bonding is considered [Rowan, S., Hough, J. and Elliffe, E., Silicon carbide bonding. UK Patent 040 7953.9, 2004. Please contact Mr. D. Whiteford for further information: D.Whiteford@admin.gla.ac.uk]. This techn

  18. Single sheet metal oxides and hydroxides

    DEFF Research Database (Denmark)

    Huang, Lizhi

    The synthesis of layered double hydroxides (LDHs) provides a relatively easy and traditional way to build versatile chemical compounds with a rough control of the bulk structure. The delamination of LDHs to form their single host layers (2D nanosheets) and the capability to reassemble them offer ...

  19. Polysulfide intercalated layered double hydroxides for metal capture applications

    Science.gov (United States)

    Kanatzidis, Mercouri G.; Ma, Shulan

    2017-04-04

    Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

  20. Polysulfide intercalated layered double hydroxides for metal capture applications

    Energy Technology Data Exchange (ETDEWEB)

    Kanatzidis, Mercouri G.; Ma, Shulan

    2017-04-04

    Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

  1. New trend for synthesizing of magnetic nanorods with titanomaghemite structure

    Science.gov (United States)

    Saber, Osama

    2016-07-01

    This research aims at developing magnetic and optical materials through fabrication of uniform nanorods by facile and novel technique. In this trend, titanium and iron were successfully combined together forming nanorods without template or high temperature by urea hydrolysis. TEM images showed uniform and homogeneous nanorods with dimensions; 10 nm in width and 50 nm in length. In the same time, fine nanoparticles were observed around the nanorods. With further treatment for the nanorods at high temperature and pressure, FESEM images revealed that the dimensions of the rods slightly increased to be 70 nm in length and 12 nm in width with a complete disappearance of the nanoparticles. Using X-ray diffraction, thermal analyses and infrared spectra in addition to the results of the electron microscopy, the oriented attachment mechanism was suggested for the formation of titanium iron oxides nanorods. The magnetic measurements revealed that the prepared nanorods possess ferromagnetic behavior and exhibit high saturation magnetization. Also, the optical properties showed that the nanorods have high absorption in the visible region and possess low band gap energy. Finally, we concluded that it is probably the first time to prepare nanorods by urea hydrolysis. The advanced optical and magnetic properties give the prepared nanorods relevance to use as building blocks in functional nanoscale devices.

  2. Bismuth titanate nanorods and their visible light photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn; Liu, H.D.; Lin, N.; Yu, H.Y.

    2015-02-15

    Highlights: • Bismuth titanate nanorods have been synthesized by a simple hydrothermal process. • The size of bismuth titanate nanorods can be controlled by growth conditions. • Bismuth titanate nanorods show good photocatalytic activities of methylene blue and Rhodamine B. - Abstract: Bismuth titanate nanorods have been prepared using a facile hydrothermal process without additives. The bismuth titanate products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and UV-vis diffusion reflectance spectrum. XRD pattern shows that the bismuth titanate nanorods are composed of cubic Bi{sub 2}Ti{sub 2}O{sub 7} phase. Electron microscopy images show that the length and diameter of the bismuth titanate nanorods are 50-200 nm and 2 μm, respectively. Hydrothermal temperature and reaction time play important roles on the formation and size of the bismuth titanate nanorods. UV-vis diffusion reflectance spectrum indicates that bismuth titanate nanorods have a band gap of 2.58 eV. The bismuth titanate nanorods exhibit good photocatalytic activities in the photocatalytic degradation of methylene blue (MB) and Rhodamine B (RB) under visible light irradiation. The bismuth titanate nanorods with cubic Bi{sub 2}Ti{sub 2}O{sub 7} phase are a promising candidate as a visible light photocatalyst.

  3. Beyond spheres: Murphy's silver nanorods and nanowires.

    Science.gov (United States)

    Zhang, Qiao; Yin, Yadong

    2013-01-11

    In this viewpoint we discuss the early work of Murphy et al. on the colloidal synthesis of silver nanorods and nanowires, which represents a milestone in the controllable synthesis of anisotropic metal nanoparticles. We present here an overview of the impact of this pioneering work on the later drastic development of solution phase synthesis of shape-controlled metal nanostructures.

  4. Colloidal nanorod heterostructures for photovoltaics and optoelectronics

    Science.gov (United States)

    Shim, Moonsub

    2017-05-01

    Colloidal quantum dots (QDs) synthesized in versatile, easy-to-process solutions are opening up exciting prospects in multiple areas, especially in biomedical imaging, photovoltaics, solid-state lighting and displays. The success of most of these prospects relies on high-quality heterostructures that improve optical properties. In particular, the core/shell heterostructure with a type I straddling band offset has been indispensable but the applicability is often limited to those exploiting only photoluminescence. QDs and their heterostructures can also be made with anisotropic shapes that allow access to essentially an unlimited number of combinations of size, shape and composition. Structures that allow enhancement of optical properties and physical accessibility for carrier injection/extraction simultaneously can open up new and exciting prospects in photovoltaics and optoelectronics. This topical review focuses on nanorod-based colloidal semiconductor heterostructures. Two-component, type II staggered band offset nanorod heterostructures capable of efficiently separating photoinduced charges are first discussed. Double heterojunction nanorods that contain three different phases are then considered with respect to their novelty and potential as emissive materials in light-emitting diodes. We conclude with an outlook on the possibility of developing colloidal nanorods that contain epitaxial interfaces beyond the conventional semiconductor heterojunctions.

  5. Mechanochemical synthesis of finite particle of layered double hydroxide-acetate intercalation compound: Swelling, thin film and ion exchange

    Science.gov (United States)

    Kuramoto, Kyoko; Intasa-Ard, Soontaree (Grace); Bureekaew, Sareeya; Ogawa, Makoto

    2017-09-01

    Acetate intercalated Mg-Al layered double hydroxide was successfully synthesized by the solid-state reactions between magnesium acetate and aluminum hydroxide as the starting materials using a planetary mil. The acetate intercalated Mg-Al layered double hydroxide prepared by the present solid-state reaction was finite particle and was processed into stable aqueous suspension with variable transparency and viscosity depending on the concentration. By drying the suspension on a substrate under nitrogen atmosphere, thin film (with the thickness of several micrometers) of the acetate intercalated Mg-Al layered double hydroxide with the basal plane oriented parallel to the substrate was obtained. The ion exchange ability of the film, which is as an advantage of the acetate form of layered double hydroxide, was shown by the ion exchange with coumarin-3-carboxylate to give a photoluminescent film. The solid-solid reaction is advantageous for the preparation of layered double hydroxides due to the simple and eco-friendly nature (no solvent) of the operation, lower possibility of carbonate contamination and finite particles of the products.

  6. Preparation of hydroxide ion conductive KOH–layered double hydroxide electrolytes for an all-solid-state iron–air secondary battery

    Directory of Open Access Journals (Sweden)

    Taku Tsuneishi

    2014-06-01

    Full Text Available Anion conductive solid electrolytes based on Mg–Al layered double hydroxide (LDH were prepared for application in an all-solid-state Fe–air battery. The ionic conductivity and the conducting ion species were evaluated from impedance and electromotive force measurements. The ion conductivity of LDH was markedly enhanced upon addition of KOH. The electromotive force in a water vapor concentration cell was similar to that of an anion-conducting polymer membrane. The KOH–LDH obtained was used as a hydroxide ion conductive electrolyte for all-solid-state Fe–air batteries. The cell performance of the Fe–air batteries was examined using a mixture of KOH–LDH and iron-oxide-supported carbon as the negative electrode.

  7. Study of organo-hybrid layered double hydroxides by medium and near infrared spectroscopy

    Science.gov (United States)

    Mora, Manuel; López, M. Isabel; Jiménez-Sanchidrián, César; Ruiz, J. Rafael

    2011-03-01

    An Mg/Al layered double hydroxide (LDH) containing carbonate ion in its interlayer region was examined by medium infrared (MIR) and near infrared reflectance spectroscopy (NIRS). The MIR and NIR spectroscopy techniques was also used to study two organo-hybrid LDHs containing interlayer dodecylbenzenesulphonate (DBS) and dodecylsulphate (DS) ions, respectively. The NIR spectra for the latter solids were found to exhibit the overtone and combination bands for the hydroxyl groups in addition to those typical bands of the organic host functions.

  8. Optical characterization of CdS nanorods capped with starch

    Science.gov (United States)

    Roy, J. S.; Pal Majumder, T.; Schick, C.

    2015-05-01

    Well crystalline uniform CdS nanorods were grown by changing the concentration of maize starch. The highly polymeric (branched) structure of starch enhances the growth of CdS nanorods. The average diameter of the nanorods is 20-25 nm while length is of 500-600 nm as verified from SEM and XRD observations. The optical band gaps of the CdS nanorods are varying from 2.66 eV to 2.52 eV depending on concentration of maize starch. The photoluminescence (PL) emission bands are shifted from 526 nm to 529 nm with concentration of maize starch. We have also observed the enhanced PL intensity in CdS nanorods capped with starch. The Fourier transform infrared (FTIR) spectroscopy shows the significant effect of starch on CdS nanorods.

  9. Cadmium Sulphide Nanorods: Synthesis, Characterization and their Photocatalytic Activity

    Energy Technology Data Exchange (ETDEWEB)

    Giribabu, Krishnamoorthy; Suresh, Ranganathan; Manigandan, Ramadoss; Vijayaraj, Arunachalam; Prabu, Raju; Narayanan, Vengidusamy [Univ. of Madras, Madras (India)

    2012-09-15

    Cadmium sulphide (CdS) nanorods were prepared by a single precursor thermal decomposition (SPTD) method. The formation of CdS nanorods and their structure, morphology and elemental composition were studied by means of FT-IR, XRD, FE-SEM, HR-TEM and EDAX analysis. Photoluminescence (PL) and lifetime measurements were recorded to study the luminescence properties of the material. The PL spectrum of the CdS nanorods showed one broad peak and four shoulders and the cause for this emission was discussed. The PL emissions from the band edge and deep trap state of the CdS nanorods were studied by lifetime measurements. Further, the synthesized CdS nanorods showed an increase in efficiency of photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB). The increase in the photocatalytic activity was attributed to the mixed phase of the CdS nanorods.

  10. Analysis of driven nanorod transport through a biopolymer matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mair, Lamar O., E-mail: Lamar.Mair@gmail.com [Weinberg Medical Physics LLC, Bethesda, MD 20817 (United States); Weinberg, Irving N.; Nacev, Alek; Urdaneta, Mario G.; Stepanov, Pavel; Hilaman, Ryan; Himelfarb, Stephanie [Weinberg Medical Physics LLC, Bethesda, MD 20817 (United States); Superfine, Richard [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599 (United States)

    2015-04-15

    Applying magnetic fields to guide and retain drug-loaded magnetic particles in vivo has been proposed as a way of treating illnesses. Largely, these efforts have been targeted at tumors. One significant barrier to long range transport within tumors is the extracellular matrix (ECM). We perform single particle measurements of 18 nm diameter nanorods undergoing magnetophoresis through ECM, and analyze the motion of these nanorods in two dimensions. We observe intra-particle magnetophoresis in this viscoelastic environment and measure the fraction of time these nanorods spend effectively hindered, versus effectively translating. - Highlights: • We study the magnetophoretic transport of 18 nm diameter nickel nanorods through a protein-rich matrix. • We note that nanorods move with low velocity (less than 1 μm per minute) for approximately 95% of the total experiment time. • We plot nanorod velocity over the course of hundreds of seconds. • Finally, we observe intra-particle magnetophoresis events in this viscoelastic environment.

  11. Controlled novel route to synthesis and characterization of silver nanorods.

    Science.gov (United States)

    Gautam, A; Mukherjee, Shaibal; Ram, S

    2010-07-01

    Silver nanorods were synthesized by burning out the as prepared Ag-PVA nanocomposite films at 300 degrees C in air. Aqueous PVA solution is acts as stabilizing agents for silver nanorods. The formation of silver nanorods was confirmed from the appearance of two surface plasmon absorption maxima at 425 and 465 nm due to transverse and longitudinal mode of vibration of electrons. SEM micrograph showed the resultant nanorods were 500-600 nm in length and 50-70 nm in diameter. It is supported by TEM with more 1000 nm in length and 40-60 nm diameters. The XRD demonstrated that the nanorods were present in fcc crystal of pure silver. Finally the X-ray photoelectron spectroscopy (XPS) also confirmed the formation of silver nanorods with 3d(5/2) and 3d(3/2) band at 368.6 and 374.6 eV respectively.

  12. Reductive dehalogenation by layered iron(II)-iron(III) hydroxides and related iron(II) containing solids

    DEFF Research Database (Denmark)

    Yin, Weizhao

    In the present PhD project, novel synthesis and modifications of layered Fe(II)-Fe(III) hydroxides (green rusts, GRs) were investigated with focus on improved dehalogenation of carbon tetrachloride by using modified green rusts and/or altered reaction conditions. The Ph.D. project has comprised: 1...

  13. Collective plasmonic properties in few-layer gold nanorod supercrystals

    OpenAIRE

    Hamon, Cyrille; Novikov, Sergey M.; Scarabelli, Leonardo; Solis, Diego M.; Altantzis, Thomas; Bals, Sara; Taboada, Jose M.; Obelleiro, Fernando; Liz-Marzán, Luis M.

    2015-01-01

    Abstract: Gold nanorod supercrystals have been widely employed for the detection of relevant bioanalytes with detection limits ranging from nano- to picomolar levels, confirming the promising nature of these structures for biosensing. Even though a relationship between the height of the supercrystal (i.e., the number of stacked nanorod layers) and the enhancement factor has been proposed, no systematic study has been reported. In order to tackle this problem, we prepared gold nanorod supercry...

  14. Functionalized Gold Nanorods for Tumor Imaging and Targeted Therapy

    OpenAIRE

    Gui, Chen; Cui, Da-Xiang

    2012-01-01

    Gold nanorods, as an emerging noble metal nanomaterial with unique properties, have become the new exciting focus of theoretical and experimental studies in the past few years. The structure and function of gold nanorods, especially their biocompatibility, optical property, and photothermal effects, have been attracting more and more attention. Gold nanorods exhibit great potential in applications such as tumor molecular imaging and photothermal therapy. In this article, we review some of the...

  15. Electromechanical characteristics of ZnO:Al nanorods.

    Science.gov (United States)

    Fang, Te-Hua; Kang, Shao-Hui

    2010-01-01

    In this study, we explore the effect of aluminum doping on the mechanical, piezoelectric, and semiconductive properties of zinc oxide (ZnO) nanorods using scanning probe microscopy. The results show that the size of ZnO:Al nanorods can be changed by tuning the dopant concentrations during nanorod growth. The average surface potentials of the samples were -42.2-34.4 mV. Single nanorod bending generation output surface potentials were 0.05-0.08 V. The power density per unit substrate area was 0.72 nW/mm(-2) for a device outputting ultrasonic wavelengths.

  16. Longitudinal Plasmonic Detection of Glucose Using Gold Nanorods

    Directory of Open Access Journals (Sweden)

    Ching-An Peng

    2014-04-01

    Full Text Available Gold nanorod-based affinity sensors were developed\tutilizing\tconcanavalin-A/dextran/glucose chemistry to detect glucose. The gold nanorods, synthesized using the seed-mediated method, were first coated with dextran sulfate. The dextran sulfate coating changed the local refractive index, which was observed as a red shift in the longitudinal plasmon band. After the addition of 8 μM concanavalin-A, gold nanorod aggregates were formed as shown by TEM analysis. The corresponding UV-Vis spectrum peak wavelength showed a red shift from 701 nm of dextran sulfate coated gold nanorods to 718 nm of concanavalin-A promoted gold nanorod aggregates. The gold nanorod aggregates were dissociated when 12 mM glucose was introduced, as illustrated by TEM images. The longitudinal plasmon resonance of the UV-Vis spectrum also showed a blue shift from 718 nm of dextran sulfate-coated gold nanorods associated by concanavalin-A to 714 nm of dissociated dextran sulfate-coated gold nanorods. The degree of the spectrum peak wavelength shift of the dextran sulfate-coated gold nanorods associated by concanavalin-A can be modulated using glucose ranging from 1 to 30 mM.

  17. Highly stable organic fluorescent nanorods for living- cell imaging

    Institute of Scientific and Technical Information of China (English)

    Minhuan Lan[1,3; Jinfeng Zhang[1,3; Xiaoyue Zhu[1; Pengfei Wang[2; Xianfeng Chen[1; Chun-Sing Lee[1; Wenjun Zhang[1

    2015-01-01

    Metal-free, organic-dye-based fluorescent nanorods were fabricated through a simple solvent-exchange procedure. The as-prepared nanorods exhibit low toxicity to living cells and excellent photostability. Furthermore, they are stable in solutions of various pHs and high ionic strength and in solutions with interfering metal ions. Compared with the free DPP-Br molecules in THF, these nanorods exhibit larger Stokes shift, broader absorption spectra, and greatly improved photostability. We successfully demonstrated the application of the nanorods, including their aforementioned beneficial characteristics, as a good fluorescence probe for bio-imaging.

  18. Thermal behaviour of hydroxides, hydroxysalts and hydrotalcites

    Indian Academy of Sciences (India)

    Parthasarathi Bera; Michael Rajamathi; M S Hegde; P Vishnu Kamath

    2000-04-01

    Mass spectrometric analysis of gases evolved during thermal decomposition of divalent metal hydroxides, hydroxysalts and hydrotalcites show that all these compounds undergo dehydration in the temperature range 30 < T < 220°C followed by decomposition at temperatures above 250°C. The latter step involves simultaneous deanation and dehydroxylation of the layers. Our observations conclusively prove that alternative mechanisms which envisage CO2 evolution due to deanation at lower temperatures proposed by Kanezaki to be wrong.

  19. Layered Double Hydroxide as Cordycepin Delivery Nanocarrier

    Institute of Scientific and Technical Information of China (English)

    Qin Zheng YANG; Jing YANG; Chang Kai ZHANG

    2006-01-01

    Layered double hydroxide was investigated as cordycepin delivery nanocarrier for the first time in this study. Negatively charged biomolecule-cordycepin was intercalated in the gallery spaces of [Mg-Al-NO3], which was confirmed by the results of X-ray diffraction and electrophoretic mobility. Cell experiment suggested that the new bio-LDH nanohybrid could prevent cordycepin decomposition by adenosine deaminase. This new formulation could possibly be used as a novel form cordycepin intravenous injection.

  20. Single sheet metal oxides and hydroxides

    DEFF Research Database (Denmark)

    Huang, Lizhi

    the possibility to gain precise control of the structure, composition, morphology, and property of desired nanostructures. In the present Ph.D. project, examples to produce 2D nanosheets with novel functionalities are presented. This comprises: (1) Synthesis of LDHs with a new structure and composition. (2......) Delamination of the LDHs structure (oxGRC12) with the formation of single sheet iron (hydr)oxide (SSI). (3) Assembly of the new 2D nanosheets layer by layer to achieve desired functionalities....

  1. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available Nickel hydroxide films were prepared by electrodeposition from a solution Ni(NO32 0,05 mol L ?¹ on ITO electrodes (Tin oxide doped with Indium on PET-like plastic film, applying a current of - 0,1 A cm ?² during different time intervals between 1800 and 7200 s. The electrochemical behavior of the nickel hydroxide electrode was investigated through a cyclic voltammogram, in NaOH 1,0 mol L ?¹, where it was observed two peaks in the profile in 0,410 and 0,280 V, corresponding to redox couple Ni(II/Ni(III. A sensor for urea presenting a satisfactory answer can be obtained when, after the deposit of the film of Ni(OH2 on the electrode of nickel, it is immersed in a solution of NaOH 1,0 mol L ?¹ and applying a potential of + 0,435 V, where the maximum of the anodic current occurs in the cyclic voltammogram. Analyzing the results it can be observed that, for a range of analite concentration between 5 to 50 m mol L ?¹, the behavior is linear and the sensibility found was of 20,3 mA cm?² (mol L?¹?¹, presenting reproducibility confirming the nickel hydroxide electrodes utilization for the determination of urea.

  2. Calcium hydroxide silylation reaction with trimethylchlorosilane

    Directory of Open Access Journals (Sweden)

    Novoselnov Anatoliy A.

    2016-01-01

    Full Text Available The silylation reaction of a calcium hydroxide with a trimethylchlorosilane is studied as a silylation model by the gas-liquid chromatography. The silylation process is divided into three stages. A material balance of these stages is calculated. The schemes of the reactions at each stage of the process are proposed. The modified calcium hydroxide obtained at three repetitive stages of the silylation reaction has been investigated by the x-ray phase analysis, IR spectroscopy, thermal analysis, electron microscopy in a combination with the elemental analysis. It has been determined that at the first stage of the interaction the processes of the trimethylchlorosilane hydrolysis and of the hydrolysis products condensation dominate, and at the same time an adsorption process of the trimethylchlorosilane and its derivatives starts. Further, the hydrolysis of the trimethylchlorosilane by the «new» portions of a water formed in the reaction of a calcium hydroxide with a hydrogen chloride takes place, simultaneously the secondary reactions of the Si-O-Ca – ties’ formation and cleavage occur including as a silylation-desilylation dynamic equilibrium process.

  3. Effect of three different calcium hydroxide mixtures (calcium hydroxide with glycerine, normal saline and distilled water on root dentin microhardness

    Directory of Open Access Journals (Sweden)

    Hasheminia SM

    2007-06-01

    Full Text Available Background and Aim: During root canal therapy, it is necessary to remove as many bacteria as possible from the root canal. The use of medicaments is recommended to reduce the microbial population prior to root filling. Calcium hydroxide pastes have been used because of their antibacterial effects and the ability of tissue dissolving. The aim of this study was to evaluate the effect of calcium hydroxide/glycerine mixture, calcium hydroxide/normal saline mixture and calcium hydroxide/distilled water mixture on root dentin microhardness in storage times of 7 and 14 days.Materials and Methods: In this in vitro study, fifteen extracted maxillary canines and central incisors were selected. The crowns of the teeth were removed and the canals were prepared. Teeth were sectioned transversally to produce a total of 30 dentin discs from the middle third of the roots. Specimens were divided into three groups of 10 discs each. Dentin samples were subjected to calcium hydroxide/glycerine, calcium hydroxide/normal saline and calcium hydroxide/distilled water mixtures for 7 and 14 days. Dentin microhardness was measured by a Vickers indenter with a load of 200 g for 15 seconds. Data were analyzed using ANOVA, Paired t-test and LSD with p<0.05 as the level of significance.Results: Statistical analysis showed that all three mixtures decreased dentin microhardness. After 7 days, reduction in dentin microhardness by calcium hydroxide/glycerine combination was significantly higher than calcium hydroxide/normal saline and calcium hydroxide/distilled water combinations. After 14 days, reduction in dentin microhardness by calcium hydroxide/distilled water combination was significantly higher than the other two groups.Conclusion: Based on the results of this study, the use of calcium hydroxide combinations for intracanal dressing reduces dentin microhardness. After 7 days calcium hydroxide/glycerine combination and after 14 days calcium hydroxide/distilled water

  4. Fabrication of copper nanorods by low-temperature metal organic chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; Frank Leung-Yuk Lam; HU Xijun; YAN Zifeng

    2006-01-01

    Copper nanorods have been synthesized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD)employing copper (Ⅱ) acetylacetonate, Cu(acac)2,and hydrogen as a precursor and reactant gas, respectively. The hydrogen plays an important role in chemical reduction of oganometallic precursor which enhances mass transfer in the interior of the SBA-15 porous substrate. Such copper nanostructures are of great potentials in the semiconductor due to their unusual optical, magnetic and electronic properties.In addition, it has been found that chemically modifying the substrate surface by carbon deposition is crucial to such synthesis of copper nanostructures in the interior of the SBA-15, which is able to change the surface properties of SBA-15 from hydrophilic to hydrophobic to promote the adsorption of organic cupric precursor. It has also been found that the copper nanoparticles deposited on the external surface are almost eliminated and the copper nanorods are more distinct while the product was treated with ammonia. This approach could be achieved under a mild condition: a low temperature (400℃) and vacuum (2 kPa) which is extremely milder than the conventional method. It actually sounds as a foundation which is the first time to synthesize a copper nanorod at a mild condition of a low reaction temperature and pressure.

  5. Synthesis of one-dimensional silver oxide nanoparticle arrays and silver nanorods templated by Langmuir monolayers.

    Science.gov (United States)

    Liu, Hong-Guo; Xiao, Fei; Wang, Chang-Wei; Xue, Qingbin; Chen, Xiao; Lee, Yong-Ill; Hao, Jingcheng; Jiang, Jianzhuang

    2007-10-01

    One-dimensional (1D) silver oxide nanoparticle arrays were synthesized by illuminating the composite Langmuir-Blodgett monolayers of porphyrin derivatives/Ag(+) and n-hexadecyl dihydrogen phosphate (n-HDP)/Ag(+) deposited on carbon-coated copper grids with daylight and then exposing them to air. Transmission electron microscopy (TEM) observation shows that the nanoparticle size is around 3 nm, with the separation of about 2-3 nm. High-resolution TEM (HRTEM) investigation indicates that the particles are made up of Ag(2)O. Ag nanorods with the width of 15-35 nm and the length of several hundreds of nanometers were synthesized by irradiating the composite Langmuir monolayers of porphyrin derivatives/Ag(+) and n-HDP/Ag(+) by UV-light directly at the air/water interface at room temperature. HRTEM image and selected-area electron diffraction (SAED) pattern indicate that the nanorods are single crystals with the (110) face of the face-centered cubic (fcc) silver parallel to the air/water interface. The formation of the 1D arrays and the nanorods should be attributed to the templating effect of the linear supramolecules formed by porphyrin derivative or n-HDP molecules in Langmuir monolayers through non-covalent interactions.

  6. Electrical contacts to nanorod networks at different length scales: From macroscale ensembles to single nanorod chains

    KAUST Repository

    Lavieville, Romain

    2013-11-01

    The nature of metal-semiconductor interfaces at the nanoscale is an important issue in micro- and nanoelectronic engineering. The study of charge transport through chains of CdSe semiconductor nanorods linked by Au particles represents an ideal model system for this matter, because the metal semiconductor interface is an intrinsic feature of the nanosystem. Here we show the controlled fabrication of all-inorganic hybrid metal-semiconductor networks with different size, in which the semiconductor nanorods are linked by Au domains at their tips. We demonstrate different approaches to selectively contact the networks and single nanorod chains with planar electrodes, and we investigate their charge transport at room temperature. © 2013 Elsevier B.V. All rights reserved.

  7. Lasing Action with Gold Nanorod Hyperbolic Metamaterials

    CERN Document Server

    Chandrasekar, Rohith; Meng, Xiangeng; Shalaginov, Mikhail Y; Lagutchev, Alexei; Kim, Young L; Wei, Alexander; Kildishev, Alexander V; Boltasseva, Alexandra; Shalaev, Vladimir M

    2016-01-01

    Coherent nanoscale photon sources are of paramount importance to achieving all-optical communication. Several nanolasers smaller than the diffraction limit have been theoretically proposed and experimentally demonstrated using plasmonic cavities to confine optical fields. Such compact cavities exhibit large Purcell factors, thereby enhancing spontaneous emission, which feeds into the lasing mode. However, most plasmonic nanolasers reported so far have employed resonant nanostructures and therefore had the lasing restricted to the proximity of the resonance wavelength. Here, we report on an approach based on gold nanorod hyperbolic metamaterials for lasing. Hyperbolic metamaterials provide broadband Purcell enhancement due to large photonic density of optical states, while also supporting surface plasmon modes to deliver optical feedback for lasing due to nonlocal effects in nanorod media. We experimentally demonstrate the advantage of hyperbolic metamaterials in achieving lasing action by its comparison with ...

  8. Thermochemistry of calcium oxide and calcium hydroxide in fluoride slags

    Science.gov (United States)

    Chattopadhyay, S.; Mitchell, A.

    1990-08-01

    Calcium oxide activity in binary CaF2-CaO and ternary CaF2-CaO-Al2O3 and CaF2-CaO-SiO2 slags has been determined by CO2-slag equilibrium experiments at 1400 °C. The carbonate ca-pacity of these slags has also been computed and compared with sulfide capacity data available in the literature. The similarity in trends suggests the possibility of characterizing carbonate capacity as an alternative basicity index for fluoride-base slags. Slag-D2O equilibrium experi-ments are performed at 1400°C with different fluoride-base slags to determine water solubility at two different partial pressures of D2O, employing a new slag sampling technique. A novel isotope tracer detection technique is employed to analyze water in the slags. The water solubility data found show higher values than the previous literature data by an order of magnitude but show a linear relationship with the square root of water vapor partial pressure. The activity of hydroxide computed from the data is shown to be helpful in estimating water solubility in in-dustrial electroslag remelting (ESR) slags.

  9. Polytypic transformations of aluminum hydroxide: A mechanistic investigation

    Institute of Scientific and Technical Information of China (English)

    Thimmasandra Narayan Ramesh

    2012-01-01

    The diffusion of ammonia vapors into a solution of aluminum nitrate or ferric nitrate results in the precipitation of their respective hydroxides and oxyhydroxides.Polymorphic phase formation of aluminum hydroxide is controlled by the rate of crystallization.The PXRD patterns of products obtained via vapor phase diffusion revealed that poorly ordered aluminum hydroxide is formed during the initial stages of crystallization.After 8 days,the formation of the bayerite phase of aluminum hydroxide was observed.Upon prolonged exposure to ammonia vapors,bayerite was transformed into gibbsite.The infrared spectrum of the product confirmed the presence of different polytypic phases of aluminum hydroxide.The results demonstrated that the crystal structure of metal hydroxides is controlled by the rate of crystallization,nature of the metal ion,site selectivity and specificity and preparative conditions.

  10. Pulp response to a novel adhesive calcium hydroxide based cement.

    Science.gov (United States)

    Watts, A; Paterson, R C; Cohen, B D; Combe, E C

    1994-09-01

    This study compares pulp responses to 3 formulations of calcium hydroxide, namely: a) An experimental adhesive calcium hydroxide cement containing polyacrylic acid, b) Dycal (L.D> Caulk Co, Milford, Delaware) Batch Nos 176970/176990, c) "Analar" calcium hydroxide mixed with sterile distilled water. After 28 days dentine bridges were present in 77% of teeth capped with the test material, 64% of teeth treated with Dycal and in 62% of teeth capped with calcium hydroxide and water. Inflammatory infiltrates were observed in a number of teeth remote from the bridges. Bacteria were detected in these specimens. Exposed rat molar pulp responses to an experimental adhesive calcium hydroxide cement were similar to to those observed with 2 other calcium hydroxide formulations.

  11. Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review

    Science.gov (United States)

    Shalavi, S; Yazdizadeh, M

    2012-01-01

    The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial. PMID:23323217

  12. THE DIGESTION OPERATION IN THE ALKALI ALUMINAT SOLUTIONS OF ALUMINUM HYDROXIDES IN THE BOEHMITIC BAUXITES

    Directory of Open Access Journals (Sweden)

    Sami ŞAHİN

    1999-01-01

    Full Text Available At present more than 90 per cent of the world's alumina is produced by the Bayer process, a simple technology providing high purity final product. A part from some exceptional local conditions, bauxite is processed almost solely by this technology. As a benefication process, alumina production releases the aluminum oxide content of bauxite from other accompanying oxides thus providing alumina suitable for electrolysis in a cryolite melt. The basic theory of the Bayer process was elaborated by K.J. Bayer and described in his patents in 1887 and 1892. The first patent refers to the aid of seed crystals of aluminum hydroxide or of carbonic acid, that is, to the precipitation and carbonation processes. The second patent formulates the concept that the aluminum oxide content of bauxites can be dissolved in sodium hydroxide solutions, with the formulation of sodium aluminate, a process called digestion nowadays. The most important operations of the Bayer technology are bauxite preparation, crushing, grinding, digestion, red mud separation, thickening, washing, filtration, precipitation, calcination and evaporation. In spite of its great significance as regards the complete Bayer technology, the structure of sodium aluminate solutions has not been cleared up definitely yet. Boehmite is the most important aluminum mineral of karstic bauxites. Some experimental results showing the various effects on aluminum hydroxides by alkali process from boehmitic bauxites and the factors gowerning the digestion operation of aluminate solutions were investigated.

  13. Raman Study on Pompeii Potteries: The Role of Calcium Hydroxide on the Surface Treatment

    Directory of Open Access Journals (Sweden)

    Daniele Chiriu

    2014-01-01

    Full Text Available Pottery samples from the Pompeii archaeological site were investigated by IR Raman spectroscopy and EDAX measurements. The analysis of the Raman spectra of the surfaces reveals the presence calcium hydroxide (peak at about 780 cm−1 while the calcium carbonate is totally absent. The comparative studies on the carbonation effect of the surfaces were performed on laboratory grown samples of calcium hydroxide. The samples were treated at high temperature and exposed to different ambient conditions, and the analysis suggests that the original surfaces of Roman pottery were scattered by calcium hydroxide (limewash before the cooking process in the furnace. The result of this surface treatment not only permits a vitrification of the surfaces but also seems to reduce the content of CO2 in the furnace atmosphere and then obtain a more oxidant ambient during the cooking of the pottery. These results give new insights on the real degree of knowledge of the Romans about the art of ceramics and more generally about chemistry and technologies.

  14. Preparation and Electrocatalytic Activity of Tungsten Carbide Nanorod Arrays

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High density tungsten carbide nanorod arrays have been prepared by magnetron sputtering (MS) using the aluminum lattice membrane (ALM) as template. Electrocatalytic properties of nitromethane electroreduction on the tungsten carbide nanorod arrays electrode were investigated by electrochemical method, and their electrocatalytic activity is approached to that of the Pt foil electrode.

  15. Enhancement of antibacterial properties of Ag nanorods by electric field

    Directory of Open Access Journals (Sweden)

    Omid Akhavan and Elham Ghaderi

    2009-01-01

    Full Text Available The effect of an electric field on the antibacterial activity of columnar aligned silver nanorods was investigated. Silver nanorods with a polygonal cross section, a width of 20–60 nm and a length of 260–550 nm, were grown on a titanium interlayer by applying an electric field perpendicular to the surface of a Ag/Ti/Si(100 thin film during its heat treatment at 700 °C in an Ar+H2 environment. The optical absorption spectrum of the silver nanorods exhibited two peaks at wavelengths of 350 and 395 nm corresponding to the main surface plasmon resonance bands of the one-dimensional silver nanostructures. It was found that the silver nanorods with an fcc structure were bounded mainly by {100} facets. The antibacterial activity of the silver nanorods against Escherichia coli bacteria was evaluated at various electric fields applied in the direction of the nanorods without any electrical connection between the nanorods and the capacitor plates producing the electric field. Increasing the electric field from 0 to 50 V cm−1 resulted in an exponential increase in the relative rate of reduction of the bacteria from 3.9×10−2 to 10.5×10−2 min−1. This indicates that the antibacterial activity of silver nanorods can be enhanced by applying an electric field, for application in medical and food-preserving fields.

  16. Enhancement of antibacterial properties of Ag nanorods by electric field

    Energy Technology Data Exchange (ETDEWEB)

    Akhavan, Omid [Department of Physics, Sharif University of Technology, PO Box 11155-9161, Tehran (Iran, Islamic Republic of); Ghaderi, Elham [Tehran University of Medical Sciences, PO Box 14155-6447, Tehran (Iran, Islamic Republic of)], E-mail: oakhavan@sharif.edu

    2009-01-15

    The effect of an electric field on the antibacterial activity of columnar aligned silver nanorods was investigated. Silver nanorods with a polygonal cross section, a width of 20-60 nm and a length of 260-550 nm, were grown on a titanium interlayer by applying an electric field perpendicular to the surface of a Ag/Ti/Si(100) thin film during its heat treatment at 700 deg. C in an Ar+H{sub 2} environment. The optical absorption spectrum of the silver nanorods exhibited two peaks at wavelengths of 350 and 395 nm corresponding to the main surface plasmon resonance bands of the one-dimensional silver nanostructures. It was found that the silver nanorods with an fcc structure were bounded mainly by {l_brace}100{r_brace} facets. The antibacterial activity of the silver nanorods against Escherichia coli bacteria was evaluated at various electric fields applied in the direction of the nanorods without any electrical connection between the nanorods and the capacitor plates producing the electric field. Increasing the electric field from 0 to 50 V cm{sup -1} resulted in an exponential increase in the relative rate of reduction of the bacteria from 3.9x10{sup -2} to 10.5x10{sup -2} min{sup -1}. This indicates that the antibacterial activity of silver nanorods can be enhanced by applying an electric field, for application in medical and food-preserving fields.

  17. Directed Nanorod Assembly Using Block Copolymer-Based Supramolecules

    Science.gov (United States)

    Thorkelsson, Kari; Mastroianni, Alexander; Ercius, Peter; Xu, Ting

    2013-03-01

    Nanorods display many unique electrical, mechanical, and optical properties unavailable in traditional bulk materials, and are attractive building blocks toward functional materials. The collective properties of anisotropic building blocks often depend strongly on their spatial arrangements, interparticle ordering, and macroscopic alignment. We have systematically investigated the phase behavior of nanocomposites composed of nanorods and block copolymer (BCP)-based supramolecules forming spherical, cylindrical and lamellar morphologies. Initial exploration showed that the nanorods can be readily dispersed in polymeric matrix and the overall morphology of nanorod-containing supramolecular nanocomposite depends on the nanorod-polymer interactions, inter-rod interactions and entropy associated with polymer chain deformation. The energetic contributions from the components of the system can be tailored to disperse nanorods with control over inter-rod ordering and the alignment of nanorods within BCP microdomains. By varying the supramolecular morphology and composition, arrays, sheets, and interconnected networks of nanorods are demonstrated that may prove useful for fabrication of optically and electrically active nanodevices.

  18. Evaporation induced self-assembly and characterization of gold nanorods

    NARCIS (Netherlands)

    Ahmad, I.

    2015-01-01

    Assembly of nanoparticles into superstructures in suspension and at interfaces exhibits many different and interesting features. In this thesis we present results of different studies into the assembly of gold nanorods. We describe the synthesis of low aspect ratio gold nanorods as used in this thes

  19. Evaporation induced self-assembly and characterization of gold nanorods

    NARCIS (Netherlands)

    Ahmad, Imtiaz

    2015-01-01

    Assembly of nanoparticles into superstructures in suspension and at interfaces exhibits many different and interesting features. In this thesis we present results of different studies into the assembly of gold nanorods. We describe the synthesis of low aspect ratio gold nanorods as used in this thes

  20. Shape-induced separation of nanospheres and aligned nanorods

    NARCIS (Netherlands)

    Ahmad, I.; Zandvliet, H.J.W.; Kooij, E.S.

    2014-01-01

    We studied the phase separation and spatial arrangement of gold nanorods and nanospheres after evaporative self-assembly from aqueous suspension. Depending on the position relative to the contact line of the drying droplet, spheres and rods separate into various liquid-crystalline phases. Nanorods e

  1. Fabrication of ZnO Nanorod Modified Electrode and Its Application to the Direct Electrochemical Determination of Hemoglobin and Cytochrome c

    Institute of Scientific and Technical Information of China (English)

    张成林; 刘梅川; 李平; 鲜跃仲; 程欲晓; 张芬芬; 王晓丽; 金利通

    2005-01-01

    A novel electrochemical method as a sensitive and convenient technique for the determination of heme proteins based on their interaction with ZnO nanorods was developed. A ZnO nanorod modified glassy carbon electrode (ZnO/GCE) was prepared and the electrochemical behaviors of heme proteins, such as hemoglobin (HB) and cytochrome c (Cyt-c), on this modified electrode have been studied. The results showed that both HB and Cyt-c could be oxidized on the modified electrode and the oxidation currents were linear to the concentrations of the analytes in aqueous solutions. In addition, the results of flow injection analysis (FIA) further suggested the high stability and reproducibility of the ZnO nanorod modified electrode. So this method can be applied to the determination of HB and Cyt-c in biological systems.

  2. Synthesis of nanocomposite 2-methyl-4-chlorophenoxyacetic acid with layered double hydroxide: physicochemical characterization and controlled release properties

    Energy Technology Data Exchange (ETDEWEB)

    Sarijo, Siti Halimah, E-mail: izaddinizaddin@yahoo.com; Ghazali, Sheikh Ahmad Izaddin Sheikh Mohd [Faculty of Applied Sciences, Universiti Teknologi MARA (Malaysia); Hussein, Mohd Zobir [Universiti Putra Malaysia, Department of Chemistry, Faculty of Science (Malaysia); Sidek, Norizzah Jaafar [Faculty of Applied Sciences, Universiti Teknologi MARA (Malaysia)

    2013-01-15

    A new organic-inorganic hybrid nanocomposite Zn-Al-MCPA-layered double hydroxide (ZAM) was prepared by intercalation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) into Zn-Al-layered double hydroxide (ZAL) at various concentration of MCPA ranging from 0.1 to 0.7 M. The pH of the synthesis was kept constant at 7.5. Well-ordered hybrid nanocomposite was obtained with 0.4 M MCPA with an expansion of basal spacing from 8.9 Angstrom-Sign in the ZAL to 19.7 Angstrom-Sign in the resulting nanocomposite. The FTIR spectra of the nanocomposite show resemblance peaks of the MCPA and Zn-Al-layered double hydroxide indicating the inclusion of MCPA into the layered double hydroxide. The average particle size of ZAL and ZAM in this study was 115 and 128 nm, respectively. Percentage loading of MCPA was found to be 45.0 % (w/w), calculated based on the percentage of carbon in the sample. The release of MCPA into various aqueous solution was found to be dependent to the anion in the aqueous solution in the order of phosphate > sulfate > chloride with the percentage release of 80, 44, and 8%, respectively. This study shows that Zn-Al-layered double hydroxide can be used as a host carrier for herbicide, MCPA, with controlled release capability.

  3. Synthesis of nanocomposite 2-methyl-4-chlorophenoxyacetic acid with layered double hydroxide: physicochemical characterization and controlled release properties

    Science.gov (United States)

    Sarijo, Siti Halimah; Ghazali, Sheikh Ahmad Izaddin Sheikh Mohd; Hussein, Mohd Zobir; Sidek, Norizzah Jaafar

    2013-01-01

    A new organic-inorganic hybrid nanocomposite Zn-Al-MCPA-layered double hydroxide (ZAM) was prepared by intercalation of 2-methyl-4-chlorophenoxyacetic acid (MCPA) into Zn-Al-layered double hydroxide (ZAL) at various concentration of MCPA ranging from 0.1 to 0.7 M. The pH of the synthesis was kept constant at 7.5. Well-ordered hybrid nanocomposite was obtained with 0.4 M MCPA with an expansion of basal spacing from 8.9 Å in the ZAL to 19.7 Å in the resulting nanocomposite. The FTIR spectra of the nanocomposite show resemblance peaks of the MCPA and Zn-Al-layered double hydroxide indicating the inclusion of MCPA into the layered double hydroxide. The average particle size of ZAL and ZAM in this study was 115 and 128 nm, respectively. Percentage loading of MCPA was found to be 45.0 % (w/w), calculated based on the percentage of carbon in the sample. The release of MCPA into various aqueous solution was found to be dependent to the anion in the aqueous solution in the order of phosphate > sulfate > chloride with the percentage release of 80, 44, and 8 %, respectively. This study shows that Zn-Al-layered double hydroxide can be used as a host carrier for herbicide, MCPA, with controlled release capability.

  4. Enhancing diamond color center fluorescence via optimized plasmonic nanorod configuration

    CERN Document Server

    Szenes, Andras; Szabo, Lorant Zs; Szabo, Gabor; Csendes, Tibor; Csete, Maria

    2016-01-01

    Optimization of nanorod based configurations was realized to enhance fluorescence of NV and SiV color centers in diamond. Comparative study was performed on gold and silver nanorod based configurations optimized to enhance excitation and emission, as well as both phenomena simultaneously. Considerable excitation enhancement is achieved by silver nanorod, while both metals are appropriate to enhance emission. More significant improvement can be realized via silver nanorod at both wavelengths of both color centers. The optimal configuration is determined by preferences corresponding to the emission. Larger emission enhancement is achieved via both metals in case of SiV with respect to the NV center. Gold and silver nanorod based configurations making possible to improve SiV quantum efficiency by factor of 1.18 and 5.25 are proposed.

  5. Fabrication of Syringe-Shaped GaN Nanorods

    Institute of Scientific and Technical Information of China (English)

    XUE Cheng-Shan; CAO Yu-Ping; WU Yu-Xin; ZHUANG Hui-Zhao; TIAN De-Heng; LIU Yi-An; HE Jian-Ting; AI Yu-Jie; SUN Li-Li; WANG Fu-Xue

    2006-01-01

    @@ Syringe-shaped GaN nanorods are synthesized on Si(111) substrates by annealing sputtered Ga2O3/BN films under flowing ammonia at temperature of 950° C. Most of the nanorods consist of a main rod and a top needle, looking like a syringe. X-ray diffraction and selected-area electron diffraction confirm that the syringe-shaped nanorods are hexagonal wurtzite GaN. Scanning electron microscopy and high-resolution transmission electron microscopy reveal that these nanorods are as long as several micrometres, with diameters ranging from 100 to 300 nm. In addition to the BN intermediate layer, the proper annealing temperature has been demonstrated to be a crucial factor for the growth of syringe-shaped nanorods by this method.

  6. In Situ Transmission Electron Microscopy of Cadmium Selenide Nanorod Sublimation.

    Science.gov (United States)

    Hellebusch, Daniel J; Manthiram, Karthish; Beberwyck, Brandon J; Alivisatos, A Paul

    2015-02-19

    In situ electron microscopy is used to observe the morphological evolution of cadmium selenide nanorods as they sublime under vacuum at a series of elevated temperatures. Mass loss occurs anisotropically along the nanorod's long axis. At temperatures close to the sublimation threshold, the phase change occurs from both tips of the nanorods and proceeds unevenly with periods of rapid mass loss punctuated by periods of relative stability. At higher temperatures, the nanorods sublime at a faster, more uniform rate, but mass loss occurs from only a single end of the rod. We propose a mechanism that accounts for the observed sublimation behavior based on the terrace-ledge-kink (TLK) model and how the nanorod surface chemical environment influences the kinetic barrier of sublimation.

  7. Synthesis and optical properties of gold nanorods with controllable morphology

    Science.gov (United States)

    Ye, Tianyu; Dai, Zhigao; Mei, Fei; Zhang, Xingang; Zhou, Yuanming; Xu, Jinxia; Wu, Wei; Xiao, Xiangheng; Jiang, Changzhong

    2016-11-01

    Searching for architectural building blocks with tunable morphology and peculiarity is a prominent challenge for novel diagnostic and therapeutic applications. Here, the aqueous-based seed-mediated methods for preparing highly mono-dispersed Au nanorods with a different aspect ratio are systematically studied by controlling the amounts of Ag ions and seeds. We also explore the effect of pH on the synthesis of gold nanorods. The realization of the overlap of longitudinal plasmon band and excitation source with different degrees is made by changing the aspect ratio of nanorod in order to determine its effect on the overall surface enhancement. In addition, the gold octahedra are prepared by overgrowth on Au nanorods. The SERS effects of Au nanorods are researched and the FDTD simulations are performed to reveal the morphology induced plasmon modes.

  8. Functionalized gold nanorods for tumor imaging and targeted therapy.

    Science.gov (United States)

    Gui, Chen; Cui, Da-Xiang

    2012-12-01

    Gold nanorods, as an emerging noble metal nanomaterial with unique properties, have become the new exciting focus of theoretical and experimental studies in the past few years. The structure and function of gold nanorods, especially their biocompatibility, optical property, and photothermal effects, have been attracting more and more attention. Gold nanorods exhibit great potential in applications such as tumor molecular imaging and photothermal therapy. In this article, we review some of the main advances made over the past few years in the application of gold nanorods in surface functionalization, molecular imaging, and photothermal therapy. We also explore other prospective applications and discuss the corresponding concepts, issues, approaches, and challenges, with the aim of stimulating broader interest in gold nanorod-based nanotechnology and improving its practical application.

  9. Sensing based on the motion of enzyme-modified nanorods

    DEFF Research Database (Denmark)

    Bunea, Ada-Ioana; Pavel, Ileana-Alexandra; David, Sorin;

    2015-01-01

    Asymmetric modification with an enzyme confers nanorods an enhanced diffusive motion that is dependent on the concentration of the enzyme substrate. In turn, such a motion opens the possibility of determining the concentration of the enzyme substrate by measuring the diffusion coefficient...... of nanorods modified with the appropriate enzyme. Nanorods, with a Pt and a polypyrrole (PPy) segment, were fabricated. The PPy segment of such nanorods was then modified with glucose oxidase (GOx), glutamate oxidase (GluOx), or xanthine oxidase (XOD). Calibration curves, linking the diffusion coefficient...... media. Based on the obtained results we are confident that our motion-based approach to sensing can be developed to the point where different nanorods in a mixture simultaneously report on the concentration of different compounds with good temporal and spatial resolution....

  10. Cadmium-Aluminum Layered Double Hydroxide Microspheres for Photocatalytic CO2Reduction

    KAUST Repository

    Saliba, Daniel

    2016-03-30

    We report the synthesis of cadmium-aluminum layered double hydroxide (CdAl LDH) using the reaction-diffusion framework. As the hydroxide anions diffuse into an agar gel matrix containing the mixture of aluminum and cadmium salts at a given ratio, they react to give the LDH. The LDH self-assembles inside the pores of the gel matrix into a unique spherical-porous shaped microstructure. The internal and external morphologies of the particles are studied by electron microscopy and tomography revealing interconnected channels and a high surface area. This material is shown to exhibit a promising performance in the photoreduction of carbon dioxide using solar light. Moreover, the palladium-decorated version shows a significant improvement in its reduction potential at room temperature. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. A Strategy for Hydroxide Exclusion in Nanocrystalline Solid-State Metathesis Products

    Directory of Open Access Journals (Sweden)

    Jiaqi Cheng

    2013-06-01

    Full Text Available We demonstrate a simple strategy to either prevent or enhance hydroxide incorporation in nanocrystalline solid-state metathesis reaction products prepared in ambient environments. As an example, we show that ZnCO3 (smithsonite or Zn5(CO32(OH6 (hydrozincite forms extremely rapidly, in less than two minutes, to form crystalline domains of 11 ±  2 nm and 6 ± 2 nm, respectively. The phase selectivity between these nanocrystalline products is dominated by the alkalinity of the hydrated precursor salts, which may in turn affect the availability of carbon dioxide during the reaction. Thus, unlike traditional aqueous precipitation reactions, our solid-state method offers a way to produce hydroxide-free, nanocrystalline products without active pH control.

  12. Cadmium-Aluminum Layered Double Hydroxide Microspheres for Photocatalytic CO2 Reduction.

    Science.gov (United States)

    Saliba, Daniel; Ezzeddine, Alaa; Sougrat, Rachid; Khashab, Niveen M; Hmadeh, Mohamad; Al-Ghoul, Mazen

    2016-04-21

    We report the synthesis of cadmium-aluminum layered double hydroxide (CdAl LDH) using the reaction-diffusion framework. As the hydroxide anions diffuse into an agar gel matrix containing the mixture of aluminum and cadmium salts at a given ratio, they react to give the LDH. The LDH self-assembles inside the pores of the gel matrix into a unique spherical-porous shaped microstructure. The internal and external morphologies of the particles are studied by electron microscopy and tomography revealing interconnected channels and a high surface area. This material is shown to exhibit a promising performance in the photoreduction of carbon dioxide using solar light. Moreover, the palladium-decorated version shows a significant improvement in its reduction potential at room temperature.

  13. Degradation of l-polylactide during melt processing with layered double hydroxides

    DEFF Research Database (Denmark)

    Gerds, Nathalie; Katiyar, Vimal; Koch, Christian Bender;

    2012-01-01

    PLA was melt compounded in small-scale batches with two forms of laurate-modified magnesium–aluminum layered double hydroxide (Mg-Al-LDH-C12), the corresponding carbonate form (Mg-Al-LDH-CO3) and a series of other additives. Various methods were then adopted to characterize the resulting compounds...... in an effort to gain greater insights into PLA degradation during melt processing. PLA molecular weight reduction was found to vary according to the type of LDH additive. It is considered that the degree of particle dispersion and LDH exfoliation, and hence the accessibility of the hydroxide layer surfaces...... may be active degrading agents. Phosphate treatment of laurate-modified LDH was investigated and this may be a promising way of reducing PLA degradation, thereby making such processes more practically realistic....

  14. Simple synthesis of cobalt sulfide nanorods for efficient electrocatalytic oxidation of vanillin in food samples.

    Science.gov (United States)

    Sivakumar, Mani; Sakthivel, Mani; Chen, Shen-Ming

    2017-03-15

    Well-defined CoS nanorods (NR) were synthesized using a simple hydrothermal method, and were tested as an electrode material for electro-oxidation of vanillin. The NR material was characterized with regard to morphology, crystallinity, and electro-activity by use of appropriate analytical techniques. The resulting CoS NR@Nafion modified glassy carbon electrode (GCE) exhibited efficient electro-oxidation of vanillin with a considerable linear range of current-vs-concentration (0.5-56μM vanillin) and a detection limit of 0.07μM. Also, food samples containing vanillin were studied to test suitability for commercial applications.

  15. Hybrid artificial pinning centers of elongated-nanorods and segmented-nanorods in YBa2Cu3O7 films

    Science.gov (United States)

    Horide, Tomoya; Sakamoto, Nobuhiro; Ichinose, Ataru; Otsubo, Koji; Kitamura, Takanori; Matsumoto, Kaname

    2016-10-01

    To control the anisotropy of critical current density (J c), hybrid artificial pinning centers (APCs) of elongated-nanorods and segmented-nanorods were incorporated into YBa2Cu3O7 films. The elongated-nanorods and segmented-nanorods were formed by fabricating multilayer films using YBa2Cu3O7+BaSnO3 targets with a different BaSnO3 content. According to the elastic calculation, the BaSnO3-free YBa2Cu3O7 regions between BaSnO3 segmented-nanorods were highly strained, resulting in their alignment along the c-axis. Pinning of the vortex kinks and straight vortices by the nanorod ends improved J c in a wide range around B//ab. The angular dependence of J c systematically varied with the multilayer structure of layer thickness and BSO content. J c depended on the layer thickness even with keeping the constant average BSO content, showing that the BaSnO3 distribution, as well as the average BaSnO3 content, affected the J c. The hybrid pinning effect of elongated-nanorods and nanorod ends improved the J c anisotropy although the effect was not so large in the present films. The control of strain and interface is expected to lead to further improvement of J c.

  16. Manganese oxalate nanorods as ballistic modifier for composite solid propellants

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Supriya [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273009, U.P. (India); Chawla, Mohit [School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175005, H.P. (India); Siril, Prem Felix, E-mail: prem@iitmandi.ac.in [School of Basic Sciences, Indian Institute of Technology Mandi, Mandi 175005, H.P. (India); Singh, Gurdip [Department of Chemistry, DDU Gorakhpur University, Gorakhpur 273009, U.P. (India)

    2014-12-10

    Highlights: • Manganese oxalate nanorods were prepared using mild thermal precipitation and aging. • The nanorods were found to be efficient ballistic modifier for solid propellants. • The nanorods sensitized the thermolysis of ammonium perchlorate. • Controlled thermal decomposition of nanorods yielded manganese oxide nanoparticles. • MnO nanoparticles formed insitu in the condensed phase enhance the burning rates. - Abstract: Rod-shaped nanostructures of manganese oxalate (MnC{sub 2}O{sub 4}) were synthesized via mild thermal precipitation and aging process. Chemical composition of the MnC{sub 2}O{sub 4} nanorods was confirmed using Fourier transform infra-red (FTIR) spectroscopy and energy dispersive X-ray spectroscopy (EDS). X-ray diffraction (XRD) and selected area electron diffraction (SAED) studies revealed the crystal structure. Field emission scanning electron microscopy (FE-SEM) imaging and high resolution transmission electron microscopy (HR-TEM) were employed to study the structural features of the nanorods. The MnC{sub 2}O{sub 4} nanorods were found to be efficient ballistic modifier for the burning rate enhancement of composite solid propellants (CSPs). Thermal analysis using TGA-DSC showed that MnC{sub 2}O{sub 4} nanorods sensitized the thermal decomposition of ammonium perchlorate (AP) and the CSPs. Controlled thermal decomposition of the MnC{sub 2}O{sub 4} nanorods resulted in the formation of managanese oxide nanoparticles with mesoporosity. A plausible mechanism for the burning rate enhancement using MnC{sub 2}O{sub 4} nanorods was proposed.

  17. Engineering Gold Nanorod-Based Plasmonic Nanocrystals for Optical Applications

    KAUST Repository

    Huang, Jianfeng

    2015-09-01

    Plasmonic nanocrystals have a unique ability to support localized surface plasmon resonances and exhibit rich and intriguing optical properties. Engineering plasmonic nanocrystals can maximize their potentials for specific applications. In this dissertation, we developed three unprecedented Au nanorod-based plasmonic nanocrystals through rational design of the crystal shape and/or composition, and successfully demonstrated their applications in light condensation, photothermal conversion, and surface-enhanced Raman spectroscopy (SERS). The “Au nanorod-Au nanosphere dimer” nanocrystal was synthesized via the ligand-induced asymmetric growth of a Au nanosphere on a Au nanorod. This dimeric nanostructure features an extraordinary broadband optical absorption in the range of 400‒1400nm, and it proved to be an ideal black-body material for light condensation and an efficient solar-light harvester for photothermal conversion. The “Au nanorod (core) @ AuAg alloy (shell)” nanocrystal was built through the epitaxial growth of homogeneously alloyed AuAg shells on Au nanorods by precisely controlled synthesis. The resulting core-shell structured, bimetallic nanorods integrate the merits of the AuAg alloy with the advantages of anisotropic nanorods, exhibiting strong, stable and tunable surface plasmon resonances that are essential for SERS applications in a corrosive environment. The “high-index faceted Au nanorod (core) @ AuPd alloy (shell)” nanocrystal was produced via site-specific epitaxial growth of AuPd alloyed horns at the ends of Au nanorods. The AuPd alloyed horns are bound with high-index side facets, while the Au nanorod concentrates an intensive electric field at each end. This unique configuration unites highly active catalytic sites with strong SERS sites into a single entity and was demonstrated to be ideal for in situ monitoring of Pd-catalyzed reactions by SERS. The synthetic strategies developed here are promising towards the fabrication of

  18. Enormous enhancement of ZnO nanorod photoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.H.; Duan, W.J. [Department of Physics, Beijing Normal University, Beijing 100875 (China); Wu, Z.L.; Zheng, D. [Analytic and Testing Center, Beijing Normal University, Beijing 100875 (China); Zhou, X.W.; Zhou, B.Y.; Dai, L.J. [Department of Physics, Beijing Normal University, Beijing 100875 (China); Wang, Y.S., E-mail: yswang@bnu.edu.cn [Department of Physics, Beijing Normal University, Beijing 100875 (China)

    2012-08-15

    ZnO nanorod arrays were grown on quartz slices in the aqueous solution of zinc acetate and hexamethylenetetramine at 90 Degree-Sign C. Then ZnO:Mg shells were epitaxially grown on the nanorods to form core/shell structures in the aqueous solution of zinc acetate, magnesium acetate and hexamethylenetetramine at the same temperature. Effects of the shells and UV laser beam irradiation on the crystal structure and photoluminescence properties of ZnO nanorods were studied. ZnO:Mg shells suppress the green emission and enhance the UV emission intensity of the nanorods by 38 times. Enhancement of the UV emission depends on the Mg content in the shells. Short time UV laser beam irradiation could improve ZnO nanorod emission efficiently. The UV emission intensity of ZnO nanorods is enhanced by 71 times by capping and subsequent UV laser beam irradiation. - Highlights: Black-Right-Pointing-Pointer ZnO nanorod arrays were grown on quartz slices in solution at 90 Degree-Sign C. Black-Right-Pointing-Pointer The nanorods were capped by ZnO:Mg layers to form core/shell structures. Black-Right-Pointing-Pointer ZnO:MgO shells suppress the green emission and enhance the UV emission intensity by 38 times. Black-Right-Pointing-Pointer The enhancement depends on the Mg content in the shells. Black-Right-Pointing-Pointer Exposing the nanorods to 325 laser beam improves the UV emission efficiently. Black-Right-Pointing-Pointer Capping and 325 nm laser beam irradiation could enhance the nanorod UV emission intensity by 71 times.

  19. Role of bonding mechanisms during transfer hydrogenation reaction on heterogeneous catalysts of platinum nanoparticles supported on zinc oxide nanorods

    Science.gov (United States)

    Al-Alawi, Reem A.; Laxman, Karthik; Dastgir, Sarim; Dutta, Joydeep

    2016-07-01

    For supported heterogeneous catalysis, the interface between a metal nanoparticle and the support plays an important role. In this work the dependency of the catalytic efficiency on the bonding chemistry of platinum nanoparticles supported on zinc oxide (ZnO) nanorods is studied. Platinum nanoparticles were deposited on ZnO nanorods (ZnO NR) using thermal and photochemical processes and the effects on the size, distribution, density and chemical state of the metal nanoparticles upon the catalytic activities are presented. The obtained results indicate that the bonding at Pt-ZnO interface depends on the deposition scheme which can be utilized to modulate the surface chemistry and thus the activity of the supported catalysts. Additionally, uniform distribution of metal on the catalyst support was observed to be more important than the loading density. It is also found that oxidized platinum Pt(IV) (platinum hydroxide) provided a more suitable surface for enhancing the transfer hydrogenation reaction of cyclohexanone with isopropanol compared to zero valent platinum. Photochemically synthesized ZnO supported nanocatalysts were efficient and potentially viable for upscaling to industrial applications.

  20. Porphyrin coordination polymer nanospheres and nanorods

    Science.gov (United States)

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.

    2012-12-04

    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  1. Porphyrin coordination polymer nanospheres and nanorods

    Science.gov (United States)

    Wang, Zhongchun; Shelnutt, John A.; Medforth, Craig J.

    2013-09-10

    A porphyrin coordination polymer nanostructure comprising a network of pyridyl porphyrin molecules and coordinating metal ions coordinatively bound through the pyridyl groups. In some embodiments, the porphyrins are metalloporphyrins. A variety of nanostructures are formed by the network polymer, including nanospheres, polygonal nanostructures, nanorods, and nanofibers, depending on a variety of factors including coordination metal ion, porphyrin type, metal of the metalloporphyrin, and degree of agitation during nanostructure formation. Reduction of coordinating metal ions may be used to form metal nanoparticles on the coordination polymer nanostructure.

  2. 21 CFR 872.3250 - Calcium hydroxide cavity liner.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a prepared cavity before insertion of restorative material, such as amalgam, to protect the pulp of a...

  3. FIBRED MAGNESIUM HYDROXIDE AND FLAME-RESISTANT POLYENE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The fibred mangesiun hydroxide from the bracite was treated with a surface active agent. The modified fibred magesium hydroxide as f lame-retardant,boric acid, barium stearate, polydimethyl siloxane fluid,vinyltr iethoxysilane as synergists of the flame-retardant were added to polyene resin. The flame-resistance polyene material prepared meets the requirements of EWCZ -6287-1.

  4. Role of Calcium Hydroxide in Endodontics: A Review

    OpenAIRE

    Arun A; Sangameshwar Sajjanshetty; Deepak Jain; Saujanya KP; Mohammed Mustafa; Laxmi Uppin; Mahnoor Kadri

    2012-01-01

    Calcium hydroxide is a multipurpose agent, and there have been an increasing number of indications for its use in endodontics. Some of its indications include inter-appointment intracanal medicaments, endodontic sealers, pulp capping agents, apexification, pulpotomy and weeping canals. The purpose of this article is to review the properties, advantages, disadvantages and various indications for the use of calcium hydroxide in endodontics.

  5. Synthesis, structural and optical properties of ZnO and Ni-doped ZnO hexagonal nanorods by Co-precipitation method.

    Science.gov (United States)

    Raja, K; Ramesh, P S; Geetha, D

    2014-01-01

    Ni doped ZnO (Zn1-xNixO, x=0.0, 0.03, 0.06 and 0.09) nanorods have been synthesized by Co-precipitation method. Zinc acetate dehydrate [Zn(CH3COO)2⋅2H2O], nickel nitrate [Ni(NO3)3⋅6H2O], sodium hydroxide and poly (vinyl pyrrolidone) (PVP) were mixed together. The morphology, optical and microstructure were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy dispersive spectrum (EDS), atomic force microscopy (AFM), UV-DRS spectrum, photoluminescence spectra (PL) and Fourier transformer infrared spectroscopy (FT-IR). The presence of functional groups and chemical bonding is confirmed by FTIR. PL spectra of the Zn1-xNixO systems shows that the shift in near band edge (NBE) UV emission from 321 to 322 nm and a shift in red band (RB) emission from 620 to 631 nm which conforms the substitution of Ni into the ZnO lattice. The investigation conformed that the products were of the wurtzite structure of ZnO. The hexagonal nanorods have edge length 31 nm and thickness of 39 nm. EDS result showed that the amount of Ni in the product is about 9%, these Ni doped hexagonal nanorods exhibits a blue shifts and weak (UV) emission peak, compared with pure ZnO, which may be induced by the Ni-doping different concentrations 0.0, 0.3, 0.6 and 0.9 M. The growth mechanism of the doped hexagonal nanorods was also discussed.

  6. Optical properties of gold nanorods: DDA simulations supported by experiments.

    Science.gov (United States)

    Brioude, A; Jiang, X C; Pileni, M P

    2005-07-14

    Simulations of the absorption efficiency using the discrete dipole approximation (DDA) method and taking into account the real shape of gold nanorods are reported. A dominant surface plasma band corresponding to the longitudinal resonance is observed. Its maximum position lambda(max) shifts to the red as the aspect ratio increases. The transversal dipolar and multipolar mode wavelength positions are also discussed. These data are in good agreement with previous theoretical work based on classical electrostatic predictions and assuming that gold nanorods behave as ellipsoidal particles. From the experimental point of view, good agreement with the published data for gold nanorods is obtained.

  7. Electrochemical Synthesis and Absorption Properties of Gold Nanorods

    Institute of Scientific and Technical Information of China (English)

    ZHU Jian; WANG Yong-Chang; YAN Shi-Nong; LU Yi-min

    2003-01-01

    Suspended gold nanorods have been synthesized via an electrochemical methad. The absorption spectrum features show two peaks at 520nm and 650mn, which resttlt from the transverse and longitudinal surface plasmon resonance. The spectra at different growth stages indicate that the absorption peaks split and shift after electrolysis , which correspond to the anisotropy growth of nanorods . The quasi-static calculation results indicate that with increasing the mean aspect ratio of the nanorods, the longer waavelength absorption peak decreases and red shifts obviously, whereas the shorter wavelength absorption peak blue shifts slightly.

  8. Facile Hydrogen Evolution Reaction on WO3Nanorods

    Directory of Open Access Journals (Sweden)

    Rajeswari Janarthanan

    2007-01-01

    Full Text Available AbstractTungsten trioxide nanorods have been generated by the thermal decomposition (450 °C of tetrabutylammonium decatungstate. The synthesized tungsten trioxide (WO3 nanorods have been characterized by XRD, Raman, SEM, TEM, HRTEM and cyclic voltammetry. High resolution transmission electron microscopy and X-ray diffraction analysis showed that the synthesized WO3nanorods are crystalline in nature with monoclinic structure. The electrochemical experiments showed that they constitute a better electrocatalytic system for hydrogen evolution reaction in acid medium compared to their bulk counterpart.

  9. Defluoridation from aqueous solutions by granular ferric hydroxide (GFH).

    Science.gov (United States)

    Kumar, Eva; Bhatnagar, Amit; Ji, Minkyu; Jung, Woosik; Lee, Sang-Hun; Kim, Sun-Joon; Lee, Giehyeon; Song, Hocheol; Choi, Jae-Young; Yang, Jung-Seok; Jeon, Byong-Hun

    2009-02-01

    This research was undertaken to evaluate the feasibility of granular ferric hydroxide (GFH) for fluoride removal from aqueous solutions. Batch experiments were performed to study the influence of various experimental parameters such as contact time (1 min-24h), initial fluoride concentration (1-100 mgL(-1)), temperature (10 and 25 degrees C), pH (3-12) and the presence of competing anions on the adsorption of fluoride on GFH. Kinetic data revealed that the uptake rate of fluoride was rapid in the beginning and 95% adsorption was completed within 10 min and equilibrium was achieved within 60 min. The sorption process was well explained with pseudo-first-order and pore diffusion models. The maximum adsorption capacity of GFH for fluoride removal was 7.0 mgg(-1). The adsorption was found to be an endothermic process and data conform to Langmuir model. The optimum fluoride removal was observed between pH ranges of 4-8. The fluoride adsorption was decreased in the presence of phosphate followed by carbonate and sulphate. Results from this study demonstrated potential utility of GFH that could be developed into a viable technology for fluoride removal from drinking water.

  10. Carbon Dioxide Absorbers: An Engaging Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Ticich, Thomas M.

    2011-01-01

    A simple and direct method for measuring the absorption of carbon dioxide by two different substances is described. Lithium hydroxide has been used for decades to remove the gas from enclosed living spaces, such as spacecraft and submarines. The ratio of the mass of carbon dioxide absorbed to the mass of lithium hydroxide used obtained from this…

  11. Carbon Dioxide Absorbers: An Engaging Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Ticich, Thomas M.

    2011-01-01

    A simple and direct method for measuring the absorption of carbon dioxide by two different substances is described. Lithium hydroxide has been used for decades to remove the gas from enclosed living spaces, such as spacecraft and submarines. The ratio of the mass of carbon dioxide absorbed to the mass of lithium hydroxide used obtained from this…

  12. Role of sodium hydroxide in the production of hydrogen gas from the hydrothermal gasification of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Onwudili, Jude A.; Williams, Paul T. [Energy and Resources Research Institute, University of Leeds, Leeds, LS2 9JT (United Kingdom)

    2009-07-15

    The role of sodium hydroxide as a promoter of hydrogen gas production during the hydrothermal gasification of glucose and other biomass samples has been investigated. Experiments were carried out in a batch reactor with glucose and also in the presence of the alkali from 200 C, 2 MPa to 450 C, 34 MPa at constant water loading. Without sodium hydroxide, glucose decomposed to produce mainly carbon dioxide, water, char and tar. Furfural, its derivatives and reaction products dominated the ethyl acetate extract of the water (organic fraction) at lower reaction conditions. This indicated that the dehydration of glucose to yield these products was unfavourable to hydrogen gas production. In the presence of sodium hydroxide however, glucose initially decomposed to form mostly alkylated and hydroxylated carbonyl compounds, whose further decomposition yielded hydrogen gas. It was observed that at 350 C, 21.5 MPa, half of the optimum hydrogen gas yield had formed and at 450 C, 34 MPa, more than 80 volume percent of the gaseous effluent was hydrogen gas, while the balance was hydrocarbon gases, mostly methane ({>=}10 volume percent). Other biomass samples were also comparably reacted at the optimum conditions observed for glucose. The rate of hydrogen production for the biomass samples was in the following order; glucose > cellulose, starch, rice straw > potato > rice husk. (author)

  13. Facile gold nanorod purification by fractionated precipitation

    Science.gov (United States)

    Thai, T.; Zheng, Y.; Ng, S. H.; Ohshima, H.; Altissimo, M.; Bach, U.

    2014-05-01

    An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks.An efficient and facile size- and shape-selective separation of gold nanorod (GNR) solutions is developed using a fractionated precipitation strategy. This convenient method has the benefit of eliminating nanoparticulate side products that can substantially deteriorate the quality of self-assembled nanostructures. The fabrication of advanced plasmonic metamaterials crucially depends on the capacity to supply feedstocks of high-purity building blocks. Electronic supplementary information (ESI) available: Materials and chemicals, methods and Fig. S1-S8 including AFM cross-section analysis, UV-Vis studies and additional SEM images. See DOI: 10.1039/c4nr01592d

  14. A facile self-template strategy for synthesizing 1D porous Ni@C nanorods towards efficient microwave absorption

    Science.gov (United States)

    Zhang, Yanan; Zhang, Xingmiao; Quan, Bin; Ji, Guangbin; Liang, Xiaohui; Liu, Wei; Du, Youwei

    2017-03-01

    Ni@C composites, which simultaneously possess porous, core–shell and 1D nanostructures have been synthesized with a facile self-template strategy. The precursors were obtained by a hydrothermal process using NiCl2 · 6H2O and nitrilotriacetic acid as the starting material and then annealed at 400 °C, 500 °C, and 600 °C. The Ni@C composites annealed at 500 °C display a nanorod feature with a length of ∼3 μm and diameter of 230–500 nm. In addition, about 3 nm carbon shells and 4 nm Ni cores can be found in Ni@C nanorods. Attributed to the interconnected mesoporous texture in nanorods, strengthened interfacial polarization from core–shell structure, and better impedance matching benefiting from a great deal of pores, Ni@C nanorod composites exhibit perfect microwave absorption performance. The minimum reflection loss (RL) value of ‑26.3 dB can be gained at 10.8 GHz with a thickness of 2.3 mm. Moreover, the effective bandwidth (RL ≤ ‑10 dB) can be achieved, 5.2 GHz (12.24–17.4 GHz) under an absorber thickness of 1.8 mm, indicating its great potential in the microwave absorption field. Considering this technique is facile and effective, our study may provide a good reference for the synthesis of 1D carbon-based microwave absorbers with core–shell nanostructure.

  15. Potential application of carbon nanotube core as nanocontainer and nanoreactor for the encapsulated nanomaterial

    Science.gov (United States)

    Tyagi, Pawan K.; Kumari, Reetu; Bhatta, Umananda M.; Juluri, Raghavendra Rao; Rath, Ashutosh; Kumar, Sanjeev; Satyam, P. V.; Gautam, Subodh K.; Singh, Fouran

    2016-07-01

    Fe3C nanorod filled inside carbon nanotube has been irradiated inside transmission electron microscope at both room and high temperature. In-situ response of Fe3C nanorod as well as CNT walls has been studied. It has been found that when electron irradiation is performed at room temperature (RT), nanorod first bends and then tip makes at the end whereas at high temperature (∼490 °C) nanorod slides along the tube axis and then transforms into a faceting particle. Extrusion of solid particle filled in the core of CNT has also been demonstrated. It is suggested that these morphological changes in nanorod may have happened due to the compression which was generated either by shrinkage of tube or by local electron beam heating. Presented results demonstrate that CNT core could be used as nano-container or reactor.

  16. Potential application of carbon nanotube core as nanocontainer and nanoreactor for the encapsulated nanomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Pawan K., E-mail: pawan.phy@dce.edu [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Kumari, Reetu [Department of Applied Physics, Delhi Technological University, Delhi 110042 (India); Bhatta, Umananda M. [Centre for Emerging Technologies, Jain University, Jakkasandra, Kanakapura Taluk, Ramanagaram Dist, Karnataka 562 112 (India); Juluri, Raghavendra Rao; Rath, Ashutosh [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Kumar, Sanjeev [Department of Physics, Rajiv Gandhi University, Itanagar, Arunachal Pradesh 791112 (India); Satyam, P.V. [Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005 (India); Gautam, Subodh K.; Singh, Fouran [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India)

    2016-07-15

    Fe{sub 3}C nanorod filled inside carbon nanotube has been irradiated inside transmission electron microscope at both room and high temperature. In-situ response of Fe{sub 3}C nanorod as well as CNT walls has been studied. It has been found that when electron irradiation is performed at room temperature (RT), nanorod first bends and then tip makes at the end whereas at high temperature (∼490 °C) nanorod slides along the tube axis and then transforms into a faceting particle. Extrusion of solid particle filled in the core of CNT has also been demonstrated. It is suggested that these morphological changes in nanorod may have happened due to the compression which was generated either by shrinkage of tube or by local electron beam heating. Presented results demonstrate that CNT core could be used as nano-container or reactor.

  17. Laser fabrication of Au nanorod aggregates microstructures assisted by two-photon polymerization.

    Science.gov (United States)

    Masui, Kyoko; Shoji, Satoru; Asaba, Kenji; Rodgers, Thomas C; Jin, Feng; Duan, Xuan-Ming; Kawata, Satoshi

    2011-11-07

    We demonstrate fabrication of Au nanorod aggregates microstructures by means of a femtosecond near-infrared laser. The laser light was tightly focused into colloidal Au nanorods dispersed in photopolymerizable metyl-methacrylate (MMA) compound to induce two-photon polymerization (TPP). TPP of MMA glued the nanorods together to form solid microstrucures of aggregates. The laser light excited a local surface plasmon, resulting in confinement of TPP in the vicinity of nanorods. Concurrenly occurring optical accumulation of nanorods created a unique mechanism for the formation of nanorod aggregates into desired microstructures. This technique would be a clue for a novel micro/nanofabrication method for plasmonic materials and devices.

  18. Diameter Control and Photoluminescence of ZnO Nanorods from Trialkylamines

    Directory of Open Access Journals (Sweden)

    Tamar Andelman

    2007-01-01

    Full Text Available A novel solution method to control the diameter of ZnO nanorods is reported. Small diameter (2-3 nm nanorods were synthesized from trihexylamine, and large diameter (50–80 nm nanorods were synthesized by increasing the alkyl chain length to tridodecylamine. The defect (green emission of the photoluminescence (PL spectra of the nanorods varies with diameter, and can thus be controlled by the diameter control. The small ZnO nanorods have strong green emission, while the large diameter nanorods exhibit a remarkably suppressed green band. We show that this observation supports surface oxygen vacancies as the defect that gives rise to the green emission.

  19. Direct decarbonation of micrometer-scale layered double hydroxides without morphology damage

    Institute of Scientific and Technical Information of China (English)

    Kong Li Xu; Guang Ming Chen; Jian Quan Shen

    2012-01-01

    A direct decarbonation route without obvious morphology damage was developed for large micrometer-scale layered double hydroxides (LDHs).First,we synthesized pure,hexagonal-shaped LDHs with lateral dimension of micrometer-size by the recently reported urea hydrolysis method.Then,using HNO3-NaNO3 mixed solution,the obtained LDH with carbonate anions in the interlayer (LDH_CO3) was directly decarbonated to its nitrate form,LDH_NO3,its morphology and particle size were still unchanged.Compared with the recently published two-step decarbonation method,the direct decarbonation reported herein is very convenient.

  20. Synthesis and characterization of silver molybdate nanowires, nanorods and multipods

    Indian Academy of Sciences (India)

    G Nagaraju; G T Chandrappa; Jacques Livage

    2008-06-01

    Silver molybdate nanowires, nanorods and multipods like structures have been prepared by an organic free hydrothermal process using ammonium molybdate and silver nitrate solutions. The powder X-ray diffraction (PXRD) patterns reveal that the silver molybdate belongs to anorthic structure. The thickness, 200–500 nm, for silver molybdate nanorods/wires and 2–5 m for microrods are identified from SEM images. UV-visible spectrum of silver molybdate nanorods/nanowires shows maximum absorbance at 408 nm. Photoluminescence (PL) spectrum exhibits UV emission at 335 nm, violet emission at 408 nm and a weak green emission at 540 nm. The influence of hydrothermal synthesis conditions on silver molybdate nanowires, nanorods and multipods compositions were established.

  1. Novel nanorods based on PANI / PEO polymers using electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hazeem, Nabeel Z., E-mail: nabeelnano333@gmail.com [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Ministry of Education, the General Directorate for Educational Anbar (Iraq); Ahmed, Naser M.; Matjafri, M. Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Sabah, Fayroz A. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Department of Electrical Engineering, College of Engineering, Al-Mustansiriya University, Baghdad (Iraq); Rasheed, Hiba S. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Department of Physics, College of Education, Al-Mustansiriya University, Baghdad (Iraq)

    2016-07-06

    In this work, we fabricated nanorods by applying an electric potential on poly (ethylene oxide) (PEO) and polyaniline (PANI) as a polymeric solution by electrospinning method. Testing was conducted on the samples by field emission scanning Electron microscope (FE-SEM), X-ray diffraction (XRD) and Photoluminescence. And the results showed the emergence of nanorods in the sample within glass substrate. Diameters of nanorods have ranged between (52.78-122.40)nm And a length of between (1.15 – 1.32)μm. The emergence of so the results are for the first time, never before was the fabrication of nanorods for polymers using the same method used in this research.

  2. Biodegradation-tunable mesoporous silica nanorods for controlled drug delivery.

    Science.gov (United States)

    Park, Sung Bum; Joo, Young-Ho; Kim, Hyunryung; Ryu, WonHyoung; Park, Yong-il

    2015-05-01

    Mesoporous silica in the forms of micro- or nanoparticles showed great potentials in the field of controlled drug delivery. However, for precision control of drug release from mesoporous silica-based delivery systems, it is critical to control the rate of biodegradation. Thus, in this study, we demonstrate a simple and robust method to fabricate "biodegradation-tunable" mesoporous silica nanorods based on capillary wetting of anodic aluminum oxide (AAO) template with an aqueous alkoxide precursor solution. The porosity and nanostructure of silica nanorods were conveniently controlled by adjusting the water/alkoxide molar ratio of precursor solutions, heat-treatment temperature, and Na addition. The porosity and biodegradation kinetics of the fabricated mesoporous nanorods were analyzed using N2 adsorption/desorption isotherm, TGA, DTA, and XRD. Finally, the performance of the mesoporous silica nanorods as drug delivery carrier was demonstrated with initial burst and subsequent "zero-order" release of anti-cancer drug, doxorubicin.

  3. Atomic-force microscopy investigations of semiconductor nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Teichert, C. [Institute of Physics, University of Leoben (Austria); Brauer, G. [Institut f. Ionenstrahlphysik und Materialforschung, Forschungszentrum Rossendorf (Germany); Djurisic, A. [Department of Physics, University of Hong Kong (China); Sivakov, V.; Scholz, R. [Max Planck Institute of Microstructure Physics, Halle (Germany); Andrae, G. [Institute of Physical High Technology (IPHT), Jena (Germany); Christiansen, S.H. [Physics Department, Martin-Luther-University Halle-Wittenberg (Germany)

    2007-07-01

    One-dimensional nanostructures, such as nanorods or nanotubes, exhibit technological potential for many device applications like electronic, photonic or sensing devices. However, achieving control on the growth of such nanostructures leading to proper dimensional confinement (nanorods diameter, length, density and orientation) is still a challenging task. So far, scanning electron microscopy and transmission electron microscopy are the methods of choice to characterize arrays of free standing semiconductor nanowires. Atomic force microscopy - at a first glance - might not be suited for such a task. Analyzing arrays of vertical ZnO nanorods grown on Si and ITO substrates and individual Si nanowhiskers grown by electron beam evaporation on Si(111), we demonstrate the capabilities of atomic-force microscopy to yield integral information for example on the height variation of the nanorod arrays as well as detailed information on the facet structure of the nanowhiskers.

  4. Two-photon excited ultraviolet photoluminescence of zinc oxide nanorods.

    Science.gov (United States)

    Zhu, Guangping; Xu, Chunxiang; Zhu, Jing; Lu, Changgui; Cui, Yiping; Sun, Xiaowei

    2008-11-01

    High density zinc oxide nanorods with uniform size were synthesized on (100) silicon substrate by vapor-phase transport method. The scanning electron microscopy images reveal that the nanorods have an average diameter of about 400 nm. The X-ray diffraction pattern demonstrates the wurtzite crystalline structure of the ZnO nanorods growing along [0001] direction. The single-photon excited photoluminescence presents a strong ultraviolet emission band at 394 nm and a weak visible emission band at 600 nm. When the ZnO nanorods were respectively pumped by various wavelength lasers from 520 nm to 700 nm, two-photon excited ultraviolet photoluminescence was observed. The dependence of the two-photon excited photoluminescence intensity on the excitation wavelength and power was investigated in detail.

  5. Novel nanorods based on PANI / PEO polymers using electrospinning method

    Science.gov (United States)

    Al-Hazeem, Nabeel Z.; Ahmed, Naser M.; Matjafri, M. Z.; Sabah, Fayroz A.; Rasheed, Hiba S.

    2016-07-01

    In this work, we fabricated nanorods by applying an electric potential on poly (ethylene oxide) (PEO) and polyaniline (PANI) as a polymeric solution by electrospinning method. Testing was conducted on the samples by field emission scanning Electron microscope (FE-SEM), X-ray diffraction (XRD) and Photoluminescence. And the results showed the emergence of nanorods in the sample within glass substrate. Diameters of nanorods have ranged between (52.78-122.40)nm And a length of between (1.15 - 1.32)μm. The emergence of so the results are for the first time, never before was the fabrication of nanorods for polymers using the same method used in this research.

  6. Adsorption of Organophosphate Pesticide Dimethoate on Gold Nanospheres and Nanorods

    Directory of Open Access Journals (Sweden)

    Tatjana Momić

    2016-01-01

    Full Text Available Organophosphorus pesticide dimethoate was adsorbed onto gold nanospheres and nanorods in aqueous solution using batch technique. Adsorption of dimethoate onto gold nanoparticles was confirmed by UV-Vis spectrophotometry, TEM, AFM, and FTIR analysis. The adsorption of nanospheres resulted in aggregation which was not the case with nanorods. Nanoparticles adsorption features were characterized using Langmuir and Freundlich isotherm models. The Langmuir adsorption isotherm was found to have the best fit to the experimental data for both types of nanoparticles. Adsorption capacity detected for nanospheres is 456 mg/g and for nanorods is 57.1 mg/g. Also, nanoparticles were successfully used for dimethoate removal from spiked drinking water while nanospheres were shown to be more efficient than nanorods.

  7. Shape-induced separation of nanospheres and aligned nanorods.

    Science.gov (United States)

    Ahmad, I; Zandvliet, H J W; Kooij, E S

    2014-07-15

    We studied the phase separation and spatial arrangement of gold nanorods and nanospheres after evaporative self-assembly from aqueous suspension. Depending on the position relative to the contact line of the drying droplet, spheres and rods separate into various liquid-crystalline phases. Nanorods exhibit a strong preference for side-by-side alignment, giving rise to smectic phases; spheres in solution are forced out of these regions and form close-packed arrays. We discuss this self-separation into nanorod- and sphere-rich phases in terms of various interactions, including electrostatic, van der Waals, and deplection interactions forces. The experimental results are compared to quantitative calculations of the colloidal interaction energies. We also describe and discuss the role of the surfactant on the different crystal facets of the nanorods on the assembly process.

  8. Electrical, optical and dielectric properties of HCl doped polyaniline nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Chutia, P.; Kumar, A., E-mail: ask@tezu.ernet.in

    2014-03-01

    In this report we have investigated the optical, electrical and dielectric properties of HCl doped polyaniline nanorods synthesized by the interfacial polymerization technique. High resolution transmission electron microscope (HRTEM) micrographs confirm the formation of nanorods. X-ray diffraction pattern shows the semicrystalline nature of polyaniline nanorods with a diameter distribution in the range of 10–22 nm. The chemical and electronic structures of the polyaniline nanorods are investigated by micro-Raman and UV–vis spectroscopy. Dielectric relaxation spectroscopy has been applied to study the dielectric permittivity, modulus formalism and ac conductivity as a function of frequency and temperature. The ac conductivity follows a power law with frequency. The variation of frequency exponent with temperature suggests that the correlated barrier hopping is the dominant charge transport mechanism. The existence of both polaron and bipolaron in the transport mechanism has been confirmed from the binding energy calculations.

  9. Low-Temperature Synthesis and Thermodynamic and Electrical Properties of Barium Titanate Nanorods

    Directory of Open Access Journals (Sweden)

    Florentina Maxim

    2015-01-01

    Full Text Available Studies regarding the morphology dependence of the perovskite-type oxides functional materials properties are of recent interest. With this aim, nanorods (NRs and nanocubes (NCs of barium titanate (BaTiO3 have been successfully synthesized via a hydrothermal route at temperature as low as 408 K, employing barium acetate, titanium isopropoxide, and sodium hydroxide as reagents without any surfactant or template. Scanning electron microscopy (SEM, transmission electron microscopy (TEM, and X-ray powder diffraction (XRD, used for the morphology and structure analyses, showed that the NRs were formed by an oriented attachment of the NCs building-blocks with 20 nm average crystallites size. The thermodynamic properties represented by the relative partial molar free energies, enthalpies, and entropies of the oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressure of oxygen, indicated that NRs powders have lower oxygen vacancies concentration than the NCs. This NRs characteristic, together with higher tetragonallity of the structure, leads to the enhancement of the dielectric properties of BaTiO3 ceramics. The results presented in this work show indubitably the importance of the nanopowders morphology on the material properties.

  10. Gold nanorods and nanospheroids for enhancing spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, A [Department of Physics, Persian Gulf University, 75196 Bushehr (Iran, Islamic Republic of); Sandoghdar, V; Agio, M [Laboratory of Physical Chemistry, ETH Zurich, 8093 Zurich (Switzerland)], E-mail: mario.agio@phys.chem.ethz.ch

    2008-10-15

    We compute the radiative decay rate and the quantum efficiency for an emitter coupled to gold nanorods and nanospheroids using the body-of-revolution finite-difference time-domain method. We study these quantities as a function of the nanoparticle aspect ratio and volume, showing that large enhancements can be achieved with realistic parameters. Moreover, we find that nanospheroids exhibit better performances than nanorods for applications in the visible and near-infrared spectral range.

  11. GaN nanorods coated with pure BN

    Science.gov (United States)

    Han, Wei-Qiang; Zettl, A.

    2002-12-01

    We report a method to efficiently synthesize gallium nitride (GaN) nanorods coated with insulating boron nitride (BN) layers. The GaN core is crystalline (with either a cubic zincblende or hexagonal wurtzite structure) and has diameters ranging from 10 to 85 nm and lengths up to 60 μm. The outer encapsulating BN shells with typical thicknesses less than 5 nm extend fully over, and adhere well to, the entire nanorod surface.

  12. Adsorption of Organophosphate Pesticide Dimethoate on Gold Nanospheres and Nanorods

    OpenAIRE

    Tatjana Momić; Tamara Lazarević Pašti; Una Bogdanović; Vesna Vodnik; Ana Mraković; Zlatko Rakočević; Pavlović, Vladimir B.; Vesna Vasić

    2016-01-01

    Organophosphorus pesticide dimethoate was adsorbed onto gold nanospheres and nanorods in aqueous solution using batch technique. Adsorption of dimethoate onto gold nanoparticles was confirmed by UV-Vis spectrophotometry, TEM, AFM, and FTIR analysis. The adsorption of nanospheres resulted in aggregation which was not the case with nanorods. Nanoparticles adsorption features were characterized using Langmuir and Freundlich isotherm models. The Langmuir adsorption isotherm was found to have the ...

  13. Fabrication, Conductive Properties and Photocatalytic Application of Silver Nanorods

    Science.gov (United States)

    Chen, Yi-Hsun; Liu, Pai-Chung; Lin, C. B.

    2017-07-01

    This study proposes a process for fabricating silver nanorods used in conductive circuits and photocatalytic applications. In this process, UV-irradiated silver chloride nanoparticles are added to ethylene glycol solution containing polyvinyl pyrrolidone (PVP) and silver nitrate at 120 °C. With the seed crystal synthesis method, this process yielded a solution containing silver nanowires with an aspect ratio (AR) of approximately 1055 after 12 h. Aluminum foam was then placed in this solution, and the solution was stirred using a magnetic stirrer at 400 rpm. After 4 days, this process yielded a solution of silver nanorods with an AR of approximately 130. After completely washing away any PVP on the surface of the silver nanorods, a conductive ethanol ink containing 25 wt.% silver nanorods was prepared, and a conductive layer approximately 3 μm thick was applied on a glass slide. Measurements obtained using a four-point probe indicated that this layer had a sheet resistance of approximately 0.012 Ω/sq. Furthermore, a conductive ethanol ink containing 26 wt.% silver nanorods was used in a pen to draw conductive circuits on Bristol board and matte paper; the resulting sheet resistances were 132 and 0.018 Ω/sq, respectively. Finally, a visible-light-responsive photocatalyst consisting of silver nanorods dispersed over the Ag@AgCl film (Ag@AgCl/Ag nanorods; AR = 25) was synthesized through heterogeneous precipitation. The photocatalytic activity of the Ag@AgCl film can be further improved by the addition of silver nanorods.

  14. Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation.

    Science.gov (United States)

    Bhat, Pooja B; Inam, Fawad; Bhat, Badekai Ramachandra

    2014-08-11

    A magnetically separable, active nickel hydroxide (Brønsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g(-1) has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields.

  15. HYDROGEN PEROXIDE BLEACHING OF CMP PULP USING MAGNESIUM HYDROXIDE

    Directory of Open Access Journals (Sweden)

    Farhad Zeinaly

    2009-11-01

    Full Text Available Conventional bleaching of hardwood CMP pulp with magnesium hydroxide (Mg(OH2 show significant benefits over bleaching with sodium hydroxide (NaOH under various conditions. Magnesium hydroxide bleaching generate higher optical properties, higher pulp yield and lower effluent COD at the same chemical charge, but the physical properties were found to be similar for both processes. The initial freeness of the bleached pulps and refining value to reach a target freeness (about 350 ml. CSF were more for the Mg(OH2-based process. The residual peroxide of filtrate from the Mg(OH2-based process was very high as compared to conventional bleaching.

  16. Synthesis and characterization of metal (Core) - layered double hydroxide (Shell) nanostructures

    Science.gov (United States)

    Noh, Woo C.

    Layered double hydroxides (LDH) which belong to a class of inorganic ceramic layered materials have been studied since the mid-19th century for a variety of applications including catalysis, anion exchange, adsorbents and antacid, but more recently as a potential drug and gene delivery platform. Drug delivery platforms based on nano-sized geometries are nanovectors which promise a revolutionary impact on the therapy and imaging of various types of cancers and diseases. To date, various polymeric platforms have been the focus of intense research, but the development of inorganic, bio-hybrid nanoparticles for therapeutics and molecular imaging are at a stage of infancy. The hybridization of LDH with bioactive agents or the fabrication of metal (Core)---LDH (Shell) nanostructures could have many beneficial effects including multimodality, active targetability, and efficacy. For example, Core---Shell nanostructures may be designed to have a high scattering optical cross-section for imaging, but may also be tailored to strongly absorb near infrared (NIR) light for hyperthermic ablation. The central theme of this thesis was to demonstrate proof-of-concept of spherical silver and gold metal (Core)---LDH (Shell) nanostructures that have uniform size distribution and are agglomeration free. The effects of processing parameters on the characteristics of LDH as well as LDH-coated spherical metal (Ag, Au) nanoparticles have been evaluated using X-ray Diffraction, Dynamic Light Scattering, Scanning Electron Microscopy, Transmission Electron Microscopy, Rutherford Backscattering Spectrometry, and Inductively Coupled Plasma Emission Spectrometry to arrive at appropriate process windows. The core---shell nanostructures were also characterized for their optical properties in the ultra---violet---visible region, and the data were compared with simulated data, computed by using a quasi static model from Mie scattering theory. Moreover, in order to achieve a strong plasmon resonance

  17. Selective Facet Reactivity During Cation Exchange in Cadmium Sulfide Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Sadtler, Bryce; Demchenko, Denis; Zheng, Haimei; Hughes, Steven; Merkle, Maxwell; Dahmen, Ulrich; Wang, Lin-Wang; Alivisatos, A. Paul

    2008-12-18

    The partial transformation of ionic nanocrystals through cation exchange has been used to synthesize nanocrystal heterostructures. We demonstrate that the selectivity for cation exchange to take place at different facets of the nanocrystal plays an important role in determining the resulting morphology of the binary heterostructure. In the case of copper I (Cu+) cation exchange in cadmium sulfide (CdS) nanorods, the reaction starts preferentially at the ends of the nanorods such that copper sulfide (Cu2S) grows inwards from either end. The resulting morphology is very different from the striped pattern obtained in our previous studies of silver I (Ag+) exchange in CdS nanorods where non-selective nucleation of silver sulfide (Ag2S) occurs. From interface formation energies calculated for several models of epitaxialconnections between CdS and Cu2S or Ag2S, we infer the relative stability of each interface during the nucleation and growth of Cu2S or Ag2S within the CdS nanorods. The epitaxial connections of Cu2S to the end facets of CdS nanorods minimize the formation energy, making these interfaces stable throughout the exchange reaction. However, as the two end facets of wurtzite CdS nanorods are crystallographically nonequivalent, asymmetric heterostructures can be produced.

  18. Synthesis and Tribological Properties of WSe2Nanorods

    Directory of Open Access Journals (Sweden)

    Yang Jinghai

    2008-01-01

    Full Text Available Abstract The WSe2nanorods were synthesized via solid-state reaction method and characterized by X-ray diffractometer, TEM, and HRTEM. The results indicated the WSe2compounds had rod-like structures with diameters of 10–50 nm and lengths of 100–400 nm, and the growth process of WSe2nanorods was discussed on the basis of the experimental facts. The tribological properties of WSe2nanorods as additives in HVI500 base oil were investigated by UMT-2 multispecimen tribotester. Under the determinate conditions, the friction coefficient of the base oil containing WSe2nanorods was lower than that of the base oil, and decreased with increasing mass fraction of WSe2nanorods when it was <7 wt.%. Moreover, the base oil with the additives was rather suited to high load and high rotating speed. A combination of rolling friction, sliding friction, and stable tribofilm on the rubbing surface could explain the good friction and wear properties of WSe2nanorods as additives.

  19. Alignment of gold nanorods by angular photothermal depletion

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Adam B.; Chow, Timothy T. Y.; Chon, James W. M., E-mail: jchon@swin.edu.au [Centre for Micro-Photonics, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, P.O. Box 218, Hawthorn, 3122 VIC (Australia)

    2014-02-24

    In this paper, we demonstrate that a high degree of alignment can be imposed upon randomly oriented gold nanorod films by angular photothermal depletion with linearly polarized laser irradiation. The photothermal reshaping of gold nanorods is observed to follow quadratic melting model rather than the threshold melting model, which distorts the angular and spectral hole created on 2D distribution map of nanorods to be an open crater shape. We have accounted these observations to the alignment procedures and demonstrated good agreement between experiment and simulations. The use of multiple laser depletion wavelengths allowed alignment criteria over a large range of aspect ratios, achieving 80% of the rods in the target angular range. We extend the technique to demonstrate post-alignment in a multilayer of randomly oriented gold nanorod films, with arbitrary control of alignment shown across the layers. Photothermal angular depletion alignment of gold nanorods is a simple, promising post-alignment method for creating future 3D or multilayer plasmonic nanorod based devices and structures.

  20. Development of functional gold nanorods for bioimaging and photothermal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Niidome, T, E-mail: niidome.takuro.655@m.kyushu-u.ac.j [Faculty of Engineering, Kyushu University, Fukuoka 819-0395 (Japan) and Center for Future Chemistry, Kyushu University, Fukuoka 819-0395 (Japan) and PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012 (Japan)

    2010-06-01

    Gold nanorods have strong surface plasmon band at near-infrared light region, and are used as a photothermal converter. Since the near-infrared light penetrates into tissues deeply, it has been expected as a contrast agent for near infrared light bioimaging, a photosensitizer for photothermal therapy, and functional device for drug delivery system responding to near-infrared light irradiation. In this study, the surface plasmon bands of intravenously injected gold nanorods were monitored in the mouse abdomen using a spectrophotometer equipped with an integrating sphere, then we determined pharmacokinetics parameters of the gold nanorods after intravenous injection. Next, the PEG-modified gold nanorods were directly injected into subcutaneous tumors in mice, then, near-infrared pulsed laser light was irradiated the tumors. Significant tumor damage and suppression of the tumor growth was observed. We constructed targeted delivery system of the gold nanorods by modifying with a thermo-responsive polymer and a peptide responding to a protease activity. These modified gold nanorods are expected as functional nanodevices for photothermal therapy and drug delivery system.

  1. Preparation and characterization of dye-sensitized TiO{sub 2} nanorod solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Lijian, E-mail: ljm@isep.ipp.pt [Departamento de Física, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto (Portugal); Centro de Física, Universidade do Minho, 4800-058 Guimarães (Portugal); Chen, Hong [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, fine Mechanics and Physics of Chinese Academy of Science, Changchun 130033 (China); Li, Can [State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023,China (China); Santos, M.P. dos [CEFITEC, Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Departamento de Física, Escola de Ciências e Tecnologia, Universidade de Évora (Portugal)

    2015-02-27

    TiO{sub 2} nanorods were prepared by DC reactive magnetron sputtering technique and applied to dye-sensitized solar cells (DSSCs). The length of the TiO{sub 2} nanorods was varied from 1 μm to 6 μm. The scanning electron microscopy images show that the nanorods are perpendicular to the substrate. Both the X-ray diffraction patterns and Raman scattering results show that the nanorods have an anatase phase; no other phase has been observed. (101) and the (220) diffraction peaks have been observed for the TiO{sub 2} nanorods. The (101) diffraction peak intensity remained constant despite the increase of nanorod length, while the intensity of the (220) diffraction peak increased almost linearly with the nanorod length. These nanorods were used as the working electrodes in DSSCs and the effect of the nanorod length on the conversion efficiency has been studied. An optimum photoelectric conversion efficiency of 4.8% has been achieved for 4 μm length nanorods. - Highlights: • [110] oriented TiO{sub 2} nanorods were deposited on ITO substrate by dc reactive magnetron sputtering. • The structural properties of these nanorods have been studied. • The (110) texture is dominated by strain energy minimization. • DSSCs were assembled using these nanorods as electrode.

  2. Water structuring and hydroxide ion binding at the interface between water and hydrophobic Walls of varying rigidity and van der Waals interactions

    NARCIS (Netherlands)

    Vacha, Robert; Zangi, Ronen; Engberts, Jan B. F. N.; Jungwirth, Pavel

    2008-01-01

    The interfacial behavior of hydroxide ions has been investigated by means of molecular dynamics simulations of aqueous KOH solutions between hydrophobic carbon-like walls. In agreement with previous calculations, we show that a rigid, attractive wall strongly structures water molecules in neighborin

  3. Homogeneous Precipitation of Nickel Hydroxide Powders

    Energy Technology Data Exchange (ETDEWEB)

    Bora Mavis

    2003-12-12

    Precipitation and characterization of nickel hydroxide powders were investigated. A comprehensive precipitation model incorporating the metal ion hydrolysis, complexation and precipitation reactions was developed for the production of the powders with urea precipitation method. Model predictions on Ni{sup 2+} precipitation rate were confirmed with precipitation experiments carried out at 90 C. Experimental data and model predictions were in remarkable agreement. Uncertainty in the solubility product data of nickel hydroxides was found to be the large contributor to the error. There were demonstrable compositional variations across the particle cross-sections and the growth mechanism was determined to be the aggregation of primary crystallites. This implied that there is a change in the intercalate chemistry of the primary crystallites with digestion time. Predicted changes in the concentrations of simple and complex ions in the solution support the proposed mechanism. The comprehensive set of hydrolysis reactions used in the model described above allows the investigation of other systems provided that accurate reaction constants are available. the fact that transition metal ions like Ni{sup 2+} form strong complexes with ammonia presents a challenge in the full recovery of the Ni{sup 2+}. On the other hand, presence of Al{sup 3+} facilitates the complete precipitation of Ni{sup 2+} in about 3 hours of digestion. A challenge in their predictive modeling studies had been the fact that simultaneous incorporation of more than one metal ion necessitates a different approach than just using the equilibrium constants of hydrolysis, complexation and precipitation reactions. Another limitation of using equilibrium constants is that the nucleation stage of digestion, which is controlled mainly by kinetics, is not fully justified. A new program released by IBM Almaden Research Center (Chemical Kinetics Simulator{trademark}, Version 1.01) lets the user change the order of

  4. Carbon fuel particles used in direct carbon conversion fuel cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  5. Carbon Dioxide Removal via Passive Thermal Approaches

    Science.gov (United States)

    Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  6. Hydroxide-Assisted Bonding of Ultra-Low-Expansion Glass

    Science.gov (United States)

    Abramovici, Alexander; White, Victor

    2008-01-01

    A process for hydroxide-assisted bonding has been developed as a means of joining optical components made of ultra-low-expansion (ULE) glass, while maintaining sufficiently precise alignment between. The process is intended mainly for use in applications in which (1) bonding of glass optical components by use of epoxy does not enable attainment of the required accuracy and dimensional stability and (2) conventional optical contacting (which affords the required accuracy and stability) does not afford adequate bond strength. The basic concept of hydroxide-assisted bonding is not new. The development of the present process was prompted by two considerations: (1) The expertise in hydroxide-assisted bonding has resided in very few places and the experts have not been willing to reveal the details of their processes and (2) data on the reliability and strength attainable by hydroxide-assisted bonding have been scarce.

  7. Tertiary dentinogenesis with calcium hydroxide: a review of proposed mechanisms.

    Science.gov (United States)

    Sangwan, P; Sangwan, A; Duhan, J; Rohilla, A

    2013-01-01

    Calcium hydroxide has been used extensively in dentistry for a century. Despite its widespread use as a pulp-capping agent, its mechanisms of action still remain ambiguous. Understanding its modes of action will lead to a broader understanding of the mechanisms associated with induced dentinogenesis and help in optimizing the currently available agents to target specific regenerative processes to obtain the best possible clinical outcomes. A literature search relating to mechanisms of dentinogenesis of calcium hydroxide up to December 2011 was carried out using pubmed and MEDLINE database searches as well as manual searching of cross-references from identified studies. Resulting suggestions regarding dentinogenic mechanisms of calcium hydroxide range from direct irritating action of the material to induction of release of biologically active molecules. The purpose of this article is to discuss various mechanisms through which calcium hydroxide may induce tertiary dentinogenesis in the light of observations made in included studies.

  8. USING COLLOIDAL LAYERED DOUBLE HYDROXIDES AS CATIONICMICROPARTICULATE COMPONENT

    Institute of Scientific and Technical Information of China (English)

    SonglinWang; WenxiaLiu

    2004-01-01

    Layered double hydroxides consisting of layers withcationic charges may be potential candidates ofcationic microparticles forming synergetic retentioneffect with anionic polyacrylamide. In this work, thelayered double hydroxides with various molar ratiosof Mg/AI were synthesized by co-precipitation ofmagnesium chloride and aluminum chloride and pep-tized by intense washing with water. The chemicalformula, particle size, Zeta potential of the layereddouble hydroxide were analyzed. It was found thatpositively charged magnesium aluminum hydroxidewith particle diameter in nanoparticle size could beprepared. The Zeta potential and particle size varywith the feed molar ratio of Mg/A1 and the peptizingprocess, respectively. The Zeta potential is also pHdependent. The retention experiments carried out onDDJ show that when used together with anionic poly-acrylamide, the positively charged colloidal doublehydroxide greatly improves the retention of reedpulps. The chemical formula, particle size and Zetapotential of the colloidal double hydroxide all affectits retention behavior.

  9. Synthesis of beta alumina from aluminum hydroxide and oxyhydroxide precursors

    CSIR Research Space (South Africa)

    Van Zyl, A

    1993-02-01

    Full Text Available Two aluminium oxyhydroxides, boehmite and pseudoboehmite, and two aluminium hydroxides, bayerite and gibbsite, have been investigated as precursors for the synthesis of the solid electrolyte, beta alumina. Reaction pathways and products have been...

  10. Spectral Dependent Photoelectrochemical Behaviors of CdS Sensitized ZnO Nanorods.

    Science.gov (United States)

    Majumder, T; Hmar, J J L; Roy, J N; Mondal, S P

    2016-04-01

    CdS decorated ZnO nanorods have been grown by a combination of hydrothermal method and successive ion layer absorption and reaction (SILAR) method. Optical absorption and emission properties of ZnO nanorods have been studied after sensitization with CdS nanoparticles. Current-voltage characteristics of ZnO nanorods and CdS sensitized ZnO nanorods have been studied in an electrochemical cell. The spectral dependent photocurrent and photopotential behaviors of ZnO nanorods and CdS sensitized ZnO nanorods have been investigated using monochromatic light of wavelength 300-700 nm. The photopotential recovery time have been estimated for CdS sensitized nanorods and pristine nanorods.

  11. Reactivity and resizing of gold nanorods in presence of Cu2+

    Indian Academy of Sciences (India)

    T S Sreeprasad; A K Samal; T Pradeep

    2008-06-01

    Due to the inherent anisotropy of the system, gold nanorods behave differently in comparison to their spherical counterparts. Reactivity of gold nanorods, in presence of cupric ions, was probed in an attempt to understand the chemistry of anisotropic particles. The reaction progresses through a series of intermediates. It can be arrested at any stage to get nanorods of desired dimension and therefore, can be used for their reshaping. The presence or absence of cetyltrimethylammonium bromide (CTAB) on the nanorod surface was found to be determining the site of initiation of the reaction. When a large concentration of CTAB is present in the system, selective etching of the tips of the nanorod occurs and when the nanorods are purified to reduce the amount of CTAB in the solution, the side faces of the nanorod also get reacted. Gold nanorods are converted to particles by further surface reconstructions in a systematic surface specific chemistry.

  12. Structure and properties of porous ceramics obtained from aluminum hydroxide

    OpenAIRE

    Levkov, R.; Kulkov, Sergey Nikolaevich

    2016-01-01

    In this paper the study of porous ceramics obtained from aluminum hydroxide with gibbsite modification is presented. The dependence of porosity and mechanical characteristics of the material sintered at different temperatures was studied. It was shown that compressive strength of alumina ceramics increases by 40 times with decreasing the pore volume from 65 to 15%. It was shown that aluminum hydroxide may be used for pore formation and pore volume in the sintered ceramics can be controlled by...

  13. Role of Calcium Hydroxide in Endodontics: A Review

    Directory of Open Access Journals (Sweden)

    Arun A

    2012-01-01

    Full Text Available Calcium hydroxide is a multipurpose agent, and there have been an increasing number of indications for its use in endodontics. Some of its indications include inter-appointment intracanal medicaments, endodontic sealers, pulp capping agents, apexification, pulpotomy and weeping canals. The purpose of this article is to review the properties, advantages, disadvantages and various indications for the use of calcium hydroxide in endodontics.

  14. Nanotubes, nanorods and nanowires having piezoelectric and/or pyroelectric properties and devices manufactured therefrom

    Science.gov (United States)

    Russell, Thomas P [Amherst, MA; Lutkenhaus, Jodie [Wethersfield, CT

    2012-05-15

    Disclosed herein is a device comprising a pair of electrodes; and a nanotube, a nanorod and/or a nanowire; the nanotube, nanorod and/or nanowire comprising a piezoelectric and/or pyroelectric polymeric composition; the pair of electrodes being in electrical communication with opposing surfaces of the nanotube, nanorod and/or a nanowire; the pair of electrodes being perpendicular to a longitudinal axis of the nanotube, nanorod and/or a nanowire.

  15. USING COLLOIDAL LAYERED DOUBLE HYDROXIDES AS CATIONIC MICROPARTICULATE COMPONENT

    Institute of Scientific and Technical Information of China (English)

    Songlin Wang; Wenxia Liu

    2004-01-01

    Layered double hydroxides consisting of layers with cationic charges may be potential candidates of cationic microparticles forming synergetic retention effect with anionic polyacrylamide. In this work, the layered double hydroxides with various molar ratios of Mg/Al were synthesized by co-precipitation of magnesium chloride and aluminum chloride and peptized by intense washing with water. The chemical formula, particle size, Zeta potential of the layered double hydroxide were analyzed. It was found that positively charged magnesium aluminum hydroxide with particle diameter in nanoparticle size could be prepared. The Zeta potential and particle size vary with the feed molar ratio of Mg/Al and the peptizing process, respectively. The Zeta potential is also pH dependent. The retention experiments carried out on DDJ show that when used together with anionic polyacrylamide, the positively charged colloidal double hydroxide greatly improves the retention of reed pulps. The chemical formula, particle size and Zeta potential of the colloidal double hydroxide all affect its retention behavior.

  16. [Preparation and characterization of zirconium hydroxide powder for fluoride adsorption].

    Science.gov (United States)

    Yang, Shuo; Dou, Xiao-min; Liang, Wen-yan; Wang, Yi-li; Lin, Wei

    2010-07-01

    The method co-precipitation was applied to preparation the zirconium hydroxide as a type drinking-water defluoridation adsorbent. The effect of the preparation conditions on the adsorptive capacity was studied. The optimization of preparation condition for zirconium hydroxide concludes that co-precipitation time is 10 h, pH value is 7.0, drying time is 72 h, calcination temperature is below 100 degrees C. Also, the adsorbent samples were characterized. SEM measurements reveal that zirconium hydroxide powder are constructed by several small particles, with a diameter about 20-30 microm. XRD and TG/DTA measurements show that the zirconium hydroxide samples have amorphous phase and converse to tetragonal phase when calcined at 600 degrees C. Nitrogen adsorption/desorption measurements show that samples have large surface areas of 138.4 m2/g and a 2 nm average pore size distribution in the mesopore region. The performance of zirconium hydroxide regeneration process was investigated. The results show that the regeneration techniques are very suitable to restore the fluorine-removal ability for zirconium hydroxide.

  17. Amelogenin "nanorods" formation during proteolysis by Mmp-20.

    Science.gov (United States)

    Yang, Xiudong; Sun, Zhi; Ma, Ruiwen; Fan, Daming; Moradian-Oldak, Janet

    2011-11-01

    Amelogenin is cleaved by enamelysin (Mmp-20) soon after its secretion, and the cleavage products accumulate in specific locations during enamel formation, suggesting that parent amelogenin proteolysis is necessary for activating its functions. To investigate the precise roles of Mmp-20 and its influence on the assembly of amelogenin, an in vitro enzymatic digestion process mimicking the initial stages of amelogenin proteolysis was investigated at near-physiological conditions using recombinant porcine amelogenin (rP172) and enamelysin. Hierarchically organized nanorod structures formed during different digestion stages were detected by TEM. At the earliest stage, uniformly dispersed parent amelogenin spherical particles, mixed with some darker stained smaller spheres, and accompanying elongated chain-like nanostructures were observed. Cylindrical nanorods, which appeared to be the result of tight assembly of thin subunit cylindrical discs with thicknesses ranging from ∼2.5 to ∼6.0nm, were formed after an hour of proteolysis. These subunit building blocks stacked to form nanorods with maximum length of ∼100nm. With the production of more cleavage products, additional morphologies spontaneously evolved from the cylindrical nanorods. Larger ball-like aggregates ultimately formed at the end of proteolysis. The uniform spherical particles, nanorods, morphological patterns evolved from nanorods, and globular aggregated microstructures were successively formed by means of co-assembly of amelogenin and its cleavage products during a comparatively slow proteolysis process. We propose that, following the C-terminal cleavage of amelogenin, co-assembly with its fragments leads to formation of nanorod structures whose properties eventually dictate the super-structural organization of enamel matrix, controlling the elongated growth of enamel apatite crystals.

  18. Growth of rutile TiO₂ on the convex surface of nanocylinders: from nanoneedles to nanorods and their electrochemical properties.

    Science.gov (United States)

    Kong, Junhua; Wei, Yuefan; Zhao, Chenyang; Toh, Meng Yew; Yee, Wu Aik; Zhou, Dan; Phua, Si Lei; Dong, Yuliang; Lu, Xuehong

    2014-04-21

    In this work, bundles of rutile TiO₂ nanoneedles/nanorods are hydrothermally grown on carbon nanofibers (CNFs), forming free-standing mats consisting of three dimensional hierarchical nanostructures (TiO₂-on-CNFs). Morphologies and structures of the TiO₂-on-CNFs are studied using a field-emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffractometer (XRD) and thermogravimetric analyzer (TGA). Their electrochemical properties as electrodes in lithium ion batteries (LIBs) are investigated and correlated with the morphologies and structures. It is shown that the lateral size of the TiO₂ nanoneedles/nanorods ranges from a few nanometers to tens of nanometers, and increases with the hydrothermal temperature. Small interspaces are observed between individual nanoneedles/nanorods, which are due to the diverging arrangement of nanoneedles/nanorods induced by growing on the convex surface of nanocylinders. It is found that the growth process can be divided into two stages: initial growth on the CNF surface and further growth upon re-nucleation on the TiO₂ bundles formed in the initial growth stage. In order to achieve good electrochemical performance in LIBs, the size of the TiO₂ nanostructures needs to be small enough to ensure complete alloying and fast charge transport, while the further growth stage has to be avoided to realize direct attachment of TiO₂ nanostructures on the CNFs, facilitating electron transport. The sample obtained after hydrothermal treatment at 130 °C for 2 h (TiO₂-130-2) shows the above features and hence exhibits the best cyclability and rate capacity among all samples; the cyclability and rate capacity of TiO₂-130-2 are also superior to those of other rutile TiO₂-based LIB electrodes.

  19. Resolution of galactose, glucose, xylose and mannose in sugarcane bagasse employing a voltammetric electronic tongue formed by metals oxy-hydroxide/MWCNT modified electrodes

    OpenAIRE

    2016-01-01

    Second generation ethanol is produced from the carbohydrates released from the cell wall of bagasse and straw of sugarcane. The objective of this work is the characterization and application of a voltammetric electronic tongue using an array of glassy carbon electrodes modified with multi-walled carbon nanotubes containing metal (Paladium, Gold, Copper, Nickel and Cobalt) oxy-hydroxide nanoparticles (GCE/MWCNT/MetalsOOH) towards a simpler analysis of carbohydrates (glucose, xylose, galactose ...

  20. Fabrication and characterization of nanorod solar cells with an ultrathin a-Si:H absorber layer

    NARCIS (Netherlands)

    Kuang, Y.; van der Werf, C.H.M.; Houweling, Z.S.; Di Vece, M.; Schropp, R.E.I.

    2011-01-01

    In this paper, we present a three-dimensional nanorod solar cell design. As the backbone of the nanorod device, density-controlled zinc oxide (ZnO) nanorods were synthesized by a simple aqueous solution growth technique at 80 °C on ZnO thin film pre-coated glass substrate. The as-prepared ZnO nanoro

  1. Fabrication and characterization of nanorod solar cells with an ultrathin a-Si:H absorber layer

    NARCIS (Netherlands)

    Kuang, Y.; van der Werf, C.H.M.; Houweling, Z.S.; Di Vece, M.; Schropp, R.E.I.

    2011-01-01

    In this paper, we present a three-dimensional nanorod solar cell design. As the backbone of the nanorod device, density-controlled zinc oxide (ZnO) nanorods were synthesized by a simple aqueous solution growth technique at 80 °C on ZnO thin film pre-coated glass substrate. The as-prepared ZnO nanoro

  2. Low-energy electron holographic imaging of gold nanorods supported by ultraclean graphene

    Energy Technology Data Exchange (ETDEWEB)

    Longchamp, Jean-Nicolas, E-mail: longchamp@physik.uzh.ch; Escher, Conrad; Latychevskaia, Tatiana; Fink, Hans-Werner

    2014-10-15

    An ideal support for an electron microscopy should be as thin as possible and be able to interact as little as possible with the primary electrons. Since graphene is atomically thin and made up of carbon atoms arranged in a honeycomb lattice, the potential to use graphene as a substrate in electron microscopy is enormous. Until now graphene has hardly ever been used for this purpose because the cleanliness of freestanding graphene before or after deposition of the objects of interest was insufficient. We demonstrate here by means of low-energy electron holographic imaging that freestanding graphene prepared with a platinum-metal catalysis method remains ultraclean even after re-exposure to ambient conditions and deposition of gold nanorods from the liquid phase. In the holographic reconstruction of gold particles the organic shell surrounding the objects is apparent while it is not detectable in SEM images of the very same sample, demonstrating the tremendous potential of low-energy electron holography for imaging of graphene-supported single biomolecules. - Highlights: • Deposition of nanometre-sized objects onto ultraclean freestanding graphene. • TEM imaging of ultraclean freestanding graphene. • Low-energy electron imaging of gold-nanorods deposited onto freestanding graphene.

  3. Tailoring the optical and hydrophobic property of zinc oxide nanorod by coating with amorphous graphene

    Science.gov (United States)

    Pahari, D.; Das, N. S.; Das, B.; Chattopadhyay, K. K.; Banerjee, D.

    2016-09-01

    Zinc oxide (ZnO) nanorods were synthesized at room temperature on potassium permanganate activated silicon and glass substrate by simple chemical method using zinc acetate as precursor. To modify the surface energy of the as prepared ZnO thin films the samples were coated with amorphous graphene (a-G) synthesized by un-zipping of chemically synthesized amorphous carbon nanotubes (a-CNTs). All the pure and coated samples were characterized by x-ray diffraction, field emission scanning electron microscope, Raman spectroscopy, and Fourier transformed infrared spectroscopy. The roughness analysis of the as prepared samples was done by atomic force microscopic analysis. The detail optical properties of all the samples were studied with the help of a UV-Visible spectrophotometer. The surface energy of the as prepared pure and coated samples was calculated by measuring the contact angle of two different liquids. It is seen that the water repellence of ZnO nanorods got increased after they are being coated with a-Gs. Also even after UV irradiation the contact angle remain same unlike the case for the uncoated sample where the contact angle gets decreased significantly after UV irradiation. Existing Cassie-Wenzel model has been employed along with the Owen's approach to determine the different components of surface energy.

  4. Ageing behaviour of unary hydroxides in trivalent metal salt solutions: Formation of layered double hydroxide (LDH)-like phases

    Indian Academy of Sciences (India)

    Michael Rajamathi; P Vishnu Kamath

    2000-10-01

    The hydroxides of Mg, Ni, Cu and Zn transform into layered double hydroxide (LDH)-like phases on ageing in solutions of Al or Cr salts. This reaction is similar to acid leaching and proceeds by a dissolution–reprecipitation mechanism offering a simple method of LDH synthesis, with implications for the accepted theories of formation of LDH minerals in the earth’s crust.

  5. The Effects of Aluminium Hydroxide and Magnesium Hydroxide on the Mechanical Properties of Thermoplastic Polyurethane Materials

    Directory of Open Access Journals (Sweden)

    Erkin Akdoğan

    2015-12-01

    Full Text Available Thermoplastic polyurethane materials are widely used in automotive, clothing, electrical and electronics, medical, construction, machine industry due to excellent physical and chemical properties. Thermoplastic polyurethane materials combustion and resistance to high temperature characteristics are poor. Additives and fillers are added into the polyurethane matrix to improve those properties. Particularly adding these agents as a flame retardant are affect mechanical properties of polyurethane materials. Therefore, it is important to determinate the mechanical properties of these materials. In this study, 5% by weight of the thermoplastic polyurethane material, aluminium tri hydroxide (ATH, (Al2O3 3H2O and magnesium hydroxide (MgOH, (Mg(OH2 were added. Ammonium polyphosphate (APP as an intumescent flame retardant with inorganic flame retardants were added to increase the flame resistance of produced composite structure. Tensile test, tear test, hardness and Izod impact tests were made and compared of those produced composites. As a result of experiments the addition of ATH has lowered the tensile strength and tear strength contrast to this the addition of MgOH has improved those properties. Hardness and Izod impact test results were showed that both of the additives have no negative effect.

  6. Synthesis Magnesium Hydroxide Nanoparticles and Cellulose Acetate- Mg(OH2-MWCNT Nanocomposite

    Directory of Open Access Journals (Sweden)

    M. Ghorbanali

    2015-04-01

    Full Text Available Mg(OH2 nanoparticles were synthesized by a rapid microwave reaction. The effect of sodium dodecyl sulfonate (SDS as anionic surfactant and cetyl tri-methyl ammonium bromide (CTAB as cationic surfactant on the morphology of magnesium hydroxide nanostructures was investigated. Multi wall carbon nano tubes was organo-modified for better dispersion in cellulose acetate matrix. The influence of Mg(OH2 nanoparticles and modified multi wall carbon nano tubes (MWCNT on the thermal stability of the cellulose acetate (CA matrix was studied using thermo-gravimetric analysis (TGA. Nanostructures were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and Fourier transform infrared (FT-IR spectroscopy. Thermal decomposition of the nanocomposites shift towards higher temperature in the presence of Mg(OH2 nanostructures. The enhancement of thermal stability of nanocomposites is due to the endothermic decomposition of Mg(OH2 and release of water which dilutes combustible gases.

  7. Highly Uniform Epitaxial ZnO Nanorod Arrays for Nanopiezotronics

    Directory of Open Access Journals (Sweden)

    Nagata T

    2009-01-01

    Full Text Available Abstract Highly uniform and c-axis-aligned ZnO nanorod arrays were fabricated in predefined patterns by a low temperature homoepitaxial aqueous chemical method. The nucleation seed patterns were realized in polymer and in metal thin films, resulting in, all-ZnO and bottom-contacted structures, respectively. Both of them show excellent geometrical uniformity: the cross-sectional uniformity according to the scanning electron micrographs across the array is lower than 2%. The diameter of the hexagonal prism-shaped nanorods can be set in the range of 90–170 nm while their typical length achievable is 0.5–2.3 μm. The effect of the surface polarity was also examined, however, no significant difference was found between the arrays grown on Zn-terminated and on O-terminated face of the ZnO single crystal. The transmission electron microscopy observation revealed the single crystalline nature of the nanorods. The current–voltage characteristics taken on an individual nanorod contacted by a Au-coated atomic force microscope tip reflected Schottky-type behavior. The geometrical uniformity, the designable pattern, and the electrical properties make the presented nanorod arrays ideal candidates to be used in ZnO-based DC nanogenerator and in next-generation integrated piezoelectric nano-electromechanical systems (NEMS.

  8. Nano-rods of zinc oxide in nano-graphene

    Science.gov (United States)

    Ortiz, Pedro; Chavira, Elizabeth; Monroy, Marel; Elizalde, José; Santiago, Patricia; Sato, Roberto; Tejeda, Adriana; González, Guillermina; Novelo, Omar; Flores, Carlos

    2014-03-01

    It's of great interest to study the devices based on nano-ZnO and graphene, for their electromagnetic and optical properties to increase the efficiency of solar cells. The graphene multilayers synthesis was done by mechanosynthesis, grinding in a mechanical agate mortar. The zinc oxide nano-rods were synthesized from zinc acetate dihydrate, Ace, (Sigma Aldrich) and ethylene diamine, En, (Sigma Aldrich) with a 1:2 ratio of reagents En/Ace. The ZnO nano-rods in nano-tubes graphene were obtained by mechanosynthesis. The X-ray powder diffraction, shows the shift of C with PDF 12-0212 and ZnO, Zincite PDF 36-1451, both with hexagonal unit cell. The grain size and morphology of graphene (multilayers and nano-tubes), ZnO nano-rods and ZnO-graphene mixture (multilayers, nano-tubes) were observed by scanning electron microscope. Transmission electron microscope, corroborates shown in SEM. Raman spectroscopy, shows the shift of multilayer graphene and the ZnO nano-rods. In photoluminescence measurements, observe the change in intensity in the band defects. Magnetic properties characterization was carried out by Vibrating Sample Magnetometry. We conclude that graphite multilayers dislocated by cutting efforts, forming graphene nano-tubes and encapsulated ZnO nano-rods within graphene.

  9. Broadband resonances in indium-tin-oxide nanorod arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shi-Qiang, E-mail: s-li@u.northwestern.edu, E-mail: r-chang@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Dr., Evanston, Illinois 60208-3108 (United States); Sakoda, Kazuaki [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); NU-NIMS Materials Innovation Center, 2220 Campus Dr., Evanston, Illinois 60208-3108 (United States); Ketterson, John B. [NU-NIMS Materials Innovation Center, 2220 Campus Dr., Evanston, Illinois 60208-3108 (United States); Department of Physics, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208-3113 (United States); Chang, Robert P. H., E-mail: s-li@u.northwestern.edu, E-mail: r-chang@northwestern.edu [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Dr., Evanston, Illinois 60208-3108 (United States); NU-NIMS Materials Innovation Center, 2220 Campus Dr., Evanston, Illinois 60208-3108 (United States)

    2015-07-20

    There is currently much discussion within the nanophotonics community regarding the origin of wavelength selective absorption/scattering of light by the resonances in nanorod arrays. Here, we report a study of resonances in ordered indium-tin-oxide nanorod arrays resulting from waveguide-like modes. We find that with only a 2.4% geometrical coverage, micron-length nanorod arrays interact strongly with light across a surprisingly wide band from the visible to the mid-infrared, resulting in less than 10% transmission. Simulations show excellent agreement with our experimental observations. The field profile in the vicinity of the rods obtained from simulations shows that the electric field is mainly localized on the surfaces of the nanorods for all resonances. Based on our analysis, the resonances in the visible are different in character from those in the infrared. When light is incident on the array, part of it propagates in the space between the rods and part of it is guided within the rods. The phase difference (interference) at the ends of the rods forms the basis for the resonances in the visible region. The resonances in the infrared are Fabry-Perot-like resonances involving standing surface waves between the opposing ends of the rods. Simple analytical formulae predict the spectral positions of these resonances. It is suggested that these phenomena can be utilized for wavelength-selective photodetectors, modulators, and nanorod-based solar cells.

  10. Direct Nanorod Assembly Using Block Copolymer-Based Supramolecules

    Science.gov (United States)

    Thorkelsson, Kari; Mastroianni, Alexander; Ercius, Peter; Xu, Ting

    2012-02-01

    One-dimensional nanomaterials with high aspect ratios, such as nanorods, exhibit unique and useful anisotropic optical, magnetic, and electrical properties. The collective properties of 1-D nanomaterials depend on their spatial arrangements, interparticle ordering, and macroscopic alignment. Developing routes to control their organization with high precision is critical to generate functional materials. We have investigated the co-assemblies of nanorods and block copolymer (BCP)-based supramolecules that self-assemble into spherical, lamellar and cylindrical morphologies. By varying energetic contributions from the rod-rod interactions and the deformation of the supramolecule, a wide library of nanorod assemblies including highly aligned arrays, continuous networks, and clusters can be readily accessed. Since macroscopic alignment of BCP microdomains can be obtained by application of external fields, present studies open up a new route to manipulate macroscopic alignments of nanorods. Fundamentally, these studies have demonstrated that in these blends, the energetic contributions from the polymer chain deformation and rod-rod interactions are comparable and can be tailored to disperse nanorods with control over inter-rod ordering and their relative alignment.

  11. Broadband resonances in indium-tin-oxide nanorod arrays

    Science.gov (United States)

    Li, Shi-Qiang; Sakoda, Kazuaki; Ketterson, John B.; Chang, Robert P. H.

    2015-07-01

    There is currently much discussion within the nanophotonics community regarding the origin of wavelength selective absorption/scattering of light by the resonances in nanorod arrays. Here, we report a study of resonances in ordered indium-tin-oxide nanorod arrays resulting from waveguide-like modes. We find that with only a 2.4% geometrical coverage, micron-length nanorod arrays interact strongly with light across a surprisingly wide band from the visible to the mid-infrared, resulting in less than 10% transmission. Simulations show excellent agreement with our experimental observations. The field profile in the vicinity of the rods obtained from simulations shows that the electric field is mainly localized on the surfaces of the nanorods for all resonances. Based on our analysis, the resonances in the visible are different in character from those in the infrared. When light is incident on the array, part of it propagates in the space between the rods and part of it is guided within the rods. The phase difference (interference) at the ends of the rods forms the basis for the resonances in the visible region. The resonances in the infrared are Fabry-Perot-like resonances involving standing surface waves between the opposing ends of the rods. Simple analytical formulae predict the spectral positions of these resonances. It is suggested that these phenomena can be utilized for wavelength-selective photodetectors, modulators, and nanorod-based solar cells.

  12. Effects of Chromium Dopant on Ultraviolet Photoresponsivity of ZnO Nanorods

    Science.gov (United States)

    Mokhtari, S.; Safa, S.; Khayatian, A.; Azimirad, R.

    2017-07-01

    Structural and optical properties of bare ZnO nanorods, ZnO-encapsulated ZnO nanorods, and Cr-doped ZnO-encapsulated ZnO nanorods have been investigated. Encapsulated ZnO nanorods were grown using a simple two-stage method in which ZnO nanorods were first grown on a glass substrate directly from a hydrothermal bath, then encapsulated with a thin layer of Cr-doped ZnO by dip coating. Comparative study of x-ray diffraction patterns showed that Cr was successfully incorporated into the shell layer of ZnO nanorods. Moreover, energy-dispersive x-ray spectroscopy confirmed presence of Cr in this sample. It was observed that the thickness of the shell layer around the core of the ZnO nanorods was at least about 20 nm. Transmission electron microscopy of bare ZnO nanorods revealed single-crystalline structure. Based on optical results, both the encapsulation process and addition of Cr dopant decreased the optical bandgap of the samples. Indeed, the optical bandgap values of Cr-doped ZnO-encapsulated ZnO nanorods, ZnO-encapsulated ZnO nanorods, and bare ZnO nanorods were 2.89 eV, 3.15 eV, and 3.34 eV, respectively. The ultraviolet (UV) parameters demonstrated that incorporation of Cr dopant into the shell layer of ZnO nanorods considerably facilitated formation and transportation of photogenerated carriers, optimizing their performance as a practical UV detector. As a result, the photocurrent of the Cr-doped ZnO-encapsulated ZnO nanorods was the highest (0.6 mA), compared with ZnO-encapsulated ZnO nanorods and bare ZnO nanorods (0.21 mA and 0.06 mA, respectively).

  13. Tailored Au nanorods: optimizing functionality, controlling the aspect ratio and increasing biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Cai Xiaoqing; Wang, Cheng-Liang; Chen, Hsiang-Hsin; Chien, Chia-Chi; Lai Shengfeng; Chen Yiyun; Hua, Tzu-En; Kempson, Ivan M; Hwu, Y [Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan (China); Yang, C S [Center for Nanomedicine, National Health Research Institutes, Miaoli, Taiwan (China); Margaritondo, G, E-mail: phhwu@sinica.edu.tw [Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2010-08-20

    Monodisperse gold nanorods with high aspect ratio were synthesized by x-ray irradiation. Irradiation was first used to stimulate the creation of seeds. Afterward, nanorod growth was stimulated either by chemical reduction or again by x-ray irradiation. In the last case, the entire process took place without reducing agents. The shape of the final products could be controlled by modulating the intensity of the x-ray irradiation during the seed synthesis. In turn, the nanorod aspect ratio determines the absorption wavelength of the nanorods that can thus be optimized for different applications. Likewise, the aspect ratio influences the uptake of the nanorods by HeLa cells.

  14. Electromagnetic field manipulation in planar nanorod antennas metamaterial for slow light application

    Science.gov (United States)

    Wang, Junqiao; Zhang, Jia; Fan, Chunzhen; Mu, Kaijun; Liang, Erjun; Ding, Pei

    2017-01-01

    We numerically investigated the optical properties of planar nanorod antennas metamaterial that exhibits plasmon-induced transparency (PIT) effect. The designed metamaterial is made of a silver nanorod dimer antenna surrounded by two parallel silver nanorods. The interaction between two parallel nanorods and middle nanorod dimer antenna leads to a single PIT band in the transmission spectrum. Moreover, the double PIT windows and slow light can be realized by breaking the structure symmetry. The multi-bands PIT effect offers an excellent potential to manipulate the light speed at multi-frequencies.

  15. Irreversible thermochromic behavior in gold and silver nanorod/polymeric ionic liquid nanocomposite films.

    Science.gov (United States)

    Tollan, Christopher M; Marcilla, Rebeca; Pomposo, Jose A; Rodriguez, Javier; Aizpurua, Javier; Molina, Jon; Mecerreyes, David

    2009-02-01

    The novel application of gold and silver nanorods as irreversible thermochromic dyes in polymeric ionic liquid (PIL) nanocomposites is proposed here. These materials have been synthesized by anion exchange of an imidazolium-based PIL in a solution that also contained gold nanorods. This resulted in the entrapment of the nanoobjects within a solid polymer precipitate. In this article, the effect of the temperature was studied in relation to the change of shape and, consequently, color of the gold or silver nanorods within the films. For the nanocomposites studied here, a maximum of two visual thermochromic transitions was observed for gold nanorods and up to three transitions were observed for silver nanorods.

  16. Enhancement of Photoluminescence Lifetime of ZnO Nanorods Making Use of Thiourea

    OpenAIRE

    Erdal Sönmez; Kadem Meral

    2012-01-01

    We have investigated correlation of photoluminescence lifetime between zinc oxide (ZnO) nanorods and thiourea-doped ZnO nanorods (tu: CH4N2S). Aqueous solutions of ZnO nanorods were deposited on glass substrate by using pneumatic spray pyrolysis technique. The as-prepared specimens were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and time-resolved photoluminescence spectroscopy (TRPL). The photoluminescence lifetime of ZnO nanorods and ZnO nanorods containing...

  17. In situ synthesized one-dimensional porous Ni@C nanorods as catalysts for hydrogen storage properties of MgH2

    Science.gov (United States)

    An, Cuihua; Liu, Guang; Li, Li; Wang, Ying; Chen, Chengcheng; Wang, Yijing; Jiao, Lifang; Yuan, Huatang

    2014-02-01

    We have demonstrated an extremely facile procedure for the preparation of 1D porous Ni@C nanostructures by pyrolysis of Ni-based coordination polymer nanorods. The highly aligned Ni-based polymer nanorods were prepared using nitrilotriacetic acid (NTA) as a chelating agent by a one-step solvothermal approach. The obtained precursors are demonstrated to have a well-designed 1D nanostructure and a 3D interconnected mesoporous texture. After thermal treatment, 1D porous Ni@C nanorods were obtained, which basically preserved the morphology of the precursors. In addition, the carbon in the porous Ni@C nanorods is in both crystalline and amorphous states. The as-prepared Ni@C sample displays nanorod-like morphology with about 3 μm length and about 200 nm diameter. With a large surface area of 161.4 m2 g-1, this novel material had a good catalytic effect on de/hydrogenation of MgH2. The desorption peak temperature of MgH2-5 wt% Ni@C composites can be lowered more than 57 °C than the pure as-milled MgH2. The MgH2-5 wt% Ni@C composite could desorb 6.4 wt% H2 within 10 min at 300 °C, in contrast, only 2.3 wt% H2 was desorbed even after 100 min for pure MgH2. In addition, an activation energy of 108 kJ mol-1 for the as-milled MgH2-5 wt% Ni@C composites has been obtained, which exhibit an enhanced kinetics.We have demonstrated an extremely facile procedure for the preparation of 1D porous Ni@C nanostructures by pyrolysis of Ni-based coordination polymer nanorods. The highly aligned Ni-based polymer nanorods were prepared using nitrilotriacetic acid (NTA) as a chelating agent by a one-step solvothermal approach. The obtained precursors are demonstrated to have a well-designed 1D nanostructure and a 3D interconnected mesoporous texture. After thermal treatment, 1D porous Ni@C nanorods were obtained, which basically preserved the morphology of the precursors. In addition, the carbon in the porous Ni@C nanorods is in both crystalline and amorphous states. The as-prepared Ni

  18. Ferromagnetic behavior and exchange bias effect in akaganeite nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Tadic, Marin, E-mail: marint@vinca.rs [Condensed Matter Physics Laboratory, Vinca Institute of Nuclear Science, University of Belgrade, P.O. Box 522, 11001 Belgrade (Serbia); Milosevic, Irena; Motte, Laurence [Laboratoire CSPBAT, UMR 7244 CNRS Université Paris 13, 93017 Bobigny Cedex (France); Kralj, Slavko [Department for Materials Synthesis, Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Saboungi, Marie-Louise [CNRS, University of Orleans, F-45071 Orleans 2 (France); IMPMC, Sorbonne Univ-UPMC Univ Paris 06, UMR CNRS 7590, Museum National d' Histoire Naturelle, IRD UMR 206, 4 Place Jussieu, F-75005 Paris (France)

    2015-05-04

    We report ferromagnetic-like properties and exchange bias effect in akaganeite (β-FeOOH) nanorods. They exhibit a Néel temperature T{sub N} = 259 K and ferromagnetic-like hysteresis behavior both below and above T{sub N}. An exchange bias effect is observed below T{sub N} and represents an interesting behavior for akaganeite nanorods. These results are explained on the basis of a core-shell structure in which the core has bulk akaganeite magnetic properties (i.e., antiferromagnetic ordering) while the shell exhibits a disordered spin state. Thus, the nanorods show ferromagnetic properties and an exchange bias effect at the same time, increasing their potential for use in practical applications.

  19. Fabrication and Wettability of ZnO Nanorod Array

    Institute of Scientific and Technical Information of China (English)

    Meng Sun; Yi Du; Weichang Hao; Huaizhe Xu; Youxing Yu; Tianmin Wang

    2009-01-01

    ZnO nanorod arrays were prepared in an open system by using a simple aqueous solution method. Spindle-like, wimble-like, tower-like and hexagonal rod-like ZnO rods were obtained under different conditions. ZnO nanorod arrays with different morphology and size were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and contact angle measurement (CAM). The size of ordered zinc oxide rods can be controlled by temperature of water bath, because this temperature can influences growing speeds in different crystal directions. Some additives, such as urea and thiourea, were introduced into reaction solution to improve quality of arrays. Surface character of ZnO nanorod arrays can be changed from hydrophilic to hydrophobic, which was proved to be dependence on size of air grooves on surface.

  20. Mechanistic study of ZnO nanorod array electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    El Belghiti, H.; Pauporte, T.; Lincot, D. [Laboratoire d' Electrochimie et Chimie Analytique, UMR7575, Ecole Nationale Superieure de Chimie de Paris-Universite Paris 6 (France)

    2008-10-15

    The growth of ZnO nanorods by electrodeposition from oxygenated aqueous mixture of zinc chloride and potassium chloride is studied experimentally as a function of the deposition time, zinc concentration and the substrate. These parameters influence markedly the characteristics of the deposits (rod density, aspect ratio, orientation). A mechanistic model is presented in order to explain the formation of ZnO nanorod arrays by electrodeposition. The model is based on the effect of zinc concentration on the interfacial pH at the electrode surface and then on the charged stable zinc species able to react with the growing film. The charge of the complex seems to be the key parameter which stops the lateral growth and then significantly increases the aspect ratio of the single crystalline nanorods. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Fabrication and Photocatalytic Properties of ZnSe Nanorod Films

    Directory of Open Access Journals (Sweden)

    Jiajia Yin

    2016-01-01

    Full Text Available ZnSe nanorod films grown on fused quartz glass substrates via a simple two-step synthesis protocol were demonstrated to be environmentally safe and effective recyclable photocatalysts. These films showed greatly enhanced photocatalytic activity compared to pulsed laser deposition ZnSe films in the degradation of methyl orange dye solutions. The well-crystalized ZnSe nanorods had a length of 15 µm and a diameter of 200 nm and were densely grown on the substrate. The morphology, crystal structure, crystal phase, and photophysical properties of the ZnSe nanorod films were investigated using field-emission scanning electron microscopy (FE-SEM, UV-Vis spectroscopy, X-ray diffraction (XRD, transmission electron microscopy (TEM, and high resolution transmission electron microscopy (HRTEM.

  2. Tin Oxide Nanorod Array-Based Electrochemical Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    Liu Jinping

    2010-01-01

    Full Text Available Abstract SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM−1 cm−2, low detection limit (0.2 μM and high selectivity with the apparent Michaelis–Menten constant estimated to be as small as 33.9 μM. Our work further demonstrates the advantages of ordered array architecture in electrochemical device application and sheds light on the construction of other high-performance enzymatic biosensors.

  3. Surface area-dependent second harmonic generation from silver nanorods.

    Science.gov (United States)

    Ngo, Hoang Minh; Luong, Thanh Tuyen; Ledoux-Rak, Isabelle

    2016-08-17

    The nonlinear optical (NLO) properties of metallic nanoparticles strongly depend on their size and shape. Metallic gold nanorods have already been widely investigated, but other noble metals could also be used for nanorod fabrication towards applications in photonics. Here we report on the synthesis and NLO characterization of silver nanorods (AgNRs) with controllable localized surface plasmon resonance. We have implemented an original, one-step and seedless synthesis method, based on a spontaneous particle growth technique in the presence of polyvinylpyrrolidone (PVP) as a capping agent. Colloidal solutions of AgNRs with various aspect ratios (5.0; 6.3; 7.5; 8.2 and 9.7) have been obtained and characterized using Harmonic light scattering (HLS) at 1064 nm, in order to investigate their quadratic NLO properties. From HLS experiments, we demonstrate that hyperpolarizability (β) values of AgNRs display a strong dependence on their surface area.

  4. EFFICACY OF DIFFERENT ENDODONTIC IRRIGATION PROTOCOLS IN CALCIUM HYDROXIDE REMOVAL

    Directory of Open Access Journals (Sweden)

    Elka N. Radeva

    2016-10-01

    Full Text Available Introduction: Calcium hydroxide is widely used in the field of endodontics as a temporary root canal filling. This medicament significantly increases pH and optimizes the treatment outcome. Its total removal before final obturation is very important. Otherwise it could affect the hermetic filling and respectively the endodontic success. Aim: To evaluate the most effective irrigation protocol of calcium hydroxide removal from root canals. Materials and methods: In this study 36 single root canal teeth were observed. They were randomly divided into three groups (n=10 each group according to the technique applied for calcium hydroxide removal - manual irrigation, irrigation and Revo-S rotary instrumentation; and passive ultrasonic irrigation, and a control group (n=6 – irrigation with distilled water only. After calcium hydroxide removals following the procedures above, teeth were separated longitudinally in a buccal-lingual direction and remnants of medicaments were observed in the apical, middle and coronal part of each tooth. Then all of the specimens were observed using scanning electron microscopy and evaluated by a specified scale. The results have undergone statistical analysis. Results: In the case of calcium hydroxide in the apex and in the middle with highest average is Revo-S, followed by Ultrasonic and irrigation. In the coronal part the highest average belongs to Revo-S, irrigation and Ultrasonic. In all groups the highest average is represented by control group. Conclusion: There is not a universal technique for removal of intracanal medicaments and applying more than one protocol is required.

  5. The citotoxicity of calcium hydroxide intracanal dressing by MTT assay

    Directory of Open Access Journals (Sweden)

    Nanik Zubaidah

    2007-12-01

    Full Text Available Calcium hydroxide had been used as the intracanal dressing in endodontic treatment due to its high alkaline and high antimicrobial capacity. It also be able to dissolve the necrotic tissue, prevent the root resorbtion and regenerate a new hard tissue. The aim of this study is to identify the concentration of calcium hydroxide that has the lowest citotoxicity. There are 5 groups, each group had 8 samples with different concentration of calcium hydroxide. Group I: 50%, Group II: 55%, Group III: 60%, Group IV: 65% and Group V: 70%. The citotoxicity test by using enzymatic assay of MTT [3-(4.5- dimethylthiazol-2yl ]-2.5 diphenyl tetrazolium bromide, against fibroblast cell (BHK-21. The result of susceptibility test was showed by the citotoxicity detection of the survive cell of fibroblast that was measured spectrophotometrically using 595 nm beam. The data was analyzed using One-Way ANOVA test with significant difference α = 0.05 and subsequently LSD test. The result showed that in concentration 50%, 55%, 60%, 65%, and 70% calcium hydroxide had low toxicity, but calcium hydroxide 60%, had the lowest toxicity.

  6. Hydrothermal synthesis of cerium titanate nanorods and its application in visible light photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Pei, L.Z., E-mail: lzpei@ahut.edu.cn; Liu, H.D.; Lin, N.; Yu, H.Y., E-mail: yuhy@ahut.edu.cn

    2015-01-15

    Highlights: • Cerium titanate nanorods have been synthesized by a simple hydrothermal process. • The size of the cerium titanate nanorods can be controlled by growth conditions. • Cerium titanate nanorods exhibit good photocatalytic activities for methyl blue. - Abstract: Cerium titanate nanorods have been prepared via a hydrothermal process using sodium dodecyl sulfate (SDS) as the surfactant. The cerium titanate nanorods have been analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and ultraviolet–visible (UV–vis) diffuse reflectance spectrum. XRD shows that the nanorods are composed of CeTi{sub 21}O{sub 38} phase. Electron microscopy observations indicate that the nanorods have good single crystalline nature. The diameter and length of the nanorods are about 50–200 nm and 1–2 μm, respectively. Cerium titanate nanorods have a band gap of 2.65 eV. The photocatalytic activities of the nanorods have been investigated by degrading methylene blue (MB) under visible light irradiation. MB solution with the concentration of 10 mg L{sup −1} can be degraded totally with the irradiation time increasing to 240 min. Cerium titanate nanorods exhibit great potential in photocatalytic degradation of MB under visible light irradiation.

  7. Effect of shear on the symmetric diblock copolymer/nanorod mixture: A dissipative particle dynamics study

    Institute of Scientific and Technical Information of China (English)

    He Lin-Li; Zhang Rui-Fen; Ji Yong-Yun

    2012-01-01

    The phase behaviours of a lamellar diblock copolymer/nanorod composite under steady shear are investigated using dissipative particle dynamics.We consider a wide range of nanorod concentrations,where the nanorods each have a preferential affinity to one of the blocks.Our results suggest that shear not only aligns the orientations of the diblock copolymer templates and nanorods towards flow direction,but also regulates the distribution of the nanorods within the polymer matrix.Meanwhile,the shear-induced reorientation and morphology transitions of the systems also significantly depend on the nanorod concentration.At certain nanorod concentrations,the competitions between shearinduced polymer thinning and nanorods dispersion behaviours determine the phase behaviours of the composites.For high nanorod concentrations,no morphology transition is observed,but reorientation is present,in which the sheared nanorods are arranged into hexagonal packing arrays.Additionally,the orientation behaviour of nanorods is determined directly by the applied shear,also interfered with by the shear-stretched copolymer molecules.

  8. Enhancement of Photoluminescence Lifetime of ZnO Nanorods Making Use of Thiourea

    Directory of Open Access Journals (Sweden)

    Erdal Sönmez

    2012-01-01

    Full Text Available We have investigated correlation of photoluminescence lifetime between zinc oxide (ZnO nanorods and thiourea-doped ZnO nanorods (tu: CH4N2S. Aqueous solutions of ZnO nanorods were deposited on glass substrate by using pneumatic spray pyrolysis technique. The as-prepared specimens were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and time-resolved photoluminescence spectroscopy (TRPL. The photoluminescence lifetime of ZnO nanorods and ZnO nanorods containing thiourea was determined as =1.56±0.05 ns (2=0.9 and =2.12±0.03 ns (2=1.0, respectively. The calculated lifetime values of ZnO nanorods revealed that the presence of thiourea in ZnO nanorods resulted in increasing the exciton lifetime. In addition to the optical quality of ZnO nanorods, their exciton lifetime is comparable to the longest lifetimes reported for ZnO nanorods. The structural improvement of ZnO nanorods, containing thiourea, was also elucidated by taking their SEM images which show the thinner and longer ZnO nanorods compared to those without thiourea.

  9. Photo-oxidation of EPDM/layered double hydroxides composites: Influence of layered hydroxides and stabilizers

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available The photo-oxidation of ethylene propylene diene monomer (EPDM/ layered double hydroxide (LDH composites as well as EPDM/LDH with stabilizers is studied under accelerated UV irradiation (λ≥290 nm at 60°C for different time intervals. The development of functional groups during oxidation was monitored by FT-IR spectroscopy. The photodegradation of the pristine polymer and composites take place and the increase in hydroxyl and carbonyl groups with irradiation times, was estimated. EPDM filled LDH showed higher degradation rate than pristine EPDM, while in acidic medium EPDM/LDH showed almost equal degradation as in isolated conditions. These results show the advantages of LDHs as a filler as well as an acid killer. The effect of stabilizers is very less because of their concentration in comparison of LDH.

  10. Electric field induced orientational order of gold nanorods in dilute organic suspensions

    Science.gov (United States)

    Fontana, Jake; da Costa, Greice K. B.; Pereira, Joao M.; Naciri, Jawad; Ratna, Banahalli R.; Palffy-Muhoray, Peter; Carvalho, Isabel C. S.

    2016-02-01

    The electric field controlled alignment of gold nanorods offers a paradigm for anisotropic molecules with the potential for a wide variety of phases and structures. We experimentally study the optical absorption from gold nanorod suspensions aligned using external electric fields. We show that the absorption from these suspensions depends linearly on the orientational order parameter. We provide evidence that the critical electric field needed to orient the gold nanorods is proportional to the nanorod volume and depolarization anisotropy. Utilizing this critical field dependence, we demonstrate for suspensions with two different nanorod sizes that the alignment of each population can be controlled. We also develop a technique to determine the imaginary parts of the longitudinal and transverse electric susceptibilities of the nanorods. The ability to selectively address specific parts of the nanorod populations in a mixture using external fields may have significant potential for future display and optical filter applications.

  11. III-nitride core-shell nanorod array on quartz substrates.

    Science.gov (United States)

    Bae, Si-Young; Min, Jung-Wook; Hwang, Hyeong-Yong; Lekhal, Kaddour; Lee, Ho-Jun; Jho, Young-Dahl; Lee, Dong-Seon; Lee, Yong-Tak; Ikarashi, Nobuyuki; Honda, Yoshio; Amano, Hiroshi

    2017-03-27

    We report the fabrication of near-vertically elongated GaN nanorods on quartz substrates. To control the preferred orientation and length of individual GaN nanorods, we combined molecular beam epitaxy (MBE) with pulsed-mode metal-organic chemical vapor deposition (MOCVD). The MBE-grown buffer layer was composed of GaN nanograins exhibiting an ordered surface and preferred orientation along the surface normal direction. Position-controlled growth of the GaN nanorods was achieved by selective-area growth using MOCVD. Simultaneously, the GaN nanorods were elongated by the pulsed-mode growth. The microstructural and optical properties of both GaN nanorods and InGaN/GaN core-shell nanorods were then investigated. The nanorods were highly crystalline and the core-shell structures exhibited optical emission properties, indicating the feasibility of fabricating III-nitride nano-optoelectronic devices on amorphous substrates.

  12. III-nitride core–shell nanorod array on quartz substrates

    Science.gov (United States)

    Bae, Si-Young; Min, Jung-Wook; Hwang, Hyeong-Yong; Lekhal, Kaddour; Lee, Ho-Jun; Jho, Young-Dahl; Lee, Dong-Seon; Lee, Yong-Tak; Ikarashi, Nobuyuki; Honda, Yoshio; Amano, Hiroshi

    2017-01-01

    We report the fabrication of near-vertically elongated GaN nanorods on quartz substrates. To control the preferred orientation and length of individual GaN nanorods, we combined molecular beam epitaxy (MBE) with pulsed-mode metal–organic chemical vapor deposition (MOCVD). The MBE-grown buffer layer was composed of GaN nanograins exhibiting an ordered surface and preferred orientation along the surface normal direction. Position-controlled growth of the GaN nanorods was achieved by selective-area growth using MOCVD. Simultaneously, the GaN nanorods were elongated by the pulsed-mode growth. The microstructural and optical properties of both GaN nanorods and InGaN/GaN core–shell nanorods were then investigated. The nanorods were highly crystalline and the core–shell structures exhibited optical emission properties, indicating the feasibility of fabricating III-nitride nano-optoelectronic devices on amorphous substrates. PMID:28345641

  13. Dependence of bonding interactions in Layered Double Hydroxides on metal cation chemistry

    Science.gov (United States)

    Shamim, Mostofa; Dana, Kausik

    2016-12-01

    The evolution of various Infrared bands of Layered Double Hydroxides (LDH) with variable Zn:Al ratio was analyzed to correlate it with the changes in octahedral metal cation chemistry, interlayer carbonate anion and hydroxyl content of LDH. The synthesized phase-pure LDHs were crystallized as hexagonal 2H polytype with a Manasseite structure. The broad and asymmetric hydroxyl stretching region (2400-4000 cm-1) can be deconvoluted into four different bands. With increase in Zn2+:Al3+ metal ratio, the peak position of stretching frequencies of Al3+sbnd OH and carbonate-bridged hydroxyl (water) decrease almost linearly. Individual band's peak position and area under the curve have been successfully correlated with the carbonate and hydroxyl content of LDH. Due to lowering of symmetry of the carbonate anion, the IR-inactive peak νCsbnd O, symm at 1064 cm-1 becomes IR active. The peak position of metal-oxygen bands and carbonate bending modes are practically unaffected by the Zn2+:Al3+ ratio but the area under the individual M-O bands shows a direct correlation.

  14. Modelling of Packed Co Nanorods for Hard Magnetic Applications

    Directory of Open Access Journals (Sweden)

    Toson P.

    2014-07-01

    Full Text Available We present a numerical algorithm based on the bullet physics library to generate densely packed (39% - 41% structures of high-aspect-ratio nanorods for finite element micromagnetic simulations. The coercivities µ0Hc of the corresponding Cobalt nanorod structures vary between 0.50T and 0.67T, depending on the overall orientation of nanorods, which is in good agreement with experimental results. The simulations make it possible to estimate the coercivity loss due to incoherent reversal processes (27% as well as the gain due to shape anisotropy (59%. Our calculations show permanent magnets consisting of packed Co nanorods with an energy density product (BHmax of 83kJ/m3. We estimate that this value can be increased to 103kJ/m3 by increasing the packing density from 40% to 45%. Another way to optimize (BHmax is the usage of novel materials. By varying the anisotropy constant K1 and the saturation polarisation JS we found lower limits for these parameters to reach a certain energy density product. To increase (BHmax to 160 kJ/m3, K1 and JS have to be in the order of 450kJ/m3 and 2.25T, respectively. The thermal stability of this approach was verified by elastic band calculations. Cobalt nanorods with a diameter of 10nm and a height of 50nm are thermally stable at room temperature, but problematic at 900K. Doubling the nanorods' height to 100nm increases that limit considerably.

  15. The effect of calcium hydroxide treatment on the nutritive and feeding value of Albizia procera for growing goats

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M.R. [Department of Animal Science, Bangladesh Agricultural University, Mymensingh (Bangladesh)]. E-mail: mralam@royalten.net.bd; Kabir, A.K.M.A.; Amin, M.R. [Department of Animal Science, Bangladesh Agricultural University, Mymensingh (Bangladesh); McNeill, D.M. [Faculty of Veterinary Science, University of Sydney, Camden, NSW (Australia)

    2005-08-19

    Albizia procera (Albizia) is widely planted in Bangladesh for timber and the leaves are also used as forage. In the dry season the leaves are less palatable than in the wet season and this may be a consequence of an excessive content of tannin. Albizia foliage was collected in the wet (June) and dry (January) seasons from six agro-ecological zones across Bangladesh and chemical composition, for tannins in particular, was determined. Variation in the tannin content across the six zones proved to be minimal. However, the concentration of tannins was almost two-fold higher in the dry compared to the wet season. To assess the potential for deactivating the tannins in Albizia so as to improve its nutritive value, leaves were treated with alkali (either calcium hydroxide or potassium carbonate) or polyethylene glycol (PEG). Alkali treatment reduced the concentrations of extractable tannin by as much as 92%. The ability of calcium hydroxide to deactivate tannin was then tested in vivo. Young goats, fed a basal diet of hay and wheat bran, were allocated to 4 equal groups (n = 4 per group) and supplemented with fresh Albizia foliage (at 300 g/kg of the diet) that was either untreated, or treated with either PEG, calcium hydroxide or calcium hydroxide + PEG. The supplements were fed daily for 9 weeks to allow the effects of chemical treatment on intake and growth rate to be defined. In vivo digestibility, nitrogen (N) balance, and microbial N supply were measured over the 5th week. Intakes of feed dry matter (DM) and the digestibility of DM were similar across treatments (mean intake 32 g/(kg LW day), mean DM digestibility 0.63). However, both the PEG and the PEG + calcium hydroxide treatments, compared to the control and calcium hydroxide only treatments, increased N digestibility (0.72, 0.70 versus 0.60, 0.61), N retention (0.43, 0.48 mg N/mg versus 0.26, 0.27 mg N/mg N intake), and microbial N supply (23.7, 21.4 g/day versus 14.2, 12.4 g/day). These increases translated

  16. Insitu grown superhydrophobic Zn–Al layered double hydroxides films on magnesium alloy to improve corrosion properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Meng; Pang, Xiaolu; Wei, Liang; Gao, Kewei, E-mail: kwgao@yahoo.com

    2015-05-15

    Highlights: • Hierarchical superhydrophobic Zn–Al LDHs film has been fabricated on a magnesium alloy substrate. • The superhydrophobic surface has good long-term stability under atmospheric environment. • The superhydrophobic surface can provide a stable corrosion protection for the Mg alloys. - Abstract: A hierarchical superhydrophobic zinc–aluminum layered double hydroxides (Zn–Al LDHs) film has been fabricated on a magnesium alloy substrate via a facile hydrothermal crystallization method following chemical modification. The characteristics of the films were investigated by X-ray diffraction (XRD), scanning electronic microscope (SEM), and energy dispersive spectroscopy (EDS). XRD patterns and SEM images showed that the micro/nanoscale hierarchical LDHs film surfaces composed of ZnO nanorods and Zn–Al LDHs nanowalls structures. The static contact angle (CA) for the prepared surfaces was observed at around 165.6°. The corrosion resistance of the superhydrophobic films was estimated by electrochemical impedance spectroscopy (EIS) and potentiondynamic polarization measurement. EIS and polarization measurements revealed that the superhydrophobic Zn–Al LDHs coated magnesium alloy had better corrosion resistance in neutral 3.5 wt.% NaCl solution.

  17. Hollow Co2P nanoflowers organized by nanorods for ultralong cycle-life supercapacitors

    KAUST Repository

    Cheng, Ming

    2017-08-24

    Hollow Co2P nanoflowers (Co2P HNF) are successfully prepared via a one-step, template-free method. Microstructure analysis reveals that Co2P HNF is assembled by nanorods, possesses abundant mesopores and a amorphous carbon shell. Density functional theory calculation and electrochemical measurements demonstrate the high electrical conductivity of Co2P. Benefiting from the unique nanostructures, when employed as electrode material for supercapacitors, Co2P HNF exhibits a high specific capacitance, an outstanding rate capability, and an ultralong cycle stability. Furthermore,. the constructed Co2P HNF//AC ASC yields a high energy density of 30.5 Wh kg-1 at a power density of 850 W kg-1, along with an superior cycling performance (108.0% specific capacitance retained after 10000 cycles at 5 A g-1). These impressive results make Co2P HNF a promising candidate for supercapacitor applications.

  18. Performance Improvement of GaN-Based Flip-Chip White Light-Emitting Diodes with Diffused Nanorod Reflector and with ZnO Nanorod Antireflection Layer

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The GaN-based flip-chip white light-emitting diodes (FCWLEDs with diffused ZnO nanorod reflector and with ZnO nanorod antireflection layer were fabricated. The ZnO nanorod array grown using an aqueous solution method was combined with Al metal to form the diffused ZnO nanorod reflector. It could avoid the blue light emitted out from the Mg-doped GaN layer of the FCWLEDs, which caused more blue light emitted out from the sapphire substrate to pump the phosphor. Moreover, the ZnO nanorod array was utilized as the antireflection layer of the FCWLEDs to reduce the total reflection loss. The light output power and the phosphor conversion efficiency of the FCWLEDs with diffused nanorod reflector and 250 nm long ZnO nanorod antireflection layer were improved from 21.15 mW to 23.90 mW and from 77.6% to 80.1% in comparison with the FCWLEDs with diffused nanorod reflector and without ZnO nanorod antireflection layer, respectively.

  19. Growth, structure and applications of nanorods by glancing angle deposition

    Science.gov (United States)

    Kesapragada, Sree Rangasai V.

    Glancing angle deposition (GLAD) is a thin-film deposition technique where the deposition flux, consisting of atoms and molecules from gas phase, impinges on substrate at oblique angles, resulting in highly under-dense, columnar microstructures which are purposely engineering to achieve novel desired properties. GLAD is a simple, one-step process to obtain many novel nanostructures of current interest. The primary objective of this thesis is to extend the current capabilities of the GLAD technique for the creation of multi-component nanostructures. It is aimed to study the growth dynamics of nanostructures during GLAD. This work also aims to demonstrate, both theoretically and experimentally, the capabilities and limitations of a novel simultaneously opposing GLAD (SOGLAD) technique by creating branched Cu nanostructures. Two of the potential applications of the nanostructures have been investigated. It is shown for Cr, Si, and Ta single-component, and Cr-Si multi-component nanorods that growth on flat and patterned substrates results in strikingly different morphologies. This observation was explained on the basis of a competitive growth mode which occurs during the growth process favoring the larger rods to grow at the expense of smaller ones. Substrate patterning, achieved by colloid self-assembly and electron beam lithography, prior to GLAD delays or completely prevents intercolumnar competition. Intrinsic crystal properties such as stacking faults and three dimensional EhrlichSchwoebel barriers can result in the formation of branched nanostructures during glancing angle deposition. This is demonstrated using a combination of molecular dynamics simulations and GLAD experiments on Cu nanorod arrays. SOGLAD on to a stationery substrate results in the anisotropic broadening in Cu nanorods. A numerical model provides a qualitative understanding of the lateral growth in the nanorods when the deposition is switched from continuous substrate rotation to stationery

  20. Spontaneous Superlattice Formation in Nanorods through PartialCation Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Richard D.; Sadtler, Bryce; Demchenko, Denis O.; Erdonmez, Can K.; Wang, Lin-Wang; Alivisatos, A. Paul

    2007-03-14

    Lattice mismatch strains are widely known to controlnanoscale pattern formation in heteroepitaxy, but such effects have notbeen exploited in colloidal nanocrystal growth. We demonstrate acolloidal route to synthesizing CdS-Ag2S nanorod superlattices throughpartial cation exchange. Strain induces the spontaneous formation ofperiodic structures. Ab initio calculations of the interfacial energy andmodeling of strain energies show that these forces drive theself-organization. The nanorod superlattices exhibit high stabilityagainst ripening and phase mixing. These materials are tunablenear-infrared emitters with potential applications as nanometer-scaleoptoelectronic devices.

  1. Far-Infrared Absorption of PbSe Nanorods

    KAUST Repository

    Hyun, Byung-Ryool

    2011-07-13

    Measurements of the far-infrared absorption spectra of PbSe nanocrystals and nanorods are presented. As the aspect ratio of the nanorods increases, the Fröhlich sphere resonance splits into two peaks. We analyze this splitting with a classical electrostatic model, which is based on the dielectric function of bulk PbSe but without any free-carrier contribution. Good agreement between the measured and calculated spectra indicates that resonances in the local field factors underlie the measured spectra. © 2011 American Chemical Society.

  2. Assembling Ordered Nanorod Superstructures and Their Application as Microcavity Lasers

    Science.gov (United States)

    Liu, Pai; Singh, Shalini; Guo, Yina; Wang, Jian-Jun; Xu, Hongxing; Silien, Christophe; Liu, Ning; Ryan, Kevin M.

    2017-01-01

    Herein we report the formation of multi-layered arrays of vertically aligned and close packed semiconductor nanorods in perfect registry at a substrate using electric field assisted assembly. The collective properties of these CdSexS1-x nanorod emitters are harnessed by demonstrating a relatively low amplified spontaneous emission (ASE) threshold and a high net optical gain at medium pump intensity. The importance of order in the system is highlighted where a lower ASE threshold is observed compared to disordered samples. PMID:28272427

  3. Optical extinction in a single layer of nanorods

    CERN Document Server

    Ghenuche, Petru; Laroche, Marine; Bardou, Nathalie; Haïdar, Riad; Pelouard, Jean-Luc; Collin, Stéphane

    2012-01-01

    We demonstrate that almost 100 % of incident photons can interact with a monolayer of scatterers in a symmetrical environment. Nearly-perfect optical extinction through free-standing transparent nanorod arrays has been measured. The sharp spectral opacity window, in the form of a characteristic Fano resonance, arises from the coherent multiple scattering in the array. In addition, we show that nanorods made of absorbing material exhibit a 25-fold absorption enhancement per unit volume compared to unstructured thin film. These results open new perspectives for light management in high-Q, low volume dielectric nanostructures, with potential applications in optical systems, spectroscopy, and optomechanics.

  4. Uptake, translocation, and toxicity of gold nanorods in maize

    Science.gov (United States)

    Moradi Shahmansouri, Nastaran

    Nanomaterials are widely used in many different products, such as electronics, cosmetics, industrial goods, biomedical uses, and other material applications. The heavy emission of nanomaterials into the environment has motived increasing concern regarding the effects on ecosystems, food chains, and, human health. Plants can tolerate a certain amount of natural nanomaterials, but large amounts of ENMs released from a variety of industries could be toxic to plants and possibly threaten the ecosystem. Employing phytoremediation as a contamination treatment method may show promise. However a pre-requisite to successful treatment is a better understanding of the behavior and effects of nanomaterials within plant systems. This study is designed to investigate the uptake, translocation, bioavailability, and toxicity of gold nanorods in maize plants. Maize is an important food and feed crop that can be used to understand the potential hazardous effects of nanoparticle uptake and distribution in the food chain. The findings could be an important contribution to the fields of phytoremediation, agri-nanotechnology, and nanoparticle toxicity on plants. In the first experiment, hydroponically grown maize seedlings were exposed to similar doses of commercial non-coated gold nanorods in three sizes, 10x34 nm, 20x75 nm, and 40x96 nm. The three nanorod species were suspended in solutions at concentrations of 350 mg/l, 5.8 mg/l, and 14 mg/l, respectively. Maize plants were exposed to all three solutions resulting in considerably lower transpiration and wet biomass than control plants. Likewise, dry biomass was reduced, but the effect is less pronounced than that of transpiration and wet biomass. The reduced transpiration and water content, which eventually proved fatal to exposed plants, were most likely a result of toxic effect of gold nanorod, which appeared to physically hinder the root system. TEM images proved that maize plants can uptake gold particles and accumulate them in

  5. Surfactant-directed synthesis of silver nanorods and characteristic spectral changes occurred by their morphology evolution

    Science.gov (United States)

    Zhang, Wen; Hu, Guansong; Zhang, Wanzhong; Qiao, Xueliang; Wu, Kai; Chen, Qingyuan; Cai, Yuchun

    2014-11-01

    Silver nanorods with different polydispersity were synthesized in the cetyltrimethylammonium bromide (CTAB) rod-shaped micelles by inducing the orientation growth of silver seeds and adjusting the volumes of CTAB. The reaction for the formation of silver nanorods had basically finished in 10 min. A suitable volume of CTAB (i.e., 15.0 mL of 0.1 M CTAB) is beneficial to obtain high-quality silver nanorods in the given reaction system. That is, the volume of added CTAB is a key factor to determine the polydispersity of the formed nanorods. The aging time plays a critical role in the morphology evolution of silver nanorods due to the oxidation of silver nanorods with Br-, O2 and the Ostwald ripening of the nanoparticles. As a result, the characteristic spectral changes occurred due to the morphology evolution of silver nanorods. The ablation in the top ends of the longer nanorods is often accompanied by the growth of some shorter nanorods and nanospheres. The size distribution of silver nanorods might be more uniform in the early aging stage. All the nanorods in the colloidal solution should turn into the near-spherical nanoparticles with larger sizes and thus the characteristic absorption should change to single peak centered at about 400 nm. Based on the research results, mathematical models are proposed for explaining the formation and morphology changes of silver nanorods. The morphology evolution of silver nanorods may be important and can be used as a reference for preparing silver nanorods, nanowires and other anisotropic nanomaterials.

  6. Structure and properties of porous ceramics obtained from aluminum hydroxide

    Science.gov (United States)

    Levkov, R.; Kulkov, S.

    2016-08-01

    In this paper the study of porous ceramics obtained from aluminum hydroxide with gibbsite modification is presented. The dependence of porosity and mechanical characteristics of the material sintered at different temperatures was studied. It was shown that compressive strength of alumina ceramics increases by 40 times with decreasing the pore volume from 65 to 15%. It was shown that aluminum hydroxide may be used for pore formation and pore volume in the sintered ceramics can be controlled by varying the aluminum hydroxide concentration and sintering temperature. Based on these results one can conclude that the obtained structure is very close to inorganic bone matrix and can be used as promising material for bone implants production.

  7. ANTIBACTERIAL EFFECT OF CALCIUM HYDROXIDE IN DIFFER ENT VEHICLES

    Directory of Open Access Journals (Sweden)

    Hari

    2012-11-01

    Full Text Available ABSTRACT: AIM: This study evaluated the antibacterial effect of ca lcium hydroxide in different vehicles in an in vitro model. MATERIAL AND METHODS: Calcium hydroxide paste prepared with two conventionally used vehicles namely, campho rated monochlophenol, distilled water and also propylene glycol. The antibacterial activity of these paste were tested against five micro- organisms that can commonly occur in the inf ected root canals. RESULTS AND CONCLUSIONS: The results of the study indicate that a paste of ca lcium hydroxide made with propylene glycol exerts significant antibacterial act ion. Hence, it can be recommended for use as an intracanal medicament in preference to a paste prepa red with a tissue toxic phenolic compound like camphorated mono chlorophenol

  8. Oxidative leaching of chromium from layered double hydroxides: Mechanistic studies

    Indian Academy of Sciences (India)

    A V Radha; P Vishnu Kamath

    2004-08-01

    The layered double hydroxide (LDH) of Zn with Cr on treatment with a hypochlorite solution releases chromate ions as a result of oxidative leaching by a dissolution–reprecipitation mechanism. The residue is found to be -Zn(OH)2. The LDH of Mg with Cr on the other hand is resistant to oxidative leaching. In contrast, a X-ray amorphous gel of the coprecipitated hydroxides of Mg and Cr yields chromate ions. These results suggest that the oxidation potential of Cr(III) in LDHs is determined by the nature of the divalent ion and the crystallinity of the phase while being unaffected by the nature of the intercalated anions.

  9. The effect of sodium hydroxide treatment on biomass binder preparation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.; Xu, D.; Xu, Z.; Chen, Q. [China University of Mining and Technology, Beijing (China). Beijing Campus

    2001-02-01

    The possibility of rice straw which has been treated with sodium hydroxide for use as coal briquette binder was studied. The main factor which influenced the binder preparation was the concentration of sodium hydroxide. It was found that the binding ability of the solid component was higher than the liquid part. The prepared rice straw binder was mixed with inorganic material, bentonite, or high molecular synthetic organic materials to manufacture a compound coal briquette binder. This compound binder is waterproofing and can further enhance the strength of the briquette. 5 refs., 5 figs., 2 tabs.

  10. A high-performance carbon derived from corn stover via microwave and slow pyrolysis for supercapacitors

    DEFF Research Database (Denmark)

    Jin, Hong; wang, Xiaomin; Shen, Yanbin

    2014-01-01

    Microwave and slow pyrolysis were conducted for converting corn stover to biochar. Chemical agents of sodium hydroxide and potassium hydroxide were used to progressively produce activated carbon. The pore structures and surface area of the samples were characterized by nitrogen adsorption...

  11. A high-performance carbon derived from corn stover via microwave and slow pyrolysis for supercapacitors

    DEFF Research Database (Denmark)

    Jin, Hong; wang, Xiaomin; Shen, Yanbin

    2014-01-01

    Microwave and slow pyrolysis were conducted for converting corn stover to biochar. Chemical agents of sodium hydroxide and potassium hydroxide were used to progressively produce activated carbon. The pore structures and surface area of the samples were characterized by nitrogen adsorption...

  12. Double layered hydroxides as potential anti-cancer drug delivery agents.

    Science.gov (United States)

    Riaz, Ufana; Ashraf, S M

    2013-04-01

    The emergence of nanotechnology has changed the scenario of the medical world by revolutionizing the diagnosis, monitoring and treatment of cancer. This nanotechnology has been proved miraculous in detecting cancer cells, delivering chemotherapeutic agents and monitoring treatment from non-specific to highly targeted killing of tumor cells. In the past few decades, a number of inorganic materials have been investigated such as calcium phosphate, gold, carbon materials, silicon oxide, iron oxide, and layered double hydroxide (LDH) for examining their efficacy in targeting drug delivery. The reason behind the selection of these inorganic materials was their versatile and unique features efficient in drug delivery, such as wide availability, rich surface functionality, good biocompatibility, potential for target delivery, and controlled release of the drug from these inorganic nanomaterials. Although, the drug-LDH hybrids are found to be quite instrumental because of their application as advanced anti-cancer drug delivery systems, there has not been much research on them. This mini review is set to highlight the advancement made in the use of layered double hydroxides (LDHs) as anti-cancer drug delivery agents. Along with the advantages of LDHs as anti-cancer drug delivery agents, the process of interaction of some of the common anti-cancer drugs with LDH has also been discussed.

  13. Cobalt hydroxide nanoflakes and their application as supercapacitors and oxygen evolution catalysts

    Science.gov (United States)

    Rovetta, A. A. S.; Browne, M. P.; Harvey, A.; Godwin, I. J.; Coleman, J. N.; Lyons, M. E. G.

    2017-09-01

    Finding alternative routes to access and store energy has become a major issue recently. Transition metal oxides have shown promising behaviour as catalysts and supercapacitors. Recently, liquid exfoliation of bulk metal oxides appears to be an effective route which provides access to two-dimensional (2D) nano-flakes, the size of which can be easily selected. These 2D materials exhibit excellent electrochemical charge storage and catalytic activity for the oxygen evolution reaction. In this study, various sized selected cobalt hydroxide nano-flake materials are fabricated by this time efficient and highly reproducible process. Subsquently, the electrochemical properties of the standard size Co(OH)2 nanoflakes were investigated. The oxide modified electrodes were prepared by spraying the metal oxide flake suspension onto a porous conductive support electrode foam, either glassy carbon or nickel. The cobalt hydroxide/nickel foam system was found to have an overpotential value at 10 mA cm-2 in 1 M NaOH as low as 280 mV and an associated redox capacitance exhibiting numerical values up to 1500 F g-1, thereby making it a viable dual use electrode.

  14. Advanced phosphorus removal from membrane filtrates by adsorption on activated aluminium oxide and granulated ferric hydroxide.

    Science.gov (United States)

    Genz, Arne; Kornmüller, Anja; Jekel, Martin

    2004-09-01

    The advanced phosphorus (P) removal by adsorption was studied for its suitability as a post-treatment step for membrane bioreactor (MBR) effluents low in P concentration and particle content. Two commercial adsorbents, granulated ferric hydroxide (GFH) and activated aluminium oxide (AA), were studied in batch tests and lab-scale filter tests for P adsorption in MBR filtrates. GFH showed a higher maximum capacity for phosphate and a higher affinity at low P concentrations compared to AA. Competition by inorganic ions was negligible for both adsorbents at the original pH (8.2). When equilibrium P concentrations exceeded 2 mg L(-1) in the spiked MBR filtrates, a precipitation of calcium phosphates occurred additionally to adsorption. During column studies the effluent criteria of 50 microgL(-1) P was reached after a throughput of 8000 bed volumes for GFH and 4000 for AA. Dissolved organic carbon appears to be the strongest competitor for adsorption sites. A partial regeneration and reloading of both adsorbents could be achieved by the use of sodium hydroxide.

  15. Mechanochemical synthesis of Cu-Al and methyl orange intercalated Cu-Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun, E-mail: forsjun@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); He, Xiaoman; Chen, Min; Hu, Huimin [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Zhang, Qiwu, E-mail: zhangqw@whut.edu.cn [School of Resources and Environmental Engineering, Wuhan University of Technology, Luoshi Road 122, Wuhan, Hubei 430070 (China); Liu, Xinzhong [College of Ecological Environment and Urban Construction, Fujian University of Technology, Fuzhou 350118 China (China)

    2017-04-15

    In this study, a mechanochemical route to synthesize a Cu-Al layered double hydroxide (LDH) and a methyl orange (MO) intercalated one (MO-LDH) was introduced, in which basic cupric carbonate (Cu{sub 2}(OH){sub 2}CO{sub 3}) and aluminum hydroxide (Al(OH){sub 3}) with Cu/Al molar ratio at 2/1 was first dry ground for 2 h and then agitated in water or methyl orange solution for another 4 h to obtain the LDH and MO-LDH products without any heating operation. The prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG), Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM). The products showed high crystallinity phase of Cu-Al and MO intercalated Cu-Al LDH with no evident impurities, proving that the craft introduced here was facile and effective. The new idea can be applied in other fields to produce organic-inorganic composites. - Highlights: • A facile mechanochemical route to synthesize Cu-Al and MO intercalated Cu-Al LDH. • The products possesses high crystalline of LDH phase with no impure phases. • The dry milling process induces the element substitution between the raw materials. • The agitation operation helps the grain growth of LDH.

  16. Influence of pH on the thixotropy of magnesium aluminum hydroxide-kaolinite suspension

    Institute of Scientific and Technical Information of China (English)

    DAI; Xiaonan

    2001-01-01

    [1]Chen Zongqi, Shi Lin, Wu Shiying et al., The negative thixotropy, Chemistry (in Chinese), 1991, 54(2): 31-34.[2]Hou Wanguo, Sun Dejun, Han Shuhua et al., A novel thixotropic phenomenon-complex thixotropic behavior, Chem. Res. Chin. Univ., 1997, 13(1): 86-88.[3]Mo 2+ Al3+[4]Constantino. V. R. L., Pinnavaia, T. J., Basic properties of Mg2+l-x Ai3+x layered double hydroxides intercalated by carbonate. hydroxide, chloride, and sulfate anions, Inorg. Chem., 1995, 34(4): 883-892.[5]Albiston, L., Frankin, K. R., Lee, E. et al., Rheology and microstructure of aqueous layered double hydroxide dispersions, J. Mater. Chem., 1996, 6(5): 871-877.[6]Abend, S., Bonnke, N., Gutschner, U. et al., Stabilization of emulsions by heterocoagulation of clay minerals and layered double hydroxides, Colloid Polym. Sci., 1998, 276(8): 730-737.[7]Heckroodt, R. O., Ryan, W., Clay suspensions with negative thixotropy, Trans. J. Brit. Ceram. Sci., 1978, 77(2): 180- 183.[8]Chen Zongqi, Yu Wanglin, Hao Ce et al., The rheological properties of SiO2 suspension and PHPA system, Acta Chimica Sinica, 1990, 48(7): 666-72.[9]Benna, M., Kbir-Ariguib, N., Magnin, A. et al., Effect of pH on rheological properties of purified sodium bentonite suspensions, J. Colloid Interface Sci., 1999, 218(4): 442-445.[10]Sohm, R., Tadros, T. F., Viscoelastic Properties of sodium montmorillonite (Gelwhite H) suspensions, J. Colloid Interface Sci.. 1989, 132(1): 62-71.[11]Torrance, K. J., Pirmat, M., Effect of pH on the rheology of marine clay from the site of the south Nation River, Clays Clay Miner, 1984, 32(5): 384-390.[12]Heath, D., Tadros, T. F., Influence of pH, electrolyte, and poly (vinyl alcohol) addition on the rheological characteristics of aqueous dispersions of sodium montmorillonite, J. Colloid Interface Sci., 1983, 93(2): 307-319.

  17. Structural evolution of SnO 2 nanostructure from core-shell faceted pyramids to nanorods and its gas-sensing properties

    Science.gov (United States)

    Das, Soumen; Kim, Dae-Young; Choi, Cheol-Min; Hahn, Y. B.

    2011-01-01

    Tin oxide (SnO 2) nanorods were synthesized through an aqueous hexamethylenetetramine (HMTA) assisted synthesis route and their structural evolution from core-shell type faceted pyramidal assembly was investigated. Structural analysis revealed that the as-synthesized faceted SnO 2 structures were made of randomly arranged nanocrystals with diameter of 2-5 nm. The shell thickness (0-80 nm) was dependent on the molar concentration of HMTA (1-10 mM) in aqueous solution. It was revealed that the self-assembly was possible only with tin (II) chloride solution as precursor and not with tin (IV) chloride solution. At longer synthesis hours, the pyramidal nanostructures were gradually disintegrated into single crystalline nanorods with diameter of about 5-10 nm and length of about 100-200 nm. The SnO 2 nanorods showed high sensitivity towards acetone, but they were relatively less sensitive to methane, butane, sulfur dioxide, carbon monoxide and carbon dioxide. Possible mechanisms for the growth and sensing properties of the nanostructures were discussed.

  18. Carbonation of metal silicates for long-term CO.sub.2 sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Blencoe, James G.; Palmer, Donald A.; Anovitz, Lawrence M.; Beard, James S.

    2017-08-01

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  19. Fabrication and efficient visible light photocatalytic properties of novel zinc indium sulfide (ZnIn2S4) - graphitic carbon nitride (g-C3N4)/bismuth vanadate (BiVO4) nanorod-based ternary nanocomposites with enhanced charge separation via Z-scheme transfer.

    Science.gov (United States)

    Jo, Wan-Kuen; Natarajan, Thillai Sivakumar

    2016-11-15

    Novel ZnIn2S4-g-C3N4/BiVO4 nanorod-based ternary nanocomposite photocatalysts with enhanced visible light absorption were synthesized and systematically characterized to confirm the formation of ZnIn2S4 marigold flowers, the layered structure of the g-C3N4, BiVO4 nanorods, and the formation of binary and ternary nanocomposites. The visible light absorption of BiVO4 was significantly improved after coupling with g-C3N4 and ZnIn2S4, which was confirmed by UV-visible diffuse reflectance spectroscopic analysis. Ternary ZnIn2S4-g-C3N4/BiVO4 nanocomposites exhibited excellent visible light photocatalytic decomposition efficiency (VL-PDE) when used for the degradation of congo red (CR) dye and metronidazole (MTZ) pharmaceutical, as well as excellent stability and reusability. The ternary 5%ZnIn2S4-50%-g-C3N4/BiVO4 nanocomposite showed higher VL-PDE for CR (81.5%) and MTZ (59%) degradation than the binary composites, g-C3N4 and BiVO4. Radical quenching experiments showed that h(+), OH, and O2(-) were the reactive radicals, validating that the Z-scheme charge carrier transfer mechanism was responsible for the enhanced VL-PDE of the ternary ZnIn2S4-g-C3N4/BiVO4 nanocomposites, which was further confirmed by photoluminescence analysis. Furthermore, kinetic studies showed that the degradation followed pseudo-first-order kinetics, and that the ternary photocatalysts could be reused up to three times with good stability. The enhanced visible light absorption, high surface area, high adsorption capacity, Z-scheme charge carrier transfer, and increased lifetime of photo-produced electron-hole pairs were responsible for the increased visible light photocatalytic decomposition efficiency.

  20. Synthesis of non-aggregated nicotinic acid coated magnetite nanorods via hydrothermal technique

    Energy Technology Data Exchange (ETDEWEB)

    Attallah, Olivia A., E-mail: olivia.adly@hu.edu.eg [Center of Nanotechnology, Nile University, 12677 Giza (Egypt); Pharmaceutical Chemistry Department, Heliopolis University, 11777 El Salam, Cairo (Egypt); Girgis, E. [Solid State Physics Department, National Research Center, 12622 Dokki, Giza (Egypt); Advanced Materials and Nanotechnology Lab, CEAS, National Research Center, 12622 Dokki, Giza (Egypt); Abdel-Mottaleb, Mohamed M.S.A. [Center of Nanotechnology, Nile University, 12677 Giza (Egypt)

    2016-02-01

    Non-aggregated magnetite nanorods with average diameters of 20–30 nm and lengths of up to 350 nm were synthesized via in situ, template free hydrothermal technique. These nanorods capped with different concentrations (1, 1.5, 2 and 2.5 g) of nicotinic acid (vitamin B3); possessed good magnetic properties and easy dispersion in aqueous solutions. Our new synthesis technique maintained the uniform shape of the nanorods even with increasing the coating material concentration. The effect of nicotinic acid on the shape, particle size, chemical structure and magnetic properties of the prepared nanorods was evaluated using different characterization methods. The length of nanorods increased from 270 nm to 350 nm in nicotinic acid coated nanorods. Goethite and magnetite phases with different ratios were the dominant phases in the coated samples while a pure magnetite phase was observed in the uncoated one. Nicotinic acid coated magnetic nanorods showed a significant decrease in saturation magnetization than uncoated samples (55 emu/g) reaching 4 emu/g in 2.5 g nicotinic acid coated sample. The novel synthesis technique proved its potentiality to prepare coated metal oxides with one dimensional nanostructure which can function effectively in different biological applications. - Highlights: • We synthesize nicotinic acid coated magnetite nanorods via hydrothermal technique • Effect of nicotinic acid concentration on the nanorods properties was significant • Nanorods maintained uniform shape with increased concentration of nicotinic acid • Alterations occurred in particle size, mineral phases and magnetics of coated samples.

  1. Rapid synthesis of gold nanorods using a one-step photochemical strategy.

    Science.gov (United States)

    Ahmed, Marya; Narain, Ravin

    2010-12-07

    Rapid synthesis of gold nanorods of controlled dimensions is one of the desired aspects of nanotechnology as a result of the potential of these nanomaterials for biomedical applications. The synthesis of gold nanorods has been achieved using a photoinitiator as an instant source of ketyl radicals, which allows the synthesis of gold nanorods in minutes. This is the first report providing a one-step synthesis of nanorods of controlled dimensions in 20-30 min using photoinitiator I-2959 as a source of ketyl radicals. Furthermore, the role of UV intensity, the concentration of silver ions, and the presence of cosolvents and a cosurfactant have been studied in detail in an effort to produce nanorods with controlled dimensions in higher yields. The role of acetone in nanorod synthesis has been explored in detail, and it has been demonstrated that, for the photochemical synthesis of nanorods using a photoinitiator, acetone is not a critical component and can be replaced by other water-miscible solvents, thus the successful synthesis of nanorods in tetrahydrofuran (THF) has been demonstrated. It has also been found that a cosurfactant and an organic solvent are not required for the synthesis of nanorods; however, their presence is found to improve the monodispersity of nanorod samples, in addition to providing a higher yield.

  2. Using gold nanorods and nanoshells in photothermal cancer therapy

    Science.gov (United States)

    Nhung, Tran; Duong, Vu; Tracy, Dustin; Drosdoff, David; Woods, Lilia; Nguyen, Huong; Nga, Do; Viet, N. A.; Phan, Anh

    2014-03-01

    The ability of strongly absorbing near-infrared radiation and efficiently scattering photon energy of gold nanoshells and nanorods has been investigated for cancer treatments. The nanostructures sizes are chosen to achieve a surface plasmon resonance localized peak in the ``human-being skin windows'' (650-900 nm), which is the best possible regime of operation for cancer treatment. After injecting nanoshell and nanorod solutions into chicken tissues, variations of temperature of samples as a function of time with and without near-infrared-light irradiation at 808 nm are reported. The temperature of chicken tissues injected with nanorods is found to be greater than that of the samples with nanoshells for the same absorbance of nanomaterials. The photothermal transduction efficiency of nanorods is also proved to be higher than that of nanoshells. Our theoretical calculations show excellent agreement with the experimental data. This work was supported by the Nafosted Grant No. 103.01-2013.25 and 103.06.101.09. THN is partially supported by USDA NIFA grant 2013-67017-21221. L.M.W. acknowledges support from the Department of Energy under contract DE-FG02-06ER46297.

  3. Surfactant-Assisted Hydrothermal Synthesis of PMN-PT Nanorods

    Science.gov (United States)

    Li, Chuan; Liu, Xingzhao; Luo, Wenbo; Xu, Dong; He, Kai

    2016-02-01

    The effects of surfactant polyacrylate acid (PAA) on shape evolution of 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (0.7PMN-0.3PT) nanorods were studied. The results revealed that the polyacrylic acid content had great influence on the morphology of 0.7PMN-0.3PT. With increasing PAA concentration from 0.45 to 0.82 g/ml, the ratio of perovskite phase (PMN-PT nanorod) increased, while the ratio of pyrochlore phase decreased. When the PAA concentration was 0.82 g/ml, pure 0.7PMN-0.3PT nanorods were obtained. However, when PAA concentration was higher than 0.82 g/ml, the excess of PAA would hindered their [100] orientation growth. The piezoelectric coefficient d 33 of 0.7PMN-0.3PT nanorod was obtained by linear fitting, and the d 33 value was 409 pm/V.

  4. Resonances and permittivity dispersion effects in ITO nanorod arrays

    CERN Document Server

    Li, Shi-Qiang; Ketterson, John B; Chang, Robert P H

    2014-01-01

    In the nanophotonics community, there is an active discussion regarding the origin of the selective absorption/scattering of light by the resonances with nanorod arrays. Here we report a study of the resonances in ordered indium-tin-oxide (ITO) nanorod arrays from the perspective of waveguides. We discover that with only 2.4% geometrical coverage, the micron-length nanorod arrays strongly interact with light across an extra-wide band from visible to mid-infrared resulting in less than 10% transmission at the first order destructive interference. Simulations show excellent agreement with our experimental observation. Near-field profile obtained from simulation reveals the electric field is mainly localized on the surfaces of the nanorods at all the resonances. Theoretical analysis is then applied to explain the resonances and it was found that the resonances in the visible are different from those in the infrared. The former resonances are the result of the interference between guided wave and wave propagated ...

  5. Microspectroscopic characterisation of gold nanorods for cancer cell detection

    NARCIS (Netherlands)

    Hartsuiker, Liesbeth

    2011-01-01

    Gold nanoparticles have a long history in the biomedical applications. Recently in particular gold nanorods (GNR) have attracted attention. From a biocompatability point of view as well as from an optical angle, GNR are promising contrast enhancing agents in tumour detection. However, before GNR can

  6. Metastability of multitwinned Ag nanorods: Molecular dynamics study

    Science.gov (United States)

    Monk, J.; Hoyt, J. J.; Farkas, D.

    2008-07-01

    Nanoscale rods have been shown to exhibit a multiple twinned structure. The rods grow along a [110]-type crystallographic direction and have a pentagonal cross section with five (111) twins connecting the wire center to the corners of the pentagon. Here, we use molecular dynamics simulations with an embedded atom method interatomic potential for Ag to compute the ground-state energies of the multitwinned rods and compare with the bulk equilibrium crystal shape, as estimated from a Wulff construction. The excess energy of the nontwinned equilibrium nanorods and the multitwinned nanorods was obtained as a function of the wire length (L) as well as the cross sectional area (Acs) . Various contributions to the total energy, such as twin boundary energy and surface energies, are discussed and included in an analytical model that compares favorably with the simulation results. Our results show that for infinitely long nanowires with Acs<1500nm2 , the nontwinned structure is always energetically favorable. However, if the energy of the dipyramidal atomic structure at the nanorod ends is included in the model then the twinned nanorods are stable with respect to the nontwinned rods below a critical aspect ratio (L/Acs) .

  7. A Surface Acoustic Wave Ethanol Sensor with Zinc Oxide Nanorods

    Directory of Open Access Journals (Sweden)

    Timothy J. Giffney

    2012-01-01

    Full Text Available Surface acoustic wave (SAW sensors are a class of piezoelectric MEMS sensors which can achieve high sensitivity and excellent robustness. A surface acoustic wave ethanol sensor using ZnO nanorods has been developed and tested. Vertically oriented ZnO nanorods were produced on a ZnO/128∘ rotated Y-cut LiNbO3 layered SAW device using a solution growth method with zinc nitrate, hexamethylenetriamine, and polyethyleneimine. The nanorods have average diameter of 45 nm and height of 1 μm. The SAW device has a wavelength of 60 um and a center frequency of 66 MHz at room temperature. In testing at an operating temperature of 270∘C with an ethanol concentration of 2300 ppm, the sensor exhibited a 24 KHz frequency shift. This represents a significant improvement in comparison to an otherwise identical sensor using a ZnO thin film without nanorods, which had a frequency shift of 9 KHz.

  8. Gd(III) functionalized gold nanorods for multimodal imaging applications.

    Science.gov (United States)

    Sun, Hongmei; Yuan, Qinghai; Zhang, Baohua; Ai, Kelong; Zhang, Pengguo; Lu, Lehui

    2011-05-01

    We demonstrate a novel noncovalent method for producing Gd(III)-functionalized gold nanorods as multimodal contrast agents for MRI and CT imaging. The ligand is connected to the surface of the gold nanorods by a noncovalent bond making the Gd(III) ions directly accessible to water molecules, and resulting in a longitudinal relaxivity as high as 21.3 mM(-1) s(-1). In addition, compared with spherical gold nanoparticles, gold nanorods have more binding sites for Gd(III) ions due to their large surface-to-volume ratio. Benefiting from the advantages of the new type of carry material and the novel fabrication approach, the multimodal imaging probes exhibit a high longitudinal relaxivity r(1) on the order of 1.1 × 10(7) mM(-1) s(-1) on a per-particle basis, which is 24 times higher than that of Gd(III)-ion-functionalized spherical gold nanoparticles. Furthermore, CT imaging shows that such nanoprobes could induce an efficient contrast enhancement when the gold concentration is at least equal to 1.31 mg ml(-1). These results demonstrate that the as-prepared Gd functionalized gold nanorods could provide a new and versatile platform for the development of multimodal imaging probes.

  9. Synthesis and tuning of gold nanorods with surface plasmon resonance

    Science.gov (United States)

    Shajari, Daryush; Bahari, Ali; Gill, Pooria; Mohseni, Mojtaba

    2017-02-01

    Gold nanostructures in general and gold nanorods in particular due to their plasmon resonance has been employed for many applications, such as biosensors. For the biosensors uses, gold nanorods remain popular and reproducibility of them is the most important and critical. In the present work we used six different CTAB (Hexadecyltrimethylammonium bromide) products and one BDAC (Benzyldimethylhexadecylammonium chloride) with varying silver nitrate concentration in the seed-mediated growth of gold nanostructures. We synthesized gold nanorods with varying aspect ratio up to 5.5 with a longitudinal surface plasmon resonance peak from 670 to 950 nm. We obtained excellent rod-shape gold nanostructures witch were reliable and reproducible with our method based on common seed-mediated growth. The synthesized nanostructures were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). Here, we report our method in more detail as a user-friendly guide for the production of gold nanorods and tuning of their aspect ratios.

  10. Plasmonic-cavity model for radiating nano-rod antennas

    DEFF Research Database (Denmark)

    Peng, Liang; Mortensen, N. Asger

    2014-01-01

    In this paper, we propose the analytical solution of nano-rod antennas utilizing a cylindrical harmonics expansion. By treating the metallic nano-rods as plasmonic cavities, we derive closed-form expressions for both the internal and the radiated fields, as well as the resonant condition and the ......In this paper, we propose the analytical solution of nano-rod antennas utilizing a cylindrical harmonics expansion. By treating the metallic nano-rods as plasmonic cavities, we derive closed-form expressions for both the internal and the radiated fields, as well as the resonant condition...... and the radiation efficiency. With our theoretical model, we show that besides the plasmonic resonances, efficient radiation takes advantage of (a) rendering a large value of the rods' radius and (b) a central-fed profile, through which the radiation efficiency can reach up to 70% and even higher in a wide...... frequency band. Our theoretical expressions and conclusions are general and pave the way for engineering and further optimization of optical antenna systems and their radiation patterns....

  11. Preparation and electrochemical characterization of manganese dioxide-zirconia nanorods

    Science.gov (United States)

    Muthuchudarkodi, R. R.; Vedhi, C.

    2015-04-01

    MnO2-ZrO2 nanorods were prepared by wet chemical method by mixing the solutions of MnSO4 and ZrOCl2 varying in the range (0.05-0.45 M) in aqueous NaOH at an elevated temperature. The morphologies of the synthesized products are characterized by scanning electron microscopy and transmission electron microscopy (TEM). X-ray diffraction (XRD) and energy-dispersive spectroscopic measurements were also employed for the characterization of the nanostructures. The synthesized nanoparticles were also characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, electrochemical impedance and cyclic voltammetric studies. The morphological studies of the nanoparticles revealed particle distribution with uniform rod-like structure. Energy-dispersive analysis indicated the presence of Mn, Zr and O. The nanostructures of the product were characterized by TEM studies and the mixed rod and granular structure that was found clearly indicated the presence of MnO2-ZrO2 mixed oxide. The size of the synthesized nanorod was found to be 20 nm. From XRD studies the size of the nanorods was found to be in the range 39-56 nm calculated by Debye-Scherrer's formula. Thermal stability of the nanorods was characterized by thermogravimetric and differential scanning colorimetric analysis. Cyclic voltammetric studies exhibit good adherent behavior on electrode surface and good electroactivity at a pH value of 1.0.

  12. WO{sub 3} nanorods prepared by low-temperature seeded growth hydrothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Chai Yan [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Abdul Razak, Khairunisak, E-mail: khairunisak@eng.usm.my [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); NanoBiotechnology Research and Innovation (NanoBRI), Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lockman, Zainovia, E-mail: zainovia@eng.usm.my [School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia)

    2014-03-05

    Highlights: • WO{sub 3} nanorods with 5–10 nm diameter were grown directly on seeded tungsten foil. • WO{sub 3} nanorods were successfully grown at low temperature of 80 °C. • WO{sub 3} nanorods were grown on the entire surface of the seed layer after 24 h. • Annealed nanorods showed better electrochromic properties than as-made nanorods. -- Abstract: This work describes the first tungsten oxide (WO{sub 3}) nanorods hydrothermally grown on W foil. WO{sub 3} nanorods were successfully grown at low hydrothermal temperature of 80 °C by seeded growth hydrothermal reaction. The seed layer was prepared by thermally oxidized the W foil at 400 °C for 0.5 h. This work discusses the effect of hydrothermal reaction and annealing period on the morphological, structural, and electrochromic properties of WO{sub 3} nanorods. Various hydrothermal reaction periods (8–24 h) were studied. Monoclinic WO{sub 3} nanorods with 5–10 nm diameter were obtained after hydrothermal reaction for 24 h. These 24 h WO{sub 3} nanorods were also annealed at 400 °C with varying dwelling periods (0.5–4 h). Electrochromic properties of WO{sub 3} nanorods in an acidic electrolyte were analyzed using cyclic voltammetry and UV–vis spectrophotometry. WO{sub 3} nanorods annealed at 400 °C for 1 h showed the highest charge capacity and the largest optical contrast among the 24 h WO{sub 3} films. The sample also showed good cycling stability without significant degradation. Based on the results, the reaction mechanism of WO{sub 3} nanorod formation on W foil was proposed.

  13. Effects of ammonium hydroxide on the structure and gas adsorption of nanosized Zr-MOFs (UiO-66).

    Science.gov (United States)

    Abid, Hussein Rasool; Ang, Ha Ming; Wang, Shaobin

    2012-05-21

    Several zirconium-based metal-organic frameworks (Zr-MOFs) have been synthesized using ammonium hydroxide as an additive in the synthesis process. Their physicochemical properties have been characterized by N(2) adsorption/desorption, XRD, SEM, FTIR, and TGA, and their application in CO(2) adsorption was evaluated. It was found that addition of ammonium hydroxide produced some effects on the structure and adsorption behavior of Zr-MOFs. The pore size and pore volume of Zr-MOFs were enhanced with the additive, however, specific surface area of Zr-MOFs was reduced. Using an ammonium hydroxide additive, the crystal size of Zr-MOF was reduced with increasing amount of the additive. All the samples presented strong thermal stability. Adsorption tests showed that capacity of CO(2) adsorption on the Zr-MOFs under standard conditions was reduced due to decreased micropore fractions. However, modified Zr-MOFs had significantly lower adsorption heat. The adsorption capacity of carbon dioxide was increased at high pressure, reaching 8.63 mmol g(-1) at 987 kPa for Zr-MOF-NH(4)-2.

  14. Effects of ammonium hydroxide on the structure and gas adsorption of nanosized Zr-MOFs (UiO-66)

    Science.gov (United States)

    Abid, Hussein Rasool; Ang, Ha Ming; Wang, Shaobin

    2012-05-01

    Several zirconium-based metal-organic frameworks (Zr-MOFs) have been synthesized using ammonium hydroxide as an additive in the synthesis process. Their physicochemical properties have been characterized by N2 adsorption/desorption, XRD, SEM, FTIR, and TGA, and their application in CO2 adsorption was evaluated. It was found that addition of ammonium hydroxide produced some effects on the structure and adsorption behavior of Zr-MOFs. The pore size and pore volume of Zr-MOFs were enhanced with the additive, however, specific surface area of Zr-MOFs was reduced. Using an ammonium hydroxide additive, the crystal size of Zr-MOF was reduced with increasing amount of the additive. All the samples presented strong thermal stability. Adsorption tests showed that capacity of CO2 adsorption on the Zr-MOFs under standard conditions was reduced due to decreased micropore fractions. However, modified Zr-MOFs had significantly lower adsorption heat. The adsorption capacity of carbon dioxide was increased at high pressure, reaching 8.63 mmol g-1 at 987 kPa for Zr-MOF-NH4-2.

  15. 21 CFR 73.1010 - Alumina (dried aluminum hydroxide).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Alumina (dried aluminum hydroxide). 73.1010 Section 73.1010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1010 Alumina (dried...

  16. Dewatering of alumino-humic sludge: impacts of hydroxide.

    Science.gov (United States)

    Bache, D H; Papavasilopoulos, E N

    2003-08-01

    The paper draws together information on factors which influence the conditioning and dewatering behaviour of an alum sludge gained from the coagulation of a low-turbidity coloured water. A principal focus is the potential impact of aluminium hydroxide on the sludge character. Background information is provided on the composition of the source floc for the domain pH 6.0-6.5 and Al>2.0mg/l. From this, there were many pointers to the presence of Al(OH)(3)(s) within the floc. A series of comparisons were made between an alum sludge and a hydroxide suspension at a concentration equivalent to the coagulant fraction within the sludge. The parameters studied included floc size, floc density, polymer adsorption and dewatering behaviour at different time-scales. In all cases, there were strong similarities in the behaviour of the two suspensions-indicating the potential impact of the hydroxide. There was also evidence of common features being displayed by both the organic fractions and the hydroxide. It was suggested that some of the behavioural features might emanate from a common fractal structure within the source floc, the fractal dimension (approximately 1) being insensitive to composition.

  17. Recent progress in polymer/layered double hydroxide nanocomposites

    Institute of Scientific and Technical Information of China (English)

    DING Peng; CHEN Wei; QU Baojun

    2006-01-01

    New developments in the studies of nanocomposites based on polymer matrixes and layered double hydroxides (LDHs)in recent years are reviewed combining our relative research work, among which the synthesis techniques, the physicochemical characterizations, and the improved material properties are especially discussed. The possible application of polymer/LDH nanocomposites is also proposed.

  18. Intratubular disinfection with tri-antibiotic and calcium hydroxide pastes.

    Science.gov (United States)

    Pereira, Thais Cristina; Vasconcelos, Layla Reginna Silva Munhoz De; Graeff, Marcia Sirlene Zardin; Duarte, Marco Antonio Hungaro; Bramante, Clóvis Monteiro; Andrade, Flaviana Bombarda De

    2017-03-01

    The aim of this study was to compare the in vitro intradentinal antimicrobial ability of the calcium hydroxide and tri-antibiotic pastes. Standard bovine dentin tubes were sterilized and then infected with Enterococcus faecalis by a new contamination protocol of great depths of dentin. The specimens were filled with the medications, divided into two test-groups: calcium hydroxide (Group 1) and tri-antibiotic (Group 2) pastes. After 15 days, the teeth were evaluated by microbiological culture and confocal laser scanning microscopy (CLSM) with viability dye assay LIVE/DEAD inside dentinal tubules. In experiment of culture, the bacterial collection of the dentin fragments was done for counting the colony-forming units. The tri-antibiotic paste had a slightly greater antimicrobial effect; however, there was no statistical difference between the groups. It was concluded that the tri-antibiotic paste and the calcium hydroxide paste exercise the same effect on intra-tubular decontamination against E. faecalis. So, due the multiples advantages, the calcium hydroxide paste can be the choice for dentinal decontamination in regenerative procedures.

  19. Clinical and radiographic outcomes of calcium hydroxide and formocresol pulpotomies performed by dental students.

    Science.gov (United States)

    Alaçam, Alev; Odabaş, Mesut E; Tüzüner, Tamer; Sillelioğlu, Hilal; Baygin, Ozgül

    2009-11-01

    The aim of this study was to compare the clinical and radiographic success rates of 3 pulpotomy techniques: formocresol, calcium hydroxide, and calcium hydroxide/iodoform. The pulpotomies were performed by fifth-year undergraduate dental students. Members of senior staff at the clinics supervised all of the procedures. Informed consent was obtained from each child's parents. The teeth were randomly assigned to the experimental (calcium hydroxide and calcium hydroxide/iodoform) or control (formocresol) groups. After coronal pulp removal and hemostasis, remaining pulp tissue was covered with calcium hydroxide or calcium hydroxide/iodoform paste in the experimental groups. In the control group, formocresol was placed with a cotton pellet over the pulp tissue for 5 minutes and removed; the pulp tissue was then covered with zinc oxide-eugenol. All teeth were restored with stainless-steel crowns. Clinical and radiographic successes and failures were recorded at 1-, 3-, 6-, and 12-month follow-ups by the authors. Data were statistically analyzed using chi-squared tests. The follow-up evaluations revealed that the clinical success rates were 89.7% for formocresol, 33.3% for calcium hydroxide, and 17.2% for calcium hydroxide/iodoform. The radiographic success rates were 89.7% for formocresol, 33.3% for calcium hydroxide, and 13.8% for calcium hydroxide/iodoform. Formocresol was superior to calcium hydroxide and calcium hydroxide/iodoform pastes for primary molar pulpotomies. Internal resorption was the most common radiographic failure in all 3 pulpotomy techniques.

  20. Facile synthesis of graphene oxide-modified lithium hydroxide for low-temperature chemical heat storage

    Science.gov (United States)

    Yang, Xixian; Huang, Hongyu; Wang, Zhihui; Kubota, Mitsuhiro; He, Zhaohong; Kobayashi, Noriyuki

    2016-01-01

    LiOH·H2O nanoparticles supported on graphene oxide (GO) were facilely synthesized by a hydrothermal process. The mean diameter of nanoparticles on the integrated graphene sheet was about 5-10 nm showed by SEM and TEM results. XRD results suggested that the nanoparticles are in good agreement with the data of LiOH·H2O. The as-prepared sample showed a greatly enhanced thermal energy storage density and exhibit higher rate of heat release than pure lithium hydroxide, and thermal conductivity of composites increased due to the introduction of nano carbon. LiOH·H2O/GO nanocomposites are novel chemical heat storage materials for potential highly efficient energy system.

  1. Large Scale Synthesis of NiCo Layered Double Hydroxides for Superior Asymmetric Electrochemical Capacitor

    Science.gov (United States)

    Li, Ruchun; Hu, Zhaoxia; Shao, Xiaofeng; Cheng, Pengpeng; Li, Shoushou; Yu, Wendan; Lin, Worong; Yuan, Dingsheng

    2016-01-01

    We report a new environmentally-friendly synthetic strategy for large-scale preparation of 16 nm-ultrathin NiCo based layered double hydroxides (LDH). The Ni50Co50-LDH electrode exhibited excellent specific capacitance of 1537 F g-1 at 0.5 A g-1 and 1181 F g-1 even at current density as high as 10 A g-1, which 50% cobalt doped enhances the electrical conductivity and porous and ultrathin structure is helpful with electrolyte diffusion to improve the material utilization. An asymmetric ultracapacitor was assembled with the N-doped graphitic ordered mesoporous carbon as negative electrode and the NiCo LDH as positive electrode. The device achieves a high energy density of 33.7 Wh kg-1 (at power density of 551 W kg-1) with a 1.5 V operating voltage.

  2. Layered double hydroxide nanosheet as a two-dimensional support of dense platinum nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Hyo Gyoung; Cho, Se Hee; Ji, Hong Geun [H and A PharmaChem, R and D center, Bucheon (Korea, Republic of); Lee, Jong Hyeon [Dept. of Chemistry, The Catholic University of Korea, Bucheon (Korea, Republic of)

    2017-02-15

    Transition metal nanoparticles (NPs) with a narrow size distribution have been intensively synthesized on various solid supports for anti-agglomeration, and high catalytic activity and selectivity. Layered double hydroxides (LDH) are currently attracting intense interest in the field of heterogeneous catalysis as catalyst supports. In order to obtain a well-crystallized LDH nanosheet, the as-synthesize d carbonate form of LDH was hydrothermally treated according to a reported procedure, and further reacted by anion-exchange with an aqueous solution of NaNO{sub 3} and acetate buffer to give the nitrate form of LDH. Dense and uniform Pt NPs were synthesized on the exfoliated LDH nanosheets through precursor exchange and thermal reduction of the precursor ions. In this nanocomposite, the Pt Nps were uniformly grown on the surface of the LDH nano sheet and the average size of Pt Nps was 2nm.

  3. Poly I-lactide-layered double hydroxide nanocomposites via in situ polymerization of I-lactide

    DEFF Research Database (Denmark)

    Katiyar, Vimal; Gerds, N.; Koch, C.B.;

    2010-01-01

    The use of clay nanofillers offers a potential route to improved barrier properties in polylactide films. Magnesium–aluminium layered double hydroxides (LDHs) are interesting in this respect and we therefore explored synthesis of PLA-LDH nanocomposites by ring-opening polymerization. This method...... is attractive because it should ensure good dispersion of LDH in the polymer. The effect of adding either LDH carbonate (LDH-CO3) or laurate-modified LDH (LDH-C12) was investigated. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that exfoliated nanocomposites were...... obtained when using LDH-C12 but that LDH-CO3 gave a partly phase-separated morphology. Thermogravimetric analysis showed that PLA-LDH combinations exhibited higher degradation onset temperatures and differential scanning calorimetry confirmed that LDHs can act as nucleating agents. However, PLA molecular...

  4. Synthesis of size-controlled faceted pentagonal silver nanorods with tunable plasmonic properties and self-assembly of these nanorods.

    Science.gov (United States)

    Pietrobon, Brendan; McEachran, Matthew; Kitaev, Vladimir

    2009-01-27

    Monodisperse size-controlled faceted pentagonal silver nanorods were synthesized by thermal regrowth of decahedral silver nanoparticle (AgNPs) in aqueous solution at 95 degrees C, using citrate as a reducing agent. The width of the silver nanorods was determined by the size of the starting decahedral particle, while the length was varied from 50 nm to 2 mum by the amount of new silver added to the growth solution. Controlled regrowth allowed us to produce monodisperse AgNPs with a shape of elongated pentagonal dipyramid (regular Johnson solid, J(16)). Faceted pentagonal particles exhibited remarkable optical properties with sharp plasmon resonances precisely tunable across visible and NIR. Due to the narrow size distribution, faceted pentagonal silver nanorods readily self-assembled into the 3-D arrays similar to smectic mesophases. Hexagonal arrangement in the array completely overrode five-fold symmetry of the nanorods. Overall, our findings highlight the importance of pentagonal symmetry in metal nanoparticles and offer a facile method of the preparation of monodisperse AgNPs with controlled dimensions and plasmonic properties that are promising for optical applications and functional self-assembly.

  5. Imidazolium ionic liquid induced one-step synthesis of -Fe2O3 nanorods and nanorod assemblies for lithium-ion battery

    Directory of Open Access Journals (Sweden)

    Shuting Xie

    2016-12-01

    Full Text Available α-Fe2O3 nanorods and nanorod assemblies are prepared via a facile one-step method with the assistance of imidazolium-based ionic liquid. The aspect ratio of synthesized nanorods is determined by the alkyl chain length of [Cnmim]+. The inter-molecular π−π interaction and intra-molecular dipole-dipole interaction among imidazole rings of [C4mim]+[PhCOO]− play critical roles in both nucleation and assembly processes of α-Fe2O3 nanorods. The α-Fe2O3 nanorod assemblies show an excellent performance in lithium-ion batteries with a reversible capacity of 1007.3 mA h g−1 at the rate of 500 mA g−1 after 150 cycles.

  6. Enantiomerization mechanism of thalidomide and the role of water and hydroxide ions.

    Science.gov (United States)

    Tian, Chuanjin; Xiu, Peng; Meng, Yan; Zhao, Wenyan; Wang, Zhigang; Zhou, Ruhong

    2012-11-05

    The significance of the molecular chirality of drugs has been widely recognized due to the thalidomide tragedy. Most of the new drugs reaching the market today are single enantiomers, rather than racemic mixtures. However, many optically pure drugs, including thalidomide, undergo enantiomerization in vivo, thus negating the single enantiomers' benefits or inducing unexpected effects. A detailed atomic level understanding of chiral conversion, which is still largely lacking, is thus critical for drug development. Herein, we use first-principle density function theory (DFT) to explore the mechanism of enantiomerization of thalidomide. We have identified the two most plausible interconversion pathways for isolated thalidomide: 1) proton transfer from the chiral carbon center to an adjacent carbonyl oxygen atom, followed by isomerization and rotation of the glutarimide ring (before the proton hops back to the chiral carbon atom); and 2) a pathway that is the same as "1", but with the isomerization of the glutarimide ring occurring ahead of the initial proton transfer reaction. There are two remarkable energy barriers, 73.29 and 23.59 kcal mol(-1), corresponding to the proton transfer and the rotation of the glutarimide ring, respectively. Furthermore, we found that water effectively catalyzes the interconversion by facilitating the proton transfer with the highest energy barrier falling to approximately 30 kcal mol(-1), which, to our knowledge, is the first time that this important role of water in chiral conversion has been demonstrated. Finally, we show that the hydroxide ion can further lower the enantiomerization energy barrier to approximately 24 kcal mol(-1) by facilitating proton abstraction, which agrees well with recent experimental data under basic conditions. Our current findings highlight the importance of water and hydroxide ions in the enantiomerization of thalidomide and also provide new insights into the mechanism of enantiomerization at

  7. Desalination and hydrogen, chlorine, and sodium hydroxide production via electrophoretic ion exchange and precipitation.

    Science.gov (United States)

    Shkolnikov, Viktor; Bahga, Supreet S; Santiago, Juan G

    2012-08-28

    We demonstrate and analyze a novel desalination method which works by electrophoretically replacing sodium and chloride in feed salt water with a pair of ions, calcium and carbonate, that react and precipitate out. The resulting calcium carbonate precipitate is benign to health, and can be filtered or settled out, yielding low ionic strength product water. The ion exchange and precipitation employs self-sharpening interfaces induced by movement of multiple ions in an electric field to prevent contamination of the product water. Simultaneously, the electrolysis associated with the electromigration produces hydrogen gas, chlorine gas, and sodium hydroxide. We conducted an experimental study of this method's basic efficacy to desalinate salt water from 100 to 600 mol m(-3) sodium chloride. We also present physicochemical models of the process, and analyze replacement reagents consumption, permeate recovery ratio, and energy consumption. We hypothesize that the precipitate can be recycled back to replacement reagents using the well-known, commercially implemented Solvay process. We show that the method's permeate recovery ratio is 58% to 46%, which is on par with that of reverse osmosis. We show that the method's energy consumption requirement over and above that necessary to generate electrolysis is 3 to 10 W h l(-1), which is on par with the energy consumed by state-of-the-art desalination methods. Furthermore, the method operates at ambient temperature and pressure, and uses no specialized membranes. The process may be feasible as a part of a desalination-co-generation facility: generating fresh water, hydrogen and chlorine gas, and sodium hydroxide.

  8. Growth of Au@Ag core-shell pentatwinned nanorods: tuning the end facets.

    Science.gov (United States)

    Zhang, Weiqing; Goh, Hao Ying Johnny; Firdoz, Shaik; Lu, Xianmao

    2013-09-16

    Au@Ag core-shell nanorods with tunable end facets are obtained by coating Au bipyramids (BPs) with Ag. The resultant nanorods exhibit a pentatwinned crystal structure with tips terminated with either {110} or {111} facets. The control over the end facets is achieved by varying the capping agents and tuning the reduction rate of Ag. Specifically, when Ag is reduced slowly, Au@Ag nanorods with flat {110} end facets are formed with cetyltrimethylammonium bromide (CTAB) as the capping agent. If CTAB is replaced with cetyltrimethylammonium chloride (CTAC), Au@Ag nanorods with tips terminated with {111} facets are obtained. However, at a high Ag reduction rate, dumbbell-shaped Au@Ag nanorods are formed, with either CTAB or CTAC as the capping agent. The morphological evolution of the nanorods in each case is closely followed and a growth mechanism is proposed.

  9. Enhanced performance of natural dye sensitised solar cells fabricated using rutile TIO2 nanorods

    Science.gov (United States)

    Akila, Y.; Muthukumarasamy, N.; Agilan, S.; Mallick, Tapas K.; Senthilarasu, S.; Velauthapillai, Dhayalan

    2016-08-01

    Due to the lower cost, natural dye molecules are good alternatives for the ruthenium based sensitizers in the dye-sensitized solar cells. In this article, we have reported the natural sensitizer based dye-sensitized solar cells fabricated using TiO2 nanorods. Rutile phase TiO2 nanorods have been synthesized by template free hydrothermal method which results in TiO2 nanorods in the form of acropora corals. These TiO2 nanorods have been sensitized by flowers of Sesbania grandiflora, leaves of Camellia sinensis and roots of Rubia tinctorum. The maximum conversion efficiency of 1.53% has been obtained for TiO2 nanorods based solar cells sensitized with the leaves of Camellia sinensis. The flowers of Sesbania grandiflora and roots of Rubia tinctorum sensitized TiO2 nanorods based solar cells exhibited an efficiency of 0.65% and 1.28% respectively.

  10. Simple and polarization-independent Dammann grating based on all-dielectric nanorod array

    Science.gov (United States)

    Yang, Sen; Li, Chuang; Liu, Tongming; Da, Haixia; Feng, Rui; Tang, Donghua; Sun, Fangkui; Ding, Weiqiang

    2017-09-01

    In this work, we comprehensively investigate a Dammann grating (DG) that can generate a 5 × 5 diffraction spot array with an extending angle of 18^\\circ × 18^\\circ around the fiber communication wavelength of 1550 {nm}. The DG is a simple metasurface structure composed of a silicon cuboid nanorod array on a silica substrate, and only two different sizes of nanorods with square cross-sections and uniform spatial orientations are used. These simple units and this configuration are favorable in practice, and the C4 symmetry cross section of the nanorods ensures the polarization-independent operation of the DG. The phase modulation of the nanorods is achieved by the guiding mode propagating in them rather than electric or magnetic Mie-type resonance, which makes the design of the cuboid nanorods easy and robust. More importantly, the two-dimensional nanorod array is generated from a one-dimensional array, which further decreases the design and fabrication complexity.

  11. Sonochemical synthesis of silver vanadium oxide micro/nanorods: solvent and surfactant effects.

    Science.gov (United States)

    Mohandes, Fatemeh; Salavati-Niasari, Masoud

    2013-01-01

    In this investigation, a facile sonochemical route has been developed for the preparation of silver vanadium oxide (SVO) micro/nanorods by using silver salicylate and ammonium metavanadate as silver and vanadate precursor, respectively. Here, silver salicylate, [Ag(HSal)], is introduced as a new silver precursor to fabricate AgVO(3) nanorods. The effect of numerous solvents and surfactants on the morphology and sonochemical formation mechanism of AgVO(3) nanorods was studied. AgVO(3) nanorods were characterized by SEM and TEM images, XRD patterns, FT-IR, XPS, and EDS spectroscopy. SEM, TEM, and XRD results showed that AgO nanoparticles were formed onto AgVO(3) nanorods in the presence of ethanol, cyclohexanol, dimethylsulfoxide (DMSO), and acetone. By using polyethylene glycol (PEG-6000) and N,N-dimethylformamide (DMF) as organic additives, the thickness of AgVO(3) nanorods decreased.

  12. Green Synthesis of Silver Nanorods and Optimization of Its Therapeutic Cum Toxic Dose.

    Science.gov (United States)

    Suganya, T R; Devasena, T

    2015-12-01

    Germinated Fenugreek seeds are relatively rich in flavonoids and polyphenols than dry seeds. Therefore, germinated fenugreek seeds possess better pharmacological activities. We have used an aqueous extract of germinated fenugreek seeds to reduce silver nitrate into nanoscale silver rods. The silver nanorods showed Surface Plasmon peak at 450 nm as revealed from UV visible spectrum. Field Emission Scanning Electron Microscopy images revealed the monodispersity and rod morphology. X ray diffraction spectrum revealed the FCC crystal structure of nanorods. Fourier transform infrared spectroscopy peaks revealed the interaction between the phytochemicals of germinated fenugreek seeds and the silver nanorods. Characterization studies reveal the validation of the proposed green synthesis protocol to produce monodispersed silver nanorods with phytochemical capping. The phytosynthesized silver nanorods exhibited anticancer activity in skin cancer cell line, which may be due to its nanoscale dimension and the surface functionalization. For the first time, we have optimized the therapeutic cum toxic dose of phytostabilized silver nanorods using skin cancer cell model.

  13. One-step growth of gold nanorods using a β-diketone reducing agent

    Science.gov (United States)

    Tollan, Christopher M.; Echeberria, Jon; Marcilla, Rebeca; Pomposo, José A.; Mecerreyes, David

    2009-07-01

    The synthesis and characterisation of gold nanorods have been carried out by reduction of the gold salt HAuCl4. This has been done using a single reducing agent, acetylacetone, rather than the two reducing agents, sodium borohydride and ascorbic acid, normally required by standard wet chemistry methods of gold nanorod formation. Using this novel method, the nanorods were synthesised at several different pH values which were found to greatly affect both the rate at which the nanorods form and their physical dimensions. The concentrations of acetylacetone and silver nitrate used relative to the gold salt were found to alter the aspect ratio of the nanorods formed. Rods with an average length of 42 nm and an aspect ratio of 4.6 can be easily and reproducibly formed at pH 10 using this method. Nanorods formed under optimum conditions were investigated using TEM.

  14. One-step growth of gold nanorods using a {beta}-diketone reducing agent

    Energy Technology Data Exchange (ETDEWEB)

    Tollan, Christopher M., E-mail: ctollan@cidetec.e [CIDETEC-Centre for Electrochemical Technologies, Parque Tecnologico de San Sebastian, New Materials Department (Spain); Echeberria, Jon [CEIT, Centro de Investigaciones Tecnicas de Guipuzcoa (Spain); Marcilla, Rebeca; Pomposo, Jose A.; Mecerreyes, David, E-mail: dmecerreyes@cidetec.e [CIDETEC-Centre for Electrochemical Technologies, Parque Tecnologico de San Sebastian, New Materials Department (Spain)

    2009-07-15

    The synthesis and characterisation of gold nanorods have been carried out by reduction of the gold salt HAuCl{sub 4}. This has been done using a single reducing agent, acetylacetone, rather than the two reducing agents, sodium borohydride and ascorbic acid, normally required by standard wet chemistry methods of gold nanorod formation. Using this novel method, the nanorods were synthesised at several different pH values which were found to greatly affect both the rate at which the nanorods form and their physical dimensions. The concentrations of acetylacetone and silver nitrate used relative to the gold salt were found to alter the aspect ratio of the nanorods formed. Rods with an average length of 42 nm and an aspect ratio of 4.6 can be easily and reproducibly formed at pH 10 using this method. Nanorods formed under optimum conditions were investigated using TEM.

  15. Free-standing ZnO nanorods and nanowalls by aqueous solution method.

    Science.gov (United States)

    Kim, Dae-Hee; Lee, Sam-Dong; Kim, Kyoung-Kook; Park, Gyeong-Su; Lee, Ji-Myon; Kim, Sang-Woo

    2008-09-01

    Large quantity of free-standing ZnO nanorods and nanowalls were synthesized at low temperature of below 100 degrees C using zinc acetate, zinc nitrate hexahydrate, and hexamethylenetetramine by using a simple aqueous solution method. The general morphology of the grown ZnO nanostructures which include nanorods and nanowalls was strongly influenced by growth conditions. It was found that the grown ZnO nanorods are of a single-crystalline hexagonal structure and preferred c-axis growth orientation. ZnO nanorods were of better crystallinity than ZnO nanowalls, due to the higher growth temperature used to grow ZnO nanorods. Strong free exciton emission bands with relatively weak deep level emission were clearly observed from ZnO nanorods and nanowalls, indicating their good optical properties.

  16. Size-controllable growth of ZnO nanorods on Si substrate

    Science.gov (United States)

    Yu, Zhentao; Li, Hui; Qiu, Yining; Yang, Xu; Zhang, Wu; Xu, Ning; Sun, Jian; Wu, Jiada

    2017-01-01

    Here we report a simple two-step chemical-solution-based method to grow highly oriented and size-controllable ZnO nanorods on ZnO-seeded Si substrate. The morphology of the grown ZnO nanorods was examined by field emission scanning electron microscopy. The structure was characterized by X-ray diffraction and Raman scattering spectrum. Photoluminescence spectra were measured at room temperature and low temperatures to evaluate the photoluminescence properties of the ZnO nanorods. The grown ZnO nanorods are structured with hexagonal wurtzite. The diameter and length of ZnO nanorods can be controlled by varying the crystal quality of the underlying ZnO seed layers. The crystal quality of the seed layers gets improved as the deposition time and annealing temperature for ZnO seed layers are increased. The effects of annealing on the ZnO nanorods were also studied.

  17. Synthesis of ZnO nanorods and their optical absorption in visible-light region

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Single crystalline ZnO nanorods were prepared by the hydrothermal method with synthesized ZnCl2.4Zn(OH)2as the precursor. Morphologies of the nanorods were controlled by various reaction conditions with cetyltrimethylammonium bromide (CTAB) as the modifying agent. The nanorods were characterized by XRD, TEM, UV-Vis spectra, and IR spectra. The microstructure of holes in nanosize was observed on the surface of the nanorods. The UV-Vis spectra indicate that the as-prepared ZnO nanorods have absorption of visible-light as well as ultraviolet-light. Therefore, these nanorods may be good candidates for visible-light photocatalysis materials from the viewpoint of practical applications. The reason for visible-light absorption was discussed in this article.

  18. Electrochemical synthesis of nickel-iron layered double hydroxide: application as a novel modified electrode in electrocatalytic reduction of metronidazole.

    Science.gov (United States)

    Nejati, Kamellia; Asadpour-Zeynali, Karim

    2014-02-01

    A new and simple approach based on the electrochemical method was used for preparation of reproducible nanostructure thin film of Ni/Fe-layered double hydroxides (Ni/Fe-LDH) on the glassy carbon electrode (GCE). The electrochemical behavior of the Ni/Fe-LDH deposited on GCE electrode is studied. Study of the scanning electron microscopy shows the formation of a nanostructure thin film on the glassy carbon electrode. Electrochemical experiments show that Ni/Fe-LDH modified glassy carbon electrode exhibits excellent electrocatalytic reduction activity with Metronidazole. The method was successfully applied for the analysis of Metronidazole in tablets. The results were favorably compared to those obtained by the reported BP method.

  19. Layered Double Hydroxides as Effective Adsorbents for U(VI and Toxic Heavy Metals Removal from Aqueous Media

    Directory of Open Access Journals (Sweden)

    G. N. Pshinko

    2013-01-01

    Full Text Available Capacities of different synthesized Zn,Al-hydrotalcite-like adsorbents, including the initial carbonate [Zn4Al2(OH12]·CO3·8H2O and its forms intercalated with chelating agents (ethylenediaminetetraacetic acid (EDTA, diethylenetriaminepentaacetic acid (DTPA, and hexamethylenediaminetetraacetic acid (HMDTA and heat-treated form Zn4Al2O7, to adsorb uranium(VI and ions of toxic heavy metals have been compared. Metal sorption capacities of hydrotalcite-like adsorbents have been shown to correlate with the stability of their complexes with the mentioned chelating agents in a solution. The synthesized layered double hydroxides (LDHs containing chelating agents in the interlayer space are rather efficient for sorption purification of aqueous media free from U(VI irrespective of its forms of natural abundance (including water-soluble bi- and tricarbonate forms and from heavy metal ions. [Zn4Al2(OH12]·EDTA·nH2O is recommended for practical application as one of the most efficient and inexpensive synthetic adsorbents designed for recovery of both cationic and particularly important anionic forms of U(VI and other heavy metals from aqueous media. Carbonate forms of LDHs turned out to be most efficient for recovery of Cu(II from aqueous media with pH0≥7 owing to precipitation of Cu(II basic carbonates and Cu(II hydroxides. Chromate ions are efficiently adsorbed from water only by calcinated forms of LDHs.

  20. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2).

  1. Fabrication and spectroscopic studies on highly luminescent CdSe/CdS nanorod polymer composites.

    Science.gov (United States)

    Bomm, Jana; Büchtemann, Andreas; Fiore, Angela; Manna, Liberato; Nelson, James H; Hill, Diana; van Sark, Wilfried G J H M

    2010-01-01

    Highly luminescent nanocomposites were prepared by incorporating CdSe/CdS core/shell nanorods into different polymer matrices. The resulting nanocomposites show high transparency of up to 93%. A photoluminescence quantum efficiency of 70% was obtained, with an optimum combination of nanorod (0.05 wt %) and at a UV-initiator concentration of 0.1 wt % for poly(lauryl methacrylate). Nanorods tend to agglomerate in cellulose triacetate.

  2. Fabrication and spectroscopic studies on highly luminescent CdSe/CdS nanorod polymer composites

    Directory of Open Access Journals (Sweden)

    Jana Bomm

    2010-11-01

    Full Text Available Highly luminescent nanocomposites were prepared by incorporating CdSe/CdS core/shell nanorods into different polymer matrices. The resulting nanocomposites show high transparency of up to 93%. A photoluminescence quantum efficiency of 70% was obtained, with an optimum combination of nanorod (0.05 wt % and at a UV-initiator concentration of 0.1 wt % for poly(lauryl methacrylate. Nanorods tend to agglomerate in cellulose triacetate.

  3. Superhydrophobicity and enhanced UV stability in vertically standing indium oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Kavita; Mehta, B.R.; Singh, J.P., E-mail: jpsingh@physics.iitd.ac.in

    2015-08-15

    Highlights: • Our results show the effect of nanorods alignment on contact angle. • Vertically standing indium oxide nanorods show superhydrophobic nature. • We examine the effect of solid fraction on the observed contact angle. • Wetting properties are also studied upon UV irradiation. • Vertically standing indium oxide nanorods show higher UV sustainability. - Abstract: Here, we report the emergence of superhydrophobic wetting behavior and enhanced UV stability of indium oxide (IO) nanorods due to their vertical alignment. Both randomly distributed and vertically aligned IO nanorods were synthesized via chemical vapor deposition (CVD) method. Our results reveal that the static water contact angle (θ) shows a significant dependence on the alignment of the nanorods. The randomly distributed IO nanorods shows θ value of 133.7° ± 6.8° whereas for vertically aligned IO nanorods θ was found to be 159.3° ± 4.8°. Interestingly, continuous UV light illumination for 30 min exhibited the change in contact angle (Δθ) of about 41° for vertically aligned IO nanorods whereas randomly distributed IO nanorods become hydrophilic with a dramatic change in θ value of 108°. The superhydrophobicity of vertically aligned IO nanorods and their enhanced UV stability were discussed by comparing the effective solid fraction at solid-liquid interface and the reactivity of surface crystallographic planes. The superhydrophobic surface of aligned vertically standing IO nanorods along with its resistance against photoinduced wetting transition make them suitable for electronic devices with reduced surface discharge even at relatively high humidity level.

  4. Polyoxometalate based soft chemical route for preparation of Pt nanorods and self-assemblies

    Indian Academy of Sciences (India)

    S Shanmugam; B Viswanathan; T K Varadarajan

    2005-10-01

    A soft chemical route is described for the preparation of platinum nanorods and self-assemblies over photochemically reduced polyoxometalate (silicotungstate) containing composite films. Transmission electron microscopy shows that the diameters of the platinum nanorods are around 55–60 nm. The formation of platinum nanorods on solid–liquid interface reactions was explained on the basis of single site growth mechanism and diffusion limitation aggregation process.

  5. One-step synthesis of silver nanoparticles, nanorods, and nanowires on the surface of DNA network.

    Science.gov (United States)

    Wei, Gang; Zhou, Hualan; Liu, Zhiguo; Song, Yonghai; Wang, Li; Sun, Lanlan; Li, Zhuang

    2005-05-12

    Here, we describe a one-step synthesis of silver nanoparticles, nanorods, and nanowires on DNA network surface in the absence of surfactant. Silver ions were first adsorbed onto the DNA network and then reduced in sodium borohydride solution. Silver nanoparticles, nanorods, and nanowires were formed by controlling the size of pores of the DNA network. The diameter of the silver nanoparticles and the aspect ratio of the silver nanorods and nanowires can be controlled by adjusting the DNA concentration and reduction time.

  6. Fast Formation of Surface Oxidized Zn Nanorods and Urchin-Like Microclusters

    Directory of Open Access Journals (Sweden)

    R. López

    2014-01-01

    Full Text Available Entangled Zn-ZnO nanorods and urchin-like microstructures were synthesized by the hot filament chemical vapor deposition technique at 825 and 1015°C, respectively. X-ray diffraction results showed a mixture of ZnO and Zn phases in both nanorods and urchin-like structures. The presence of Zn confirms the chemical dissociation of the ZnO solid source. The Z-ZnO nanorods with diameter of about 100 nm showed dispersed-like morphology. The urchin-like structures with micrometer diameters exhibited porous and rough morphology with epitaxial formation of nanorods.

  7. Gold Nanorods as Nanodevices for Bioimaging, Photothermal Therapeutics, and Drug Delivery.

    Science.gov (United States)

    Haine, Aung Thu; Niidome, Takuro

    2017-01-01

    Gold nanorods are promising metals in several biomedical applications such as bioimaging, thermal therapy, and drug delivery. Gold nanorods have strong absorption bands in near-infrared (NIR) light region and show photothermal effects. Since NIR light can penetrate deeply into tissues, their unique optical, chemical, and biological properties have attracted considerable clinical interest. Gold nanorods are expected to act not only as on-demand thermal converters for photothermal therapy but also as mediators of a controlled drug-release system responding to light irradiation. In this review, we discuss current progress using gold nanorods as bioimaging platform, phototherapeutic agents, and drug delivery vehicles.

  8. Evolution of electronic structure and spectral evaluation in single-crystal Mn3O4 nanorods

    Science.gov (United States)

    Chen, Zhiwen; Lai, Joseph K. L.; Shek, Chan-Hung

    2006-05-01

    Single-crystal Mn3O4 nanorods with tetragonal structure have been successfully prepared by a chemical reaction route. Transmission electron microscopy (TEM) and high-resolution TEM studies prove that the single-crystal Mn3O4 nanorod is smooth and straight, and that the geometrical shape is structurally perfect. We investigated the electronic characteristics of Mn3O4 nanorods by various spectral evaluations. The present study confirms that the hybridization between oxygen 2p and manganese 3d orbits plays an important role when considering electronic structures of Mn3O4 nanorods.

  9. Facile Hydrothermal Approach to ZnO Nanorods at Mild Temperature

    Directory of Open Access Journals (Sweden)

    Yang Jiao

    2013-01-01

    Full Text Available In this work, ZnO nanorods are obtained through a facile hydrothermal route. The structure and morphology of the resultant products are characterized by X-ray diffraction (XRD and scanning electron microscope (SEM. The experimental results indicated that the as-synthesized ZnO nanorods have an average diameter of approximate 100 nm. A possible growth mechanism for ZnO nanorods was proposed based on the experimental results and found that Zn powder plays a critical role for the morphology of the products. Room temperature photoluminescence property of ZnO nanorods shows an ultraviolet emission peak at 390 nm.

  10. Solvothermal Synthesis of Well-Disperse ZnS Nanorods with Efficient Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Yun Chen

    2012-01-01

    Full Text Available Well-disperse short-range-ordered ZnS nanorods with efficient photocatalytic property for photodegradation of Rhodamin B have been successfully synthesized through a solvothermal method. Solvent used can be recovered and reused, which makes the route environment-friendly. Dodecylamine was found effective in organizing nanorods to ordered monolayer. Characterization showed that these nanorods were uniform with the diameter of about 3 nm and length of nearly 30 nm. And it is expected that these monodisperse ZnS nanorods have potential applications in electroluminescence materials.

  11. Synthesis of silicon carbide nanorods by catalyst-assisted pyrolysis of polymeric precursor

    Science.gov (United States)

    Yang, Weiyou; Miao, Hezhuo; Xie, Zhipeng; Zhang, Ligong; An, Linan

    2004-01-01

    In this Letter, we report the synthesis of β-SiC nanorods by the pyrolysis of a polysilazane polymeric precursor in the presence of 3 wt% FeCl 2 as a catalyst. The precursor is completely converted to the nanorods after heat-treated at 1700 °C for 2 h, accompanied by ˜50% weight loss. Electron microscopy study reveals that the nanorods preferentially grow along [1 1 1] direction; and the diameters of the nanorods range from 80 to 200 nm and lengths are ˜4 μm. A solid-liquid-solid growth mechanism is proposed.

  12. Synthesis and Photocatalytic Performance of RGO/ZnO Nanorod Composites

    OpenAIRE

    Lu, Jia; WANG Hui-hu; DONG Yi-fan; Chang, Ying; MA Xin-guo; DONG Shi-jie

    2016-01-01

    ZnO nanorods and RGO/ZnO nanorods composites were prepared by hydrothermal method. The influence of RGO content on the photocatalytic activity of RGO/ZnO nanorods composites was studied. ZnO nanorods and RGO/ZnO nanocomposites were characterized by X-ray diffraction (XRD), field emission electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance UV-visible absorption spectroscopy techniques. The results show that RGO/ZnO samples are synthesized successfully. W...

  13. Structural interpretation of chemically synthesized ZnO nanorod and its application in lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Samapti; Sain, Sumanta [Materials Science Division, Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India); Yoshio, Masaki [Advanced Research and Education Centre, Saga University, 1341 Yoga-machi, Saga 840-0047 (Japan); Kar, Tanusree [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, West Bengal (India); Gunawardhana, Nanda, E-mail: nandagunawardhana@pdn.ac.lk [International Research Centre, Senate Building, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Pradhan, Swapan Kumar, E-mail: skpradhan@phys.buruniv.ac.in [Materials Science Division, Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India)

    2015-02-28

    Graphical abstract: - Highlights: • ZnO nanorods are synthesized at room temperature via a simple chemical route. • Growth direction of ZnO nanorods has been determined along 〈0 0 2〉. • ZnO nanorods constructed anode shows a high discharge capacity in first cycle. • It retains good reversible capacity compared to other ZnO morphologies. - Abstract: ZnO nanorods are synthesized at room temperature via a simple chemical route without using any template or capping agent and its importance is evaluated as a suitable candidate for anode material in lithium ion battery. Structural and microstructure characterizations of these nanorods are made by analyzing the X-ray diffraction data employing the Rietveld method of powder structure refinement. It reveals that the ZnO nanorods are grown up with a preferred orientation and elongated along 〈0 0 2〉. FESEM images reveal that these uniform cylindrical shaped nanorods are of different lengths and diameters. These synthesized ZnO nanorods are tested as an anode material for lithium ion batteries. The nano grain size of the ZnO rods results in less volume expansion and/or contraction during the alloying/de-alloying process and causes in good cyclability. In addition, synthesized ZnO nanorods deliver high charge/discharge capacities compared to other reported ZnO materials.

  14. Growth and investigation of antifungal properties of ZnO nanorod arrays on the glass

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari, M., E-mail: msnano1361@yahoo.co [Nanomaterial Research Group, Academic Center for Education, Culture and Research (ACECR) on TMU, Tehran (Iran, Islamic Republic of); Haghighi, N. [Department of physics, Tehran University, Tehran (Iran, Islamic Republic of); Ahmadi, V. [Department of Electrical Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Haghighi, F.; Mohammadi, SH.R. [Department of Mycology, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2011-01-01

    In this study, we have investigated the antifungal activity of ZnO nanorods prepared by the chemical solution method against Candida albicans. In the study, Zinc oxide nanorods have been deposited on glass substrates using the chemical solution method. The as-grown samples are characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). X-ray diffraction (XRD) showed zinc oxide nanorods grown in (0 0 2) orientation. The antifungal results indicated that ZnO nanorod arrays exhibit stable properties after two months and play an important role in the growth inhibitory of Candida albicans.

  15. Growth of high aspect ratio ZnO nanorods by solution process: Effect of polyethyleneimine

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Han-Seok; Vaseem, Mohammad; Kim, Sang Gon; Im, Yeon-Ho [School of Semiconductor and Chemical Engineering, Dept. of BIN Fusion Technology, BK 21 Centre for Future Energy Materials and Devices, and Nanomaterials Processing Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Hahn, Yoon-Bong, E-mail: ybhahn@chonbuk.ac.kr [School of Semiconductor and Chemical Engineering, Dept. of BIN Fusion Technology, BK 21 Centre for Future Energy Materials and Devices, and Nanomaterials Processing Research Center, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2012-05-15

    High aspect ratio ZnO nanorods were grown vertically on ZnO seed layer deposited silicon, glass and polyimide substrates by a solution process at low-temperature using zinc nitrate hexahydrate and hexamethylenetetramine. We studied the effect of polyethlyeneimine (PEI) on the growth of ZnO nanorods. It was found that PEI has a prominent effect on controlling the aspect ratio of ZnO nanorods in solution. The morphological and photoluminescence properties of the ZnO nanorods were also examined with varying the growth temperature (60-90 Degree-Sign C). - Graphical abstract: With addition of polyehyleneimine (PEI) high aspect-ratio ZnO nanorods were grown. It is believed that during ZnO nanorods growth, protonized form of linear PEI molecules inhibits the lateral growth by being adsorbed on non-polar lateral planes. Thus the vertical growth is favored. Highlights: Black-Right-Pointing-Pointer A controlled growth of high aspect ratio ZnO nanorods on different substrates. Black-Right-Pointing-Pointer A prominent effect of polyethlyeneimine (PEI) on controlling the aspect ratio of ZnO nanorods in solution. Black-Right-Pointing-Pointer Precursor concentration and growth temperature effect for various aspect ratio ZnO nanorods.

  16. Controllable growth of ZnO nanorods via electrodeposition technique: towards UV photo-detection

    Science.gov (United States)

    Sarangi, S. N.

    2016-09-01

    An electro-chemical approach for controlled growth of seedless ZnO nanorods was investigated. Field emission scanning electron microscopy confirms ZnO nanorod morphology can be controlled by varying the electrodeposition duration. Increased growth time enhances the crystallinity of ZnO nanorods and releases the strain on ZnO nanorods, as revealed by x-ray diffraction analysis. A significant change in the near band gap and the defect level luminescence were observed for different growth time ZnO nanorods. The variation in zone-centre E 2 (high) optical phonon mode of ZnO nanorods was studied using micro-Raman measurements. The I-V characteristics of the ZnO nanorods potentially enable applications in UV photodetection even at very low voltage range. Photodetectors based on ZnO nanorods have a faster response time (~29 s) and exhibited high photosensitivity, approximately 28 at 1 V forward bias, as compared to recent reported values. The results obtained are exciting in view of using a low cost electrodeposition technique at low temperature for achieving high-quality electrodeposited ZnO nanorods and its possible use in optoelectronic devices.

  17. Thermal stability and oil absorption of aluminum hydroxide treated by dry modification with phosphoric acid

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 ℃2,but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide.

  18. Immobilization of laccase on hybrid layered double hydroxide

    Directory of Open Access Journals (Sweden)

    David Isidoro Camacho Córdova

    2009-01-01

    Full Text Available Crystals of Mg/Al layered double hydroxide were synthesized by alkaline precipitation and treated in an aqueous solution of glutamic acid. The glutamate ions were not intercalated into the interlayer space, but were detected in the material by Fourier transform infrared spectroscopy, suggesting that only the external surfaces of crystals were modified with glutamate ions. The resulting hybrid material was tested as a support for immobilization of the enzyme laccase (Myceliophthora thermophila. The immobilized enzyme preparation was characterized by electronic paramagnetic resonance spectroscopy and by assays of catalytic activity. The activity of the immobilized laccase was 97% of the activity in the free enzyme. Layered double hydroxide is a suitable support for use in remediation of soil studies.

  19. Synthesis and characterization of α-cobalt hydroxide nanobelts

    Science.gov (United States)

    Tian, L.; Zhu, J. L.; Chen, L.; An, B.; Liu, Q. Q.; Huang, K. L.

    2011-08-01

    α-Cobalt hydroxide was synthesized by a facile hydrothermal process from Co(Ac)2 and NH3·H2O in the presence of 1,3-propanediol. The large-scale-prepared cobalt hydroxide has a uniform nanobelt morphology with a considerably high aspect-ratio more than 20 which may be advantageous for exploration of their physicochemical properties. This synthetic method is convenient, economical, and controllable. The samples were characterized by powder X-ray diffraction, energy dispersive spectrum, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, CHN element analysis, thermogravimetric and differential-thermogravimetric analysis, which revealed the compound is lamellar structural cobalt organic-inorganic hybrid with the chemical formula of Co(OH)1.49(NH3)0.01(CO3 2-)0.22(Ac-)0.07(H2O)0.11 and single-crystalline.

  20. Leaching kinetics of gibbsitic bauxite with sodium hydroxide

    Directory of Open Access Journals (Sweden)

    Abdel-Aal El-Sayed A.

    2016-01-01

    Full Text Available In this paper the results of a leaching kinetics study of bauxite ore with sodium hydroxide are presented. The effect of ore particle size, sodium hydroxide concentration and reaction temperature on the Al2O3 extraction rate was determined. The results obtained showed that 99% of Al2O3 was leached out using −200+270 mesh ore particle size at a reaction temperature of 105 °C for 60 min reaction time with 250 g/L NaOH. The solid-to-liquid ratio was maintained constant at 1:20. The results indicated that leaching of bauxite is the rate controlling process. The activation energy was determined to be 46.04 kJ/mole, which was characteristic for a chemically controlled process.

  1. CALCIUM HYDROXIDE IN ENDODONTIC TREATMENT OF PERIAPICALLY INFECTED TEETH

    Directory of Open Access Journals (Sweden)

    Rahmi Alma Farah Adang

    2006-04-01

    Full Text Available An inadequate endodontic treatment may affect the root canal system and spread beyond its apical foramina that elicit periodontal tissue developing into abscess, granuloma and radicular cyst. Periodical lesions can be treated with non surgical endodontic treatment using calcium hydroxide dressing. This case study is reporting teeth 11 with periodical lesions and infection. Evidence of a clinical healing and radiographic assessments were followed by a non surgical endodontic therapy. Successful treatment outcome is related to the elimination of infection agents from the root canal. This can activate a stimulation zone to promote regeneration. Calcium hydroxide used as a root canal dressing may promote alkalinity at the adjacent tissue , create favourable environmental condition in which hard tissue formation can occur, interfere the bactericidal activity, increase mineralization, and induce healing.

  2. Skyrmion oscillations in magnetic nanorods with chiral interactions

    Science.gov (United States)

    Charilaou, M.; Löffler, J. F.

    2017-01-01

    We report that in cylindrical nanorods with chiral interactions spin textures corresponding to spatial skyrmion oscillations can be stabilized depending on the initial state, as revealed by micromagnetic calculations. The skyrmion oscillation, or skyrmion-chain state, occurs when the diameter of the rod is larger than the helical pitch length of the material, and the number of skyrmions on the chain is proportional to the length of the nanorod. The topological charge is localized, breaking translational symmetry, but in the presence of a uniaxial anisotropy, or upon the application of an external field, the localization disappears and a single skyrmion line is formed. These findings provide a deeper understanding of the interplay between geometry and topology, and show how spatial confinement specifically in curved solids can stabilize skyrmionic spin textures.

  3. Plasmonic-cavity model for radiating nano-rod antennas.

    Science.gov (United States)

    Peng, Liang; Mortensen, N Asger

    2014-01-23

    In this paper, we propose the analytical solution of nano-rod antennas utilizing a cylindrical harmonics expansion. By treating the metallic nano-rods as plasmonic cavities, we derive closed-form expressions for both the internal and the radiated fields, as well as the resonant condition and the radiation efficiency. With our theoretical model, we show that besides the plasmonic resonances, efficient radiation takes advantage of (a) rendering a large value of the rods' radius and (b) a central-fed profile, through which the radiation efficiency can reach up to 70% and even higher in a wide frequency band. Our theoretical expressions and conclusions are general and pave the way for engineering and further optimization of optical antenna systems and their radiation patterns.

  4. Toroidal dipole excitations in metamolecules formed by interacting plasmonic nanorods

    CERN Document Server

    Watson, Derek W; Ruostekoski, Janne; Fedotov, Vassili A; Zheludev, Nikolay I

    2015-01-01

    We show how the elusive toroidal dipole moment appears as a radiative excitation eigenmode in a metamolecule resonator that is formed by pairs of plasmonic nanorods. We analyze one such nanorod configuration - a toroidal metamolecule. We find that the radiative interactions in the toroidal metamolecule can be qualitatively represented by a theoretical model based on an electric point dipole arrangement. Both a finite-size rod model and the point dipole approximation demonstrate how the toroidal dipole moment is subradiant and difficult to excite by incident light. By means of breaking the geometric symmetry of the metamolecule, the toroidal mode can be excited by linearly polarized light and we provide simple optimization protocols for maximizing the toroidal dipole mode excitation. This opens up possibilities for simplified control and driving of metamaterial arrays consisting of toroidal dipole unit-cell resonators.

  5. Gold/polypyrrole nanorods for gas sensing application

    Science.gov (United States)

    Šetka, Milena; Drbohlavová, Jana; Vallejos, Stella; Márik, Marian; Llobet, Eduard; Hubálek, Jaromír.

    2017-06-01

    This work describes the preparation of gold/polypyrrole nanorods (AuPPy NRs) using anodized alumina oxide (AAO) template and both pulsed galvanic deposition and electropolymerization for the deposition of Au and polypyrrole (PPy) nanorods (NRs), respectively. Characterization of the whole structure after AAO etching revealed the formation of a high density of NRs along the substrate with uniform diameters of approximately 50 nm and total lengths of 700 nm, the last corresponding to 1/3 and 2/3 of the length of the Au and PPy NRs, respectively. These structures are provided of bottom/top electrodes and a heating element coupled to the backside of the substrate, and their gas sensing properties towards various concentrations of NO2 in resistive configuration are presented.

  6. Spectroscopic investigation on porphyrins nano-assemblies onto gold nanorods

    Science.gov (United States)

    Trapani, Mariachiara; De Luca, Giovanna; Romeo, Andrea; Castriciano, Maria Angela; Scolaro, Luigi Monsù

    2017-02-01

    The interaction between gold nanorods (Au NRs), synthesized by a conventional seeded growth protocol, and the anionic tetrakis-(4-sulfonatophenyl)porphyrin (TPPS4) has been investigated through various spectroscopic techniques. At neutral pH, the formation of H-aggregates and the inclusion of porphyrin monomers in CTAB micelles covering the nanorods have been evidenced. Under mild acidic conditions (pH = 3) a nano-hybrid assembly of porphyrin J-aggregates and Au NRs has been revealed. For the sake of comparison, Cu(II) and Zn(II) metal porphyrin derivatives as well as a cationic porphyrin have been studied in the same experimental conditions, showing that: i) CuTPPS4 forms porphyrin H-dimers onto the Au NRs; ii) ZnTPPS4 undergoes to demetallation, followed by acidification of the central core and eventually aggregation onto Au NRs; iii) cationic porphyrin does not interact with Au NRs.

  7. Investigating the optical XNOR gate using plasmonic nano-rods

    Science.gov (United States)

    Akhlaghi, Majid; Kaboli, Milad

    2016-04-01

    In this paper, a coherent perfect absorption (CPA)-type XNOR gate based on plasmonic nano particle is proposed. It consists of two plasmonic nano rod arrays on top of two parallel arms with quartz substrate. The operation principle is based on the absorbable formation of a conductive path in the dielectric layer of a plasmonic nano-particles waveguide. Since the CPA efficiency depends strongly on the number of plasmonic nano-rod and the nano rod location, an efficient binary optimization method based the Particle Swarm Optimization (PSO) algorithm is used to design an optimized array of the plasmonic nano-rod in order to achieve the maximum absorption coefficient in the 'off' state and the minimum absorption coefficient in the 'on' state. In Binary PSO (BPSO), a group of birds consists a matrix with binary entries, control the presence ('1‧) or the absence ('0‧) of nano rod in the array.

  8. Aligned Silver Nanorod Array as SERS Substrates for Viral Sensing

    Science.gov (United States)

    Zhao, Yiping; Shanmukh, Saratchandra; Chaney, Stephen B.; Jones, Les; Dluhy, Richard A.; Tripp, Ralph A.

    2006-03-01

    The aligned silver nanorod array substrates prepared by the oblique angle deposition method are capable of providing extremely high enhancement factors (˜10^9) at near-infrared wavelengths (785 nm) for a standard reporter molecule 1,2 trans-(bis)pyridyl-ethene (BPE). The enhancement factor depends strongly on the length of the Ag nanorods, the substrate coating, as well as the polarization of the excitation laser beam. With the current optimum structure, we demonstrate that the detection limit for BPE can be lower than 0.1 fM. The applicability of this substrate to the detection of bioagents has been investigated by looking several viruses, such as Adenovirus, HIV, Rhinovirus and Respiratory Syncytial Virus (RSV), at low quantities (˜0.5uL). Different viruses have different fingerprint Raman spectrum. The detection of virus presented in infected cells has also been demonstrated.

  9. Preparation of Gold Nanorods and Their Applications in Photothermal Therapy.

    Science.gov (United States)

    Xia, Kai; Zhang, Liming; Huang, Yuanfu; Lu, Zhuoxuan

    2015-01-01

    Gold nanorods (GNRs) have recently been widely studied due to their unique optical and electronic properties which are dependent on their shape, size, and aspect ratio. Seed-mediated growth method has become the most widely method for the synthesis of GNRs due to its advantages of simplicity of procedure, high yield of nanorods, and ease of aspect ratio controlling. Moreover, GNRs are especially attractive candidates for exploitation in photothermal therapy since they can be readily synthesized with various aspect ratios, which enable GNRs to selectively absorb the near-infrared (NIR) light. This review is focused on summarizing the preparation of GNRs by seed-mediated growth method and their applications in photothermal therapy.

  10. Nanoscale size effects in crystallization of metallic glass nanorods.

    Science.gov (United States)

    Sohn, Sungwoo; Jung, Yeonwoong; Xie, Yujun; Osuji, Chinedum; Schroers, Jan; Cha, Judy J

    2015-09-01

    Atomistic understanding of crystallization in solids is incomplete due to the lack of appropriate materials and direct experimental tools. Metallic glasses possess simple metallic bonds and slow crystallization kinetics, making them suitable to study crystallization. Here, we investigate crystallization of metallic glass-forming liquids by in-situ heating metallic glass nanorods inside a transmission electron microscope. We unveil that the crystallization kinetics is affected by the nanorod diameter. With decreasing diameters, crystallization temperature decreases initially, exhibiting a minimum at a certain diameter, and then rapidly increases below that. This unusual crystallization kinetics is a consequence of multiple competing factors: increase in apparent viscosity, reduced nucleation probability and enhanced heterogeneous nucleation. The first two are verified by slowed grain growth and scatter in crystallization temperature with decreasing diameters. Our findings provide insight into relevant length scales in crystallization of supercooled metallic glasses, thus offering accurate processing conditions for predictable metallic glass nanomolding.

  11. Photothermal Heating via Gold Nanorods within Polymer Nanocomposites

    Science.gov (United States)

    Bochinski, Jason; Maity, Somsubhra; Wu, Wei-Chen; Tracy, Joseph; Clarke, Laura

    2015-03-01

    Metal nanoparticles under continuous-wave (cw) optical excitation resonant with their localized surface plasmon exhibit a photothermal effect, efficiently converting the incident light into heat originating from the particle. Gold nanorods (GNRs) dispersed within a transparent material are utilized as such remotely-controlled, nano-sized heaters, with heating properties which can be manipulated and monitored by using control of the polarization direction of the excitation and probe light fields. Steady-state average temperatures within a polymer matrix embedded with GNRs undergoing cw photothermal heating are determined in the immediate vicinity of the GNR by observing the rate of driven physical rotation of the nanorods, and simultaneously across the entire sample by using an independent fluorescence method. Comparing these two observations as the concentration of dispersed GNRs is varied reveals the interplay between local and global heating in these polymer nanocomposite materials. Support from US National Science Foundation (CMMI-0800237, CMMI-106910).

  12. Vertically Aligned ZnO Nanorods: Effect of Synthesis Parameters.

    Science.gov (United States)

    Rehman, Zeeshan Ur; Heo, Si-Nae; Cho, Hyeon Ji; Koo, Bon Heun

    2016-06-01

    This report is devoted to the synthesis of high quality nanorods using spin coating technique for seed layer growth. Effect of different parameter i.e., spins coating counts, spin coating speed, and the effect of temperature during the drying process was analyzed. Hot plate and furnace technique was used for heating purpose and the difference in the morphology was carefully observed. It is worthy to mention here that there is a substantial effect of all the above mentioned parameters on the growth and morphology of the ZnO nanostructure. The ZnO nanorods were finally synthesized using wet chemical method. The morphological properties of the obtained nanostructures were analyzed by using FESEM technique.

  13. Three dimensional sensitivity characterization of plasmonic nanorods for refractometric biosensors.

    Science.gov (United States)

    Leitgeb, V; Trügler, A; Köstler, S; Krug, M K; Hohenester, U; Hohenau, A; Leitner, A; Krenn, J R

    2016-02-07

    An experimental three dimensional characterization of the local refractive index sensitivity of plasmonic gold nanorods is performed by controlled apposition of lithographic nanostructures. We show up to seven times higher sensitivity values to local changes in the refractive index at the particle tip than center. In addition, successive deposition of defined nm-thin dielectric layers on nanorods covered with stripe masks allows us to study the sensitivity decrease normal to the particle surface separately for different particle sites. Clear trends to a stronger sensitivity decay at sites of higher local sensitivity are demonstrated experimentally and theoretically. Our sensitivity characterization provides an important tool to find the most suitable particle type and particle site for specific bio-sensing applications.

  14. Probing light emission from quantum wells within a single nanorod

    Science.gov (United States)

    Bruckbauer, Jochen; Edwards, Paul R.; Bai, Jie; Wang, Tao; Martin, Robert W.

    2013-09-01

    Significant improvements in the efficiency of optoelectronic devices can result from the exploitation of nanostructures. These require optimal nanocharacterization techniques to fully understand and improve their performance. In this study we employ room temperature cathodoluminescence hyperspectral imaging to probe single GaN-based nanorods containing multiple quantum wells (MQWs) with a simultaneous combination of very high spatial and spectral resolution. We have investigated the strain state and carrier transport in the vicinity of the MQWs, demonstrating the high efficiencies resulting from reduced electric fields. Power-dependent photoluminescence spectroscopy of arrays of these nanorods confirms that their fabrication results in partial strain relaxation in the MQWs. Our technique allows us to interrogate the structures on a sufficiently small length scale to be able to extract the important information.

  15. Oriented attachment growth of quantum-sized CdS nanorods by direct thermolysis of single-source precursor.

    Science.gov (United States)

    Li, Zhiguo; Sui, Jiehe; Li, Xiaoli; Cai, Wei

    2011-03-15

    Quantum-sized CdS nanorods were synthesized by direct thermal decomposition of a single-source precursor in a monosurfactant system. The CdS nanorods were uniform, had high crystallinity, and exhibited strong quantum confinement effect. The nanorod growth was controlled by an oriented attachment mechanism, and the morphology was determined by the competition between dipole attraction and steric repulsion of nanodots. Increasing precursor concentration and prolonging reaction time were favorable for the formation of CdS nanorods.

  16. Decelerating chirped soliton formation at femtosecond laser pulse propagation in a medium with one-photon absorption and gold nanorods

    Science.gov (United States)

    Trofimov, V. A.; Lysak, T. M.

    2017-01-01

    We demonstrate the possibility of decelerating chirped soliton formation at femtosecond pulse propagation in a medium with gold nanoparticles. We take into account the dependence of one-photon absorption on the nanorod aspect ratio and time-dependent nanorod aspect ratio changing due to nanorod reshaping because of laser energy absorption. The soliton formation occurs due to laser radiation trapping by the nanorod reshaping front. We show analytically that a chirp induced by the negative phase grating is crucial for this trapping.

  17. Surface tension of calcium hydroxide associated with different substances

    OpenAIRE

    Carlos Estrela; Cyntia Rodrigues de Araújo Estrela; Luiz Fernando Guimarães; Reginaldo Santana Silva; Jesus Djalma Pécora

    2005-01-01

    The purpose of this study was to evaluate the surface tension of calcium hydroxide (CH) associated with different substances (deionized distilled water, camphorated paramonochlorophenol, 2% chlorhexidine digluconate, Otosporin, 3% sodium lauryl ether sulphate; Furacin, PMC Furacin) using tensiometer. The action of the substances studied on the dentinal structure enhances the property of surface tension. This method consists in the application of force to separate a platinum ring immersed in t...

  18. A comparison between sodium hydroxide treated and untreated bird ...

    African Journals Online (AJOL)

    determine the effect of sodium hydroxide (NaOH)treatment of bird-proof sorghum (BPS) ... (11070)and with an 8070poorer feed-utilization ratio than pigs fed NS and ... batches of grain were soaked for 2 hours in a NaOH solution made up of 500 g ... amount of 1 500 g of air-dry meal was fed to each pig in two equal portions ...

  19. [Aluminum hydroxide hydrogel to remove arsenic from water].

    Science.gov (United States)

    Luján, J C

    2001-05-01

    To describe the making of and the preliminary results from an aluminum hydroxide hydrogel that, when added directly to water, can totally eliminate arsenic, regardless of the nature of the water and the oxidation state of the metalloid. The raw materials used to make the aluminum hydroxide hydrogel were: hydrated aluminum sulfate (which is used to make water safe for drinking), calcium hypochlorite in powder form, ammonium hydroxide, and distilled water (when done at the laboratory scale), and water from inverse osmosis of the same or better quality than the distilled water (when done at a pilot scale). Quality control for the finished product consisted of determining its ability to adsorb arsenic and performing bacteriological tests to demonstrate its sterility. The product was used with water samples to which arsenic had been added in the laboratory and with water samples from the province of Tucumán, Argentina, with naturally occurring arsenic. To analyze the arsenic in the water the colorimetric silver diethyldithiocarbamate method was used. Using the hydrogel greatly reduced the amount of arsenic. Treating both the natural and laboratory-produced arsenical waters yielded arsenic concentrations under the limit (0.01 parts per million) that was detectable with the analytical method used. The bacteriological tests of the finished product indicated there were no viable bacteria. Using the aluminum hydroxide hydrogel produced the desired reduction in the arsenic concentration in the water. This method for removing arsenic is inexpensive and easy to use in scattered rural populations in areas having high arsenic levels and lacking drinkable water, as well as an adequate sanitary and electric-power infrastructure.

  20. Adsorption behavior of condensed phosphate on aluminum hydroxide

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-hong; CHEN Guang-hao; SHANG Chii

    2007-01-01

    Sodium pyrophosphate(pyro-P,Na4P207),sodium tripolyphosphate(tripoly-P,NasP3010),and sodium hexametaphosphate(metaP,(NaP03)6)were selected as the model compounds of condensed phosphate to investigate the adsorption behavior of condensed phosphate on aluminum hydroxide.The adsorption was found to be endothermic and divisible into two stages:(1)fast adsorption within 1 h:and(2)slow adsorption between 1 and 24 h.The modified Freundlich model simulated the fast adsorption stage well;the slow adsorption stage was described well by the first-order kinetics.The activation energies of pyro-P,tripoly-P,and meta-P adsorption on aluminum hydroxide were determined to be 20.2,22.8 and 10.9 kJ/mol P adsorbed,respectively,in the fast adsorption stage and to be 66.3.53.5 and 72.5 kJ/tool P adsorbed,respectively,in the slow adsorption stage.The adsorption increased the negative charge of the aluminum hydroxide surface.Transmission electron microscopy and energy dispersive X-ray analysis analyses provided evidence that the adsorption was not uniform on the surface and that the small crystals contfibuted more to the fast adsorption than the normal sites did.The results from X-ray fluorescence spectrometry and X-ray photoelectron spectroscopy tests also revealed the uneven adsorption of condensed phosphate as a function of the penetration depth.More condensed phosphates were adsorbed on the outer surface of aluminum hydroxide than in its inner parts.