Sample records for zinc oxide azo

  1. Preparation of aluminum-doped zinc oxide (AZO) nano particles by hydrothermal synthesis

    Microsoft Academic Search

    Esin Burunkaya; Nadir Kiraz; Ömer Kesmez; H. Erdem Çamurlu; Meltem Asiltürk; Ertu?rul Arpaç

    2010-01-01

    Aluminum doped zinc oxide (AZO) nanometric particles were synthesized by hydrothermal method. Aluminum nitrate hydrate, aluminum\\u000a sec-butoxide and zinc nitrate hydrate were used as the starting materials, and n-propanol and 2-butanol were used as solvents.\\u000a Ratio of Al2O3 in ZnO was kept at 10 wt%. Reaction was conducted in a Teflon autoclave at 175–225 °C for 5 h. Ratios of alcohol, H2O

  2. Exploitation of zinc oxide impregnated chitosan beads for the photocatalytic decolorization of an azo dye.

    PubMed

    Farzana, M Hasmath; Meenakshi, Sankaran

    2015-01-01

    Investigations were made to evaluate and distinguish the photocatalytic decolorization of Reactive Red 2 (RR) dye using zinc oxide (ZnO) and zinc oxide impregnated chitosan beads (ZCB) under UV and visible light irradiations. To enhance the photoresponse of ZnO toward visible light, the modification of ZnO using biopolymer, chitosan, has been carried out and synthesized the ZCB. Both ZnO and ZCB photocatalysts were characterized by Fourier transform-infrared spectra (FT-IR), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and diffuse reflectance spectra (DRS). Experiments were conducted to optimize various parameters, viz., irradiation time, the amount of catalyst, pH, co-ions and initial concentration of dye under UV and visible light irradiations. The percentage of decolorization of RR dye using ZnO and ZCB under UV as well as visible light is in the order of ZnO/UV > ZCB/vis > ZnO/vis > ZCB/UV. The mineralization/detoxification of RR dye was assessed by measuring chemical oxygen demand (COD) at optimized conditions. The kinetic studies demonstrated that the photocatalytic reactions followed the pseudo-first-order model. The reusability of as-synthesized ZCB was assessed. PMID:25304748

  3. Electrical and Optical Properties of AZO\\/Ag\\/AZO Multilayer Thin Films Prepared by DC Magnetron Sputtering

    Microsoft Academic Search

    Sutthipoj Sutthana; Chaiyut Sae-Kung; Sirapat Pratontep; Pongsri Mangkorntong; Nikorn Mangkorntong; Supab Choopun

    2008-01-01

    Silver nanoparticles were deposited on aluminium doped zinc oxide (AZO) thin films and coated with AZO to fabricate AZO\\/Ag\\/AZO multilayer thin films by DC magnetron sputtering. The electrical and optical properties of the multilayer thin films were studies by using Hall measurement and UV- visible spectroscopy and compared with AZO thin films. It was found that the sheet resistance and

  4. In vitro metabolic N-oxidation of azo compounds. I. Evidence for formation of azo N-oxides (azoxy compounds).

    PubMed

    Koh, M H; Gorrod, J W

    1989-01-01

    Certain azo compounds and their N-oxides have been prepared and characterized by spectroscopic methods. A HPLC method for the quantification of azo-N-oxide metabolites of those azo compounds is described. The enzymic N-oxidation of azo compounds in vitro has been demonstrated as a general metabolic pathway. In the case of the mixed aryl-alkyl azo compound, only one N-oxide was detected. The identity of N-oxide metabolites has been confirmed by CG/MS. Azo-N-oxidase activity was detected principally in the liver, but also in lung, heart and kidney whole organ homogenates. Studies using subcellular fractions showed that azo N-oxidase activity resides mainly in the hepatic microsomal fraction. The amount of N-oxide formed under optimised incubation conditions by hamster microsomal preparations is greatest with omega, omega'-azoxytoluene (AXT) and least with azoxybenzene (AXB); while omega-(phenylazoxy)toluene (PAXT) is intermediate. PMID:2489197

  5. Light extraction enhancement of organic light-emitting diodes using aluminum zinc oxide embedded anodes.

    PubMed

    Hsu, Ching-Ming; Lin, Bo-Ting; Zeng, Yin-Xing; Lin, Wei-Ming; Wu, Wen-Tuan

    2014-12-15

    Aluminum zinc oxide (AZO) has been embedded onto indium tin oxide (ITO) anode to enhance the light extraction from an organic light-emitting diode (OLED). The embedded AZO provides deflection and scattering interfaces on the newly generated AZO/organics and AZO/ITO interfaces rather than the conventional ITO/organic interface. The current efficiency of AZO embedded OLEDs was enhanced by up to 64%, attributed to the improved light extraction by additionally created reflection and scattering of emitted light on the AZO/ITO interfaces which was roughed in AZO embedding process. The current efficiency was found to increase with the increasing AZO embedded area ratio, but limited by the accompanying increases in haze and electrical resistance of the AZO embedded ITO film. PMID:25607483

  6. Zinc oxide hexagram whiskers

    NASA Astrophysics Data System (ADS)

    Xu, C. X.; Sun, X. W.; Dong, Z. L.; Zhu, G. P.; Cui, Y. P.

    2006-02-01

    Through vapor-phase transport method, zinc oxide hexagram whiskers with uniform size and morphology were fabricated by heating a mixture source of zinc oxide, indium oxide, and graphite powders in air. Each whisker presented a hexagonal disk core closed by six equivalent surfaces of {101¯0} and was surrounded by side nanorods grown along the diagonal of the core disk in the 6-symmetric directions of ±[112¯0], ±[21¯1¯0], and ±[12¯10]. Based on the vapor-liquid-solid mechanism, the growth process of the zinc oxide hexagrams were discussed by considering the thermal dynamic properties of zinc oxide and indium oxide.

  7. Zinc oxide hexagram whiskers

    Microsoft Academic Search

    C. X. Xu; X. W. Sun; Z. L. Dong; G. P. Zhu; Y. P. Cui

    2006-01-01

    Through vapor-phase transport method, zinc oxide hexagram whiskers with uniform size and morphology were fabricated by heating a mixture source of zinc oxide, indium oxide, and graphite powders in air. Each whisker presented a hexagonal disk core closed by six equivalent surfaces of {1010} and was surrounded by side nanorods grown along the diagonal of the core disk in the

  8. Development of Novel Aluminum-Doped Zinc Oxide Film and Its Application to Solar Cells

    NASA Astrophysics Data System (ADS)

    Kuramochi, Hideto; Akiike, Ryo; Iigusa, Hitoshi; Tamano, Kimiaki; Utsumi, Kentaro; Shibutami, Tetsuo; Sichanugrist, Porponth; Konagai, Makoto

    2012-10-01

    We have developed novel aluminum-doped zinc oxide films (AZO-X and AZO-HX films) with a high haze value using wet-chemical etching for various times after dc magnetron sputtering, and have investigated their electrical and optical properties, durability under high-humidity condition, and surface morphology. The AZO-X and AZO-HX films showed good balance between transmittance in the near-infrared area and durability under 85 °C-85%RH condition. These novel films also had a higher haze value after wet chemical etching than normal AZO films. The crater size and haze value of the AZO-HX film increased with increasing etching time in comparison with those of the AZO-X film. The haze value of the AZO-HX film was higher than that of the AZO-X film; their values are 90% at 550 nm and 60% at 800 nm. Furthermore, the AZO-HX film was applied in amorphous silicon (a-Si) single-type solar cells as the front electrode. The short-circuit current of the solar cell using the AZO-HX film was higher than that of the solar cell using the AZO-X film. As an optimization-based result, an efficiency as high as 10.2% was obtained, showing that the new AZO-HX film is a promising material for the front electrode of a-Si solar cells.

  9. Highly stable inverted organic photovoltaics using aluminum-doped zinc oxide as electron transport layers

    NASA Astrophysics Data System (ADS)

    Chen, Mei-Hsin; Kuo, Ya-Ching; Lin, Hung-Hsuan; Chao, Yi-Ping; Wong, Ming-Show

    2015-02-01

    In this paper, we demonstrate highly stable inverted bulk heterojunction organic solar cells using aluminum-doped zinc oxide (AZO) as electron transport layers fabricated via a non-toxic so-gel process. The conductivity of the AZO layers can be enhanced fourfold as compared to that of intrinsic zinc oxide (ZnO) layers. The transmittance of AZO films is improved and the Haze value of the films is reduced by more than 50% in comparison to that of ZnO. The power conversion efficiency of the device reaches 6.51% and still has approximately 98% of the initial power conversion efficiency (PCE) after over 900 h without encapsulation.

  10. Doped zinc oxide microspheres

    DOEpatents

    Arnold, Jr., Wesley D. (Oak Ridge, TN); Bond, Walter D. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  11. Doped zinc oxide microspheres

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-12-14

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  12. The physical properties of Al-doped zinc oxide films prepared by RF magnetron sputtering

    Microsoft Academic Search

    Ki Cheol Park; Dae Young Ma; Kun Ho Kim

    1997-01-01

    Al-doped zinc oxide (AZO) films are prepared by RF magnetron sputtering on glass and Si substrates with specifically designed ZnO targets containing different amounts of Al2O3 powder as a doping source. The physical properties of the AZO films are investigated in terms of the preparation conditions, such as Al2O3 content in the target, RF power (PRF), substrate temperature (Ts) and

  13. Zinc oxide hexagram microrods

    Microsoft Academic Search

    Guo Xing-Yuan; Ding Zhan-Hui; Zhou Jing; Xu Da-Peng

    2011-01-01

    Zinc oxide (ZnO) microrods were grown by the floating zone method, the as-grown ZnO microrods have uniform size. Scanning electron microscope image reveals that the ZnO microrods are grown with a hexagonal structure, well faceted ends and side surfaces. Most of ZnO microrods have diameters of about 20-30Jlm and lengths of about 1-2 mm. Polarizing microscopy image of ZnO microrods

  14. Synthesis of nano-sized powders of transparent conductive aluminum-doped zinc oxide by electrolysis-modified co-precipitation method

    Microsoft Academic Search

    Hsin-Chun Lu; Chen-Sung Chang; Chia-Wei Li; Yu-Shiang Lin; Chun-Lung Chu; Chi-you Lai

    2008-01-01

    Nano-sized powders of transparent conductive aluminum-doped zinc oxide (AZO) have been successfully prepared by electrolysis-modified co-precipitation method. By adding ammonium hydroxide into the precursor solution prepared by electrolytic dissolution of zinc metal in a buffered electrolyte solution of nitric acid and ammonium nitrate with adequate addition of aluminum nitrate, co-precipitate precursors of AZO with particle size between 30 to 60

  15. Aluminum-doped zinc oxide as anode for organic near-infrared photodetectors

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Fang, Fang; Su, Zisheng; Fang, Xuan; Zhang, Guang; Wang, Junbo; Wei, Zhipeng; Li, Jinhua; Wang, Xiaohua

    2014-08-01

    High transparency and low resistivity aluminum-doped zinc oxide (AZO) films were prepared by atomic layer deposition. The AZO films show a transparency of about 80% in the near-infrared (NIR) region and a resistivity of the order of 10-3 ? cm. Organic small molecule NIR-photodetectors (NIR-PDs) with AZO as the anode have been demonstrated for the first time with lead phthalocyanine (PbPc) and C60 as the donor and acceptor, respectively. The optimized NIR-PD exhibited an external quantum efficiency of 6.2% at 760 nm. This result indicated that AZO can be used as the anode for high efficiency NIR-PDs.

  16. Morphological and Electrical Properties of Self-Textured Aluminum-Doped Zinc Oxide Films Prepared by Direct Current Magnetron Sputtering for Application to Amorphous Silicon Solar Cells

    NASA Astrophysics Data System (ADS)

    Kim, Young Baek; Choi, Bum Ho; Lee, Jong Ho; Hyeok Kim, Jin

    2011-06-01

    Self-textured Al-doped zinc oxide (AZO) transparent conducting oxide (TCO) layers were grown by DC magnetron sputtering, and their morphological and electrical properties were investigated. The self-textured AZO layers were fabricated by controlling the deposition conditions, without employing wet or dry etching for surface texturing. The polycrystalline AZO layers with a high surface roughness (42 nm) were grown on a glass substrate at various DC plasma power. The lowest sheet resistance was 3.7×10-4 ? cm and the highest carrier mobility obtained was 30 cm2 V-1 s-1, which are comparable to those of chemically textured AZO layers. The electrical and optical characteristics of the self-textured AZO films are comparable to those of wet-etched AZO films that were etched using the conventional HCl solution. Our study suggests a possible way to inexpensively fabricate amorphous silicon thin-film solar cells.

  17. Zinc oxide varistors and/or resistors

    DOEpatents

    Arnold, Jr., Wesley D. (Oak Ridge, TN); Bond, Walter D. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1993-01-01

    Varistors and/or resistors that includes doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  18. Zinc oxide varistors and/or resistors

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-07-27

    Varistors and/or resistors are described that include doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  19. Zinc oxide nanoparticles on silicon

    NASA Astrophysics Data System (ADS)

    Giannakopoulos, K.; Boukos, N.; Travlos, A.

    2006-01-01

    Self-assembled ZnO nanoparticles are grown by electron beam evaporation of Zn on silicon oxide and silicon substrates and subsequent annealing in oxygen. Characterization by TEM and EELS shows that the nanoparticles can be zinc oxide single crystals grown with their c-axis perpendicular to the substrate; their distribution, size and crystallinity depend on the deposition parameters of zinc and the growth substrate. We discuss the effect of these parameters on the morphology of the resulting material.

  20. Impact of thin metal layer on the optical and electrical properties of indium-doped-tin oxide and aluminum-doped-zinc oxide layers

    NASA Astrophysics Data System (ADS)

    Kumar, Melvin David; Park, Yun Chang; Kim, Joondong

    2015-06-01

    The distinguished transparent conductive oxide (TCO) layers like indium-doped-tin oxide (ITO) and aluminum-doped-zinc oxide (AZO) layers were prepared in different combinations with and without thin Ni metal layer. The optical and electrical properties of prepared samples were analyzed and compared with the objective to understand the role and influence of the Ni layer in each TCO combination. The highest transmittance value of 91.49% was exhibited by prepared AZO layers. Even though if the transmittance of Ni inserting TCO layers was marginally reduced than that of the ordinary TCO samples, they exhibited balanced optical properties with enhanced electrical properties. Carrier concentration of indium doped tin-oxide and aluminum doped zinc oxide (ITO/AZO) bilayer sample is increased more than double the times when the Ni layer was inserted between ITO and AZO. Thin layer of Ni in between TCO layers reduced sheet resistance and offered substantial transmittance, so that the figure of merit (FOM) value of Ni embedding TCOs was greater than that of TCOs without Ni layer. The ITO/Ni/AZO combination provided optimum results in all the electrical properties. As compared to other TCO/metal combinations, the overall performance of ITO/Ni/AZO tri-layer combination was appreciable. These results show that the optical and electrical properties of TCO layers could be enhanced by inserting a Ni layer with optimum thickness in between them.

  1. Effects of Oxygen Flux on the Aluminum Doped Zinc Oxide Thin Films By Direct Current Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Li, L. N.; Zhao, Y.; Chen, X. L.; Sun, J.; Zhang, X. D.

    Aluminum doped zinc oxide (AZO) thin films were prepared by direct current (DC) magnetron sputtering with pure argon gas on glass substrates, usually showed relatively low transmission in our experiments. It was unfavorable for AZO as front electrode for silicon thin film solar cells. In order to increase the transmission of AZO thin films, we tried to add oxygen gas into vacuum chamber during sputtering processes. The microstructures, optical and electrical properties of AZO films were investigated. During the process of sputtering, the O2 flow rate indicated a greater negative impact on the electrical properties of AZO thin films than the improvement of optical properties. Raman peak related to zinc interstitial atoms (560cm-1) was observed in the AZO thin films grown with different O2 flow rates. With the increasing of O2 flow rate, intensity of Raman peak at 560cm-1 decreased. When the O2 flow rate increased, more O atoms involved in the process of reactive sputtering, and O and Zn interstitial atoms combined to Zn-O bond, which reduced the Zn interstitial atoms. The transmission between 400 nm and 1100 nm was enhanced by the increase of O2 flow rate. The average transmissions of AZO thin films were more than 90% in the visible and near-infrared range and the resistivity of these films increased acutely.

  2. Different properties of aluminum doped zinc oxide nanostructured thin films prepared by radio frequency magnetron sputtering

    SciTech Connect

    Bidmeshkipour, Samina, E-mail: samina204@gmail.com; Shahtahmasebi, Nasser [Ferdowsi University of Mashhad, Department of Physics (Iran, Islamic Republic of)

    2013-06-15

    Aluminium doped zinc oxide (AZO) nanostructured thin films are prepared by radio frequency magnetron sputtering on glass substrate using specifically designed ZnO target containing different amount of Al{sub 2}O{sub 3} powder as the Al doping source. The optical properties of the aluminium doped zinc oxide films are investigated. The topography of the deposited films were investigated by Atomic Force Microscopy. Variation of the refractive index by annealing temperature are considered and it is seen that the refractive index increases by increasing the annealing temperature.

  3. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    NASA Astrophysics Data System (ADS)

    Shasti, M.; Mortezaali, A.; Dariani, R. S.

    2015-01-01

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  4. Salicylic acid as a tridentate anchoring group for azo-bridged zinc porphyrin in dye-sensitized solar cells.

    PubMed

    Gou, Faliang; Jiang, Xu; Li, Bo; Jing, Huanwang; Zhu, Zhenping

    2013-12-11

    Two series dyes of azo-bridged zinc porphyrins have been devised, synthesized, and performed in dye-sensitized solar cells, in which salicylic acids and azo groups were introduced as a new anchoring group and ?-conjugated bridge via a simple synthetic procedure. The representation of the new dyes has been investigated by optical, photovoltaic, and electrochemical means. The photoelectric conversion efficiency of their DSSC devices has been improved compared with other DSSC devices sensitized by symmetrical porphyrin dyes. The results revealed that tridentate binding modes between salicylic acid and TiO2 nanoparticles could enhance the efficiency of electron injection. The binding modes between salicylic acid and TiO2 nanoparticles may play a crucial role in the photovoltaic performance of DSSCs. PMID:24229086

  5. Study on the structural, electrical, and optical properties of aluminum-doped zinc oxide films by direct current pulse reactive magnetron sputtering

    Microsoft Academic Search

    Gao Xiao-Yong; Lin Qing-Geng; Feng Hong-Liang; Liu Yu-Fen; Lu Jing-Xiao

    2009-01-01

    A series of polycrystalline aluminum-doped zinc oxide (AZO) films were deposited on glass substrates by direct current pulse reactive magnetron sputtering at substrate temperatures (Ts) ranging from 210 °C to 290 °C. The effect of Ts on the crystalline structure, electrical, and optical properties of the as-deposited AZO films was systematically investigated by X-ray diffractometry, four-point probe measurements, and spectrophotometry. After 3

  6. Fabrication and optimization of Al-doped zinc oxide layer for application in radial p-n junction silicon solar cells

    Microsoft Academic Search

    Seong-Ho Baek; Jae Hyun Kim; Jang-Kyoo Shin

    2010-01-01

    The influence of thickness of optimized Al-doped zinc oxide (AZO) front contact layer on an efficiency of a radial p-n junction silicon (Si) solar cell has been studied. Vertically aligned Si wire arrays for the radial p-n junction solar device were fabricated by metal catalytic etching and p-n junction was prepared by spin-on-dopant (SOD) diffusion method. AZO thin films as

  7. Effect of Zinc, Zinc Oxide and Zinc Borate on the Flammability of Polycarbonate

    Microsoft Academic Search

    Ramazan Benrashid; Gordon L. Nelson; Donald J. Ferm; Leland W. Chew

    1995-01-01

    Polycarbonate was blended with zinc, zinc borate (2ZnO·3B2O 3·3.5H2O) and zinc oxide. Blends made of zinc\\/polycarbonate and especially zinc borate\\/polycarbonate show major improvement in oxygen index values. Ohio State University (OSU) heat release studies show reduction in heat release only for zinc borate\\/polycarbonate blends compared to virgin polycarbonate. No improvement in smoke suppression was observed from NBS Smoke Chamber studies

  8. Degradation of azo dyes by Trametes villosa laccase over long periods of oxidative conditions.

    PubMed

    Zille, Andrea; Górnacka, Barbara; Rehorek, Astrid; Cavaco-Paulo, Artur

    2005-11-01

    Trametes villosa laccase was used for direct azo dye degradation, and the reaction products that accumulated after 72 h of incubation were analyzed. Liquid chromatography-mass spectrometry (LC-MS) analysis showed the formation of phenolic compounds during the dye oxidation process as well as a large amount of polymerized products that retain azo group integrity. The amino-phenol reactions were also investigated by 13C-nuclear magnetic resonance and LC-MS analysis, and the polymerization character of laccase was shown. This study highlights the fact that laccases polymerize the reaction products obtained during long-term batch decolorization processes with azo dyes. These polymerized products provide unacceptable color levels in effluents, limiting the application of laccases as bioremediation agents. PMID:16269701

  9. Degradation of Azo Dyes by Trametes villosa Laccase over Long Periods of Oxidative Conditions

    PubMed Central

    Zille, Andrea; Górnacka, Barbara; Rehorek, Astrid; Cavaco-Paulo, Artur

    2005-01-01

    Trametes villosa laccase was used for direct azo dye degradation, and the reaction products that accumulated after 72 h of incubation were analyzed. Liquid chromatography-mass spectrometry (LC-MS) analysis showed the formation of phenolic compounds during the dye oxidation process as well as a large amount of polymerized products that retain azo group integrity. The amino-phenol reactions were also investigated by 13C-nuclear magnetic resonance and LC-MS analysis, and the polymerization character of laccase was shown. This study highlights the fact that laccases polymerize the reaction products obtained during long-term batch decolorization processes with azo dyes. These polymerized products provide unacceptable color levels in effluents, limiting the application of laccases as bioremediation agents. PMID:16269701

  10. Efficient indium-tin-oxide free inverted organic solar cells based on aluminum-doped zinc oxide cathode and low-temperature aqueous solution processed zinc oxide electron extraction layer

    SciTech Connect

    Chen, Dazheng; Zhang, Chunfu, E-mail: cfzhang@xidian.edu.cn; Wang, Zhizhe; Zhang, Jincheng; Tang, Shi; Wei, Wei; Sun, Li; Hao, Yue, E-mail: yhao@xidian.edu.cn [State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology, School of Microelectronics, Xidian University, No. 2 South Taibai Road, Xi'an 710071 (China)

    2014-06-16

    Indium-tin-oxide (ITO) free inverted organic solar cells (IOSCs) based on aluminum-doped zinc oxide (AZO) cathode, low-temperature aqueous solution processed zinc oxide (ZnO) electron extraction layer, and poly(3-hexylthiophene-2, 5-diyl):[6, 6]-phenyl C{sub 61} butyric acid methyl ester blend were realized in this work. The resulted IOSC with ZnO annealed at 150?°C shows the superior power conversion efficiency (PCE) of 3.01%, if decreasing the ZnO annealing temperature to 100?°C, the obtained IOSC also shows a PCE of 2.76%, and no light soaking issue is observed. It is found that this ZnO film not only acts as an effective buffer layer but also slightly improves the optical transmittance of AZO substrates. Further, despite the relatively inferior air-stability, these un-encapsulated AZO/ZnO IOSCs show comparable PCEs to the referenced ITO/ZnO IOSCs, which demonstrates that the AZO cathode is a potential alternative to ITO in IOSCs. Meanwhile, this simple ZnO process is compatible with large area deposition and plastic substrates, and is promising to be widely used in IOSCs and other relative fields.

  11. Zinc hydroxide sulphate and its transformation to crystalline zinc oxide.

    PubMed

    Moezzi, Amir; Cortie, Michael B; McDonagh, Andrew M

    2013-10-28

    The thermal transformation of zinc hydroxide sulphate hydrate to zinc oxide has been examined using synchrotron X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and surface area measurements. By collecting X-ray diffraction data in situ, we found that the dehydration of zinc hydroxide sulphate pentahydrate proceeded in discrete steps to form anhydrous zinc hydroxide sulphate. This compound then decomposed to a mixture of zinc oxide and a compound tentatively identified as Zn3(OH)2(SO4)2 at ~235 °C. At ~360 °C, the final dehydroxylation occurred with the formation of zinc oxy-sulphate, Zn3O(SO4)2, which then decomposed to ZnO at about ~800 °C. Interruption of the dehydration process can be used to synthesize the intermediate compounds. PMID:23963063

  12. Development of Novel Al-Doped Zinc Oxide Films Fabricated on Etched Glass and Their Application to Solar Cells

    NASA Astrophysics Data System (ADS)

    Hongsingthong, Aswin; Aino, Akehiro; Sichanugrist, Porponth; Konagai, Makoto; Kuramochi, Hideto; Akiike, Ryo; Iigusa, Hitoshi; Utsumi, Kentaro; Shibutami, Tetsuo

    2012-10-01

    We have successfully developed novel aluminum-doped zinc oxide (AZO-X) films with a high haze ratio by the combined use of an etched glass substrate and wet-etched AZO-X films. The effects of the use of an etched glass substrate and wet-chemical etching on the properties of AZO-X films were investigated. The texture size and rms roughness of these films largely increased with glass surface roughening. Post-treatment using wet chemical etching slightly increased the texture size and rms roughness. The etched glass approach has been found to be a promising method for achieving an AZO-coated glass substrate with a high haze ratio. Using high-haze ratio AZO-X films as the front transparent conductive oxide (TCO) layers in solar cells, we improved the quantum efficiency (QE) of these solar cells particularly in the long-wavelength region. Thus, the AZO-X films deposited on etched glass have a high potential for use as front TCO layers in silicon-based thin-film solar cells.

  13. Comparative toxicity of a zinc salt, zinc powder and zinc oxide to Eisenia fetida, Enchytraeus albidus and Folsomia candida

    Microsoft Academic Search

    Koen Lock; Colin R. Janssen

    2003-01-01

    The pore water zinc concentration and the calcium chloride extracted zinc fraction are higher in the soils spiked with a zinc salt (ZnCl2) compared to soils spiked with zinc oxide or zinc powder. Based on total zinc concentrations in the soil, the acute toxicity of zinc salt to the compost worm Eisenia fetida, the potworm Enchytraeus albidus and the springtail

  14. Azo-conjugated half-sandwich Rh/Ru complexes for homogeneous water-oxidation catalysis.

    PubMed

    Yu, Wei-Bin; He, Qing-Ya; Shi, Hua-Tian; Jia, Juan-Ying; Wei, Xianwen

    2014-05-01

    Herein we report the molecular structures and electronic properties of ionic, hydrophobic, half-sandwich complexes of the formula [?(5)-Cp*Rh(L)(MeOH)] (1) and [?(6)-CyRu(L)(H2O)] (2), where L is azo-dye compound of (p-(2-hydroxy-1-naphthylazo)benzenesulfonic acid sodium salt). Both these complexes have been investigated electrochemically and found to display good electronic properties for use as water-oxidation catalysts potentially. PMID:24626311

  15. The growth of zinc oxide nanocrystals on the zinc oxide thin film by chemical bath deposition

    Microsoft Academic Search

    Michal Byrczek; Miroslaw Malewicz; Helena Teterycz

    2009-01-01

    In the paper the low temperature deposition of zinc oxide called Chemical Bath Deposition (CBD) will be described. Zinc oxide nanocrystals grow on the thin layer of ZnO. In our investigation the thin film of ZnO was deposited using spin coating, on the glass substrate covered with thin film of Indium Tin Oxide (ITO). The goal of our research is

  16. Comparative study of zinc oxide and aluminum doped zinc oxide transparent thin films grown by direct current magnetron sputtering

    E-print Network

    Comparative study of zinc oxide and aluminum doped zinc oxide transparent thin films grown January 2007 Abstract Pure and aluminum (Al) doped zinc oxide (ZnO and ZAO) thin films have been grown.V. All rights reserved. Keywords: Zinc oxide; dc magnetron sputtering; Surface morphology; Sensors 1

  17. Rapid thermal oxidation of zinc nitride film

    NASA Astrophysics Data System (ADS)

    Lin, Chiung-Wei; Song, Yue-Pu; Chang, Shih-Chieh

    2015-04-01

    In this work, a zinc nitride (ZnN) film was deposited at room temperature and subjected to pulse-mode rapid thermal oxidation. The physical and chemical structures of ZnN film were changed during the rapid thermal oxidation process. The presence of zinc-oxygen bonds in the oxidized ZnN film indicated that some nitrogen atoms within the ZnN film are replaced by oxygen atoms. Through the rapid thermal oxidation process, ZnN was converted into a zinc oxide material containing nitrogen atoms. The oxidized ZnN possessed more acceptor states than donor states, which resulted in p-type conduction. The carrier concentration, mobility, and resistivity of the rapid-thermal-oxidized ZnN were 6.49 × 1018 cm?3, 12.9 cm2 V?1 s?1 and 0.7 ? cm, respectively.

  18. Self-assembled zinc oxide nanodots on silicon oxide

    NASA Astrophysics Data System (ADS)

    Giannakopoulos, K.; Boukos, N.; Travlos, A.

    2005-01-01

    Self assembled ZnO nanodots are grown by electron beam evaporation of Zn on thermally oxidized silicon substrates and subsequent annealing in oxygen. Characterization by TEM and EELS shows that the quantum dots are indeed zinc oxide single crystals grown with their c-axis perpendicular to the substrate; their distribution and size depends on the deposition parameters of zinc onto the substrates.

  19. Thin zinc oxide and cuprous oxide films for photovoltaic applications

    Microsoft Academic Search

    Seongho Jeong

    2010-01-01

    Metal oxide semiconductors and heterojunctions made from thin films of metal oxide semiconductors have broad range of functional properties and high potential in optical, electrical and magnetic devices such as light emitting diodes, spintronic devices and solar cells. Among the oxide semiconductors, zinc oxide (ZnO) and cuprous oxide (Cu2O) are attractive because they are inexpensive, abundant and nontoxic. As synthesized

  20. Zinc Oxide Transparent Thin Films For Optoelectronics

    Microsoft Academic Search

    Karthik Sivaramakrishnan

    2010-01-01

    The object of this body of work is to study the properties and suitability of zinc oxide thin films with a view to engineering them for optoelectronics applications, making them a cheap and effective alternative to indium tin oxide (ITO), the most used transparent conducting oxides in the industry. Initially, a study was undertaken to examine the behavior of silver

  1. Influence of RF power on magnetron sputtered AZO films

    SciTech Connect

    Agarwal, Mohit; Modi, Pankaj; Dusane, R. O. [Semiconductor Thin Films and Plasma Processing Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2013-02-05

    Al-doped Zinc Oxide (AZO) transparent conducting films are prepared on glass substrate by RF magnetron sputtering under different RF power with a 3 inch diameter target of 2 wt%Al{sub 2}O{sub 3} in zinc oxide. The effect of RF power on the structural, optical and electrical properties of AZO films was investigated by X-ray Diffraction (XRD), Hall measurement and UV-Visible spectrophotometry. The XRD data indicates a preferential c-axis orientation for all the films. All films exhibit high transmittance (<90%) in visible region. Films deposited at 60 W power exhibit lowest resistivity of 5.7 Multiplication-Sign 10{sup -4}{omega}cm. Such low-resistivity and high-transmittance AZO films when prepared using low RF power at room temperature could find important applications in flexible electronics.

  2. Highly thermostable, flexible, transparent, and conductive films on polyimide substrate with an AZO/AgNW/AZO structure.

    PubMed

    Huang, Qijin; Shen, Wenfeng; Fang, Xingzhong; Chen, Guofei; Yang, Ye; Huang, Jinhua; Tan, Ruiqin; Song, Weijie

    2015-02-25

    Flexible transparent conductive films (TCFs) are used in a variety of optoelectronic devices. However, their use is limited due to poor thermostability. We report hybrid TCFs incorporation in both aluminum-doped zinc oxide (AZO) and silver nanowires (AgNWs). The layered AZO/AgNWs/AZO structure was deposited onto a transparent polyimide (PI) substrate and displayed excellent thermostability. When heated to 250 °C for 1 h, the change in resistivity (Rc) was less than 10% (Rc of pure AgNW film > 500) while retaining good photoelectric properties (Rsh = 8.6 Ohm/sq and T = 74.4%). Layering the AgNW network between AZO films decreased the surface roughness (Rrms < 8 nm) and enhances the mechanical flexibility of the hybrid films. The combination of these characteristics makes the hybrid film an excellent candidate for substrates of novel flexible optoelectronic devices which require high-temperature processing. PMID:25629397

  3. Effect of Zinc and Zinc Borate on Fire Properties of Modified Polyphenylene Oxide

    Microsoft Academic Search

    R. Benrashid; G. L. Nelson; Donald J. Ferm

    1993-01-01

    Modified polyphenylene oxide resin (m-PPO) (virgin) and m-PPO flame retarded with triaryl phosphate (FR m-PPO) were blended with zinc borate, zinc, and zinc\\/zinc borate. Both virgin and FR m-PPO containing zinc borate showed a marked reduction in smoke production (flaming and non- flaming-NBS Smoke Chamber). In FR m-PPO a reduction in oxygen index values was seen for zinc borate, except

  4. Nanostructured zinc oxide film for urea sensor

    Microsoft Academic Search

    Azahar Ali; Anees A. Ansari; Ajeet Kaushik; Pratima R. Solanki; A. Barik; M. K. Pandey; B. D. Malhotra

    2009-01-01

    Nanostructured zinc oxide (Nano-ZnO) film has been electrochemically deposited onto indium-tin-oxide (ITO) coated glass plate to co-immobilized urease (Urs) and glutamate dehydrogenase (GLDH) for urea detection. The observed reflection planes corresponding to wurtzite ZnO nanoparticles (~25nm) in XRD diffraction pattern and UV-visible absorption band at 338nm reveal the formation of Nano-ZnO. Urs-GLDH\\/Nano-ZnO\\/ITO bioelectrode shows high sensitivity for urea detection within

  5. Highly transparent conductive electrode with ultra-low HAZE by grain boundary modification of aqueous solution fabricated alumina-doped zinc oxide nanocrystals

    NASA Astrophysics Data System (ADS)

    Nian, Qiong; Callahan, Michael; Look, David; Efstathiadis, Harry; Bailey, John; Cheng, Gary J.

    2015-06-01

    Commercial production of transparent conducting oxide (TCO) polycrystalline films requires high electrical conductivity with minimal degradation in optical transparency. Aqueous solution deposited TCO films would reduce production costs of TCO films but suffer from low electrical mobility, which severely degrades both electrical conductivity and optical transparency in the visible spectrum. Here, we demonstrated that grain boundary modification by ultra-violet laser crystallization (UVLC) of solution deposited aluminium-doped zinc oxide (AZO) nanocrystals results in high Hall mobility, with a corresponding dramatic improvement in AZO electrical conductance. The AZO films after laser irradiation exhibit electrical mobility up to 18.1 cm2 V-1 s-1 with corresponding electrical resistivity and sheet resistances as low as 1 × 10-3 ? cm and 75 ?/sq, respectively. The high mobility also enabled a high transmittance (T) of 88%-96% at 550 nm for the UVLC films. In addition, HAZE measurement shows AZO film scattering transmittance as low as 1.8%, which is superior over most other solution deposited transparent electrode alternatives such as silver nanowires. Thus, AZO films produced by the UVLC technique have a combined figure of merit for electrical conductivity, optical transparency, and optical HAZE higher than other solution based deposition techniques and comparable to vacuumed based deposition methods.

  6. LPG sensing performance of nanostructured zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Bari, A. R.; Patil, L. A.

    2013-06-01

    Nanostructured zinc oxide thin films were prepared using ultrasonic spray pyrolysis technique. Zinc acetate was used as a starting precursor. As prepared thin films were characterized using different analytical techniques. The sensing performance of the nanostructured zinc oxide thin films was studied on exposure of various gases. The films were observed to be most sensitive (S= 1727) to LPG at 300°C.

  7. RF Characteristics of Room-Temperature-Deposited, Small Gate Dimension Indium Zinc Oxide TFTs

    E-print Network

    Pearton, Stephen J.

    RF Characteristics of Room-Temperature-Deposited, Small Gate Dimension Indium Zinc Oxide TFTs Yu, North Carolina 27709, USA Depletion-mode indium zinc oxide channel thin film transistors TFTs with gate semiconductors such as zinc oxide, zinc tin oxide, indium gallium oxide, and indium gallium zinc tin oxide have

  8. Room temperature deposition of alumina-doped zinc oxide on flexible substrates by direct pulsed laser recrystallization

    NASA Astrophysics Data System (ADS)

    Zhang, Martin Y.; Nian, Qiong; Cheng, Gary J.

    2012-04-01

    In this study, a method combining room temperature pulsed laser deposition (PLD) and direct pulsed laser recrystallization (DPLR) is introduced to deposit transparent conductive oxide (TCO) layer on low melting point flexible substrates. Alumina-doped zinc oxide (AZO), as one of the most promising TCO candidates, has now been widely used in solar cells. However, to achieve optimal, electrical, and optical properties of AZO on low melting point, flexible substrate is challenging. DPLR technique is a scalable, economic, and fast process to remove crystal defects and generate recrystallization at room temperature. It features selective processing by only heating up the TCO thin film and preserve the underlying substrate at low temperature. In this study, AZO thin film is pre-deposited by PLD on flexible and rigid substrates. DPLR is then introduced to achieve a uniform TCO layer on these substrates, i.e., commercialized Kapton polyimide film, micron-thick Al-foil, and sold lime glass (SLG). Both finite element analysis simulation and designed experiments are carried out to demonstrate that DPLR is promising in manufacturing high quality AZO layers without any damage to the underlying flexible substrates. The hall mobility of AZO after DPLR on Kapton and SLG reached 198 cm2/v . s and 398 cm2/v . s respectively, while the carrier concentrations are reduced to 2.68 × 1018 and 4.3 × 1019/cm-2, respectively. These characteristics are exactly what an ideal TCO layer should carry: high conductivity and high transmission. The property changes are due to the reduction of defect density after DPLR.

  9. Correlation of zinc with oxidative stress biomarkers.

    PubMed

    Morales-Suárez-Varela, María; Llopis-González, Agustín; González-Albert, Verónica; López-Izquierdo, Raúl; González-Manzano, Isabel; Cháves, Javier; Huerta-Biosca, Vicente; Martin-Escudero, Juan C

    2015-03-01

    Hypertension and smoking are related with oxidative stress (OS), which in turn reports on cellular aging. Zinc is an essential element involved in an individual's physiology. The aim of this study was to evaluate the relation of zinc levels in serum and urine with OS and cellular aging and its effect on the development of hypertension. In a Spanish sample with 1500 individuals, subjects aged 20-59 years were selected, whose zinc intake levels fell within the recommended limits. These individuals were classified according to their smoking habits and hypertensive condition. A positive correlation was found (Pearson's C=0.639; p=0.01) between Zn serum/urine quotient and oxidized glutathione levels (GSSG). Finally, risk of hypertension significantly increased when the GSSG levels exceeded the 75 percentile; OR=2.80 (95%CI=1.09-7.18) and AOR=3.06 (95%CI=0.96-9.71). Low zinc levels in serum were related with OS and cellular aging and were, in turn, to be a risk factor for hypertension. PMID:25774936

  10. Correlation of Zinc with Oxidative Stress Biomarkers

    PubMed Central

    Morales-Suárez-Varela, María; Llopis-González, Agustín; González-Albert, Verónica; López-Izquierdo, Raúl; González-Manzano, Isabel; Cháves, Javier; Huerta-Biosca, Vicente; Martin-Escudero, Juan C.

    2015-01-01

    Hypertension and smoking are related with oxidative stress (OS), which in turn reports on cellular aging. Zinc is an essential element involved in an individual’s physiology. The aim of this study was to evaluate the relation of zinc levels in serum and urine with OS and cellular aging and its effect on the development of hypertension. In a Spanish sample with 1500 individuals, subjects aged 20–59 years were selected, whose zinc intake levels fell within the recommended limits. These individuals were classified according to their smoking habits and hypertensive condition. A positive correlation was found (Pearson’s C = 0.639; p = 0.01) between Zn serum/urine quotient and oxidized glutathione levels (GSSG). Finally, risk of hypertension significantly increased when the GSSG levels exceeded the 75 percentile; OR = 2.80 (95%CI = 1.09–7.18) and AOR = 3.06 (95%CI = 0.96–9.71). Low zinc levels in serum were related with OS and cellular aging and were, in turn, to be a risk factor for hypertension.  PMID:25774936

  11. Fe-exchanged Y zeolite as catalyst for wet peroxide oxidation of reactive azo dye Procion Marine H-EXL

    Microsoft Academic Search

    Mariana Neam; Carmen Zaharia; Cezar Catrinescu; Ayfer Yediler; Matei Macoveanu; Antonius Kettrup

    2004-01-01

    This paper evaluates the degradation of a reactive azo dye, Procion Marine H-EXL, by catalytic wet hydrogen peroxide oxidation (CWHPO). The catalyst was prepared by ion-exchange, starting from a commercially available ultrastable Y zeolite. All experiments were performed on a laboratory scale set-up. The effects of different reaction parameters such as initial pH, catalyst and hydrogen peroxide concentrations on the

  12. Facile Cu(I)-catalyzed oxidative coupling of anilines to azo compounds and hydrazines with diaziridinone under mild conditions.

    PubMed

    Zhu, Yingguang; Shi, Yian

    2013-04-19

    A mild and highly efficient Cu(I)-catalyzed oxidative coupling of anilines is described. Various primary and secondary anilines can be efficiently coupled under mild conditions to the corresponding azo compounds and hydrazines in high yields. This method provides a direct and practical access to these compounds and is also amenable to gram scale with no special precautions to exclude air or moisture. PMID:23545123

  13. A Facile Cu(I)-Catalyzed Oxidative Coupling of Anilines to Azo Compounds and Hydrazines with Diaziridinone under Mild Conditions

    PubMed Central

    Zhu, Yingguang; Shi, Yian

    2013-01-01

    A mild and highly efficient Cu(I)-catalyzed oxidative coupling of anilines is described. Various primary and secondary anilines can be efficiently coupled under mild conditions to the corresponding azo compounds and hydrazines in high yields. This method provides a direct and practical access to these compounds, and is also amenable to gram scale with no special precautions to exclude air or moisture. PMID:23545123

  14. Zinc oxide nanostructures: growth, properties and applications

    Microsoft Academic Search

    Zhong Lin Wang

    2004-01-01

    Zinc oxide is a unique material that exhibits semiconducting and piezoelectric dual properties. Using a solid–vapour phase thermal sublimation technique, nanocombs, nanorings, nanohelixes\\/nanosprings, nanobelts, nanowires and nanocages of ZnO have been synthesized under specific growth conditions. These unique nanostructures unambiguously demonstrate that ZnO probably has the richest family of nanostructures among all materials, both in structures and in properties. The

  15. Zinc oxide as a formose catalyst

    Microsoft Academic Search

    A. H. Weiss; S. Trigerman

    1980-01-01

    Zinc oxide heterogeneously catalyzes formaldehyde condensation to a complex mixture of formose sugars. The reaction proceeds at pH 5.5 and unwanted Cannizzaro side reaction does not occur. The catalyzed reaction is exceptionally slow. At 100°C and 1.00 M ZnO, 0.61 M HCHO starting concentration, the induction period lasts 70 h and 90% conversion does not occur until 92 h. Either

  16. Surface Wettability of Nanostructured Zinc Oxide Films

    Microsoft Academic Search

    Jie Han; Wei Gao

    2009-01-01

    Zinc oxide (ZnO) nanograin and nanorod films were prepared by magnetron sputter deposition and an aqueous solution growth\\u000a method. Their surface wettability was studied in relation to their surface morphologies. While the surfaces of both films\\u000a were hydrophobic, the nanorod films exhibited higher surface hydrophobicity. A superhydrophobic surface was obtained on a\\u000a ZnO nanorod film with a water contact angle

  17. Zinc oxide-based diluted magnetic semiconductors

    Microsoft Academic Search

    Ram Seshadri

    2005-01-01

    The current experimental situation on the occurrence or absence of ferromagnetism in diluted magnetic semiconductors based on wurtzite zinc oxide hosts is presented, focusing mainly on the many recent experiments which have been performed on bulk systems. Numerous reports have suggested that partial (typically less than 10at.%) substitution of Zn2+ in ZnO by magnetic transition metal (tM) ions, particularly Mn2+

  18. Summary review of health effects associated with zinc and zinc oxide: health issue assessment

    SciTech Connect

    Not Available

    1987-07-01

    Zinc is a dense, bluish-white, relatively soft metal used extensively in the galvanizing of iron and steel. Zinc oxide, the most valued of the variety of compounds formed by zinc is used principally in rubber products as an activator in the vulcanization process and in the treatment of burns, infections, and skin diseases. Zinc occurs naturally in the environment; however, zinc may also enter the environment as the result of mining and processing the production of zinc oxide and the manufacture and use of products containing zinc oxide, the combustion of coal and oil, the production of iron and steel, and the incineration of refuse. Humans are mainly exposed to zinc through the ingestion of food (between 8 and 18.6 mg/kg/day) and drink (averaging up to 10 mg/day). Based on annual average airborne zinc concentrations in areas throughout the United States without mines or smelters of generally < 1mg/cu. m., the contribution of zinc from inhaled air represents an insignificant amount of daily zinc exposure, averaging approximately 20 micrograms. The literature on the toxic effects of zinc is limited. The most widely known systemic effect resulting from acute inhalation of freshly formed zinc oxide fumes is a disease called metal fume fever. Metal fume fever occurs in certain occupational settings and the exposure level at which the fever occurs is not known.

  19. Thermally oxidized zinc oxide nanowires for use as chemical sensors.

    PubMed

    Zappa, D; Comini, E; Sberveglieri, G

    2013-11-01

    Zinc oxide (ZnO) mat-based conductometric devices were fabricated using a thermal oxidation technique. A metallic zinc layer was deposited on the alumina transducer and then oxidized in a controlled atmosphere, in order to obtain ZnO nanostructures. Two different batches of sensors have been prepared, and their sensing performances have been evaluated towards oxidizing and reducing gases. Functional measurements showed very good sensing performances towards ethanol and acetone at 500 °C, and NO2 at 200 °C, indirectly confirming the n-type behaviour of the material. The influence of the humidity on the response has been explored. In practical conditions the interference of humidity is very small, and could be neglected in many applications. Simultaneous measurements on different devices from the same batch confirm the high reproducibility of the response within the batch. PMID:24113169

  20. Variable-Temperature Electrical Measurements of Zinc Oxide/Tin Oxide-Cosubstituted Indium Oxide

    E-print Network

    Poeppelmeier, Kenneth R.

    Variable-Temperature Electrical Measurements of Zinc Oxide/Tin Oxide-Cosubstituted Indium Oxide A-), undoped In2O3, and indium-tin oxide (ITO) were studied vs cation composition, state of reduction of choice, tin-doped indium oxide (ITO) has a typical conductivity of 1-5 × 103 S/cm and a transpar- ency

  1. Recent developments in zinc oxide target chemistry

    SciTech Connect

    Heaton, R.C.; Taylor, W.A.; Phillips, D.R.; Jamriska, D.J. Sr.; Garcia, J.B.

    1994-04-01

    Zinc oxide targets irradiated with high energy protons at the Los Alamos Meson Physics Facility (LAMPF) contain a number of radioactive spallation products in quantities large enough to warrant recovery. This paper describes methods for recovering {sup 7}Be, {sup 46}Sc, and {sup 48}V from such targets and offers suggestions on possible ways to recover additional isotopes. The proposed methods are based on traditional precipitation and ion exchange techniques, are readily adaptable to hot cell use, and produce no hazardous waste components. The products are obtained in moderate to high yields and have excellent radiopurity.

  2. Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays

    Microsoft Academic Search

    Zhong Lin Wang; Jinhui Song

    2006-01-01

    We have converted nanoscale mechanical energy into electrical energy by means of piezoelectric zinc oxide nanowire (NW) arrays. The aligned NWs are deflected with a conductive atomic force microscope tip in contact mode. The coupling of piezoelectric and semiconducting properties in zinc oxide creates a strain field and charge separation across the NW as a result of its bending. The

  3. Ultra fast synthesis of zinc oxide nanostructures by microwaves

    Microsoft Academic Search

    N. Tabet; R. Al Ghashani; S. Achour

    2009-01-01

    We describe a novel route for the synthesis of nanostructured zinc oxide powder using a modified kitchen microwave. A SiC-based composite showing a very strong absorption of microwaves was used as a microwave heater. Tests showed that high temperatures exceeding 1700 ?C can be reached in less than hundred second exposure of the composite material of microwaves. Zinc oxide nanopowder was

  4. Influence of growth temperature on electrical, optical, and plasmonic properties of aluminum:zinc oxide films grown by radio frequency magnetron sputtering

    SciTech Connect

    Dondapati, Hareesh; Santiago, Kevin; Pradhan, A. K. [Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, Virginia 23504 (United States)] [Center for Materials Research, Norfolk State University, 700 Park Avenue, Norfolk, Virginia 23504 (United States)

    2013-10-14

    We have investigated the responsible mechanism for the observation of metallic conductivity at room temperature and metal-semiconductor transition (MST) at lower temperatures for aluminum-doped zinc oxide (AZO) films. AZO films were grown on glass substrates by radio-frequency magnetron sputtering with varying substrate temperatures (T{sub s}). The films were found to be crystalline with the electrical resistivity close to 1.1 × 10{sup ?3} ? cm and transmittance more than 85% in the visible region. The saturated optical band gap of 3.76 eV was observed for the sample grown at T{sub s} of 400 °C, however, a slight decrease in the bandgap was noticed above 400 °C, which can be explained by Burstein–Moss effect. Temperature dependent resistivity measurements of these highly conducting and transparent films showed a MST at ?110 K. The observed metal-like and metal-semiconductor transitions are explained by taking into account the Mott phase transition and localization effects due to defects. All AZO films demonstrate crossover in permittivity from positive to negative and low loss in the near-infrared region, illustrating its applications for plasmonic metamaterials, including waveguides for near infrared telecommunication region. Based on the results presented in this study, the low electrical resistivity and high optical transmittance of AZO films suggested a possibility for the application in the flexible electronic devices, such as transparent conducting oxide film on LEDs, solar cells, and touch panels.

  5. Transient laser annealing of zinc oxide nanoparticle inks to fabricate zinc oxide thin film transistors

    NASA Astrophysics Data System (ADS)

    Willemann, Michael

    Display technology, which relies exclusively on amorphous silicon as the active material for driver electronics, has reached multiple impasses that limit future progress. In order to deliver higher resolutions, higher refresh rates, new display technologies, and innovative form factors, driver electronics must transition to higher performance materials like amorphous oxide semiconductors (AOSs). Transient laser annealing offers an attractive means to maximize performance while minimizing thermal budget, making it compatible with flexible back plane materials and roll-to-roll processing. This research investigates the deposition and annealing of zinc oxide nanoparticle inks to form fully densified crystalline and amorphous zinc oxide films. Processing routes for nanoparticle annealing, including ligand removal, calcining, and excimer pulse laser sintering on the nanosecond time scale, will be introduced that minimize defect formation and suppress the anomalous n-conductivity which is a major challenge to zinc oxide processing. Resistivities as high as 6 x 107 O-cm have been demonstrated. Laser processing on longer millisecond time scales can control defect formation to produce ZnO films without extrinsic doping which have low resistivity for intrinsic oxides, in the range of 10-1 - 10-2 O-cm. Finally, a viable process for the production of backgated ZnO transistors with promising characteristics is presented and the future implications for AOSs and transient thermal processing will be discussed.

  6. UV irradiation-induced zinc dissociation from commercial zinc oxide sunscreen and its action in human epidermal keratinocytes

    E-print Network

    Li, Yang V.

    UV irradiation-induced zinc dissociation from commercial zinc oxide sunscreen and its action Summary Zinc oxide (ZnO) is an active ingredient in sunscreen owing to its properties of broadly filtering of solar radiation on the skin. This study investigated the dissociation of zinc (Zn2+ ) from Zn

  7. Zinc Oxide Nanomaterials for Biomedical Fluorescence Detection

    PubMed Central

    Hahm, Jong-in

    2014-01-01

    One-dimensional zinc oxide nanomaterials have been recently developed into novel, extremely effective, optical signal-enhancing bioplatforms. Their usefulness has been demonstrated in various biomedical fluorescence assays. Fluorescence is extensively used in biology and medicine as a sensitive and noninvasive detection method for tracking and analyzing biological molecules. Achieving high sensitivity via improving signal-to-noise ratio is of paramount importance in fluorescence-based, trace-level detection. Recent advances in the development of optically superior one-dimensional materials have contributed to this important biomedical area of detection. This review article will discuss major research developments that have so far been made in this emerging and exciting topical field. The discussion will cover a broad range of subjects including synthesis of zinc oxide nanorods (ZnO NRs), various properties differentiating them as suitable optical biodetection platforms, their demonstrated applicability in DNA and protein detection, and the nanomaterial characteristics relevant for biomolecular fluorescence enhancement. This review will then summarize the current status of ZnO NR-based biodetection and further elaborate future utility of ZnO NR platforms for advanced biomedical assays, based on their proven advantages. Lastly, present challenges experienced in this topical area will be identified and focal subject areas for future research will be suggested as well. PMID:24730276

  8. Effect of deposition condition and UV-ozone post-treatment on work function of DC magnetron sputtered AZO thin films

    Microsoft Academic Search

    Quanyu Feng; Weiyan Wang; Kemin Jiang; Jinhua Huang; Yulong Zhang; Weijie Song; Ruiqin Tan

    Highly transparent and conductive aluminum-doped zinc oxide (AZO) thin films were successfully deposited on glass by DC magnetron\\u000a sputtering. The effects of Al-doping content (1–4 at.%), substrate temperature (250–350 °C) and ultraviolet (UV)-ozone treatment\\u000a time (0–20 min) on AZO film work function were systematically investigated. It was revealed that the AZO work function increased\\u000a with the decrease of Al content, while it

  9. Preparation and properties of polymer\\/zinc oxide nanocomposites using functionalized zinc oxide quantum dots

    Microsoft Academic Search

    Moriyuki Sato; Akihito Kawata; Shigekazu Morito; Yuzuru Sato; Isao Yamaguchi

    2008-01-01

    Poly(methyl methacrylate) (PMMA)\\/zinc oxide (ZnO) or carbazole polymer (PCEM)\\/ZnO nanocomposites, which are composed of high molecular weight PMMA or PCEM with narrow molecular weight distributions and ZnO nanoparticles, were successfully prepared by atom transfer radical polymerization (ATRP) initiated by 2-bromo-2-methylpropionyl (BMP) group (ZnBM) introduced onto the ZnO nanoparticle surfaces. Introduction of the BMP group onto the ZnO surfaces was achieved

  10. Antifouling properties of zinc oxide nanorod coatings.

    PubMed

    Al-Fori, Marwan; Dobretsov, Sergey; Myint, Myo Tay Zar; Dutta, Joydeep

    2014-01-01

    In laboratory experiments, the antifouling (AF) properties of zinc oxide (ZnO) nanorod coatings were investigated using the marine bacterium Acinetobacter sp. AZ4C, larvae of the bryozoan Bugula neritina and the microalga Tetraselmis sp. ZnO nanorod coatings were fabricated on microscope glass substrata by a simple hydrothermal technique using two different molar concentrations (5 and 10?mM) of zinc precursors. These coatings were tested for 5?h under artificial sunlight (1060?W?m(-2) or 530?W?m(-2)) and in the dark (no irradiation). In the presence of light, both the ZnO nanorod coatings significantly reduced the density of Acinetobacter sp. AZ4C and Tetraselmis sp. in comparison to the control (microscope glass substratum without a ZnO coating). High mortality and low settlement of B. neritina larvae was observed on ZnO nanorod coatings subjected to light irradiation. In darkness, neither mortality nor enhanced settlement of larvae was observed. Larvae of B. neritina were not affected by Zn(2+) ions. The AF effect of the ZnO nanorod coatings was thus attributed to the reactive oxygen species (ROS) produced by photocatalysis. It was concluded that ZnO nanorod coatings effectively prevented marine micro and macrofouling in static conditions. PMID:25115521

  11. Azo dye Acid Red 27 decomposition kinetics during ozone oxidation and adsorption processes

    Microsoft Academic Search

    Mi H. Beak; Christianah O. Ijagbemi; Dong S. Kim

    2009-01-01

    To elucidate the effects of ozone dosage, catalysts, and temperature on azo dye decomposition rate in treatment processes, the decomposition kinetics of Acid Red 27 by ozone was investigated. Acid Red 27 decomposition rate followed the first-order reaction with complete dye discoloration in 20 min of ozone reaction. The dye decay rate increases as ozone dosage increases. Using Mn, Zn

  12. Optical and Luminescence Properties of Zinc Oxide

    E-print Network

    Rodnyi, P A; 10.1134/S0030400X11120216

    2012-01-01

    We generalize and systematize basic experimental data on optical and luminescence properties of ZnO single crystals, thin films, powders, ceramics, and nanocrystals. We consider and study mechanisms by which two main emission bands occur, a short-wavelength band near the fundamental absorption edge and a broad long-wavelength band, the maximum of which usually lies in the green spectral range. We determine a relationship between the two luminescence bands and study in detail the possibility of controlling the characteristics of ZnO by varying the maximum position of the short-wavelength band. We show that the optical and luminescence characteristics of ZnO largely depend on the choice of the corresponding impurity and the parameters of the synthesis and subsequent treatment of the sample. Prospects for using zinc oxide as a scintillator material are discussed. Additionally, we consider experimental results that are of principal interest for practice.

  13. Sprayed lanthanum doped zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Bouznit, Y.; Beggah, Y.; Ynineb, F.

    2012-01-01

    Lanthanum doped zinc oxide thin films were deposited on soda-lime glass substrates using a pneumatic spray pyrolysis technique. The films were prepared using different lanthanum concentrations at optimum deposition parameters. We studied the variations in structural, morphological and optical properties of the samples due to the change of doping concentration in precursor solutions. X-ray diffraction (XRD) patterns show that pure and La-doped ZnO thin films are highly textured along c-axis perpendicular to the surface of the substrate. Scanning electron micrographs show that surface morphology of ZnO films undergoes a significant change according to lanthanum doping. All films exhibit a transmittance higher than 80% in the visible region.

  14. Optical and Luminescence Properties of Zinc Oxide

    E-print Network

    P. A. Rodnyi; I. V. Khodyuk

    2012-03-20

    We generalize and systematize basic experimental data on optical and luminescence properties of ZnO single crystals, thin films, powders, ceramics, and nanocrystals. We consider and study mechanisms by which two main emission bands occur, a short-wavelength band near the fundamental absorption edge and a broad long-wavelength band, the maximum of which usually lies in the green spectral range. We determine a relationship between the two luminescence bands and study in detail the possibility of controlling the characteristics of ZnO by varying the maximum position of the short-wavelength band. We show that the optical and luminescence characteristics of ZnO largely depend on the choice of the corresponding impurity and the parameters of the synthesis and subsequent treatment of the sample. Prospects for using zinc oxide as a scintillator material are discussed. Additionally, we consider experimental results that are of principal interest for practice.

  15. Production of nano zinc, zinc sulphide and nanocomplex of magnetite zinc oxide by Brevundimonas diminuta and Pseudomonas stutzeri.

    PubMed

    Mirhendi, Mansoureh; Emtiazi, Giti; Roghanian, Rasoul

    2013-12-01

    ZnO (Zincite) nanoparticle has many industrial applications and is mostly produced by chemical reactions, usually prepared by decomposition of zinc acetate or hot-injection and heating-up method. Synthesis of semi-conductor nanoparticles such as ZnS (Sphalerite) by ultrasonic was previously reported. In this work, high-zinc tolerant bacteria were isolated and used for nano zinc production. Among all isolated microorganisms, a gram negative bacterium which was identified as Brevundimonas diminuta could construct nano magnetite zinc oxide on bacterial surface with 22 nm in size and nano zinc with 48.29 nm in size. A piece of zinc metal was immersed in medium containing of pure culture of B. diminuta. Subsequently, a yellow-white biofilm was formed which was collected from the surface of zinc. It was dried at room temperature. The isolated biofilm was analysed by X-ray diffractometer. Interestingly, the yield of these particles was higher in the light, with pH 7 at 23°C. To the best of the authors knowledge, this is the first report about the production of nano zinc metal and nano zinc oxide that are stable and have anti-bacterial activities with magnetite property. Also ZnS (sized 12 nm) produced by Pseudomonas stutzeri, was studied by photoluminescence and fluorescent microscope. PMID:24206770

  16. Microwave Synthesis of Zinc Hydroxy Sulfate Nanoplates and Zinc Oxide Nanorods in the Classroom

    ERIC Educational Resources Information Center

    Dziedzic, Rafal M.; Gillian-Daniel, Anne Lynn; Peterson, Greta M.; Martínez-Herna´ndez, Kermin J.

    2014-01-01

    In this hands-on, inquiry-based lab, high school and undergraduate students learn about nanotechnology by synthesizing their own nanoparticles in a single class period. This simple synthesis of zinc oxide nanorods and zinc hydroxy sulfate nanoplates can be done in 15 min using a household microwave oven. Reagent concentration, reaction…

  17. Ultra fast synthesis of zinc oxide nanostructures by microwaves

    NASA Astrophysics Data System (ADS)

    Tabet, N.; Al Ghashani, R.; Achour, S.

    2009-06-01

    We describe a novel route for the synthesis of nanostructured zinc oxide powder using a modified kitchen microwave. A SiC-based composite showing a very strong absorption of microwaves was used as a microwave heater. Tests showed that high temperatures exceeding 1700 ?C can be reached in less than hundred second exposure of the composite material of microwaves. Zinc oxide nanopowder was obtained by evaporation and oxidation of metallic zinc in the ambient atmosphere of the microwave oven. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) techniques revealed the prepared powder includes a wide variety of nanostructures including nanoparticles, nanosheets and tetrapods.

  18. Zinc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

  19. The interaction between zinc oxide and titanium dioxide in water

    Microsoft Academic Search

    L. H. Princen; Marilyn J. DeVena

    1962-01-01

    A mechanism is proposed for the reaction between zinc oxide and titanium dioxide in water. Between certain limits of weight\\u000a ratios of zinc oxide and titanium dioxide definite increases in viscosity, pH, and sedimentation volumes with time have been\\u000a observed which support the belief that tridimensional structures are formed from the individual particles. The same mechanism\\u000a may be responsible for

  20. Acetone sensor based on zinc oxide hexagonal tubes

    NASA Astrophysics Data System (ADS)

    Hastir, Anita; Singh, Onkar; Anand, Kanika; Singh, Ravi Chand

    2014-04-01

    In this work hexagonal tubes of zinc oxide have been synthesized by co-precipitation method. For structural, morphological, elemental and optical analysis synthesized powders were characterized by using x-ray diffraction, field emission scanning microscope, EDX, UV-visible and FTIR techniques. For acetone sensing thick films of zinc oxide have been deposited on alumina substrate. The fabricated sensors exhibited maximum sensing response towards acetone vapour at an optimum operating temperature of 400°C.

  1. Zinc oxide nanowire rigid platforms on elastomeric substrates.

    PubMed

    Bendall, James S; Graz, Ingrid; Lacour, Stéphanie P

    2011-08-01

    Zinc oxide nanostructured thin films are transparent semiconducting ceramics increasingly used in a wide range of integrated devices. This paper outlines a simple strategy to integrate arrays of zinc oxide nanostructured thin films on elastomeric substrates using templated patterning. The arrays are robust to large uniaxial strains (up to 20% strain), do not fracture, and maintain electrical functionality. The integration of brittle nanostructured semiconducting materials on elastomeric substrates opens promising routes for the manufacture of deformable and stretchable electronics. PMID:21740041

  2. Zinc oxide nanoflowers make new blood vessels

    NASA Astrophysics Data System (ADS)

    Barui, Ayan Kumar; Veeriah, Vimal; Mukherjee, Sudip; Manna, Joydeb; Patel, Ajay Kumar; Patra, Sujata; Pal, Krishnendu; Murali, Shruthi; Rana, Rohit K.; Chatterjee, Suvro; Patra, Chitta Ranjan

    2012-11-01

    It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H2O2)--a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role.It is well established that angiogenesis is the process of formation of new capillaries from pre-existing blood vessels. It is a complex process, involving both pro- and anti-angiogenic factors, and plays a significant role in physiological and pathophysiological processes such as embryonic development, atherosclerosis, post-ischemic vascularization of the myocardium, tumor growth and metastasis, rheumatoid arthritis etc. This is the first report of zinc oxide (ZnO) nanoflowers that show significant pro-angiogenic properties (formation of new capillaries from pre-existing blood vessels), observed by in vitro and in vivo angiogenesis assays. The egg yolk angiogenesis assay using ZnO nanoflowers indicates the presence of matured blood vessels formation. Additionally, it helps to promote endothelial cell (EA.hy926 cells) migration in wound healing assays. Formation of reactive oxygen species (ROS), especially hydrogen peroxide (H2O2)--a redox signaling molecule, might be the plausible mechanism for nanoflower-based angiogenesis. Angiogenesis by nanoflowers may provide the basis for the future development of new alternative therapeutic treatment strategies for cardiovascular and ischemic diseases, where angiogenesis plays a significant role. Electronic supplementary information (ESI) available: See DOI: 10.1039/c2nr32369a

  3. Sliding droplets on superomniphobic zinc oxide nanostructures.

    PubMed

    Perry, Guillaume; Coffinier, Yannick; Thomy, Vincent; Boukherroub, Rabah

    2012-01-10

    This study reports on liquid-repellency of zinc oxide nanostructures (ZnO NS). The ZnO NS are synthesized by an easy and fast chemical bath deposition technique. Three different nanostructured surfaces consisting of nanorods, flowers, and particles are prepared, depending on the deposition time and the presence of ethanolamine in the reaction mixture. Chemical functionalization of the ZnO NS with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (PFTS) in liquid (PFTS L) and vapor phase (PFTS V) or through octafluorobutane (C(4)F(8)) plasma deposition led to the formation of superomniphobic surfaces. A comprehensive characterization of the wetting properties (static contact angle and contact angle hysteresis) has been performed using liquids composed of deionized water and various concentrations of ethanol (surface tension between 35 and 72.6 mN/m). Depending on the nanostructures morphology, coating nature and liquid employed, high static apparent contact angles ? ? 150-160°, and low contact angle hysteresis ?? ? 0° are obtained. The different ZnO NS are characterized using scanning electron microscopy (SEM) and contact angle measurements. The results reported in this work permit preparation of sliding omniphobic surfaces using a simple and low cost technique. PMID:22053956

  4. A new copper species based on an azo-compound utilized as a homogeneous catalyst for water oxidation.

    PubMed

    Yu, Wei-Bin; He, Qing-Ya; Ma, Xiu-Fang; Shi, Hua-Tian; Wei, Xianwen

    2015-01-01

    A new azo-complex [(L)Cu(II)(NO3)] [L = (E)-3-(pyridin-2-yldiazenyl)naphthalen-2-ol (HL)], was prepared via a one-pot synthetic method at 60 °C and was structurally characterized by IR, EA, PXRD and single crystal X-ray diffraction. In addition, TGA studies indicated that the complex was stable in air. The redox properties were determined by cyclic voltammetry, which revealed that the complex could be utilized as a catalyst for water oxidation under mild conditions. Subsequently, the complex was employed as a catalyst to take part in water oxidation reaction in the presence of a Ce(IV) salt utilized as an oxidant at pH 11 in PBS (Phosphate Buffered Saline) solution. The results suggested that the catalyst exhibited a high stability and activity toward water oxidation reaction under these conditions with an initial TOF of 4.0 kPa h(-1). Calculation methodology was performed to study the mechanism of the reaction, which revealed that in this catalytic process, the initial oxidation of Cu(II) to Cu(III) occurred by the formation of an intermediate "Cu(III)-O-O-Cu(III)". The formation of this intermediate, resulted in a release of oxygen and closing of the catalytic cycle. PMID:25382024

  5. Genotoxic effects of zinc oxide nanoparticles.

    PubMed

    Heim, Julia; Felder, Eva; Tahir, Muhammad Nawaz; Kaltbeitzel, Anke; Heinrich, Ulf Ruediger; Brochhausen, Christoph; Mailänder, Volker; Tremel, Wolfgang; Brieger, Juergen

    2015-05-01

    The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and 100 ?g mL(-1) using the cell line A549. Internalised NPs were only infrequently detectable by TEM, but strongly increased Zn(2+) levels in the cytoplasm and even more in the nuclear fraction, as measured by atom absorption spectroscopy, indicative of an internalised zinc and nuclear accumulation. We observed a time and dosage dependent reduction of cellular viability after ZnO NP exposure. ZnCl2 exposure to cells induced similar impairments of cellular viability. Complexation of Zn(2+) with diethylene triamine pentaacetic acid (DTPA) resulted in the loss of toxicity of NPs, indicating the relevant role of Zn(2+) for ZnO NP toxicity. Foci analyses showed the induction of DNA double strand breaks (DSBs) by ZnO NPs and increased intracellular reactive oxygen species (ROS) levels. Treatment of the cells with the ROS scavenger N-acetyl-l-cysteine (NAC) resulted in strongly decreased intracellular ROS levels and reduced DNA damage. However, a slow increase of ROS after ZnO NP exposure and reduced but not quashed DSBs after NAC-treatment suggest that Zn(2+) may exert genotoxic activities without the necessity of preceding ROS-induction. Our data indicate that ZnO NP toxicity is a result of cellular Zn(2+) intake. Subsequently increased ROS-levels cause DNA damage. However, we found evidence for the assumption that DNA-DSBs could be caused by Zn(2+) without the involvement of ROS. PMID:25916659

  6. Thermodynamics and kinetics of extracting zinc from zinc oxide ore by the ammonium sulfate roasting method

    NASA Astrophysics Data System (ADS)

    Sun, Yi; Shen, Xiao-yi; Zhai, Yu-chun

    2015-05-01

    Thermodynamic analyses and kinetic studies were performed on zinc oxide ore treatment by (NH4)2SO4 roasting technology. The results show that it is theoretically feasible to realize a roasting reaction between the zinc oxide ore and (NH4)2SO4 in a temperature range of 573-723 K. The effects of reaction temperature and particle size on the extraction rate of zinc were also examined. It is found that a surface chemical reaction is the rate-controlling step in roasting kinetics. The calculated activation energy of this process is about 45.57 kJ/mol, and the kinetic model can be expressed as follows: 1 - (1 - ?)1/3 = 30.85 exp(-45.57/ RT)· t. An extraction ratio of zinc as high as 92% could be achieved under the optimum conditions.

  7. Sulfidation and reduction of zinc titanate and zinc oxide sorbents for injection in gasifier exit ducts

    Microsoft Academic Search

    K. Ishikawa; C. Krueger; M. Flytzani-Stephanopoulos; W. Jl; R. J. Higgins; B. A. Bishop; R. L. Goldsmith

    1995-01-01

    The sulfidation reaction kinetics of fine particles of zinc titanate and zinc oxide with HâS were studied in order to test the potential of the sorbent injection hot-gas desulfurization process. Fine sorbent particles with diameter between 0.3 and 60 μm were sulfided with HâS and\\/or reduced with Hâ in a laminar flow reactor over the temperature range of 500-900°C. Sulfidation\\/reduction

  8. Genotoxic effects of zinc oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Heim, Julia; Felder, Eva; Tahir, Muhammad Nawaz; Kaltbeitzel, Anke; Heinrich, Ulf Ruediger; Brochhausen, Christoph; Mailänder, Volker; Tremel, Wolfgang; Brieger, Juergen

    2015-05-01

    The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and 100 ?g mL-1 using the cell line A549. Internalised NPs were only infrequently detectable by TEM, but strongly increased Zn2+ levels in the cytoplasm and even more in the nuclear fraction, as measured by atom absorption spectroscopy, indicative of an internalised zinc and nuclear accumulation. We observed a time and dosage dependent reduction of cellular viability after ZnO NP exposure. ZnCl2 exposure to cells induced similar impairments of cellular viability. Complexation of Zn2+ with diethylene triamine pentaacetic acid (DTPA) resulted in the loss of toxicity of NPs, indicating the relevant role of Zn2+ for ZnO NP toxicity. Foci analyses showed the induction of DNA double strand breaks (DSBs) by ZnO NPs and increased intracellular reactive oxygen species (ROS) levels. Treatment of the cells with the ROS scavenger N-acetyl-l-cysteine (NAC) resulted in strongly decreased intracellular ROS levels and reduced DNA damage. However, a slow increase of ROS after ZnO NP exposure and reduced but not quashed DSBs after NAC-treatment suggest that Zn2+ may exert genotoxic activities without the necessity of preceding ROS-induction. Our data indicate that ZnO NP toxicity is a result of cellular Zn2+ intake. Subsequently increased ROS-levels cause DNA damage. However, we found evidence for the assumption that DNA-DSBs could be caused by Zn2+ without the involvement of ROS.The potential toxicity of nanoparticles has currently provoked public and scientific discussions, and attempts to develop generally accepted handling procedures for nanoparticles are under way. The investigation of the impact of nanoparticles on human health is overdue and reliable test systems accounting for the special properties of nanomaterials must be developed. Nanoparticular zinc oxide (ZnO) may be internalised through ambient air or the topical application of cosmetics, only to name a few, with unpredictable health effects. Therefore, we analysed the determinants of ZnO nanoparticle (NP) genotoxicity. ZnO NPs (15-18 nm in diameter) were investigated at concentrations of 0.1, 10 and 100 ?g mL-1 using the cell line A549. Internalised NPs were only infrequently detectable by TEM, but strongly increased Zn2+ levels in the cytoplasm and even more in the nuclear fraction, as measured by atom absorption spectroscopy, indicative of an internalised zinc and nuclear accumulation. We observed a time and dosage dependent reduction of cellular viability after ZnO NP exposure. ZnCl2 exposure to cells induced similar impairments of cellular viability. Complexation of Zn2+ with diethylene triamine pentaacetic acid (DTPA) resulted in the loss of toxicity of NPs, indicating the relevant role of Zn2+ for ZnO NP toxicity. Foci analyses showed the induction of DNA double strand breaks (DSBs) by ZnO NPs and increased intracellular reactive oxygen species (ROS) levels. Treatment of the cells with the ROS scavenger N-acetyl-l-cysteine (NAC) resulted in strongly decreased intracellular ROS levels and reduced DNA damage. However, a slow increase of ROS after ZnO NP exposure and reduced but not quashed DSBs after NAC-treatment suggest that Zn2+ may exert genotoxic activities without the necessity of preceding ROS-induction. Our data indicate that ZnO NP toxicity is a result of cellular Zn2+ intake. Subsequently increased ROS-levels cause DNA damage. However, we found evidence for the assumption tha

  9. Electrolyte optimization for cathodic growth of zinc oxide films

    Microsoft Academic Search

    Masanobu Izaki; Takashi Omi

    1996-01-01

    Zinc oxide is of considerable interest to the optical and electronic industries, because of its electrical, optical, and acoustic characteristics. ZnO films can be prepared by several techniques, such as radio frequency (RF) magnetron sputtering, chemical vapor deposition, and molecular beam epitaxy. Preparation of oxide films by electrodeposition from aqueous solutions has several potential advantages over the other techniques. However,

  10. Antibacterial effects of zinc oxide nanorod surfaces.

    PubMed

    Jansson, Tobias; Clare-Salzler, Zachary J; Zaveri, Toral D; Mehta, Shahil; Dolgova, Natalia V; Chu, Byung-Hwan; Ren, Fan; Keselowsky, Benjamin G

    2012-09-01

    Antibacterial coating approaches are being investigated to modify implants to reduce bacterial adhesion and viability in order to reduce implant-associated infection. Nanostructured materials possess unique surface properties, and nanotopographic surfaces have been reported to modulate bacterial adhesion. Zinc oxide (ZnO) films presenting well-controlled nanorod surface structures have recently been developed. To assess the efficacy of ZnO nanorod surfaces as an anti-bacterial coating, we evaluated bacterial adhesion and viability, compared to sputtered ZnO substrates (a relatively flat control) and glass substrates (as a reference). Common implant-associated pathogens, Pseudomonas aeruginosa and Staphylococcus epidermidis were investigated. The number of adherent P. aeruginosa on ZnO nanorod surfaces was found to be reduced compared to glass and sputtered ZnO, while the adherent number of S. epidermidis on the ZnO nanorods was equivalent to glass. Regarding bacteria viability, the ZnO nanorod and sputtered ZnO surfaces demonstrated a modest, but significant bactericidal effect on adherent P. aeruginosa, killing 2.5-fold and 1.7-fold more over the number of dead P. aeruginosa on glass, respectively. A greater bactericidal effect of ZnO substrates on S. epidermidis was found, with sputtered ZnO and ZnO nanorod substrates killing -20-fold and 30-fold more over the number of dead S. epidermidis on glass, respectively. These data support the further investigation and optimization of ZnO nanorod coatings with potential for bacterial adhesion resistance and bactericidal properties. PMID:23035444

  11. Leaching of oxidic zinc materials with chlorine and chlorine hydrate

    NASA Astrophysics Data System (ADS)

    Thomas, B. K.; Fray, D. J.

    1981-06-01

    Low grade zinc ores and residues were leached in chlorine water and chlorine hydrate water mixtures. It was found that the rate of leaching Adrar ore and Electric Arc Furnace dust obeyed a shrinking core diffusion model, whereas, the rate of leaching of Turkish ore appeared to be controlled by a surface reaction. In all cases, lead leached with the zinc but the iron oxides remained virtually undissolved.

  12. Characterization of zinc oxide and zinc ferrite doped with Ti or Cu as sorbents for hot gas desulphurization

    Microsoft Academic Search

    Miguel Pineda; José L. G. Fierro; José M. Palacios; Cristina Cilleruelo; Enrique García; José V. Ibarra

    1997-01-01

    Three series of samples based on zinc oxide and zinc ferrite doped with copper or titanium oxides have been prepared in order to improve their performance as regenerable sorbents for hot gas desulphurization. In each series the oxide concentration was varied over a broad range to enhance the formation of different chemical species. The stability against reducing agents and the

  13. The effect of parallel electric fields on the orientation of polycrystalline zinc oxide thin films produced by reactive evaporation and oxidation of zinc

    Microsoft Academic Search

    H. Kashani

    1996-01-01

    The effect of an electric field (detached electrodes) on the crystal orientation of zinc oxide thin film was investigated. Two methods, direct and indirect, were utilized to produce zinc oxide thin films. In the direct method (reactive evaporation) oxygen was introduced into the zinc vapour stream and ZnO films were deposited on cold substrates in a vacuum system. Parallel electric

  14. Synthesis of 5-aminotetrazole-1N-oxide and its azo derivative: a key step in the development of new energetic materials.

    PubMed

    Fischer, Dennis; Klapötke, Thomas M; Piercey, Davin G; Stierstorfer, Jörg

    2013-04-01

    1-Hydroxy-5-aminotetrazole (1), which is a long-desired starting material for the synthesis of hundreds of new energetic materials, was synthesized for the first time by the reaction of aqueous hydroxylamine with cyanogen azide. The use of this unique precursor was demonstrated by the preparation of several energetic compounds with equal or higher performance than that of commonly used explosives, such as hexogen (RDX). The prepared compounds, including energetic salts of 1-hydroxy-5-aminotetrazole (hydroxylammonium (2, two polymorphs) and ammonium (3)), azo-coupled derivatives (potassium (5), hydroxylammonium (6), ammonium (7), and hydrazinium 5,5'-azo-bis(1-N-oxidotetrazolate (8, two polymorphs)), as well as neutral compounds 5,5'-azo-bis(1-oxidotetrazole) (4) and 5,5'-bis(1-oxidotetrazole)hydrazine (9), were intensively characterized by low-temperature X-ray diffraction, IR, Raman, and multinuclear NMR spectroscopy, elemental analysis, and DSC. The calculated energetic performance, by using the EXPLO5 code, based on the calculated (CBS-4M) heats of formation and X-ray densities confirm the high energetic performance of tetrazole-N-oxides as energetic materials. Last but not least, their sensitivity towards impact, friction, and electrostatic discharge were explored. 5,5'-Azo-bis(1-N-oxidotetrazole) deflagrates close to the DDT (deflagration-to-detonation transition) faster than all compounds that have been investigated in our research group to date. PMID:23417994

  15. Photo Response in Zinc Oxide Doped Alizarin Thin Film

    NASA Astrophysics Data System (ADS)

    Sreekala, C. O.; Balraju, P.; Deol, Y. S.; Pradeep, P.; Roy, M. S.

    2008-04-01

    Hybrid structure based on organic and inorganic materials are emerging as most promising materials for photovoltaic applications. We have designed a hybrid structurc based on Alizarin (1, 2 dihydroxy anthraquinone) and a wide band gap zinc oxide. Alizarin acts as donor and zinc oxide acts as an acceptor material. The device having configuration of ITO/Aln:ZnO/Ag was characterized by analyzing its optical and electrical characteristics. It is found that the doping with zinc oxide imparts an accelerated improvement in device performance particularly in terms of its photo response. Impedance analysis of the device was carried out by recording Cole-Cole plot in between real and imaginary impedance under biasing varying from 0 to 5 V.

  16. Crystalline state and acoustic properties of zinc oxide films

    SciTech Connect

    Kal'naya, G.I.; Pryadko, I.F.; Yarovoi, Yu.A.

    1988-08-01

    We study the effect of the crystalline state of zinc oxide films, prepared by magnetron sputtering, on the efficiency of SAW transducers based on the layered system textured ZnO film-interdigital transducer (IDT)-fused quartz substrate. The crystalline perfection of the ZnO films was studied by the x-ray method using a DRON-2.0 diffractometer. The acoustic properties of the layered system fused quartz substrate-IDT-zinc oxide film were evaluated based on the squared electromechanical coupling constant K/sup 2/ for strip filters. It was found that K/sup 2/ depends on the magnitude of the mechanical stresses. When zinc oxide films are deposited by the method of magnetron deposition on fused quartz substrates, depending on the process conditions limitations can arise on the rate of deposition owing to mechanical stresses, which significantly degrade the efficiency of SAW transducers based on them, in the ZnO films.

  17. Heterostructured nanohybrid of zinc oxide-montmorillonite clay.

    PubMed

    Hur, Su Gil; Kim, Tae Woo; Hwang, Seong-Ju; Hwang, Sung-Ho; Yang, Jae Hun; Choy, Jin-Ho

    2006-02-01

    We have synthesized heterostructured zinc oxide-aluminosilicate nanohybrids through a hydrothermal reaction between the colloidal suspension of exfoliated montmorillonite nanosheets and the sol solution of zinc acetate. According to X-ray diffraction, N2 adsorption-desorption isotherm, and field emission-scanning electron microscopic analyses, it was found that the intercalation of zinc oxide nanoparticles expands the basal spacing of the host montmorillonite clay, and the crystallites of the nanohybrids are assembled to form a house-of-cards structure. From UV-vis spectroscopic investigation, it becomes certain that calcined nanohybrid contains two kinds of the zinc oxide species in the interlayer space of host lattice and in mesopores formed by the house-of-cards type stacking of the crystallites. Zn K-edge X-ray absorption near-edge structure/extended X-ray absorption fine structure analyses clearly demonstrate that guest species in the nanohybrids exist as nanocrystalline zinc oxides with wurzite-type structure. PMID:16471722

  18. The insert of zinc oxide thin film in indium tin oxide anode for organic electroluminescence devices q

    E-print Network

    Boo, Jin-Hyo

    The insert of zinc oxide thin film in indium tin oxide anode for organic electroluminescence-746, South Korea Received 30 August 2003; accepted 7 November 2003 Available online 6 May 2004 Abstract Zinc high-purity of zinc oxide (99.99%) powder. Systematic study on dependence of target

  19. Statistical analysis of the effect of aromatic, azo and sulphonic acid groups on decolouration of acid dye effluents using advanced oxidation processes

    Microsoft Academic Search

    M. Muthukumar; D. Sargunamani; N. Selvakumar

    2005-01-01

    In the present study, the effect of advanced oxidation processes such as ozone\\/UV, ozone\\/H2O2 and ozone\\/UV\\/H2O2 on decolouration of Acid Red 88, Acid Orange 7, Acid Orange 10 and Acid Red 73 dye effluents in the presence of sodium sulphate salt were considered. Studies were carried out to analyse and compare the effect of aromatic, azo and sulphonic acid groups

  20. Zinc hydroxyacetate and its transformation to nanocrystalline zinc oxide.

    PubMed

    Moezzi, Amir; McDonagh, Andrew; Dowd, Annette; Cortie, Michael

    2013-01-01

    The synthesis of nanocrystalline ZnO by thermal decomposition of zinc hydroxyacetate, Zn(5)(OH)(8)(CH(3)CO(2))(2)·nH(2)O, was investigated. The decomposition process was examined using X-ray diffraction, thermogravimetric analysis, mass spectrometry, electron microscopy, Brunauer-Emmett-Teller surface area analysis, and solid-state NMR spectroscopy. Intermediate Zn(5)(OH)(8)(CH(3)CO(2))(2)·nH(2)O phases form at temperatures up to 110 °C from the starting compound Zn(5)(OH)(8)(CH(3)CO(2))(2)·2H(2)O by partial dehydration. At ?110 °C, 4 equiv of ZnO and 1 equiv of Zn(CH(3)CO(2))(2) are formed. Further heating causes Zn(CH(3)CO(2))(2) to decompose to acetone, acetic acid, acetic anhydride, and ZnO. Notably, a portion of Zn(CH(3)CO(2))(2) sublimes during the process. Overall, the product of the calcination is equiaxed ZnO nanocrystals of 20-100 nm diameter. PMID:23249099

  1. Hydrogen Reduction of Zinc and Iron Oxides Containing Mixtures

    NASA Astrophysics Data System (ADS)

    de Siqueira, Rogério Navarro C.; de Albuquerque Brocchi, Eduardo; de Oliveira, Pamela Fernandes; Motta, Marcelo Senna

    2013-10-01

    Zinc is a metal of significant technological importance and its production from secondary sources has motivated the development of alternative processes, such as the chemical treatment of electrical arc furnace (EAF) dust. Currently, the extraction of zinc from the mentioned residue using a carbon-containing reducing agent is in the process of being established commercially and technically. In the current study, the possibility of reducing zinc from an EAF dust sample through a H2 constant flux in a horizontal oven is studied. The reduction of a synthetic oxide mixture of analogous composition is also investigated. The results indicated that the reduction process is thermodynamically viable for temperatures higher than 1123 K (850 °C), and all zinc metal produced is transferred to the gas stream, enabling its complete separation from iron. The same reaction in the presence of zinc crystals was considered for synthesizing FeZn alloys. However, for the experimental conditions employed, although ZnO reduction was indeed thermodynamically hindered because of the presence of zinc crystals (the metal's partial pressure was enhanced), the zinc metal's escape within the gaseous phase could not be effectively avoided.

  2. J Am Cerom Soc 73 [lo] 3026-32 (19901 Electrical Properties of Individual Zinc Oxide

    E-print Network

    Rohrer, Gregory S.

    J Am Cerom Soc 73 [lo] 3026-32 (19901 Electrical Properties of Individual Zinc Oxide Grain properties of single interfaces and grain boundaries. [Keywords: grain boundaries, zinc oxide, varistors semiconductor, zinc oxide (ZnO), which is used commercially as a varistor material. This is an excellent

  3. Molecular Orbital Studies of Zinc Oxide Chemical Vapor Deposition: Gas-Phase Radical Reactions

    E-print Network

    Schlegel, H. Bernhard

    Molecular Orbital Studies of Zinc Oxide Chemical Vapor Deposition: Gas-Phase Radical Reactions-phase reactions involved in the radical mechanism for zinc oxide chemical vapor deposition have been examined in the radical and closed shell mechanisms for zinc oxide chemical vapor deposition shows that the barrier

  4. Size effects on varistor properties made from zinc oxide nanoparticles by low temperature spark plasma sintering

    E-print Network

    Paris-Sud XI, Université de

    1 Size effects on varistor properties made from zinc oxide nanoparticles by low temperature spark of nanostructured varistors by Spark Plasma Sintering (SPS) are investigated, using 8 nm zinc oxide nanoparticles to 600°C. Keywords: Organometallic, Zinc oxide, Nanoparticles, Spark plasma sintering, Varistor hal

  5. Volatile organic compound gas sensor based on aluminum-doped zinc oxide with nanoparticle.

    PubMed

    Choi, Nak-Jin; Lee, Hyung-Kun; Moon, Seung Eon; Yang, Woo Seok; Kim, Jongdae

    2013-08-01

    Thick film semiconductor gas sensors based on aluminum-doped zinc oxide (AZO) with nanoparticle size were fabricated to detect volatile organic compound (VOC) existed in building, especially, formaldehyde (HCHO) gas which was known as the cause of sick building syndrome. The sensing materials for screen printing were prepared using roll milling process with binder. The crystallite sizes of prepared materials were about 15 nm through X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM). Gas response characteristics were examined for formaldehyde (HCHO), benzene, carbon monoxide, carbon dioxide gas existing in building. In particular, the sensors showed responses to HCHO gas at sub ppm as a function of operating temperatures and gas concentrations. Also, we investigated sensitivity, repeativity, selectivity, and response time of sensor. The transients were very sharp, taking less than 2 s for 90% response. The sensor has shown very stable response at 350 degrees C and followed a very good behavior and showed 60% response in 50 ppb HCHO concentration at 350 degrees C operating temperatures. PMID:23882782

  6. Study of Aluminum-doped zinc oxide current spreading layer on P-side up thin-film AlGaInP-based light-emitting diodes by ALD

    NASA Astrophysics Data System (ADS)

    Tseng, Ming-Chun; Chen, Chi-Lu; Lai, Nan-Kai; Wuu, Dong-Sing; Lee, Hsin-Ying; Lin, Yu-Chang; Horng, Ray-Hua

    2015-03-01

    A twice wafer-transfer technique can be used to fabricate high-brightness p-side-up thin-film AlGaInP-based light-emitting diodes (LEDs) with an aluminum-doped zinc oxide (AZO) thin films transparent conductive layer deposited on a GaP window layer. The GaP window layer consist of the two different doping profile, the carbon doped Gap (GaP:C) window layer of 50 nm is on the top of Mg doped GaP window layer of 8 ?m. The GaP:C window layer is used to improved the ohmic contact properties of GaP:C/AZO. The AZO with different cycle ratio of Zn:Al (15:1, 20:1 and 25:1) is deposited on GaP:C window layer as current spreading layer by atomic layer deposition. The AZO layer can be used to improve light extraction, which enhances light output power. The output power of p-side-up thin-film AlGaInP LED with an AZO layer of 20:1 cycle ratio has improved up to 19.2 % at injection current of 350 mA, as compared with that of LED without AZO film. The p-side-up thin-film AlGaInP LED with AZO current spreading layer exhibited excellent performance stability, the emission wavelength shift of p-side-up thin-film AlGaInP LED without and with AZO thin film(Zn:Al=20:1) are 17 nm and 3 nm under the injection current increased from 20 mA to 1000mA, respectively. This stability can be attributed to the following factors: 1) Refractive index matching, performed by introducing AZO thin film between the epoxy and the GaP window layer enhances light extraction; and 2) the favorable thermal dissipation of the silicon substrate reduces thermal degradation.

  7. Zinc oxide microcapsules obtained via a bio-inspired approach

    NASA Astrophysics Data System (ADS)

    Lipowsky, Peter; Hirscher, Michael; Hoffmann, Rudolf C.; Bill, Joachim; Aldinger, Fritz

    2007-04-01

    Hollow zinc oxide microcapsules have been synthesized by a sacrificial template route involving the chemical bath deposition of nanostructured zinc oxide thin films on sulfonate-modified polystyrene microspheres and subsequent removal of the polymer core by dissolution in a solvent or by thermolysis. Scanning electron micrographs show that uniform coating of the templates is achieved when ZnO is deposited from a solution containing zinc acetate, the polymer polyvinylpyrrolidone, and a base in methanol, and that the ZnO shells remain intact after removal of the cores. A focused ion beam is used to cut slices from the spheres and demonstrate their inner morphology and hollowness. X-ray diffraction yields evidence that the shells consist of nanocrystalline ZnO with the zincite structure.

  8. Anomalous coarsening of nanocrystalline zinc oxide particles in humid air

    NASA Astrophysics Data System (ADS)

    Dargatz, Benjamin; Gonzalez-Julian, Jesus; Guillon, Olivier

    2015-06-01

    Zinc acetate in combination with water plays a key role during the coarsening of zinc oxide (ZnO) nanocrystals at moderate temperature (85 °C) in air. The growth of ZnO nanocrystals is well known in liquid phase systems, but this work shows that this process is strongly enhanced in powder form by the presence of residual acetate. The growth of the ZnO nanocrystals was documented by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM), showing a preferred growth along [0001] crystallographic direction. An increase of more than 400% in crystal size was observed, which could be related to coarsening but not due to precipitation from solution. In contrast, particle size stayed almost constant if pure zinc oxide powder was used. This growth is expected to slowly occur during storage even under ambient conditions. The limited stability of nanopowders limits their applicability as well as pressing into bulk materials.

  9. Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

    NASA Astrophysics Data System (ADS)

    Acarali, Nil Baran; Bardakci, Melek; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

    2013-06-01

    The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120°C), cooling temperature (10-80°C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (1wt%-6wt%), and oleic acid (OA, 1wt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

  10. Resputtering of zinc oxide films prepared by radical assisted sputtering

    SciTech Connect

    Song Qiuming [Hefei National Laboratory for Physical Science at Microscale and USTC-SHINCRON Joint Laboratory, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); CAS/CUHK Shenzhen Institute of Advanced Integration Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong 518054 (China); Wu Bingjun; Xie Bin; Huang Feng; Li Ming; Wang Haiqian [Hefei National Laboratory for Physical Science at Microscale and USTC-SHINCRON Joint Laboratory, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Jiang Yousong; Song Yizhou [Shincron Co., LTD., Shinagawa-Ku, Tokyo 140-0011 (Japan)

    2009-02-15

    Sputtering losses of zinc oxide films prepared by radical assisted sputtering were studied. It was found that the sputtering loss can be very severe in oxygenous sputtering processes of zinc oxide films. In general, resputtering caused by negative oxygen ions dominates the sputtering loss, while diffuse deposition plays a minor role. Resputtering is strongly correlated with the sputtering threshold energy of the deposited films and the concentration of O{sup -} in the sputtering zone. The balance between the oxygen concentration in the sputtering zone and the oxidation degree of the growing films depends on the sputtering rate. Our research suggests that a lower oxygen concentration in the sputtering zone and a higher oxidation degree of the growing films are favorable for reducing the resputtering losses. The sputtering loss mechanisms discussed in this work are also helpful for understanding the deposition processes of other magnetron sputtering systems.

  11. RF sputtered piezoelectric zinc oxide thin film for transducer applications

    E-print Network

    Tang, William C

    surface acoustic wave (SAW) device, acousto-optical device, acoustic microscopy, electromechanical filters:653­661 DOI 10.1007/s10854-007-9415-1 #12;turn is more effectively modulated by the RF power than any otherRF sputtered piezoelectric zinc oxide thin film for transducer applications Yu-Hsiang Hsu Æ John

  12. Process for fabricating doped zinc oxide microsphere gel

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1991-11-05

    Disclosed are a new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  13. Process for fabricating doped zinc oxide microsphere gel

    DOEpatents

    Arnold, Jr., Wesley D. (Oak Ridge, TN); Bond, Walter D. (Knoxville, TN); Lauf, Robert J. (Oak Ridge, TN)

    1991-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  14. Investigations on solution derived aluminium doped zinc oxide thin films

    Microsoft Academic Search

    S. B Majumder; M Jain; P. S Dobal; R. S Katiyar

    2003-01-01

    Aluminium (Al) doped transparent zinc oxide thin films have been successfully grown on sapphire (0001) substrates by an economical chemical solution deposition technique. These films were characterized in terms of their structural, optical, and electrical properties. Detailed XPS analysis of the O1s core level spectra has been carried out for the ZnO films annealed at different temperatures. Lower binding energy

  15. Nanocomposite electrical generator based on piezoelectric zinc oxide nanowires

    E-print Network

    Endres. William J.

    piezoelectric nanomaterials for energy harvesting applications is still a matter of debate.4,11 MultiscaleNanocomposite electrical generator based on piezoelectric zinc oxide nanowires K. Momeni, G. M Institute of Physics. doi:10.1063/1.3517095 I. INTRODUCTION Energy generation utilizing piezoelectric

  16. Application of zinc oxide quantum dots in food safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc oxide quantum dots (ZnO QDs) are nanoparticles of purified powdered ZnO. The ZnO QDs were directly added into liquid foods or coated on the surface of glass jars using polylactic acid (PLA) as a carrier. The antimicrobial activities of ZnO QDs against Listeria monocytogenes, Salmonella Enteriti...

  17. Interfacial electron transfer dynamics of photosensitized zinc oxide nanoclusters

    SciTech Connect

    Murakoshi, Kei; Yanagida, Shozo [Osaka Univ. (Japan). Graduate School of Engineering; Capel, M. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1997-06-01

    The authors have prepared and characterized photosensitized zinc oxide (ZnO) nanoclusters, dispersed in methanol, using carboxylated coumarin dyes for surface adsorption. Femtosecond time-resolved emission spectroscopy allows the authors to measure the photo-induced charge carrier injection rate constant from the adsorbed photosensitizer to the n-type semiconductor nanocluster. These results are compared with other photosensitized semiconductors.

  18. Surface modification of zinc oxide nanoparticles by aminopropyltriethoxysilane

    Microsoft Academic Search

    F Grasset; N Saito; D Li; I Sakaguchi; N Ohashi; H Haneda; T Roisnel; S Mornet; E Duguet

    2003-01-01

    Commercial zinc oxide nanoparticles (20–30 nm) were coated by aminopropyltriethoxysilane (APTES) under varying environments. Three different processes, acidic, basic and toluene were used. The effects of coating conditions (acidic, basic and toluene) on the grafting, structural and optical properties of these nanoparticles were studied. In the three cases, it was possible to control the coating and according to X-ray diffraction,

  19. Electrodeposited zinc oxide thin films: Nucleation and growth mechanism

    Microsoft Academic Search

    A. I. Inamdar; S. H. Mujawar; S. B. Sadale; A. C. Sonavane; M. B. Shelar; P. S. Shinde; P. S. Patil

    2007-01-01

    The nucleation and growth mechanism of the electrodeposited zinc oxide thin films on fluorine-doped tin oxide (FTO) coated (10–20?\\/cm2) glass substrates from acetate solution, without and with ex situ oxygen bubbling, has been studied by cyclic voltammetry (CV), chronoamperometry (CA) and scanning electron microscopy (SEM) techniques. Ethylene diamine tetra acetic acid (EDTA) was used as a complexing agent. The cyclic

  20. Zinc oxide-chitosan nanobiocomposite for urea sensor

    Microsoft Academic Search

    Pratima R. Solanki; Ajeet Kaushik; Anees A. Ansari; G. Sumana; B. D. Malhotra

    2008-01-01

    Zinc oxide (ZnO)-chitosan (CH) nanobiocomposite film onto indium-tin-oxide (ITO) coated glass has been used to immobilize urease (Urs) and glutamate dehydrogenase (GLDH) for urea detection. The presence of ZnO nanoparticles in CH results in its increased surface area and enhanced electron transfer kinetics. The Urs-GLDH\\/CH-ZnO\\/ITO bioelectrode characterized using electrochemical, Fourier transform infrared, and scanning electron microscopy studies exhibit linearity of

  1. Epitaxial Growth of Zinc Oxide on Single Crystalline Gold Plates

    NASA Astrophysics Data System (ADS)

    Greenberg, Kathryn; Joo, John; Baram, Mor; Clarke, David; Hu, Evelyn

    2012-02-01

    Although metal-oxide interfaces are the critical components of many electronic and optical devices, it is rare to find epitaxial metal-oxide structures. We demonstrate for the first time, a method for the low temperature, epitaxial growth of zinc oxide (ZnO) on single crystalline gold plates. The gold plates, up to 100?m in width, are grown from a gold-surfactant complex. Even with the large lattice mismatch between (111) gold and (0001) ZnO, we are able to form epitaxial zinc oxide at 90^oC on top of the single crystal gold plates. This epitaxial growth is confirmed using transmission electron microscopy, electron diffraction, and electron backscatterer diffraction. Micro-photoluminescence is also performed to investigate the optical properties of the epitaxial zinc oxide. We remove the grown ZnO membranes from the gold plates using a stamping and etching process. These membranes can potentially be used to fabricate high quality microdisks and photonic crystals. The metal-oxide interfaces that we have fabricated may have the ability to be used in a number of technologically important applications, including as better electrical contacts and for improved light extraction from planar LED structures.

  2. Hydrogen sensors based on zinc oxide nanoparticles

    Microsoft Academic Search

    Thanittha Samerjai; C. Liewhiran; A. Wisitsoraat; Sukon Phanichphant

    2010-01-01

    Pure ZnO, pure MgO and 5 wt%MgO\\/ZnO nanocomposites were produced by flame spray pyrolysis (FSP) in a single step using zinc naphthenate and magnesium acetate tetrahydrate as Zn and Mg precursors. The particle properties were analyzed by XRD, BET and TEM analyses. The sensing films were prepared by mixing the nanoparticles into an organic paste composed of ethyl cellulose and

  3. Strength-controllable graphene oxide amphiprotic aerogels as highly efficient carrier for anionic and cationic azo molecules

    NASA Astrophysics Data System (ADS)

    Xiong, Jiaqing; Jiao, Chenlu; Xu, Sijun; Tao, Jin; Zhang, Desuo; Lin, Hong; Chen, Yuyue

    2015-06-01

    Ice-bath self-assembly was employed to fabricate the GO/AP-MCC/CS aerogel based on natural materials. The components are amphiprotic microcrystalline cellulose (AP-MCC), chitosan (CS), and graphene oxide (GO), which act as the main framework, auxiliary framework and adhesive, respectively. The results of characterization determines the components form the GO/AP-MCC/CS aerogel according to chemical interactions. The mechanical properties depend largely on the mass ratio of AP-MCC/CS, which can be regulated by controlling the contents of AP-MCC and CS. The resultant GO/AP-MCC/CS aerogel was observed possessing three-dimensional (3D) interpenetrating porous networks with wrinkled structure on the inner wall, which provide a good encapsulation capacity for the guest molecules. As expected, owing to the amphiprotic properties and large specific surface area, GO/AP-MCC/CS aerogel exhibits high-efficiency load capacity for both anionic (CR) and cationic azo molecules (MB), which can reach up to about 132.2 mg/g for CR and 123.2 mg/g for MB, respectively.

  4. Burn-induced oxidative stress is altered by a low zinc status: kinetic study in burned rats fed a low zinc diet

    E-print Network

    Paris-Sud XI, Université de

    1 Burn-induced oxidative stress is altered by a low zinc status: kinetic study in burned rats fed a low zinc diet Richard Claeyssen1,2 , Maud Andriollo-Sanchez1 , Josiane Arnaud2,3 , Laurence Touvard1 Cedex 9, France. Keywords: Burn injury, zinc intakes, zinc status, oxidative stress, rat model

  5. Zinc sorption by iron oxides and soil samples 

    E-print Network

    Yli-Halla, Markku Juhani

    1989-01-01

    ZINC SORPTION BY IRON OMIDES AND SOIL SAMPLES A Thesis MARKKU JUHANI YLI-HALLA Submitted to the Office of Graduate Studies Texas A&M University in a partial fulfillment of the requirements for the degree of MASTEF. OR SCIENCE May 1989 Majo...'r Subject: Soil Science ZINC SORPTION BY IRON OXIDES AND SOIL SAMPLES A Thesis by MARKKU JUHANI YLI-HALLA Approved as to style and content by: Richard H. Loeppert (Chair of Committee) A. Clearfield (Membe ) Joe B. Dixon (Member) E. C. A. Runge...

  6. Zinc sorption by iron oxides and soil samples

    E-print Network

    Yli-Halla, Markku Juhani

    1989-01-01

    ZINC SORPTION BY IRON OMIDES AND SOIL SAMPLES A Thesis MARKKU JUHANI YLI-HALLA Submitted to the Office of Graduate Studies Texas A&M University in a partial fulfillment of the requirements for the degree of MASTEF. OR SCIENCE May 1989 Majo...'r Subject: Soil Science ZINC SORPTION BY IRON OXIDES AND SOIL SAMPLES A Thesis by MARKKU JUHANI YLI-HALLA Approved as to style and content by: Richard H. Loeppert (Chair of Committee) A. Clearfield (Membe ) Joe B. Dixon (Member) E. C. A. Runge...

  7. Rapid degradation of zinc oxide nanoparticles by phosphate ions

    PubMed Central

    García-García, F Javier; Reller, Armin

    2014-01-01

    Summary Zinc oxide nanoparticles are highly sensitive towards phosphate ions even at pH 7. Buffer solutions and cell culture media containing phosphate ions are able to destroy ZnO nanoparticles within a time span from less than one hour to one day. The driving force of the reaction is the formation of zinc phosphate of very low solubility. The morphology of the zinc oxide particles has only a minor influence on the kinetics of this reaction. Surface properties related to different production methods and the presence and absence of labelling with a perylene fluorescent dye are more important. Particles prepared under acidic conditions are more resistant than those obtained in basic or neutral reaction medium. Surprisingly, the presence of a SiO2 coating does not impede the degradation of the ZnO core. In contrast to phosphate ions, ?-glycerophosphate does not damage the ZnO nanoparticles. These findings should be taken into account when assessing the biological effects or the toxicology of zinc oxide nanoparticles. PMID:25383310

  8. Analytic bond-order potential for atomistic simulations of zinc oxide

    E-print Network

    Nordlund, Kai

    Analytic bond-order potential for atomistic simulations of zinc oxide Paul Erhart1 , Niklas Juslin2 for zinc oxide and its elemental constituents is derived based on an analytical bond-order formalism. The model potential provides a good description of the bulk properties of various solid structures of zinc

  9. Polyurethane–zinc borate composites with high oxidative stability and flame retardancy

    Microsoft Academic Search

    Basar Y?ld?z; M. Özgür Seydibeyo?lu; F. Seniha Güner

    2009-01-01

    Novel polyurethane zinc borate composites were prepared with the main aim to increase the flame retardancy of the polyurethane. It was discovered that the zinc borate had very significant effects on the oxidative stability of the neat polymer which was first observed by oxygen induction time tests and supported with actual weathering chamber tests. The oxidative stability of zinc borate-filled

  10. Nanocrystalline zinc oxide thin films by novel double pulse single step electrodeposition

    Microsoft Academic Search

    A. I. Inamdar; A. C. Sonavane; S. K. Sharma; Hyunsik Im; P. S. Patil

    2010-01-01

    An attempt has been made to fabricate nanocrystalline zinc oxide thin films by using double pulse potentiostatic electrodeposition in oxygen saturated zinc acetate bath onto FTO coated conducting glass substrates. Zinc oxide formation mechanism has been studied by using linear sweep voltammetry (LSV) and electrochemical quartz crystal microbalance (EQCM) in presence of oxygen. The influence of pulse parameters like nucleation

  11. Influence of doping with third group oxides on properties of zinc oxide thin films

    SciTech Connect

    Palimar, Sowmya, E-mail: sowmya0124@gmail.com; Bangera, Kasturi V.; Shivakumar, G. K. [National Institute of Technology Karnataka, Thin Film Laboratory, Physics Department (India)

    2013-03-15

    The study of modifications in structural, optical and electrical properties of vacuum evaporated zinc oxide thin films on doping with III group oxides namely aluminum oxide, gallium oxide and indium oxide are reported. It was observed that all the films have transmittance ranging from 85 to 95%. The variation in optical properties with dopants is discussed. On doping the film with III group oxides, the conductivity of the films showed an excellent improvement of the order of 10{sup 3} {Omega}{sup -1} cm{sup -1}. The measurements of activation energy showed that all three oxide doped films have 2 donor levels below the conduction band.

  12. Differences between nanoscale structural and electrical properties of AZO:N and AZO used in polymer light-emitting diodes.

    PubMed

    Chen, Sy-Hann; Yu, Chang-Feng

    2010-03-01

    Conducting atomic force microscopy and scanning surface potential microscopy were adopted to investigate the nanoscale surface electrical properties of N-doped aluminum zinc oxide (AZO:N) films that were prepared by pulsed laser deposition (PLD) at various substrate temperatures. Experimental results demonstrated that when the substrate temperature is 150 degrees C and the N(2)O background pressure is 150 mTorr, the N-dopant concentration on the surface is optimal. In addition, the root-mean-square roughness value of the film surface, the low contact current (<400 nA) conducting region as a percentage of the total area, and the mean work function value are 1.43 nm, 96.9%, and 4.88 eV, respectively, all of which are better than those of the optimal AZO film made by PLD. This result indicates that N-doped AZO films are better for use as window materials in polymer light-emitting diodes. PMID:19725067

  13. Scale-up synthesis of zinc borate from the reaction of zinc oxide and boric acid in aqueous medium

    Microsoft Academic Search

    Mert Kilinç; Gaye Ö. Çakal; Sertan Yesil; Göknur Bayram; Inci Eroglu; Saim Özkar

    2010-01-01

    Synthesis of zinc borate was conducted in a laboratory and a pilot scale batch reactor to see the influence of process variables on the reaction parameters and the final product, 2ZnO·3B2O3·3.5H2O. Effects of stirring speed, presence of baffles, amount of seed, particle size and purity of zinc oxide, and mole ratio of H3BO3:ZnO on the zinc borate formation reaction were

  14. Supermicroporous alumina?silica zinc oxides

    SciTech Connect

    Shpeizer, Boris G.; Bakhmutov, Vladimir I.; Clearfield, Abraham (TAM)

    2008-09-29

    A new family of porous mixed oxides with pores largely in the 8-20 {angstrom} range have been prepared. TEOS acts as a solvent and as a source of silica to which aluminum butoxide and transition metal acetates are added. Neutral amines are added as templates and to effect hydrolysis. This paper describes the ZnO-Al{sub 2}O{sub 5}-SiO{sub 2} system but similar results have been obtained with other transition metal oxides. An interesting feature of the technique is that the larger the amine template the greater is the surface area of the mixed oxide with only a slight increase in the average pore diameter. Both NMR and atomic pair distribution functional methods have been used to prove the homogeneity of the mixed oxide products. This preparative method complements our earlier report in Chemical Communications on mixed oxides prepared with ZrO{sub 2} and TiO{sub 2} incorporating transition metal oxides.

  15. Zinc oxide-based sorbents and processes for preparing and using same

    DOEpatents

    Gangwal, Santosh Kumar; Turk, Brian Scott; Gupta, Raghubir Prasad

    2005-10-04

    Zinc oxide-based sorbents, and processes for preparing and using them are provided, wherein the sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents contain an active zinc component, optionally in combination with one or more promoter components and/or one or more substantially inert components. The active zinc component is a two phase material, consisting essentially of a zinc oxide (ZnO) phase and a zinc aluminate (ZnAl.sub.2 O.sub.4) phase. Each of the two phases is characterized by a relatively small crystallite size of typically less than about 500 Angstroms. Preferably the sorbents are prepared by converting a precursor mixture, containing a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

  16. Zinc in a +III oxidation state

    E-print Network

    Samanta, Devleena

    2012-01-01

    The possibility of Group 12 elements, such as Zn, Cd, and Hg existing in an oxidation state of +III or higher and hence transforming them into transition metals has fascinated chemists for decades. It took nearly 20 years before experiment could confirm the theoretical prediction that Hg indeed can exist in an oxidation state of +IV. While this unusual property of Hg is attributed to the relativistic effects, Zn being much lighter than Hg has not been expected to have an oxidation state higher than +II. Using density functional theory we show that an oxidation state of +III for Zn can be realized by choosing specific ligands with large electron affinities. We demonstrate this by a systematic study of the interaction of Zn with F, BO2, and AuF6 ligands whose electron affinities are progressively higher, namely, 3.4 eV, 4.5 eV, and 8.6 eV, respectively. Discovery of higher oxidation states of elements can help in the formulation of new reactions and hence in the development of new chemistry.

  17. Growth and Process Induced Dislocations in Zinc Oxide Crystals

    SciTech Connect

    Dhanaraj,G.; Dudley, M.; Bliss, D.; Callahan, M.; Harris, M.

    2006-01-01

    Zinc oxide crystals were grown using hydrothermal method, and the habit faces were indexed by computing from inter-axial angles of the as grown boules. The dislocation structures were studied using synchrotron white beam X-ray topography. Grown-in dislocations as well as process-induced defects were characterized in the ZnO crystals. Knoop and Vickers micro-hardness were studied on sliced crystal plates. Chemical etching was used to study the dislocations running perpendicular to the wafer.

  18. Optical properties of zinc oxide nanocrystals embedded in mesoporous silica

    Microsoft Academic Search

    T. S. Vaishnavi; Prathap Haridoss; C. Vijayan

    2008-01-01

    This paper reports on the synthesis and characterization of a nanocomposite incorporating zinc oxide (ZnO) in mesoporous silica (MPS), a host medium for stabilizing the nanoparticles. The composite is prepared using a chemical route involving in-situ synthesis of ZnO in pores of host material in an acidic medium. The samples are characterized by X-ray Diffraction (XRD), Energy Dispersive Spectroscopy (EDS),

  19. Zinc oxide nanowire enhanced multifunctional coatings for cotton fabrics

    Microsoft Academic Search

    Elif Selen Ates; Husnu Emrah Unalan

    Zinc oxide (ZnO) nanowires have been grown on cotton fabric to impart self-cleaning, superhydrophobicity and UV-blocking properties. ZnO nanowires were grown by the microwave assisted hydrothermal method and subsequently functionalized with steraic acid to obtain a water contact angle of 150°, showing their superhydrophobic nature which is found to be stable up to 4 washings. UV protection of the resulting

  20. Giant negative magnetoresistance in Manganese-substituted Zinc Oxide

    PubMed Central

    Wang, X. L.; Shao, Q.; Zhuravlyova, A.; He, M.; Yi, Y.; Lortz, R.; Wang, J. N.; Ruotolo, A.

    2015-01-01

    We report a large negative magnetoresistance in Manganese-substituted Zinc Oxide thin films. This anomalous effect was found to appear in oxygen-deficient films and to increase with the concentration of Manganese. By combining magnetoresistive measurements with magneto-photoluminescence, we demonstrate that the effect can be explained as the result of a magnetically induced transition from hopping to band conduction where the activation energy is caused by the sp-d exchange interaction. PMID:25783664

  1. Random lasing from surface modified films of zinc oxide nanoparticles

    Microsoft Academic Search

    A. Stassinopoulos; R. N. Das; E. P. Giannelis; S. H. Anastasiadis; D. Anglos

    2005-01-01

    The photoluminescence properties of zinc oxide (ZnO) ceramic thin films, prepared by spin coating of ZnO nanoparticle aqueous suspensions, were studied with emphasis on the influence of film structure and surface morphology on the observation of random laser action. Surface processing employing laser annealing transforms the particulate grain structure of the as-deposited films into a porous channel-like network. This modification

  2. Zinc oxide nanoparticle and polymer antimicrobial biomaterial composites

    Microsoft Academic Search

    Justin T. Seil; Thomas J. Webster

    2010-01-01

    Particulate zinc oxide (ZnO) is a known antibacterial agent. Studies show that reducing the size of ZnO particles to nanoscale dimensions further enhances their antibacterial properties. Polymers, like all biomaterials, run the risk of harboring bacteria which may produce an antibiotic-resistant biofilm. The addition of ZnO nanoparticles, to form a composite, may reduce undesirable bacteria activity. The purpose of the

  3. Photoresponse characteristics of nanostructured aluminum doped Zinc oxide thin films

    Microsoft Academic Search

    M. F. Malek; S. A. Arbain; M. H. Mamat; M. Z. Sahdan; M. Z. Musa; Z. Khusaimi; M. Rusop; A. S Rodzi

    2011-01-01

    Aluminium doped Zinc oxide (ZnO) thin films were prepared through sol gel dip coating technique with various doping concentrations from 0 to 1.5 at.%. The thin films were characterized using X-ray Diffractometer (XRD), Field Emission Scanning Electron Microscope (FESEM), UV-Vis-NIR spectrophotometer and current voltage (I-V) measurement system. From the XRD analysis, increasing of doping concentration affected structural properties of the

  4. Paradoxical zinc toxicity and oxidative stress in the mammary gland during marginal dietary zinc deficiency.

    PubMed

    Bostanci, Zeynep; Mack, Ronald P; Lee, Sooyeon; Soybel, David I; Kelleher, Shannon L

    2015-07-01

    Zinc (Zn) regulates numerous cellular functions. Zn deficiency is common in females; ?80% of women and 40% of adolescent girls consume inadequate Zn. Zn deficiency enhances oxidative stress, inflammation and DNA damage. Oxidative stress and inflammation is associated with breast disease. We hypothesized that Zn deficiency increases oxidative stress in the mammary gland, altering the microenvironment and architecture. Zn accumulated in the mammary glands of Zn deficient mice and this was associated with macrophage infiltration, enhanced oxidative stress and over-expression of estrogen receptor ?. Ductal and stromal hypercellularity was associated with aberrant collagen deposition and disorganized e-cadherin. Importantly, these microenvironmental alterations were associated with substantial impairments in ductal expansion and mammary gland development. This is the first study to show that marginal Zn deficiency creates a toxic microenvironment in the mammary gland impairing breast development. These changes are consistent with hallmarks of potential increased risk for breast disease and cancer. PMID:25088245

  5. Inkjet-printed zinc tin oxide thin-film transistor.

    PubMed

    Kim, Dongjo; Jeong, Youngmin; Song, Keunkyu; Park, Seong-Kee; Cao, Guozhong; Moon, Jooho

    2009-09-15

    Recently, there has been considerable interest in adapting printing approaches that are typically used in the graphic arts to the printing of electronic circuits and circuit components. We report the fabrication of solution-processed oxide transistors using inkjet printing. A zinc tin oxide sol-gel precursor is utilized as the ink for directly printing a thin uniform semiconducting layer. The printed device performance is significantly influenced by printing conditions such as the surface wettability and substrate temperature. The inkjet-printed transistors exhibit reproducible electrical performance, demonstrating their potential application in low-cost manufacturing of large-area flat panel displays. PMID:19735156

  6. Selective real-time nitric oxide detection by functionalized zinc oxide This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-print Network

    Selective real-time nitric oxide detection by functionalized zinc oxide This article has been) doi:10.1088/0022-3727/42/15/155105 Selective real-time nitric oxide detection by functionalized zinc chloride (haemin)-functionalized Al-doped zinc oxide (ZnO) is used for nitric oxide (NO) sensing at room

  7. Oxidative Modification of Guanine Bases Initiated by Oxyl Radicals Derived From Photolysis of Azo Compounds

    PubMed Central

    Shao, Jie; Geacintov, Nicholas E.; Shafirovich, Vladimir

    2010-01-01

    Oxidative damage to guanine bases initiated by photolysis of the water-soluble radical generator 2,2?-azobis(2-amidinopropane) dihydrochloride (AAPH) has been investigated by laser kinetic spectroscopy. In the neutral oxygenated aqueous solutions, 355 nm laser flash photolysis of AAPH generates a whole spectrum of free radicals including 2-amidinoprop-2-peroxyl (ROO•), 2-amidinoprop-2-oxyl (RO•), and superoxide (O2•?) radicals. These oxyl radicals with negligible absorption in a near UV – visible range were monitored in the reactions leading to the products with characteristic absorption spectra. This approach reveals that RO• radicals induce fast one-electron oxidation of 2?-deoxyguanosine (dG) to form guanine neutral radicals, dG(-H)•. In contrast, ROO• radicals do not react with observable rates with dG. The O2•? radicals were detected using a classical test reaction with tetranitromethane to form nitroform. The major pathway for formation of the end products of guanine oxidation is combination of the G(-H)• and O2•? radicals to form 2,5-diamino-4H-imidazolone (Iz). This mechanism was confirmed by analysis of the end products produced by oxidation of two substrates: (1) guanosine derivative 2?,3?,5?-tri-O-acetylguanosine (tri-O-Ac-G), and (2) the 5?-d(CCATCGCTACC) sequence. The major products isolated by HPLC and identified by mass spectrometry methods were the tri-O-Ac-Iz and 5?-d(CCATC[Iz]CTACC products. PMID:20415485

  8. Influences of Urea on Preparation of Zinc Oxide Nanostructures through Chemical Precipitation in Ammonium Hydrogencarbonate Solution

    Microsoft Academic Search

    Zahra Monsef Khoshhesab; Mohammad Sarfaraz; Zari Houshyar

    2012-01-01

    Zinc oxide nanostructures have been successfully prepared through dissolving of micro-sized zinc oxide powder in ammonium hydrogencarbonate solution at 25 ºC, followed by calcination of the resultant precipitates at 350 ºC for 1h. The influence of urea presence on morphology and particle size of the as-prepared zinc oxide was also investigated. The obtained products were characterized by XRD, SEM, FT-IR,

  9. Nearly full-dense and fine-grained AZO:Y ceramics sintered from the corresponding nanoparticles.

    PubMed

    Yang, Ye; Lan, Pinjun; Wang, Muqin; Wei, Tiefeng; Tan, Ruiqin; Song, Weijie

    2012-01-01

    Aluminum-doped zinc oxide ceramics with yttria doping (AZO:Y) ranging from 0 to 0.2 wt.% were fabricated by pressureless sintering yttria-modified nanoparticles in air at 1,300°C. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, a physical property measurement system, and a densimeter were employed to characterize the precursor nanoparticles and the sintered AZO ceramics. It was shown that a small amount of yttria doping can remarkably retard the growth of the as-received precursor nanoparticles, further improve the microstructure, refine the grain size, and enhance the density for the sintered ceramic. Increasing the yttria doping to 0.2 wt.%, the AZO:Y nanoparticles synthetized by a coprecipitation process have a nearly sphere-shaped morphology and a mean particle diameter of 15.1 nm. Using the same amount of yttria, a fully dense AZO ceramic (99.98% of theoretical density) with a grain size of 2.2 ?m and a bulk resistivity of 4.6?×?10-3??·cm can be achieved. This kind of AZO:Y ceramic has a potential to be used as a high-quality sputtering target to deposit ZnO-based transparent conductive films with better optical and electrical properties. PMID:22929049

  10. Zinc-histidine complex protects cultured cortical neurons against oxidative stress-induced damage.

    PubMed

    Williams, Robert J; Spencer, Jeremy P E; Goni, Faisal M; Rice-Evans, Catherine A

    2004-11-23

    The levels of zinc in the brain are directly affected by dietary zinc and deficiency has been associated with alcohol withdrawal seizures, excitotoxicity, impaired learning and memory and an accelerated rate of dysfunction in aged brain. Although zinc is essential for a healthy nervous system, high concentrations of zinc are neurotoxic, thus it is important to identify the most effective forms of zinc for treatment of conditions of the central nervous system. Accumulating evidence suggests that zinc-histidine complex (Zn(His)(2)) has greater biological potency and enhanced bioavailability compared with other zinc salts and also has antioxidant potential. Therefore, in this study we investigated the ability of zinc-histidine to protect cultured cortical neurons against hydrogen peroxide-induced damage. Pre-treating neurons for 18 h with subtoxic concentrations of zinc-histidine (5-25 microM) improved neuronal viability and strongly inhibited hydrogen peroxide-induced (75 microM, 30 min) cell damage as assessed by MTT turnover and morphological analysis 24h later. Low concentrations of zinc-histidine were more neuroprotective than zinc chloride. There was evidence of an anti-apoptotic mechanism of action as zinc-histidine inhibited hydrogen peroxide-induced caspase-3 activation and c-jun-N-terminal kinase phosphorylation. In summary, zinc supplementation with zinc-histidine protects cultured neurons against oxidative insults and inhibits apoptosis which suggests that zinc-histidine may be beneficial in the treatment of diseases of the CNS associated with zinc deficiency. PMID:15519738

  11. Experimental and Molecular Dynamics Simulations of Tribochemical Reactions with ZDDP: Zinc Phosphate–Iron Oxide Reaction

    Microsoft Academic Search

    Clotilde Minfray; Thierry Le Mogne; Jean-Michel Martin; Tasuku Onodera; Sayaka Nara; Shuko Takahashi; Hideyuki Tsuboi; Michihisa Koyama; Akira Endou; Hiromitsu Takaba; Momoji Kubo; Carlos A. Del Carpio; Akira Miyamoto

    2008-01-01

    Zinc phosphate glass is considered to be the main constituent of tribofilms generated under boundary lubrication with zinc dialkyldithiophosphate (ZDDP), a well-known antiwear additive. The reaction occurring during friction between zinc phosphate glasses and steel native iron oxide layer is investigated by both an experimental approach and by Molecular Dynamics simulations (MD). The importance of this “tribochemical” reaction in the

  12. Rare earth doped zinc oxide varistors

    DOEpatents

    McMillan, A.D.; Modine, F.A.; Lauf, R.J.; Alim, M.A.; Mahan, G.D.; Bartkowiak, M.

    1998-12-29

    A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2--4.0% oxide of at least one rare earth element, 0.5--4.0% Co{sub 3}O{sub 4}, 0.05--0.4% K{sub 2}O, 0.05--0.2% Cr{sub 2}O{sub 3}, 0--0.2% CaO, 0.00005--0.01% Al{sub 2}O{sub 3}, 0--2% MnO, 0--0.05% MgO, 0--0.5% TiO{sub 3}, 0--0.2% SnO{sub 2}, 0--0.02% B{sub 2}O{sub 3}, balance ZnO. 4 figs.

  13. Rare earth doped zinc oxide varistors

    DOEpatents

    McMillan, April D. (Knoxville, TN); Modine, Frank A. (Oak Ridge, TN); Lauf, Robert J. (Oak Ridge, TN); Alim, Mohammad A. (Medina, OH); Mahan, Gerald D. (Oak Ridge, TN); Bartkowiak, Miroslaw (Oak Ridge, TN)

    1998-01-01

    A varistor includes a Bi-free, essentially homogeneous sintered body of a ceramic composition including, expressed as nominal weight %, 0.2-4.0% oxide of at least one rare earth element, 0.5-4.0% Co.sub.3 O.sub.4, 0.05-0.4% K.sub.2 O, 0.05-0.2% Cr.sub.2 O.sub.3, 0-0.2% CaO, 0.00005-0.01% Al.sub.2 O.sub.3, 0-2% MnO, 0-0.05% MgO, 0-0.5% TiO.sub.3, 0-0.2% SnO.sub.2, 0-0.02% B.sub.2 O.sub.3, balance ZnO.

  14. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor.

    PubMed

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying; Lee, Hyung-Sool; Wang, Ai-Jie

    2012-11-15

    Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8±1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 gm(-3) d(-1)) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 gm(-3) d(-1) (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China. PMID:23009797

  15. Light Management in Transparent Conducting Oxides by Direct Fabrication of Periodic Surface Arrays

    NASA Astrophysics Data System (ADS)

    Eckhardt, S.; Sachse, C.; Lasagni, A. F.

    Line- and hexagonal-like periodic textures were fabricated on aluminium zinc oxide (AZO) using direct laser interference patterning method. It was found that hexagonally patterned surfaces show a higher performance in both transparency and diffraction properties compared to line-like textured and non-patterned substrates. Furthermore, the electrical resistance of the processed AZO coated substrates remained below the tolerance values for transparent conducting electrodes.

  16. An image processing approach to approximating interface textures of microcrystalline silicon layers grown on existing aluminum-doped zinc oxide textures.

    PubMed

    Hertel, Kai; Hüpkes, Jürgen; Pflaum, Christoph

    2013-11-01

    We present an algorithm for generating a surface approximation of microcrystalline silicon (?c-Si) layers after plasma enhanced chemical vapor deposition (PECVD) onto surface textured substrates, where data of the textured substrate surface are available as input. We utilize mathematical image processing tools and combine them with an ellipsoid generator approach. The presented algorithm has been tuned for use in thin-film silicon solar cell applications, where textured surfaces are used to improve light trapping. We demonstrate the feasibility of this method by means of optical simulations of generated surface textures, comparing them to simulations of measured atomic force microscopy (AFM) scan data of both Aluminum-doped zinc oxide (AZO, a transparent and conductive material) and ?c-Si layers. PMID:24514939

  17. The synthesis and optical properties of different zinc oxide nanostructures

    NASA Astrophysics Data System (ADS)

    Al Rifai, S. A.; Domashevskaya, E. P.

    2013-12-01

    The tetrapod-like whiskers (T-ZnO), nanoaeroplanes, nanocombs, nanobelts, bead-like nanoforms and many other forms of hexagonal zinc oxide were synthesized by the chemical deposition process (CVD). From the experimental results it can be seen that the composition of source gases and the speed of oxidation are essential to the growth of each of these morphologies of zinc oxide. By controlling the growth conditions, one novel morphology of ZnO (bead-like nanoform) has been obtained. The ZnO tetrapod-like whiskers were grown without catalysts on the walls of quartz tube. The structure and morphology of the T-ZnO was characterized. All four legs of as-grown ZnO nanotetrapods are needle-like and hexagonal shaped and grow in the ±[0001] direction. The effect of synthesis conditions on the morphology and size T-ZnO was observed. Possible mechanisms of growth were investigated. The lengths of the legs of the tetrapods range from 1 to 15 ?m and diameter varying from 0.03 to 1 ?m during the synthesis. In the photoluminescence spectra T-ZnO clearly shows two maxima at UV and visible regions. The oxygen impurity, particularly, oxygen flow rates mainly influences on increasing (decreasing) at PL peaks. The maximum near of 590-610 nm (˜2 eV), confirming the influence of native defects (oxygen vacancies and interstitials) on the PL intensity and optical quenching exciton peak.

  18. Efficient activation of peroxymonosulfate by manganese oxide for the degradation of azo dye at ambient condition.

    PubMed

    Tang, Dandan; Zhang, Gaoke; Guo, Sheng

    2015-09-15

    This study determines the potential of manganese oxide (MnOx) nanoparticles for the activation of peroxymonosulfate (PMS). The MnOx nanoparticles were prepared by a facile co-precipitation method and the degradation rates of acid red G (ARG) by the as-prepared catalysts in the presence of PMS were measured. The results showed that the Mn3O4 nanoparticles with tetragonal structure exhibited high catalytic activity for the degradation of ARG by activating PMS to generate radicals. The effects of the operational parameters on the catalytic property of the obtained nanosized Mn3O4 catalyst were investigated in detail. The catalyst exhibits excellent catalytic activity in a wide range of pH from 2 to 12. Moreover, it still maintained high catalytic activity even after five reaction cycles, indicating the good stability of the catalyst. In addition, radical quenching studies were carried out to ascertain the dominating radical species and a proper mechanism was also proposed. PMID:26002338

  19. Eshelby Twist and Magic Helical Zinc Oxide Nanowires and Nanotubes

    NASA Astrophysics Data System (ADS)

    Dumitrica, Traian; Akatyeva, Evgeniya

    2014-03-01

    Twisted zinc oxide nanowires and nanotubes were recently synthesized by screw-dislocation growth. We show theoretically that once their diameter increases above a critical size of the order of a few atomic spacings, the existence of these structures can be rationalized in terms of the energetics of surfaces and veritable Eshelby's twist linear elasticity mechanics supplemented by a nonlinear core term. For Burgers vector larger than the minimum allowed one, a twisted nanotube with well-defined thickness, rather than a nanowire, is the most stable nanostructure. Results are assistive for designing ultrathin nanostructures made out of nonlayered materials.

  20. Structural characterization of impurified zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Trinca, L. M.; Galca, A. C.; Stancu, V.; Chirila, C.; Pintilie, L.

    2014-11-01

    Europium doped zinc oxide (Eu:ZnO) thin films have been obtained by pulsed laser deposition (PLD). 002 textured thin films were achieved on glass and silicon substrates, while hetero-epilayers and homo-epilayers have been attained on single crystal SrTiO3 and ZnO, respectively. X-ray Diffraction (XRD) was employed to characterize the Eu:ZnO thin films. Extended XRD studies confirmed the different thin film structural properties as function of chosen substrates.

  1. Preparation and characterization of nanostructured zinc oxide thin films

    NASA Astrophysics Data System (ADS)

    Abd Elkader, Omar

    2012-09-01

    Thin films of Zinc Oxide (ZnO) were deposited on slide glass substrates by the chemical bath deposition technique (CBD). The formation of nanostructured ZnO thin films have been confirmed through XRD, TEM, and SEM. The structure properties were investigated by XRD. The optical properties were measured by UV-VIS spectrophotometer. The absorption coefficient is calculated from recorded data and it is best fitted for direct band gap. The direct band gap was in range 3.8-4.0 eV.

  2. Growth and characterization of electrosynthesised zinc oxide thin films

    SciTech Connect

    Mahalingam, T.; John, V.S.; Sebastian, P.J

    2003-01-25

    Zinc oxide (ZnO) films have been electrodeposited from an aqueous solution containing 0.1 M zinc nitrate as the electrolyte with pH around 5{+-}0.1. The deposition was carried out by galvanostatic reduction with an applied cathodic current density in the range between 5 and 20 mA cm{sup -2}. The influence of bath composition on the preparation of ZnO films is studied. The effects of zinc nitrate concentration and cathodic current density on the deposition rate of ZnO films were also studied. An optimum current density of 10 mA cm{sup -2} is identified for the growth of ZnO film with improved crystallinity and optical transmittance. The crystalline structure of the deposits studied by X-ray diffraction reveals the possibility of growing hexagonal ZnO films under suitable electrochemical conditions. The surface morphological studies by scanning electron micrographs revealed the presence of nodular appearance for films deposited at 800 deg. C bath temperatures.

  3. Diameter control of ultrathin zinc oxide nanofibers synthesized by electrospinning

    NASA Astrophysics Data System (ADS)

    Liao, Yingjie; Fukuda, Takeshi; Kamata, Norihiko; Tokunaga, Makoto

    2014-05-01

    Electrospinning is a versatile technique, which can be used to generate nanofibers from a rich variety of materials. We investigate the variation of a zinc oxide (ZnO)-polyvinylpyrrolidone (PVP) composite structure in morphology by electrospinning from a series of mixture solutions of ZnO sol-gel and PVP. Calcination conditions for the crystallization of ZnO nanofibers and removal of the PVP component from the ZnO-PVP composite nanofibers were also studied. The progression of the ZnO-PVP composite structure from grains to nanofibers was observed, and ZnO-PVP nanofibers as thin as 29.9 ± 0.8 nm on average were successfully fabricated. The size of the resultant ZnO-PVP composite nanofibers was considerably affected by two parameters: the concentrations of zinc acetate and PVP in the precursor solution. The concentration of zinc acetate particularly influenced the diameter distribution of the ZnO-PVP nanofibers. The ZnO-PVP nanofibers could be subsequently converted into ZnO nanofibers of a pure wurtzite phase via calcination in air at 500°C for 2 h.

  4. Synthesis And Characterization Of Zinc Oxide Nanoparticles Prepared Via Precipitation And Self-Combustion Methods

    Microsoft Academic Search

    Noorhana Yahya; Shikh Mohd. Shahrul Nizan Shikh Zahari; Anita Ramli; Noraini Muti Mohamad; Poppy Puspitasari; Nur Liyana Che Zul

    2009-01-01

    Zinc oxide is an important chemical substance that is widely used in the production of various industrial products. However, to produce nano particle ZnO remains a challenge. This paper describes the synthesis of zinc oxide nanoparticles via precipitation and self-combustion methods. By precipitation method, the dissolved zinc nitrate solution is drop wisely into aqueous sodium hydroxide, NaOH as precipitating agent.

  5. Preparation and gas-sensitivity of ultra-fine zinc-oxide powders from roasted zinc-blended

    Microsoft Academic Search

    Xun Feng; Zhongjun Li; Peiyuan Wang; Yifeng Zhou

    2005-01-01

    Ultra-fine zinc oxide is an important versatile semiconductor material, which has attracted attention for its wide range of applications such as solar cell, luminescent and chemical sensors that detect the combustible or toxic gases by virtue of their high sensitivity and stability [1]. The gas sensing mechanism involves the chemisorption of oxygen on the oxide surface followed by charge transfer

  6. A combined marginal deficiency of copper and zinc does not exacerbate oxidant stress asssociated with copper or zinc deficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both copper deficiency (Cu-def) and zinc deficiency (Zn-def) result in oxidative stress. Thus, an experiment was conducted to determine whether a marginal Zn-def amplified oxidative stress responses to a marginal Cu-def, or vice versa. Weanling male Sprague-Dawley rats were assigned to groups of 10 ...

  7. Preparation and properties of composite particles made by nano zinc oxide coated with titanium dioxide

    Microsoft Academic Search

    W. Wu; Y. W. Cai; J. F. Chen; S. L. Shen; A. Martin; L.-X. Wen

    2006-01-01

    In this paper, composite particles of nano zinc oxide coated with titanium dioxide were prepared and characterized by TEM, XRD, XPS and FT-IR, and the properties of the composite particles for photo catalysis and light absorption were studied. Tetrabutyl titanate (TBT) was hydrolyzed in an alcoholic suspension of nano zinc oxide with diethanolamine (DEA) as an additive, resulting in a

  8. The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films

    E-print Network

    Shahriar, Selim

    MRSEC The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films D Science & Engineering Center For zinc-indium-tin oxide (ZITO) films, grown by pulsed-laser deposition, ZITO-50 and ZITO-70 in which, respectively, 30%, 50% and 70% of the indium in the In2O3 structure

  9. Optimization and modelling of synthetic azo dye wastewater treatment using Graphene oxide nanoplatelets: Characterization toxicity evaluation and optimization using Artificial Neural Network.

    PubMed

    Banerjee, Priya; Sau, Shubhra; Das, Papita; Mukhopadhayay, Aniruddha

    2015-09-01

    Azo dyes pose a major threat to current civilization by appearing in almost all streams of wastewater. The present investigation was carried out to examine the potential of Graphene oxide (GO) nanoplatelets as an efficient, cost-effective and non-toxic azo dye adsorbent for efficient wastewater treatment. The treatment process was optimized using Artificial Neural Network for maximum percentage dye removal and evaluated in terms of varying operational parameters, process kinetics and thermodynamics. A brief toxicity assay was also designed using fresh water snail Bellamya benghalensis to analyze the quality of the treated solution. 97.78% removal of safranin dye was obtained using GO as adsorbent. Characterization of GO nanoplatelets (using SEM, TEM, AFM and FTIR) reported the changes in its structure as well as surface morphology before and after use and explained its prospective as a good and environmentally benign adsorbent in very low quantities. The data recorded when subjected to different isotherms best fitted the Temkin isotherm. Further analysis revealed the process to be endothermic and chemisorption in nature. The verdict of the toxicity assay rendered the treated permeate as biologically safe for discharge or reuse in industrial and domestic purposes. PMID:25966335

  10. Zinc-catalyzed copolymerization of carbon dioxide and propylene oxide 

    E-print Network

    Katsurao, Takumi

    1994-01-01

    insolubility, some other zinc compounds were studied. A homogeneous catalyst, bis(ethyl fumarato)zinc, showed similar polycarbonate yield to zinc glutarate, and the method of the catalyst preparation affected its catalytic activity. Only a small amount...

  11. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...false Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic). 721...9538 Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic). ...generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  12. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...false Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic). 721...9538 Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic). ...generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  13. Terminal oxidation and the effects of zinc in prostate versus liver mitochondria

    PubMed Central

    Costello, Leslie C.; Guan, Zhixin; Kukoyi, Boone; Feng, Pei; Franklin, Renty B.

    2015-01-01

    Although the total zinc content of cells generally approximates 0.2 mM, the cytosolic free zinc ion concentration is negligible (subnanomolar concentrtations). However, all reported studies of effects of zinc on cellular respiration and terminal oxidation involved ?M–mM levels of free zinc ions. Prostate cells and their mitochondria accumulate 3–10 fold more zinc than other mammalian cells. We considered that a cytosolic pool of mobile reactive low molecular weight zinc ligands could inhibit respiration and terminal oxidation. The effects of ZnLigands, especially ZnCitrate, versus free Zn + + ions on respiration and terminal oxidation were studied with prostate and liver mitochondria. ZnLigands were equally as effective as free Zn + + ions in the inhibition of respiration and terminal oxidation of both prostate and liver mitochondria, which supports our concept that zinc can be transferred from cytosolic donor ZnLigands directly to zinc-binding sites of terminal oxidation components. Also, the respiration and specific activities of terminal oxidation components of prostate mitochondria are 20–50% of liver mitochondria. Zinc inhibition and inherently low levels of electron transport components are likely major factors responsible for the low respiration that characterizes prostate cells. PMID:16120396

  14. An assessment of zinc oxide nanosheets as a selective adsorbent for cadmium

    PubMed Central

    2013-01-01

    Zinc oxide nanosheet is assessed as a selective adsorbent for the detection and adsorption of cadmium using simple eco-friendly extraction method. Pure zinc oxide nanosheet powders were characterized using field emission scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The zinc oxide nanosheets were applied to different metal ions, including Cd(II), Cu(II), Hg(II), La(III), Mn(II), Pb(II), Pd(II), and Y(III). Zinc oxide nanosheets were found to be selective for cadmium among these metal ions when determined by inductively coupled plasma-optical emission spectrometry. Moreover, adsorption isotherm data provided that the adsorption process was mainly monolayer on zinc oxide nanosheets. PMID:24011201

  15. Zinc oxide nanoparticles as novel alpha-amylase inhibitors

    NASA Astrophysics Data System (ADS)

    Dhobale, Sandip; Thite, Trupti; Laware, S. L.; Rode, C. V.; Koppikar, Soumya J.; Ghanekar, Ruchika-Kaul; Kale, S. N.

    2008-11-01

    Amylase inhibitors, also known as starch blockers, contain substances that prevent dietary starches from being absorbed by the body via inhibiting breakdown of complex sugars to simpler ones. In this sense, these materials are projected as having potential applications in diabetes control. In this context, we report on zinc oxide nanoparticles as possible alpha-amylase inhibitors. Zinc oxide nanoparticles have been synthesized using soft-chemistry approach and 1-thioglycerol was used as a surfactant to yield polycrystalline nanoparticles of size ˜18 nm, stabilized in wurtzite structure. Conjugation study and structural characterization have been done using x-ray diffraction technique, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and transmission electron microscopy. Cytotoxicity studies on human fibrosarcoma (HT-1080) and skin carcinoma (A-431) cell lines as well as mouse primary fibroblast cells demonstrate that up to a dose of 20 ?g/ml, ZnO nanoparticles are nontoxic to the cells. We report for the first time the alpha-amylase inhibitory activity of ZnO nanoparticles wherein an optimum dose of 20 ?g/ml was sufficient to exhibit 49% glucose inhibition at neutral pH and 35 °C temperature. This inhibitory activity was similar to that obtained with acarbose (a standard alpha-amylase inhibitor), thereby projecting ZnO nanoparticles as novel alpha-amylase inhibitors.

  16. Preparation and characterization of silver and zinc oxide heat mirrors

    SciTech Connect

    Min, Y.L.

    1987-01-01

    A heat mirror is a spectrally selective coating for windows which transmits solar radiation and highly reflects infrared radiation. When applied to the inside surface of a window the heat mirror maintains the visibility of the window yet suppresses the radiative heat loss. The heat mirror thus functions as a transparent heat insulation. Techniques were developed for preparing two types of heat mirrors that utilize two different mechanisms for achieving high infrared reflectivity. The first type consists of a very thin (70A) silver film prepared by resistive evaporation. The highly visible transparent and infrared reflective silver film is deposited onto a water-cooled polyester substrate through a helium plasma, which acts to provide a uniform film without clustering of the silver layer into isolated islands. An antireflecting dielectric coating of Al/sub 2/O/sub 3/ enhances the visible transparency and protects the delicate silver film. The second type of heat mirror consists of a thick (2000A) layer of zinc oxide prepared by reactive triode D.C. magnetron sputtering. High infrared reflectance is obtained by making the zinc oxide slightly nonstoichiometric which introduces free carriers into the otherwise empty conduction band of the ZnO.

  17. Nanosized Zinc Oxide Induces Toxicity in Human Lung Cells

    PubMed Central

    Sahu, Devashri; Kannan, G. M.; Vijayaraghavan, R.; Anand, T.; Khanum, Farhath

    2013-01-01

    Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, biosensors, food additives, pigments, rubber manufacture, and electronic materials. With the wide application of ZnO-NPs, concern has been raised about its unintentional health and environmental impacts. This study investigates the toxic effects of ZnO-NPs in human lung cells. In order to assess toxicity, human lung epithelial cells (L-132) were exposed to dispersion of 50?nm ZnO-NPs at concentrations of 5, 25, 50, and 100??g/mL for 24?h. The toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, DNA damage analysis, and gene expression. Exposure to 50?nm ZnO-NPs at concentrations between 5 and 100??g/mL decreased cell viability in a concentration-dependent manner. Morphological examination revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The oxidative stress parameters revealed significant depletion of GSH level and increase in ROS levels suggesting generation of oxidative stress. ZnO-NPs exposure caused DNA fragmentation demonstrating apoptotic type of cell death. ZnO-NPs increased the expression of metallothionein gene, which is considered as a biomarker in metal-induced toxicity. To summarize, ZnO-NPs cause toxicity in human lung cells possibly through oxidative stress-induced apoptosis. PMID:23997968

  18. Myeloperoxidase-derived oxidants rapidly oxidize and disrupt zinc-cysteine/histidine clusters in proteins.

    PubMed

    Cook, Naomi L; Pattison, David I; Davies, Michael J

    2012-12-01

    Zinc is an abundant cellular transition metal ion, which binds avidly to protein cysteine (Cys) and histidine (His) residues to form zinc-Cys/His clusters; these play a key role in the function of many proteins (e.g., DNA binding and repair enzymes, transcription factors, nitric oxide synthase). Leukocyte-derived myeloperoxidase generates powerful oxidants including hypochlorous (HOCl), hypobromous (HOBr), and hypothiocyanous (HOSCN) acids from H(2)O(2) and (pseudo)halide ions. Excessive or misplaced formation of these species is associated with cellular dysfunction, apoptosis and necrosis, and multiple inflammatory diseases. HOCl and HOBr react rapidly with sulfur-containing compounds, and HOSCN reacts specifically with thiols. Consequently, we hypothesized that zinc-Cys/His clusters would be targets for these oxidants, and the activity of such enzymes would be perturbed. This hypothesis has been tested using yeast alcohol dehydrogenase (YADH), which contains a well-characterized Zn(1)Cys(2)His(1) cluster. Incubation of YADH with pathologically relevant concentrations of HOSCN, HOCl, and HOBr resulted in rapid oxidation of the protein (rate constants, determined by competition kinetics, for reaction of HOCl and HOSCN with YADH being (3.3±0.9)×10(8) and (2.9±0.4)×10(4) M(-1) s(-1) per YADH monomer, respectively), loss of enzyme activity, Zn(2+) release, changes in protein structure (particularly formation of disulfide cross-links), and oxidation of Cys residues. The loss of enzyme activity correlated with Zn(2+) release, loss of thiols, and changes in protein structure. We conclude that exposure of zinc-Cys/His clusters to inflammatory oxidants can result in impaired protein activity, thiol oxidation, and Zn(2+) release. These reactions may contribute to inflammation-induced tissue damage. PMID:23032100

  19. Scale-up synthesis of zinc borate from the reaction of zinc oxide and boric acid in aqueous medium

    NASA Astrophysics Data System (ADS)

    K?l?nç, Mert; Çakal, Gaye Ö.; Ye?il, Sertan; Bayram, Göknur; Ero?lu, ?nci; Özkar, Saim

    2010-11-01

    Synthesis of zinc borate was conducted in a laboratory and a pilot scale batch reactor to see the influence of process variables on the reaction parameters and the final product, 2ZnO·3B 2O 3·3.5H 2O. Effects of stirring speed, presence of baffles, amount of seed, particle size and purity of zinc oxide, and mole ratio of H 3BO 3:ZnO on the zinc borate formation reaction were examined at a constant temperature of 85 °C in a laboratory (4 L) and a pilot scale (85 L) reactor. Products obtained from the reaction in both reactors were characterized by chemical analysis, X-ray diffraction, particle size distribution analysis, thermal gravimetric analysis and scanning electron microscopy. The kinetic data for the zinc borate production reaction was fit by using the logistic model. The results revealed that the specific reaction rate, a model parameter, decreases with increase in particle size of zinc oxide and the presence of baffles, but increases with increase in stirring speed and purity of zinc oxide; however, it is unaffected with the changes in the amount of seed and reactants ratio. The reaction completion time is unaffected by scaling-up.

  20. ZINC

    EPA Science Inventory

    This report summarizes the available information on zinc as it relates to its effects on man and his environment. Zinc is found in most soils, but some areas are deficient in it. Metallurgic operations contribute to zinc contamination in air, water and soil. Trace amounts of zinc...

  1. Physiological characterization of the Arabidopsis thaliana Oxidation-related Zinc Finger 1, a plasma membrane protein involved in oxidative stress

    Microsoft Academic Search

    Ping Huang; Moon-Soo Chung; Hyun-Woo Ju; Hyun-Seok Na; Dong Ju Lee; Hyeon-Sook Cheong; Cheol Soo Kim

    The CCCH-type zinc finger proteins are a superfamily containing tandem zinc-binding motifs involved in many aspects of plant\\u000a growth and development. However, the precise role of these proteins involved in plant stress tolerance is poorly understood.\\u000a This study was to examine the regulatory and functional role of the CCCH-type zinc finger protein, AtOZF1 (At2g19810), under oxidative stress. Interestingly, the AtOZF1

  2. Poly(vinylidene fluoride)/zinc oxide smart composite material

    NASA Astrophysics Data System (ADS)

    Ö?üt, Erdem; Yördem, O. Sinan; Mencelo?lu, Yusuf Z.; Papila, Melih

    2007-04-01

    This work aimed at fabrication and electromechanical characterization of a smart material system composed of electroactive polymer and ceramic materials. The idea of composite material system is on account of complementary characteristics of the polymer and ceramic for flexibility and piezoelectric activity. Our preliminary work included Polyvinylidene Fluoride (PVDF) as the flexible piezoelectric polymer, and Zinc Oxide (ZnO) as the piezoelectric ceramic brittle, but capable to respond strains without poling. Two alternative processes were investigated. The first process makes use of ZnO fibrous formation achieved by sintering PVA/zinc acetate precursor fibers via electrospinning. Highly brittle fibrous ZnO mat was dipped into a PVDF polymer solution and then pressed to form pellets. The second process employed commercial ZnO nanopowder material. The powder was mixed into a PVDF/acetone polymer solution, and the resultant paste was pressed to form pellets. The free standing composite pellets with electrodes on the top and bottom surfaces were then subjected to sinusoidal electric excitation and response was recorded using a fotonic sensor. An earlier work on electrospun PVDF fiber mats was also summarized here and the electromechanical characterization is reported.

  3. Nano-rods of zinc oxide in nano-graphene

    NASA Astrophysics Data System (ADS)

    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.

  4. Effect of morphology and solvent on two-photon absorption of nano zinc oxide

    SciTech Connect

    Kavitha, M.K. [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); Haripadmam, P.C.; Gopinath, Pramod; Krishnan, Bindu [Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India); John, Honey, E-mail: honey@iist.ac.in [Department of Chemistry, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala (India)

    2013-05-15

    Highlights: ? ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ? The effect of precursor concentration on the size and shape of nano ZnO. ? Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ? Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ? Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novel precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.

  5. Nanosized zinc oxide particles induce neural stem cell apoptosis

    NASA Astrophysics Data System (ADS)

    Deng, Xiaoyong; Luan, Qixia; Chen, Wenting; Wang, Yanli; Wu, Minghong; Zhang, Haijiao; Jiao, Zheng

    2009-03-01

    Given the intensive application of nanoscale zinc oxide (ZnO) materials in our life, growing concerns have arisen about its unintentional health and environmental impacts. In this study, the neurotoxicity of different sized ZnO nanoparticles in mouse neural stem cells (NSCs) was investigated. A cell viability assay indicated that ZnO nanoparticles manifested dose-dependent, but no size-dependent toxic effects on NSCs. Apoptotic cells were observed and analyzed by confocal microscopy, transmission electron microscopy examination, and flow cytometry. All the results support the viewpoint that the ZnO nanoparticle toxicity comes from the dissolved Zn2+ in the culture medium or inside cells. Our results highlight the need for caution during the use and disposal of ZnO manufactured nanomaterials to prevent the unintended environmental and health impacts.

  6. Photophysical Behaviors of Single Fluorophores Localized on Zinc Oxide Nanostructures

    PubMed Central

    Fu, Yi; Zhang, Jian; Lakowicz, Joseph R.

    2012-01-01

    Single-molecule fluorescence spectroscopy has now been widely used to investigate complex dynamic processes which would normally be obscured in an ensemble-averaged measurement. In this report we studied photophysical behaviors of single fluorophores in proximity to zinc oxide nanostructures by single-molecule fluorescence spectroscopy and time-correlated single-photon counting (TCSPC). Single fluorophores on ZnO surfaces showed enhanced fluorescence brightness to various extents compared with those on glass; the single-molecule time trajectories also illustrated pronounced fluctuations of emission intensities, with time periods distributed from milliseconds to seconds. We attribute fluorescence fluctuations to the interfacial electron transfer (ET) events. The fluorescence fluctuation dynamics were found to be inhomogeneous from molecule to molecule and from time to time, showing significant static and dynamic disorders in the interfacial electron transfer reaction processes. PMID:23109903

  7. Texture and Topography Analysis of Doxycycline Hyclate Thermosensitive Systems Comprising Zinc Oxide

    PubMed Central

    Phaechamud, T.; Mahadlek, J.; Charoenteeraboon, J.

    2013-01-01

    To characterize the thermal behavior and texture analysis of doxycycline hyclate thermosensitive gels developed for periodontitis treatment containing zinc oxide prepared by using poloxamer (Lutrol® F127) as polymeric material and N-methyl pyrrolidone was used as cosolvent. The thermosensitive gel comprising doxycycline hyclate, Lutrol® F127, and N-methyl pyrrolidone were characterized for the thermal behavior and texture analysis. The topography of the system after the dissolution test was characterized with scanning electron microscope. Differential scanning calorimetric thermogram exhibited the endothermic peaks in the systems containing high amount of N-methyl pyrrolidone in solvent. The sol-gel transition temperature of the systems decreased as the zinc oxide amount was increased. The addition of doxycycline hyclate, zinc oxide, and N-methyl pyrrolidone affected the syringeability of systems. The addition of zinc oxide into the doxycycline hyclate-Lutrol® F127 systems decreased the diameter of inhibition zone against Staphylococcus aureus, Escherichia coli, and Candida albicans since zinc oxide decreased the diffusion and prolonged release of doxycycline hyclate. From scanning electron microscope analysis, the porous surface of 20% w/w Lutrol® F127 system was notably different from that of gel comprising doxycycline hyclate which had interconnected pores and smooth surfaces. The number of pores was decreased with increasing zinc oxide and the porous structure was smaller and more compact. Therefore, the addition of zinc oxide could increase the syringeability of doxycycline hyclate-Lutrol® F127 system with the temperature dependence. Zinc oxide decreased inhibition zone against test microbes because of prolongation of doxycycline hyclate release and reduced size of continuous cells. Furthermore, zinc oxide also increased the compactness of wall surfaces of Lutrol® F127. PMID:24302791

  8. Zinc oxide tetrapods as efficient photocatalysts for organic pollutant degradation

    NASA Astrophysics Data System (ADS)

    Liu, Fangzhou; Leung, Yu Hang; Djurisi?, Aleksandra B.; Liao, Changzhong; Shih, Kaimin

    2014-03-01

    Bisphenol A (BPA) and other organic pollutants from industrial wastewater have drawn increasing concern in the past decades regarding their environmental and biological risks, and hence developing strategies of effective degradation of BPA and other organic pollutants is imperative. Metal oxide nanostructures, in particular titanium oxide (TiO2) and zinc oxide (ZnO), have been demonstrated to exhibit efficient photodegradation of various common organic dyes. ZnO tetrapods are of special interest due to their low density of native defects which consequently lead to lower recombination losses and higher photocatalytic efficiency. Tetrapods can be obtained by relatively simple and low-cost vapor phase deposition in large quantity; the micron-scale size would also be advantageous for catalyst recovery. In this study, the photodegradation of BPA with ZnO tetrapods and TiO2 nanostructures under UV illumination were compared. The concentration of BPA dissolved in DI water was analyzed by high-performance liquid chromatography (HPLC) at specified time intervals. It was observed that the photocatalytic efficiency of ZnO tetrapods eventually surpassed Degussa P25 in free-standing form, and more than 80% of BPA was degraded after 60 min. Photodegradation of other organic dye pollutants by tetrapods and P25 were also examined. The superior photocatalytic efficiency of ZnO tetrapods for degradation of BPA and other organic dye pollutants and its correlation with the material properties were discussed.

  9. Prenatal development toxicity study of zinc oxide nanoparticles in rats

    PubMed Central

    Hong, Jeong-Sup; Park, Myeong-Kyu; Kim, Min-Seok; Lim, Jeong-Hyeon; Park, Gil-Jong; Maeng, Eun-Ho; Shin, Jae-Ho; Kim, Meyoung-Kon; Jeong, Jayoung; Park, Jin-A; Kim, Jong-Choon; Shin, Ho-Chul

    2014-01-01

    This study investigated the potential adverse effects of zinc oxide nanoparticles ([ZnOSM20(+) NPs] zinc oxide nanoparticles, positively charged, 20 nm) on pregnant dams and embryo–fetal development after maternal exposure over the period of gestational days 5–19 with Sprague-Dawley rats. ZnOSM20(+) NPs were administered to pregnant rats by gavage at 0, 100, 200, and 400 mg/kg/day. All dams were subjected to a cesarean section on gestational day 20, and all of the fetuses were examined for external, visceral, and skeletal alterations. Toxicity in the dams manifested as significantly decreased body weight after administration of 400 mg/kg/day NPs; reduced food consumption after administration of 200 and 400 mg/kg/day NPs; and decreased liver weight and increased adrenal glands weight after administration of 400 mg/kg/day NPs. However, no treatment-related difference in: number of corpora lutea; number of implantation sites; implantation rate (%); resorption; dead fetuses; litter size; fetal deaths and placental weights; and sex ratio were observed between the groups. On the other hand, significant decreases between treatment groups and controls were seen for fetal weights after administration of 400 mg/kg/day NPs. Morphological examinations of the fetuses demonstrated significant differences in incidences of abnormalities in the group administered 400mg/kg/day. Meanwhile, no significant difference was found in the Zn content of fetal tissue between the control and high-dose groups. These results showed that oral doses for the study with 15-days repeated of ZnOSM20(+) NPs were maternotoxic in the 200 mg/kg/day group, and embryotoxic in the 400 mg/kg/day group. PMID:25565834

  10. Surface modification of zinc oxide nanoparticle by PMAA and its dispersion in aqueous system

    Microsoft Academic Search

    Erjun Tang; Guoxiang Cheng; Xiaolu Ma; Xingshou Pang; Qiang Zhao

    2006-01-01

    Commercial zinc oxide nanoparticles were modified by polymethacrylic acid (PMAA) in aqueous system. The hydroxyl groups of nano-ZnO particle surface can interact with carboxyl groups (COO–) of PMAA and form poly(zinc methacrylate) complex on the surface of nano-ZnO. The formation of poly(zinc methacrylate) complex was testified by Fourier-transform infrared spectra (FT-IR). Thermogravimetric analysis (TGA) indicated that PMAA molecules were absorbed

  11. Fabrication and characterization of zinc oxide nanoparticles by DC arc plasma

    NASA Astrophysics Data System (ADS)

    Shoushtari, M. Z.; Parhoodeh, S.; Farbod, M.

    2008-03-01

    Zinc oxide nanoparticles were synthesized by DC arc plasma in pure oxygen atmosphere. High DC currents were passed through two approaching zinc rods in different oxygen pressures between 50 to 5000 mbars. Samples were characterized by TEM, SEM, XRD and electron diffraction analysis. The formation of zinc oxide nanoparticles were successfully proved by those analyses, although in some cases we had some unwanted materials. The XRD patterns show crystalline formation of zinc oxide, but in low pressures we have an excess peak belong to pure zinc. The height of this peak was reduced by increase in oxygen pressure and finally vanished completely at high pressure. The TEM and SEM images of samples show that in low pressures the samples mainly tend to have rod like shapes structures, but by increasing the oxygen pressure the structures steady revolve to the hexagonal nanocrystals. Upon the resulted data, the best conditions of arc plasma for desire product were inferred.

  12. Zinc oxide waveguide produced by thermal oxidation of chemical bath deposited zinc sulphide thin films

    Microsoft Academic Search

    E. J Ibanga; C Le Luyer; J Mugnier

    2003-01-01

    ZnO waveguiding layers deposited onto soda lime glass were produced from the thermal oxidation of ZnS thin films elaborated by a carefully conducted chemical bath deposition (CBD) method. X-ray diffraction indicated that ZnO films possessing a polycrystalline hexagonal structure were obtained. M-line spectroscopy was used to determine the refractive index and the thickness of ZnO films which were 1.90 at

  13. 60 FR 47334 - Zinc Oxide; Toxic Chemical Release Reporting; Community Right-To- Know

    Federal Register 2010, 2011, 2012, 2013, 2014

    1995-09-12

    ...the stable form. The reported water solubility of zinc oxide ranges from 1.6 milligrams...Zn(OH)2 form. The reported water solubility of zinc hydroxide ranges from 2.92...29 deg.C). These variations in solubility data are most likely due to...

  14. Influence Of pH On The Transport Of Nanoscale Zinc Oxide In Saturated Porous Media

    EPA Science Inventory

    Widespread use of nanoscale zinc oxide (nZnO) in various fields causes subsurface environment contamination. Even though the transport of dissolved zinc ions in subsurface environments such as soils and sediments has been widely studied, the transport mechanism of nZnO in such e...

  15. Optical properties of zinc peroxide and zinc oxide multilayer nanohybrid films

    NASA Astrophysics Data System (ADS)

    Seb?k, Dániel; Szabó, Tamás; Dékány, Imre

    2009-05-01

    Zinc peroxide and zinc oxide nanoparticles were prepared and self-assembled hybrid nanolayers were built up using layer-by-layer (LbL) technique on the surface of glass substrate using the layer silicate hectorite and an anionic polyelectrolyte, sodium polystyrene sulfonate (PSS). Light absorption, interference and morphological properties of the hybrid films were studied to determine their thickness and refractive index. The influence of layer silicates and polymers on the self-organizing properties of ZnO 2 and ZnO nanoparticles was examined. X-ray diffraction revealed that ZnO 2 powders decomposed to ZnO (zincite phase) at relatively low temperatures (less than 200 °C). The optical thickness of the films ranged from 190 to 750 nm and increased linearly with the number of layers. Band gap energies of the ZnO 2/hectorite films were independent from the layer thickness and were larger than that of pure ZnO 2 nanodispersion. Decomposition of ZnO 2 to ZnO and O 2 at 400 °C resulted in the decrease of the band gap energy from 3.75 to 3.3 eV. Concomitantly, the refractive index increased in correlation with the formation of the zincite ZnO phase. In contrast, the band gap energies of the ZnO 2/PSS hybrid films decreased with the thickness of the nanohybrid layers. We ascribe this phenomenon to the steric stabilization of primary ZnO 2 particles present in the confined space between adjacent layers of hectorite sheets.

  16. Zinc poisoning

    MedlinePLUS

    ... other materials to make industrial items such as paint, dyes, and more. These combination substances can be ... Compounds used to make paint, rubber, dyes, wood preservatives, and ... Zinc chloride Zinc oxide (relatively nonharmful) Zinc ...

  17. Controlled Co(II) Doping of Zinc Oxide Nanocrystals

    SciTech Connect

    S Bohle; C Spina

    2011-12-31

    Dopants are non-native atoms commonly used to modify the properties of bulk semiconductors. In this paper we demonstrate that by controlling the addition of cobalt(II) to growing zinc oxide nanocrystals (ZnO NCs) it is possible to modulate the resulting properties. We show that the environment of cobalt may be controlled by varying the synthetic conditions, mainly through varying the time of dopant-precursor addition and concentration. These conditions prove critical to the resulting Co(II) configuration, which affects both the luminescent and photocatalytic properties of the ZnO NCs. Presynthetic doping with 2% Co(II) results in a 98% quenching of the visible emission of ZnO, whereas the same quantity doped post synthesis results in only a 60% quenching. The environment of cobalt in the ZnO wurtzite lattice is identified through UV-vis spectroscopy. The wurtzite structure of the ZnO lattice for all nanocrystalline species is confirmed through X-ray diffraction patterns obtained from a synchrotron radiation source. Postsynthetically doped Co(II) in ZnO NC is demonstrated to have potential applications as an 'on-off' sensor, as exemplified with nitric oxide.

  18. Biochemistry of mobile zinc and nitric oxide revealed by fluorescent sensors

    E-print Network

    Pluth, Michael D.

    Biological mobile zinc and nitric oxide (NO) are two prominent examples of inorganic compounds involved in numerous signaling pathways in living systems. In the past decade, a synergy of regulation, signaling, and translocation ...

  19. Nanohybrids of ultrathin titania nanosheets and zinc oxide nanoparticles by an electrostatic interaction.

    PubMed

    Kim, Sunmi; Paek, Seungwoo; Lee, Seonghoon

    2010-01-01

    We synthesized ultrathin titania nanosheets and zinc oxide nanoparticles, and formed the nanohybrids of them by an electrostatic interaction. The titania nanosheets were prepared by soft chemical processes: intercalation, exfoliation, and reassembly. The zinc oxide nanoparticles were prepared by the sol-gel method. And two nano-scale inorganic materials were hybridized to form nanohybrids using an electrostatic interaction as a driving force. According to the X-ray diffraction pattern and high-resolution transmission electron microscope images, it is revealed that the nanohybrid of the titania nanosheets and zinc oxide nanoparticles has a house of cards structure in which zinc oxide nanoparticles are randomly attached to layered titania nanosheets. PMID:20352811

  20. Phosphate-enhanced cytotoxicity of zinc oxide nanoparticles and agglomerates.

    PubMed

    Everett, W Neil; Chern, Christina; Sun, Dazhi; McMahon, Rebecca E; Zhang, Xi; Chen, Wei-Jung A; Hahn, Mariah S; Sue, H-J

    2014-02-10

    Zinc oxide (ZnO) nanoparticles (NPs) have been found to readily react with phosphate ions to form zinc phosphate (Zn3(PO4)2) crystallites. Because phosphates are ubiquitous in physiological fluids as well as waste water streams, it is important to examine the potential effects that the formation of Zn3(PO4)2 crystallites may have on cell viability. Thus, the cytotoxic response of NIH/3T3 fibroblast cells was assessed following 24h of exposure to ZnO NPs suspended in media with and without the standard phosphate salt supplement. Both particle dosage and size have been shown to impact the cytotoxic effects of ZnO NPs, so doses ranging from 5 to 50 ?g/mL were examined and agglomerate size effects were investigated by using the bioinert amphiphilic polymer polyvinylpyrrolidone (PVP) to generate water-soluble ZnO ranging from individually dispersed 4 nm NPs up to micron-sized agglomerates. Cell metabolic activity measures indicated that the presence of phosphate in the suspension media can led to significantly reduced cell viability at all agglomerate sizes and at lower ZnO dosages. In addition, a reduction in cell viability was observed when agglomerate size was decreased, but only in the phosphate-containing media. These metabolic activity results were reflected in separate measures of cell death via the lactate dehydrogenase assay. Our results suggest that, while higher doses of water-soluble ZnO NPs are cytotoxic, the presence of phosphates in the surrounding fluid can lead to significantly elevated levels of cell death at lower ZnO NP doses. Moreover, the extent of this death can potentially be modulated or offset by tuning the agglomerate size. These findings underscore the importance of understanding how nanoscale materials can interact with the components of surrounding fluids so that potential adverse effects of such interactions can be controlled. PMID:24362007

  1. Preparation and Desulfurization Behavior of Zinc Oxide Based Sorbent for Moderate Temperature

    Microsoft Academic Search

    Ju Shangguan; Yousheng Zhao; Huiling Fan; Liang Litong; Fang Shen; Maoqian Miao

    2010-01-01

    Zinc oxide based moderate-temperature sorbents were obtained by mixing active zinc oxide with other additives, shaping, drying and calcinating in a given order. The influences of preparation conditions on the desulfurization behaviors for the prepared ZnO based desulfurization sorbent were carried out in simulated coal gas using a fixed-bed reactor. The changes of crystal phase before and after desulfurization were

  2. Novel biocompatible composite (Chitosan–zinc oxide nanoparticle): Preparation, characterization and dye adsorption properties

    Microsoft Academic Search

    Raziyeh Salehi; Mokhtar Arami; Niyaz Mohammad Mahmoodi; Hajir Bahrami; Shooka Khorramfar

    2010-01-01

    In this paper, the preparation, characterization and dye adsorption properties of novel biocompatible composite (Chitosan–zinc oxide nanoparticle) (CS\\/n-ZnO) were investigated. Zinc oxide nanoparticles were immobilized onto Chitosan. Physical characteristics of CS\\/n-ZnO were studied using Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and wavelength dispersive X-ray spectroscopy (WDX). Two textile dyes, Direct Blue 78 (DB78) and Acid

  3. Synthesis and characterization of nanostructured zinc oxide layers for sensor applications

    SciTech Connect

    Krasteva, L. K.; Dimitrov, D. Tz.; Papazova, K. I.; Nikolaev, N. K.; Peshkova, T. V. [University of Sofia (Bulgaria); Moshnikov, V. A.; Gracheva, I. E., E-mail: iegrachova@mail.ru; Karpova, S. S. [Ul'yanov (Lenin) State Electrotechnical University LETI (Russian Federation); Kaneva, N. V. [University of Sofia (Bulgaria)

    2013-04-15

    Fractal structures and arrays of nanowires based on zinc oxide are fabricated by two different methods, sol-gel dip-coating and chemical bath deposition combined with sol-gel synthesis. The gas-sensitive properties of the structures are analyzed. It is found that the greatest sensitivity to reducing ethanol vapor is exhibited by the structure with a lower layer in the form of an array of zinc-oxide nanowires modified by four immersions in a copper nitrate solution.

  4. Studies on Zinc Oxide Nanorods Grown by Electron Beam Evaporation Technique

    Microsoft Academic Search

    P. K. Giri; P. K. Patel; C. J. Panchal; S. Bhattacharyya; Satchi Kumari; Dilip K. Singh; V. A. Kheraj; N. M. Shah; P. D. Vakil; K. J. Patel; M. S. Desai; Bharti Rehani; V. J. Rao; R. R. Desai; D. Lakshminarayana; P. B. Patel

    2007-01-01

    Nanocrystalline zinc oxide-thin films have drawn the attention of researchers due to its attractive properties like transparency in visible region, abundance in nature and gas sensitivity. Nanostructured Zinc oxide (ZnO) thin films were grown on silicon, alumina and glass substrates at various substrate temperatures using a 6 kW electron beam evaporation technique. The effects of film thickness, growth temperature and substrate

  5. Microfine zinc oxide (Z-Cote) as a photostable UVA\\/UVB sunblock agent

    Microsoft Academic Search

    Mark A. Mitchnick; David Fairhurst; Sheldon R. Pinnell

    1999-01-01

    Background: Microfine zinc oxide (Z-Cote) is used as a transparent broad-spectrum sunblock to attenuate UV radiation (UVR), including UVA I (340-400 nm). Objective: Our purpose was to assess the suitability of microfine zinc oxide as a broad-spectrum photoprotective agent by examining those properties generally considered important in sunscreens: attenuation spectrum, sun protection factor (SPF) contribution, photostability, and photoreactivity. Methods: Attenuation

  6. Hermetically sealed silver-zinc batteries operating in the silver \\/I\\/ oxide \\/Ag2O\\/ phase

    Microsoft Academic Search

    L. Hajdu; J. Zahoran

    1974-01-01

    A detailed report on research and development activities directed toward the production of a hermetically sealed miniature silver-zinc accumulator operating in the pure silver (I) oxide phase. Gas formation in the sealed accumulator, the effect of silver structure on the Ag2O phase size, and electric, life, and storage properties of silver-zinc accumulators operating in the silver (I) oxide phase are

  7. Surfactant-mediated growth of nanostructured zinc oxide thin films via electrodeposition and their photoelectrochemical performance

    Microsoft Academic Search

    A. I. Inamdar; S. H. Mujawar; V. Ganesan; P. S. Patil

    2008-01-01

    Zinc oxide (ZnO) thin films were electrodeposited from an aqueous zinc acetate solution onto fluorine-doped thin oxide (FTO) coated conducting glass substrates. The effect of organic surfactants like polyvinyl pyrrolidone (PVP), sodium dodecyl sulfate (SDS), polyethylene glycol (PEG), ethylene glycol (EG) and polyvinyl alcohol (PVA) on their structural, morphological, optical and photoelectrochemical properties was studied. The x-ray diffraction patterns revealed

  8. Enhanced ultraviolet sensitivity of zinc oxide nanoparticle photoconductors by surface passivation

    Microsoft Academic Search

    Liqiao Qin; Christopher Shing; Shayla Sawyer; Partha S. Dutta

    2011-01-01

    Zinc oxide nanoparticles were created by a top-down wet-chemical etching process and then coated with polyvinyl-alcohol (PVA), exhibiting sizes ranging from 10 to 120nm with an average size approximately 80nm. The PVA layer provides surface passivation of zinc oxide nanoparticles. As a result of PVA coating, enhancement in ultraviolet emission and suppression of parasitic green emission is observed. Photoconductors fabricated

  9. Burn-induced oxidative stress is altered by a low zinc status: kinetic study in burned rats fed a low zinc diet.

    PubMed

    Claeyssen, Richard; Andriollo-Sanchez, Maud; Arnaud, Josiane; Touvard, Laurence; Alonso, Antonia; Chancerelle, Yves; Roussel, Anne-Marie; Agay, Diane

    2008-12-01

    As an initial subdeficient status of zinc, considered as an essential antioxidant trace element, is frequent in burned patients, we aim to assess the effects of low zinc dietary intakes on burn-induced oxidative stress, in an animal model. After 8 weeks of conditioning diets containing 80 ppm (control group) or 10 ppm of zinc (depleted group), Wistar rats were 20% TBSA burned and sampled 1-10 days after injury. Kinetic evolutions of zinc status, plasma oxidative stress parameters, and antioxidant enzymes were also studied in blood and organs. The zinc-depleted diet induced, before injury, a significant decrease in zinc bone level and the increase of oxidative stress markers without stimulation of antioxidant enzyme activity. After burn, more markedly in zinc depleted animals than in controls, zinc levels decreased in plasma and bone, while increasing in liver. The decrease of thiol groups and GSH/GSSG ratio and the depression of GPx activity in liver are also moderately emphasized. Nevertheless, depleted zinc status could not be considered as determining for oxidative damages after burn injury. Further investigations must also be done to enlighten the mechanism of beneficial effects of zinc supplementation reported in burned patients. PMID:18773151

  10. The role of intracellular zinc release in aging, oxidative stress, and Alzheimer’s disease

    PubMed Central

    McCord, Meghan C.; Aizenman, Elias

    2014-01-01

    Brain aging is marked by structural, chemical, and genetic changes leading to cognitive decline and impaired neural functioning. Further, aging itself is also a risk factor for a number of neurodegenerative disorders, most notably Alzheimer’s disease (AD). Many of the pathological changes associated with aging and aging-related disorders have been attributed in part to increased and unregulated production of reactive oxygen species (ROS) in the brain. ROS are produced as a physiological byproduct of various cellular processes, and are normally detoxified by enzymes and antioxidants to help maintain neuronal homeostasis. However, cellular injury can cause excessive ROS production, triggering a state of oxidative stress that can lead to neuronal cell death. ROS and intracellular zinc are intimately related, as ROS production can lead to oxidation of proteins that normally bind the metal, thereby causing the liberation of zinc in cytoplasmic compartments. Similarly, not only can zinc impair mitochondrial function, leading to excess ROS production, but it can also activate a variety of extra-mitochondrial ROS-generating signaling cascades. As such, numerous accounts of oxidative neuronal injury by ROS-producing sources appear to also require zinc. We suggest that zinc deregulation is a common, perhaps ubiquitous component of injurious oxidative processes in neurons. This review summarizes current findings on zinc dyshomeostasis-driven signaling cascades in oxidative stress and age-related neurodegeneration, with a focus on AD, in order to highlight the critical role of the intracellular liberation of the metal during oxidative neuronal injury. PMID:24860495

  11. AZO thin film-based UV sensors: effects of RF power on the films

    NASA Astrophysics Data System (ADS)

    Akin, Nihan; Ceren Baskose, U.; Kinaci, Baris; Cakmak, Mehmet; Ozcelik, Suleyman

    2015-06-01

    Al-doped zinc oxide (AZO) thin films of thickness 150 nm were deposited on polyethylene terephthalate (PET) substrates by radio frequency (RF) magnetron sputtering method under various RF powers in the range of 25-100 W. Structural, morphological, optical and electrical properties of the films were investigated by X-ray diffractometer, atomic force microscope, UV-Vis spectrometer and Hall effect measurement system. All the obtained films had a highly preferred orientation along [002] direction of the c-axis perpendicular to the flexible PET substrate and had a high-quality surface. The energy band gap ( E g) values of the films varied in the range of 3.30-3.43 eV. The minimum resistivity of 1.84 × 10-4 ? cm was obtained at a 50 W RF power. The small changes in the RF power had a critical important role on the structural, optical and electrical properties of the sputtered AZO thin films on flexible PET substrate. In addition, UV sensing of the fabricated AZO thin film-based sensors was explored by using current-voltage (I-V) characteristics. The sensors were sensitive in the UV region of the electromagnetic spectrum.

  12. Ordered Nucleation Sites for the Growth of Zinc Oxide Nanofibers

    SciTech Connect

    Wang, J.; Ginley, D.S.; Shaheen, S.

    2006-01-01

    Organic photovoltaics (OPVs) offer a promising route to low cost photovoltaic (PV) technology that can be inexpensively manufactured on a large scale for use in power generation and commercial products. Solar power conversion efficiencies of laboratory scale OPV devices have recently reached ~5%; however, projected efficiencies of at least 10% will be required for commercialization. An analogous approach that has arisen recently that can potentially increase efficiencies employs metal oxide semiconductors as the electron acceptor, creating a hybrid organic-inorganic device. This approach offers the advantage that the conduction band of the oxide can be tuned in a systematic way through doping, thus potentially achieving higher photovoltages in the device. Additionally, nanostructures of these materials can be easily grown from precursor solutions, providing a technique to precisely control the nanoscale geometry. This work focuses on using ZnO, which is known to have high electron mobility (>100 cm2/Vs), as the electron acceptor. Nanofibers of ZnO can be grown from precursors such as zinc acetate or zinc nitrate to form arrays of nanofibers into which a conjugated polymer can be intercalated to form a composite PV device. The morphology of the nanofiber array is critical to the performance of the device, but current methods of nanofiber growth from a flat, polycrystalline nucleation layer allow for little morphological control. To overcome this limitation, we have created ordered arrays of ZnO nucleation sites with controllable size and spacing. Toluene solutions of diblock copolymer micelles with ZnCl2 incorporated into the micellar cores were spin-coated onto glass substrates and etched with an O2 plasma to yield hexagonally ordered arrays of ZnO nanoparticles that functioned as nucleation sites. Changing the concentration of ZnCl2 and the molecular weight and ratio of the diblock copolymer resulted in systematic variation in the size and spacing of the nucleation sites. Thermal anneal treatment provided further modification of the nucleation layer, from which ZnO nanofibers were successfully grown from solution, although at present it is not known if the geometry of the as-grown ZnO nanofibers precisely reflects that of the underlying nucleation layer. This work provides a simple and useful method for potentially controlling the nucleation of ZnO nanofibers to be used in hybrid ZnO/organic nanocomposite PV devices.

  13. Zinc-oxide charge trapping memory cell with ultra-thin chromium-oxide trapping layer

    SciTech Connect

    El-Atab, Nazek; Rizk, Ayman; Nayfeh, Ammar [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates)] [Institute Center for Microsystems – iMicro, Department of Electrical Engineering and Computer Science (EECS), Masdar Institute of Science and Technology Abu Dhabi (United Arab Emirates); Okyay, Ali K. [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey) [Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara (Turkey); UNAM-National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey)

    2013-11-15

    A functional zinc-oxide based SONOS memory cell with ultra-thin chromium oxide trapping layer was fabricated. A 5 nm CrO{sub 2} layer is deposited between Atomic Layer Deposition (ALD) steps. A threshold voltage (V{sub t}) shift of 2.6V was achieved with a 10V programming voltage. Also for a 2V V{sub t} shift, the memory with CrO{sub 2} layer has a low programming voltage of 7.2V. Moreover, the deep trapping levels in CrO{sub 2} layer allows for additional scaling of the tunnel oxide due to an increase in the retention time. In addition, the structure was simulated using Physics Based TCAD. The results of the simulation fit very well with the experimental results providing an understanding of the charge trapping and tunneling physics.

  14. Rambutan peels promoted biomimetic synthesis of bioinspired zinc oxide nanochains for biomedical applications.

    PubMed

    Yuvakkumar, R; Suresh, J; Saravanakumar, B; Joseph Nathanael, A; Hong, Sun Ig; Rajendran, V

    2015-02-25

    A naturally occurring rambutan peel waste was employed to synthesis bioinspired zinc oxide nanochains. Rambutan peels has the ability of ligating zinc ions as a natural ligation agent resulting in zinc oxide nanochains formation due to its extended polyphenolic system over incubation period. Successful formation of zinc oxide nanochains was confirmed employing transmission electron microscopy studies. About 60% and ?40% cell viability was lost and 50% and 10% morphological change was observed in 7 and 4 days incubated ZnO treated cells compared with control. Moreover, 50% and 55% of cell death was observed at 24 and 48 h incubation with 7 days treated ZnO cells and hence alters and disturbs the growth of cancer cells and could be used for liver cancer cell treatment. PMID:25228035

  15. Dechlorination of Zinc Oxide Dust from Waelz Kiln by Microwave Roasting

    NASA Astrophysics Data System (ADS)

    Li, Zhiqiang; Zhang, Libo; Ma, Aiyuan; Peng, Jinhui; Li, Jing; Liu, Chenhui

    2015-05-01

    The new technology of dechlorination from zinc oxide dust by microwave roasting was investigated, combined with the advantages of microwave selective heating and based on a thermodynamic analysis of zinc and lead halides. The associated dechlorination reactions were discussed in details and the effect of all the influencing parameters such as roasting temperature, holding time, stirring speed and air flow were systematically investigated. Experimental results showed that zinc oxide dust dechlorination rate could reach over 95% and meet the requirements of wet smelting electrolysis, given an air flow of 300 L/h, a stirring speed of 60 r/min, a roasting temperature of 650 °C and a holding time of 30 min. Microwave roasting provided a new solution to the dechlorination from zinc oxide dust.

  16. Hydrogen migration in single crystal and polycrystalline zinc oxide

    NASA Astrophysics Data System (ADS)

    Nickel, N. H.

    2006-05-01

    Hydrogen diffusion in single crystal and polycrystalline zinc oxide was investigated by deuterium diffusion and hydrogen effusion experiments. Deuterium concentration depth profiles were measured as a function of the passivation temperature, while in H effusion experiments the molecular hydrogen flux was measured as a function of the heating rate. The diffusion coefficient exhibits thermally activated behavior and varies between EA=0.17 and 0.37eV . The change of EA is accompanied by a change of the diffusion prefactor by eight orders of magnitude. This indicates that EA is not related to the energetic position of H transport sites or the barrier height between such sites. Using the microscopic diffusion prefactor, the position of the hydrogen chemical potential, ?H , was estimated. With increasing temperature, ?H decreases with a rate of ?0.0013eV/K . At H concentrations of less than 1017cm-3 ?H is pinned. The hydrogen density of states was derived from H effusion data, which is consistent with a diffusion activation of about 1.0eV as was originally reported by Mollwo [Z. Phys. 138, 478 (1954)] and Thomas and Lander [J. Chem. Phys. 25, 1136 (1956)]. Clear evidence for hydrogen deep traps was found in single crystal and polycrystalline ZnO .

  17. Defect controlled ferromagnetism in xenon ion irradiated zinc oxide

    NASA Astrophysics Data System (ADS)

    Satyarthi, P.; Ghosh, S.; Mishra, P.; Sekhar, B. R.; Singh, F.; Kumar, P.; Kanjilal, D.; Dhaka, R. S.; Srivastava, P.

    2015-07-01

    We report evolution of magnetic properties in zinc oxide (ZnO) single crystals and polycrystalline films induced by 500 KeV xenon ion (Xe3+) irradiation. Room temperature ferromagnetism (RT-FM) behavior is observed in as deposited polycrystalline ZnO film and strength of FM enhances with ion fluence up to 2×1017 ions/cm2 and then decreases. However, RT-FM is not observed in ZnO single crystals even after irradiation with fluence up to 3.5×1017 ions/cm2. The X-ray diffraction (XRD) and Raman measurements of ZnO single crystal reveal slightly disordered hexagonal wurtzite structure after irradiation. However, as deposited and irradiated polycrystalline ZnO films indicate excessive lattice defects in the wurtzite structure. X-ray photoelectron spectroscopy (XPS) reveals that Zn vacancy/interstitial defects are absent in all samples, although oxygen vacancy lattice defects are present. Density of oxygen vacancies is much higher in as deposited and irradiated polycrystalline ZnO films as compared to single crystals. This seems to be the determining factor for the presence and absence of RT-FM in ZnO films and single crystals respectively. The observed FM behavior in as deposited and irradiated polycrystalline ZnO films is explained on the basis of spin split impurity band formation from singly and doubly occupied oxygen vacancies which initiates d0 ferromagnetism.

  18. Structural transformation in nickel doped zinc oxide nanostructures

    SciTech Connect

    Goswami, Navendu, E-mail: navendugoswami@gmail.com [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP 201307 (India)] [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP 201307 (India); Sahai, Anshuman [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP 201307 (India)] [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, A-10, Sector-62, Noida, UP 201307 (India)

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ? A systematic study of 1–10% Ni doped ZnO nanostructures (Ni:ZnO NS). ? Effect of Ni concentration on properties of Ni:ZnO NS was intensively investigated. ? Structural transformation in Ni:ZnO NS demonstrated through characterizations. ? Alteration in vibrational modes of Ni:ZnO NS were meticulously analyzed. ? Intricacies of structural evolution, from particles to rods, were comprehended. -- Abstract: In this article, structural transformation in nickel doped zinc oxide nanostructures is reported. The ZnO nanostructures are synthesized with 1–10% of nickel doping through a chemical precipitation method. The undoped and doped nanostructures were systematically investigated employing X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM/SEM), Fourier transform infrared (FTIR) and micro-Raman spectroscopy (?RS). The wurtzite phase of the material and associated lattice parameters were ascertained through XRD analysis. TEM/SEM images reveal the structural transformation of ZnO nanostructures with variation in nickel doping. The study of vibrational modes of nanostructures at different stages of structural transformation, as performed through FTIR and Raman spectroscopy, assist in deciphering the pivotal role of doping concentration in gradual evolution of nickel doped ZnO structure from nanoparticles to nanorods.

  19. The calculation of band gap energy in zinc oxide films

    NASA Astrophysics Data System (ADS)

    Arif, Ali; Belahssen, Okba; Gareh, Salim; Benramache, Said

    2015-01-01

    We investigated the optical properties of undoped zinc oxide thin films as the n-type semiconductor; the thin films were deposited at different precursor molarities by ultrasonic spray and spray pyrolysis techniques. The thin films were deposited at different substrate temperatures ranging between 200 and 500 °C. In this paper, we present a new approach to control the optical gap energy of ZnO thin films by concentration of the ZnO solution and substrate temperatures from experimental data, which were published in international journals. The model proposed to calculate the band gap energy with the Urbach energy was investigated. The relation between the experimental data and theoretical calculation suggests that the band gap energies are predominantly estimated by the Urbach energies, film transparency, and concentration of the ZnO solution and substrate temperatures. The measurements by these proposal models are in qualitative agreements with the experimental data; the correlation coefficient values were varied in the range 0.96–0.99999, indicating high quality representation of data based on Equation (2), so that the relative errors of all calculation are smaller than 4%. Thus, one can suppose that the undoped ZnO thin films are chemically purer and have many fewer defects and less disorder owing to an almost complete chemical decomposition and contained higher optical band gap energy.

  20. Antibacterial effect of zinc oxide nanoparticles combined with ultrasound

    NASA Astrophysics Data System (ADS)

    Seil, Justin T.; Webster, Thomas J.

    2012-12-01

    Using Staphylococcus aureus (S. aureus), the present study investigated the antibacterial effect of ZnO nanoparticles both in the absence and presence of ultrasound stimulation. While the antibacterial effect of control nanoparticle chemistries (Al2O3) alone was either weak or unobservable under the conditions tested, the antibacterial effect of ZnO alone was significant, providing over a four log reduction (equivalent to antibiotics) compared to no treatment after just 8 h. The antibacterial effect was enhanced as ZnO particle diameter decreased. Specifically, when testing the antibacterial effect against bacteria populations relevant to infection, a 500 ?g ml-1 dose of zinc oxide nanoparticles with a diameter of 20 nm reduced S. aureus populations by four orders of magnitude after 8 and 24 h, compared to control groups with no nanoparticles. This was accomplished without the use of antibiotics, to which bacteria are developing a resistance anyway. The addition of ultrasound stimulation further reduced the number of viable colony-forming units present in a planktonic cell suspension by 76% compared to nanoparticles alone. Lastly, this study provided a mechanism for how ZnO nanoparticles in the presence of ultrasound decrease bacteria functions by demonstrating greater hydrogen peroxide generation by S. aureus compared to controls. These results indicated that small-diameter ZnO nanoparticles exhibited strong antibacterial properties that can be additionally enhanced in the presence of ultrasound and, thus, should be further studied for a wide range of medical device anti-infection applications.

  1. The influence of zinc chloride and zinc oxide nanoparticles on air-time survival in freshwater mussels.

    PubMed

    Gagné, François; Auclair, Joëlle; Peyrot, Caroline; Wilkinson, Kevin J

    2015-01-01

    The purpose of this study was to determine the cumulative effects of exposure to either dissolved zinc or nanozinc oxide (nanoZnO) and air-time survival in freshwater mussels. Mussels were exposed to each forms of zinc for 96h then placed in air to determine survival time. A sub-group of mussels before and after 7days of exposure to air were kept aside for the determination of the following biomarkers: arachidonate-dependent cyclooxygenase (COX) and peroxidase (inflammation and oxidative stress), lipid metabolism (total lipids, esterases activity, HO-glycerol, acetyl CoA and phospholipase A2) and lipid damage (lipid peroxidation [LPO]). The results showed that air-time survival was decreased from a mean value of 18.5days to a mean value of 12days in mussels exposed to 2.5mg/L of nanoZnO although it was not lethal based on shell opening at concentrations below 50mg/L after 96h. In mussels exposed to zinc only, the median lethal concentration was estimated at 16mg/L (10-25 95% CI). The air-time survival did not significantly change in mussels exposed to the same concentration of dissolved Zn. Significant weight losses were observed at 0.5mg/L of nanoZnO and at 2.5mg/L for dissolved zinc chloride, and were also significantly correlated with air-time survival (r=0.53; p<0.01). Air exposure significantly increased COX activity in control mussels and in mussels exposed to 0.5mg/L of nanoZnO and zinc chloride. The data also suggested fatty acid breakdown and ?-oxidation. Mussels exposed to contaminants are more susceptible to prolonged exposure to air during low water levels. PMID:25957733

  2. Novel nanostructure zinc zirconate, zinc oxide or zirconium oxide pastes coated on fluorine doped tin oxide thin film as photoelectrochemical working electrodes for dye-sensitized solar cell.

    PubMed

    Hossein Habibi, Mohammad; Askari, Elham; Habibi, Mehdi; Zendehdel, Mahmoud

    2013-03-01

    Zinc zirconate (ZnZrO(3)) (ZZ), zinc oxide (ZnO) (ZO) and zirconium oxide (ZrO(2)) (ZRO) nano-particles were synthesized by simple sol-gel method. ZZ, ZO and ZRO nano-particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectrum (DRS). Nanoporous ZZ, ZO and ZRO thin films were prepared doctor blade technique on the fluorine-doped tin oxide (FTO) and used as working electrodes in dye sensitized solar cells (DSSC). Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)(3)](PF(6))(2), [Co(pby)(3)](PF(6))(3), LiClO(4), and 4-tert-butylpyridine (TBP). The properties of DSSC have been studied by measuring their short-circuit photocurrent density (Jsc), open-circuit voltage (VOC) and fill factor (ff). The application of ZnZrO(3) as working electrode produces a significant improvement in the fill factor (ff) of the dye-sensitized solar cells (ff=56%) compared to ZnO working electrode (ff=40%) under the same condition. PMID:23266694

  3. Surface Functionalization of Oxide-Covered Zinc and Iron with Phosphonated Phenylethynyl Phenothiazine.

    PubMed

    Rechmann, Julian; Sarfraz, Adnan; Götzinger, Alissa C; Dirksen, Elena; Müller, Thomas J J; Erbe, Andreas

    2015-07-01

    Phenothiazines are redox-active, fluorescent molecules with potential applications in molecular electronics. Phosphonated phenylethynyl phenothiazine can be easily obtained in a four-step synthesis, yielding a molecule with a headgroup permitting surface linkage. Upon modifying hydroxylated polycrystalline zinc and iron, both covered with their respective native oxides, ultrathin organic layers were formed and investigated by use of infrared (IR) reflection spectroscopy, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), contact angle measurement, and ellipsometry. While stable monolayers with upright oriented organic molecules were formed on oxide-covered iron, multilayer formation is observed on oxide-covered zinc. ToF-SIMS measurements reveal a bridging bidentate bonding state of the organic compound on oxide-covered iron, whereas monodentate complexes were observed on oxide-covered zinc. Both organically modified and unmodified surfaces exhibit reactive wetting, but organic modification makes the surfaces initially more hydrophobic. Cyclic voltammetry (CV) indicates redox activity of the multilayers formed on oxide-covered zinc. On the other hand, the monolayers on oxide-covered iron desorb after electrochemical modifications in the state of the oxide, but are stable at open circuit conditions. Exploiting an electronic coupling of phenothiazines to oxides may thus assist in corrosion protection. PMID:26057456

  4. Realization of ultrathin silver layers in highly conductive and transparent zinc tin oxide\\/silver\\/zinc tin oxide multilayer electrodes deposited at room temperature for transparent organic devices

    Microsoft Academic Search

    Thomas Winkler; Hans Schmidt; Harald Flügge; Fabian Nikolayzik; Ihno Baumann; Stephan Schmale; Hans-Hermann Johannes; Torsten Rabe; Sami Hamwi; Thomas Riedl; Wolfgang Kowalsky

    We report on transparent and highly conductive multilayer electrodes prepared at room temperature by RF sputtering of zinc tin oxide (ZTO) and thermal evaporation of ultrathin silver (Ag) as top contact for transparent organic light emitting diodes (TOLED). Specifically, we study the morphological, electrical and optical properties of the multilayer structure in particular of the thin Ag film. The tendency

  5. Comparison study of electrochemical properties of porous zinc oxide/N-doped carbon and pristine zinc oxide polyhedrons

    NASA Astrophysics Data System (ADS)

    Zhou, Zhenfang; Zhang, Kun; Liu, Jinghao; Peng, Hongrui; Li, Guicun

    2015-07-01

    An in-situ calcination strategy has been developed for the synthesis of porous zinc oxide/N-doped carbon (ZnO/NC) polyhedrons, in which zeolitic imidazolate framework-8 (ZIF-8) serves as the precursor. The ZnO/NC polyhedrons with a hierarchical architecture possess a high specific surface area of 390.7 m2 g-1, high nitrogen content (19.99 at%), and robust pore structures. The porous N-doped carbon frameworks can not only increase the electronic conductivity of ZnO, but also provide interior space for the fast diffusion of Li+ ions and accommodate the volume variations during the charge and discharge cycles. When evaluated for lithium storage capacity, the hierarchical ZnO/NC polyhedrons exhibit high reversible discharge capacity (834.3 mAh g-1 at the initial low rate of 0.5C, 1C = 978 mA g-1), superior rate performance (399.2 mAh g-1 at 5C and 253.5 mAh g-1 at 10C), and excellent cycling stability (677.9 mAh g-1 at 1C after 400 cycles). The reasons are explored in terms of the well-confined primary nanocrystals (5 nm), and the finely constructed interconnected pores of the N-doped carbon networks, which facilitate the fast and effective transfer of Li+ ions and electrons, and accommodate the large volume expansions.

  6. Biol Trace Elem Res . Author manuscript Burn-induced oxidative stress is altered by a low zinc status: kinetic study

    E-print Network

    Boyer, Edmond

    Biol Trace Elem Res . Author manuscript Page /1 15 Burn-induced oxidative stress is altered by a low zinc status: kinetic study in burned rats fed a low zinc diet Richard Claeyssen 1 2 , Maud, is frequent in burned patients, we aim to assess the effects of low zinc dietary intakes on burn induced

  7. Dinuclear zinc catalysts with unprecedented activities for the copolymerization of cyclohexene oxide and CO2.

    PubMed

    Kissling, S; Lehenmeier, M W; Altenbuchner, P T; Kronast, A; Reiter, M; Deglmann, P; Seemann, U B; Rieger, B

    2015-03-18

    A variety of new dinuclear zinc catalysts was developed and tested for the copolymerization of cyclohexene oxide and carbon dioxide. Electron-withdrawing groups thereby led to unprecedented activities with turnover frequencies up to 155,000 h(-1). These are by far the highest polymerization rates ever reported for the copolymerization of cyclohexene oxide and CO2. PMID:25683286

  8. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name...substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name...substituted naphthyl)azo (substituted phenyl) azo, sodium salt (PMN...

  9. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name...substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name...substituted naphthyl)azo (substituted phenyl) azo, sodium salt (PMN...

  10. Antibacterial Activity of Dental Composites Containing Zinc Oxide Nanoparticles

    PubMed Central

    Sevinç, Berdan Aydin; Hanley, Luke

    2010-01-01

    The resin-based dental composites commonly used in restorations result in more plaque accumulation than other materials. Bacterial biofilm growth contributes to secondary caries and failure of resin-based dental composites. Methods to inhibit biofilm growth on dental composites have been sought for several decades. It is demonstrated here that zinc oxide nanoparticles (ZnO-NPs) blended at 10% (w/w) fraction into dental composites display antimicrobial activity and reduce growth of bacterial biofilms by roughly 80% for a single-species model dental biofilm. Antibacterial effectiveness of ZnO-NPs was assessed against Streptococcus sobrinus ATCC 27352 grown both planktonically and as biofilms on composites. Direct contact inhibition was observed by scanning electron microscopy and confocal laser scanning microscopy while biofilm formation was quantified by viable counts. An 80% reduction in bacterial counts was observed with 10% ZnO-NP-containing composites compared with their unmodified counterpart, indicating a statistically significant suppression of biofilm growth. Although, 20% of the bacterial population survived and could form a biofilm layer again, 10% ZnO-NP-containing composites maintained at least some inhibitory activity even after the third generation of biofilm growth. Microscopy demonstrated continuous biofilm formation for unmodified composites after one day growth, but only sparsely distributed biofilms formed on 10% ZnO-NP-containing composites. The minimum inhibitory concentration of ZnO-NPs suspended in S. sobrinus planktonic culture was 50 ?g/ml. 10% ZnO-NP-containing composites qualitatively showed less biofilm after one day anaerobic growth of a three-species initial colonizer biofilm after when compared to unmodified composites, but did not significantly reduce growth after three days. PMID:20225252

  11. Zinc

    MedlinePLUS

    ... and loss of appetite. Weight loss, problems with wound healing, decreased ability to taste food, and lower alertness ... the health problems discussed below. Immune system and wound healing The body's immune system needs zinc to do ...

  12. Anticancer activity of fungal L-asparaginase conjugated with zinc oxide nanoparticles.

    PubMed

    Baskar, G; Chandhuru, J; Sheraz Fahad, K; Praveen, A S; Chamundeeswari, M; Muthukumar, T

    2015-01-01

    Demand for developing novel delivery system for cancer treatment has increased due to the side effects present in intravenous injection of L-asparaginase. Nanoparticles are used for delivering the drugs to its destination in cancer cure. Nanobiocomposite of zinc oxide nanoparticles conjugated with L-asparaginase was produced by Aspergillus terreus and was confirmed using maximum UV-Vis absorption at 340 nm in the present work. The presence of functional groups like OH, C-H, -C=N and C=O on the surface of nanobiocomposite was found from Fourier transform infrared spectrum analysis. Size of the produced nanocomposite was found in the range of 28-63 nm using scanning electron microscope. The crystalline nature of the synthesized nanobiocomposites was confirmed by X-ray diffraction analysis. The presence of zinc oxide on synthesized nanobiocomposite was confirmed by energy dispersive spectrum analysis. The anti-cancerous nature of the synthesized zinc oxide conjugated L-asparaginase nanobiocomposite on MCF-7 cell line was studied using MTT assay. The viability of the MCF-7 cells was decreased to 35.02 % when it was treated with L-asparaginase conjugated zinc oxide nanobiocomposite. Hence it is proved that the synthesized nanobiocomposites of zinc oxide conjugated L-asparaginase has good anti-cancerous activity. PMID:25589205

  13. Extracellular synthesis of zinc oxide nanoparticle using seaweeds of gulf of Mannar, India

    PubMed Central

    2013-01-01

    Background The biosynthesis of metal nanoparticles by marine resources is thought to be clean, nontoxic, and environmentally acceptable “green procedures”. Marine ecosystems are very important for the overall health of both marine and terrestrial environments. The use of natural sources like Marine biological resources essential for nanotechnology. Seaweeds constitute one of the commercially important marine living renewable resources. Seaweeds such as green Caulerpa peltata, red Hypnea Valencia and brown Sargassum myriocystum were used for synthesis of Zinc oxide nanoparticles. Result The preliminary screening of physico-chemical parameters such as concentration of metals, concentration of seaweed extract, temperature, pH and reaction time revealed that one seaweed S. myriocystum were able to synthesize zinc oxide nanoparticles. It was confirmed through the, initial colour change of the reaction mixture and UV visible spectrophotometer. The extracellular biosynthesized clear zinc oxide nanoparticles size 36 nm through characterization technique such as DLS, AFM, SEM –EDX, TEM, XRD and FTIR. The biosynthesized ZnO nanoparticles are effective antibacterial agents against Gram-positive than the Gram-negative bacteria. Conclusion Based on the FTIR results, fucoidan water soluble pigments present in S. myriocystum leaf extract is responsible for reduction and stabilization of zinc oxide nanoparticles. by this approach are quite stable and no visible changes were observed even after 6 months. These soluble elements could have acted as both reduction and stabilizing agents preventing the aggregation of nanoparticles in solution, extracellular biological synthesis of zinc oxide nanoparticles of size 36 nm. PMID:24298944

  14. Fabrication of a super-hydrophobic nanofibrous zinc oxide film surface by electrospinning

    Microsoft Academic Search

    Bin Ding; Tasuku Ogawa; Jinho Kim; Kouji Fujimoto; Seimei Shiratori

    2008-01-01

    We report a new approach for fabricating a super-hydrophobic nanofibrous zinc oxide (ZnO) film surface. The pure poly(vinyl alcohol) (PVA) and composite PVA\\/ZnO nanofibrous films can be obtained by electrospinning the PVA and PVA\\/zinc acetate solutions, respectively. After the calcination of composite fibrous films, the inorganic fibrous ZnO films with a reduced fiber diameter were fabricated. The wettability of three

  15. Synthesis, characterization and catalytic activity of easily recyclable zinc oxide nanobundles

    Microsoft Academic Search

    M. Muruganandham; J. J. Wu

    2008-01-01

    A new self-assembly of ZnO nanobundle has been successfully synthesized in this research by thermal decomposition of zinc oxalate at atmospheric pressure without using any catalyst or solvent at moderate temperature. The XRD analysis showed that the synthesized nanobundles are hexagonal wurtzite-type pure polycrystalline zinc oxide and high resolution transmission electron microscope (HR-TEM) analysis showed that the synthesized nanoparticles size

  16. Epitaxial growth of the zinc oxide nanorods, their characterization and in vitro biocompatibility studies

    Microsoft Academic Search

    Ramya Gopikrishnan; Kai Zhang; Prabakaran Ravichandran; Santhoshkumar Biradar; Vani Ramesh; Virupaxi Goornavar; Robert B. Jeffers; Aswini Pradhan; Joseph C. Hall; Sudhakar Baluchamy; Govindarajan T. Ramesh

    Here, we have synthesized Zinc Oxide (ZnO) nanorods at room temperature using zinc acetate and hexamethylenetetramine as precursors\\u000a followed by characterization using X-ray diffraction (XRD), fourier transform infra red spectroscopy, scanning electron microscopy\\u000a (SEM) and transmission electron microscopy. The growth of the synthesized ZnO was found to be very close to its hexagonal\\u000a nature, which is confirmed by XRD. The

  17. Preparation and properties of solution-processed zinc tin oxide films from a new organic precursor

    Microsoft Academic Search

    YunLong Zhao; Lian Duan; Juan Qiao; DeQiang Zhang; GuiFang Dong; LiDuo Wang; Yong Qiu

    2011-01-01

    Transparent, smooth and dense zinc tin oxide (ZTO) thin films have been successfully produced by using a new precursor solution,\\u000a zinc acetate and tin(II) 2-ethylhexanoate mixed with 2-ethanolamine in methoxyethanol. The ZTO films have been prepared by\\u000a spin-coating, followed by thermal treatment in oxygen atmosphere. The morphology, composition, crystallinity and band gap\\u000a energy (Eg) of the ZTO thin films have

  18. Influence of pH on the transport of nanoscale zinc oxide in saturated porous media

    Microsoft Academic Search

    Sushil R. Kanel; Souhail R. Al-Abed

    Widespread use of nanoscale zinc oxide (nZnO) in various fields causes subsurface environment contamination. Even though the\\u000a transport of dissolved zinc ions in subsurface environments such as soils and sediments has been widely studied, the transport\\u000a mechanism of nZnO in such environments is poorly understood. In addition, nZnO is often combined with stabilizers or dispersing\\u000a agents to prevent its aggregation

  19. A mechanochemical synthesis of nanostructured zinc oxide via acetate route for LPG sensing

    Microsoft Academic Search

    Anuradha Yadav; B. C. Yadav

    2012-01-01

    This article reports the liquefied petroleum gas (LPG) sensing of nanostructured zinc oxide (ZnO) synthesised via zinc acetate [Zn(CH3COO)2·2H2O] as precursor. The structural and morphological characterisations of the material were analysed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). Structural analysis showed that material was highly crystalline having minimum crystallite size 15?nm. Surface morphological studies show nanospheres

  20. Morphological impact of zinc oxide layers on the device performance in thin-film transistors

    Microsoft Academic Search

    Hendrik Faber; Martin Klaumünzer; Michael Voigt; Diana Galli; Benito F. Vieweg; Wolfgang Peukert; Erdmann Spiecker; Marcus Halik

    2011-01-01

    Zinc oxide thin-films are prepared either by spin coating of an ethanolic dispersion of nanoparticles (NP, diameter 5 nm) or by spray pyrolysis of a zinc acetate dihydrate precursor. High-resolution electron microscopy studies reveal a monolayer of particles for the low temperature spin coating approach and larger crystalline domains of more than 30 nm for the spray pyrolysis technique. Thin-film

  1. Preparation of zinc oxide nanoparticles coated with homogeneous Al 2O 3 layer

    Microsoft Academic Search

    Fangli Yuan; Hu Peng; Ye Yin; Yin Chunlei; Hojin Ryu

    2005-01-01

    Zinc oxide nanoparticles coated with Al2O3 were prepared by calcining basic carbonate of zinc (BCZ) powders coated with Al(OH)3 precipitation at 400–600°C. Al(OH)3 was coated on the surface of BCZ powders which are precursor for ZnO, in stead of calcined ZnO particles. The size and shape of BCZ powders are different after coating with Al2O3, as a result, ZnO particles

  2. Inverted Organic Photovoltaic Cells with Solution-Processed Zinc Oxide as Electron Collecting Layer

    Microsoft Academic Search

    Chunfu Zhang; Hailong You; Zhenhua Lin; Yue Hao

    2011-01-01

    In this work, inverted polymer:fullerene organic photovoltaic (OPV) cells with solution-processed zinc oxide (ZnO) as the electron collecting layer are investigated. ZnO films are prepared simply by the spin-casting of a zinc acetate dehydrate precursor solution, followed by sintering under ambient conditions. The performance of the fabricated inverted OPV cells shows a clear dependence on precursor concentration and sintering conditions.

  3. Properties of Zinc Oxide Films Prepared by Ion Beam Assisted Reactive Deposition and by RF Bias Sputtering

    Microsoft Academic Search

    Deheng Zhang

    1994-01-01

    Highly transparent conducting zinc oxide films have been deposited using ion beam assisted reactive vacuum deposition. The zinc deposition rate was controlled by adding gallium to the zinc in an open rm Al_2O_3 crucible source. Oxygen is introduced into the system via a separate controlled leak and it reacts with the zinc on the substrate. Mechanically stable, polycrystalline conducting ZnO

  4. 40 CFR 721.10488 - Cuprate, [[[[[[[ (sulfonaphthalenyl)]azo]- (substitutedphenyl)]azo...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...substitutedsulfonaphthalenyl)] azo]- substituted phenyl- substituted heteromonocycle], sodium...substitutedsulfonaphthalenyl)] azo]- substituted phenyl- substituted heteromonocycle], sodium...substitutedsulfonaphthalenyl)]azo]- substituted phenyl-substituted heteromonocycle],...

  5. 40 CFR 721.10488 - Cuprate, [[[[[[[ (sulfonaphthalenyl)]azo]-(substitutedphenyl)]azo]-(substitutedsulfonaphthalenyl...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...substitutedsulfonaphthalenyl)] azo] - substituted phenyl - substituted heteromonocycle], sodium...substitutedsulfonaphthalenyl)] azo] - substituted phenyl - substituted heteromonocycle], sodium...substitutedsulfonaphthalenyl)]azo]-substituted phenyl-substituted heteromonocycle],...

  6. Effect of zinc oxide doping on the structural and optical characterization of nanostructured molybdenum oxide films.

    PubMed

    Navas, I; Vinodkumar, R; Lethy, K J; Satyanarayana, M; Ganesan, V; Pillai, V P Mahadevan

    2009-09-01

    Undoped and zinc oxide (ZnO) doped molybdenum oxide (MoO3) films were prepared by RF magnetron sputtering technique. The influence of doping and post annealing temperature on the structural and optical properties of these films were investigated systematically using X-ray diffraction (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-VIS spectroscopy and photoluminescence spectroscopy (PL). The XRD patterns indicate the presence of stoichiometric orthorhombic alpha-MoO3 phase in the annealed (573 and 673 K) undoped molybdenum oxide films and in ZnO doped molybdenum oxide film (annealed at 673 K). The crystalline grain size in the films was investigated using Debye Scherrer formula and corrected using Hall-Williamson equation. The SEM and AFM images revealed the distribution of nano leafs, nanorods and nanograins. Nanorods of length 1.4 microm and diameter 149 nm can be observed in ZnO doped films. The optical band gap energy was found to increase with increase in annealing temperature and particle size. These nanostructures show a room temperature PL emission in the UV and visible region. PMID:19928209

  7. Formation of ZnO at zinc oxidation by near- and supercritical water under the constant electric field

    NASA Astrophysics Data System (ADS)

    Shishkin, A. V.; Sokol, M. Ya.; Shatrova, A. V.; Fedyaeva, O. N.; Vostrikov, A. A.

    2014-12-01

    The work has detected an influence of a constant electric field (up to E = 300 kV/m) on the structure of a nanocrystalline layer of zinc oxide, formed on the surface of a planar zinc anode in water under supercritical (673 K and 23 MPa) and near-critical (673 K and 17. 5 MPa) conditions. The effect of an increase of zinc oxidation rate with an increase in E is observed under supercritical conditions and is absent at near-critical ones. Increase in the field strength leads to the formation of a looser structure in the inner part of the zinc oxide layer.

  8. Biocidal effects of silver and zinc oxide nanoparticles on the bioluminescent bacteria

    NASA Astrophysics Data System (ADS)

    Taran, M. V.; Starodub, N. F.; Katsev, A. M.; Guidotti, M.; Khranovskyy, V. D.; Babanin, A. A.; Melnychuk, M. D.

    2013-11-01

    The effect of silver and zinc oxide nanoparticles in combination with alginate on bioluminescent Photobacterium leiognathi Sh1 bacteria was investigated. Silver nanoparticles were found to be more toxic than zinc oxide nanoparticles on bioluminescent bacteria. The nanoparticles and their ions released results in the same effect, however, it was absent in combination with alginate. The effective inhibiting concentration (EC50) for silver nanoparticles was found about 0.3 - 0.4 ?g mL-1, which was up to two times larger then for zinc oxide nanoparticles. The absence of sodium chloride in the tested media prevented the formation of colloidal particles of larger size and the effective inhibition concentrations of metal derivatives were lower than in the presence of sodium chloride.

  9. Synthesis and characterization of zinc oxide-neem oil-chitosan bionanocomposite for food packaging application.

    PubMed

    Sanuja, S; Agalya, A; Umapathy, M J

    2015-03-01

    Nano zinc oxide at different concentrations (0.1, 0.3 and 0.5%) and neem essential oil were incorporated into the chitosan polymer by solution cast method to enhance the properties of the bionanocomposite film. The functional groups, crystalline particle size, thermal stability and morphology were determined using FTIR, XRD, TGA and SEM, respectively. The results showed that 0.5% nano zinc oxide incorporated composite film have improved tensile strength, elongation, film thickness, film transparency and decreased water solubility, swelling and barrier properties due to the presence of neem oil and nano zinc oxide in the polymer matrix. Further antibacterial activity by well diffusion assay method was followed against Escherichia coli which were found to have good inhibition effect. In addition to this food quality application were carried against carrot and compared with the commercial film. PMID:25499891

  10. Direct in situ measurement of dissolved zinc in the presence of zinc oxide nanoparticles using anodic stripping voltammetry.

    PubMed

    Jiang, Chuanjia; Hsu-Kim, Heileen

    2014-11-01

    The wide use of metal-based nanomaterials such as zinc oxide (ZnO) nanoparticles (NPs) has generated concerns regarding their environmental and health risks. For ZnO NPs, their toxicity in aquatic systems often depends on the release of dissolved zinc species, and the rate of dissolution is influenced by water chemistry, including the presence of zinc-chelating ligands. A challenge, however, remains in quantifying the dissolution of ZnO NPs, particularly for time scales that are short enough to determine rates. This paper reports the application of anodic stripping voltammetry (ASV) with a hanging mercury drop electrode to directly measure the concentration of dissolved zinc in ZnO NP suspensions, without separation of the ZnO NPs from the aqueous phase. The effects of the deposition time and the electrochemical potential scan rate on the ASV measurement were consistent with expectations for dissolved phase measurements. The dissolved zinc concentration measured by ASV ([Zn]ASV) was compared with that measured by inductively coupled plasma mass spectrometry (ICP-MS) after ultracentrifugation ([Zn]ICP-MS), for four types of ZnO NPs with different coatings and primary particle diameters. For small ZnO NPs (4-5 nm), [Zn]ASV was 20% higher than [Zn]ICP-MS, suggesting that these small NPs contributed to the voltammetric measurement. For larger ZnO NPs (approximately 20 nm), [Zn]ASV was (79 ± 19)% of [Zn]ICP-MS, despite the high concentrations of ZnO NPs in suspension. Using ASV, the dissolution of ZnO NPs was studied, with or without Suwannee River Fulvic Acid (SRFA). Although SRFA diminished the ASV stripping current, dissolution of 20 nm ZnO NPs was significantly promoted at high fulvic acid to ZnO NP ratios. The ASV method described in this paper provides a useful tool for studying the dissolution kinetics of ZnO NPs in complex environmental matrices. PMID:25220562

  11. Efficient oxidation and destabilization of Zn(Cys)? zinc fingers by singlet oxygen.

    PubMed

    Lebrun, Vincent; Tron, Arnaud; Scarpantonio, Luca; Lebrun, Colette; Ravanat, Jean-Luc; Latour, Jean-Marc; McClenaghan, Nathan D; Sénèque, Olivier

    2014-08-25

    Singlet oxygen ((1)O2) plays an important role in oxidative stress in all types of organisms, most of them being able to mount a defense against this oxidant. Recently, zinc finger proteins have been proposed to be involved in its cellular detection but the molecular basis of this process still remains unknown. We have studied the reactivity of a Zn(Cys)4 zinc finger with (1)O2 by combinations of spectroscopic and analytical techniques, focusing on the products formed and the kinetics of the reaction. We report that the cysteines of this zinc finger are oxidized to sulfinates by (1)O2. The reaction of the ZnS4 core with (1)O2 is very fast and efficient with almost no physical quenching of (1)O2. A drastic (ca. five orders of magnitude) decrease of the Zn(2+) binding constant was observed upon oxidation. This suggests that the Zn(Cys)4 zinc finger proteins would release their Zn(2+) ion and unfold upon reaction with (1)O2 under cellular conditions and that zinc finger sites are likely targets for (1)O2. PMID:25044814

  12. Preparation and Luminescence Properties of Rare Earth Doped Nanostructured Zinc Oxide Thin Films by Sol Gel Technique

    Microsoft Academic Search

    Madzlan Aziz; Sunati Otoi

    2009-01-01

    Zinc oxide is a semiconductor cosidered promising for optoelectronic and solar cell applications. The wide bandgap nature of the zinc oxide has been a limitation in producing devices. Doping has been considered as one of the ways to reduce the band gap. In the present studies rare earth ions in the form of terbium and erbium nitatres have been introduced

  13. Nanostructured zinc oxide gas sensors by successive ionic layer adsorption and reaction method and rapid photothermal processing

    E-print Network

    Chow, Lee

    temperature. The SILAR deposited zinc oxide films have been rapid photothermal processing (RPP) at various, electrical characterization of the sensors prepared from SILAR deposited nanostructured zinc oxide thin film evaporation [22,23], and reactive vapor deposition [24]. Available online at www.sciencedirect.com Thin Solid

  14. Synthesis gas production by zinc oxide reaction with methane: elimination of greenhouse gas emission from a metallurgical plant

    Microsoft Academic Search

    H. Ale Ebrahim; E. Jamshidi

    2004-01-01

    Most natural gas based petrochemical processes consist of catalytic reforming or partial oxidation units for producing synthesis gas. This research shows that it is possible to replace these units by the reaction of zinc oxide with methane, which produces metallic zinc and synthesis gas (CO+2H2) simultaneously. Therefore, by combination of the metallurgical and petrochemical units, it is possible to eliminate

  15. Electrochemical synthesis of nanocrystalline zinc oxide and phase transformations of zinc hydroxides

    Microsoft Academic Search

    Ingrid Grobelsek; Benjamin Rabung; Mario Quilitz; Michael Veith

    Nanoscaled ZnO was synthesized by an electrochemical process using zinc or Al-alloyed zinc electrodes in an aqueous system\\u000a with acetic acid as a conductive salt. Depending on the synthetical parameters, the precipitated precursor solids were found\\u000a to consist of various compounds such as zincite, presumably ?-Zn(OH)2, ?1-Zn(OH)2, ?-Zn(OH)2, Zn5(CO3)2(OH)6 and, in case an Al-alloyed electrode was used for the synthesis,

  16. Defect Mediated Ferromagnetism in Zinc Oxide Thin Film Heterostructures

    NASA Astrophysics Data System (ADS)

    Mal, Siddhartha

    Recent developments in the field of spintronics (spin based electronics) have led to an extensive search for materials in which semiconducting properties can be integrated with magnetic properties to realize the objective of successful fabrication of spin-based devices. Since zinc oxide (ZnO) posits a promising player, it is important to elucidate the critical issues regarding the origin and nature of magnetism in ZnO thin film heterostructures. Another critical issue in the development of practical devices based on metal oxides is the integration of high quality epitaxial thin films on the existing technology based on Si (100) substrates, which requires appropriate substrate templates. The present research work is focused on the study of room temperature ferromagnetism (RTFM) caused by intrinsic defects and precise control of RTFM using thermal treatments and laser and ion irradiation. We performed a systematic study of the structural, chemical, electrical, optical and magnetic properties of undoped ZnO films grown under different conditions as well as the films that were annealed in various environments. Oxygen annealed films displayed a sequential transition from ferromagnetism to diamagnetism as a function of the annealing temperature. An increase in the green band intensity has been observed in oxygen annealed ZnO films. Reversible switching of room-temperature ferromagnetism and n-type conductivity have been demonstrated by oxygen and vacuum annealing. Detailed electron energy loss spectroscopy and secondary ion mass spectroscopy studies have been presented to rule out the possibility of external source of magnetism. Electron-Paramagnetic Resonance (EPR) measurements indicate the presence of a broad peak at g=2.01. This would be most consistent with the magnetic moment arising from the oxygen vacancies (g=1.996), although the possible contribution from Zn vacancies (g=2.013) cannot be entirely ruled out. The magnetic moment in these films may arise from the unpaired 2p electrons at the O sites surrounding the zinc vacancy with each nearest-neighbor O atom carrying a magnetic moment ranging from 0.49 to 0.74 muB and the oxygen vacancies may provide the coupling mechanism. Results of EPR study are found to be in agreement with the results of magnetization and conductivity measurements. The effect of UV Excimer laser irradiation on electrical, magnetic and optical properties of ZnO thin films has been studied. Increases in the electrical conductivity and magnetic moment have been controlled precisely with the number of laser pulses, without altering the Wurtzite crystal structure and n-type semiconducting characteristics of the films. The laser-induced ferromagnetism and concomitant conductivity enhancement can be reversed through subsequent thermal annealing. It has also been shown that heavy swift ion irradiation can also create room temperature ferromagnetism in oxygen annealed insulating ZnO films. Saturation magnetic moments increase with increasing ion dose. A systematic study of the thickness dependency of the structural, electrical and magnetic properties of undoped ZnO thin films has been presented. The role of film/substrate interface in magnetism has been discussed. It has been shown by EPR study and oxidative quenching of ferromagnetism that oxygen vacancies are the key mediating defect in ferromagnetic ZnO thin films. Finally growth of epitaxial ZnO on Si (100) substrates has been achieved using a titanium nitride (TiN)/strontium titanate (STO) template layer. It has been shown that TiN can be grown epitaxially on silicon substrates. It was observed that, crystallographic orientations of ZnO on STO can be controlled by the oxygen pressure and substrate temperature during the deposition. The detailed x-ray diffraction, transmission electron microscopy (TEM), electrical and magnetic characterization results for the deposited films have been carried out. The above mentioned methods provide a controlled way to study changes in magnetic, electrical and optical properties of ZnO films and determine the mechanis

  17. Controlled Growth of one-dimensional zinc oxide nanostructures in the pulsed electrodeposition mode

    SciTech Connect

    Klochko, N. P., E-mail: klochko_np@mail.ru; Khrypunov, G. S. [National Technical University 'Kharkiv Polytechnical Institute' (Ukraine); Myagchenko, Yu. O.; Melnychuk, E. E. [Taras Shevchenko National University of Kyiv (Ukraine); Kopach, V. R.; Klepikova, E. S.; Lyubov, V. M. [National Technical University 'Kharkiv Polytechnical Institute' (Ukraine); Kopach, A. V.

    2012-06-15

    Zinc oxide nanostructures are objects of study in the field of optoelectronics, solar power engineering, nanosensorics, and catalysis. For the purpose of the controlled growth of one-dimensional submicrometer zinc oxide structures in the pulsed electrodeposition mode, the effect of the pulse electrolysis parameters on the morphology of ZnO layers, their optical properties, and structural and substructural characteristics is determined using X-ray diffraction, optical spectrophotometry, and atomic-force microscopy. The possibility of fabricating arrays of ZnO nanowires with different geometrical shapes, perpendicular to the substrate surface, by varying the frequency of cathode-substrate potential pulses is shown.

  18. Zinc regulates iNOS-derived nitric oxide formation in endothelial cells

    PubMed Central

    Cortese-Krott, Miriam M.; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.; Suschek, Christoph V.

    2014-01-01

    Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-?B transactivation activity, as determined by a decrease in both NF-?B-driven luciferase reporter activity and expression of NF-?B target genes, including cyclooxygenase 2 and IL-1?. However, zinc did not affect NF-?B translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-?B-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation. PMID:25180171

  19. Migration of point defects and a defect pair in zinc oxide using the dimer method

    SciTech Connect

    Chen, Dong; Gao, Fei; Dong, Mingdong; Liu, Bo

    2012-09-24

    The migration mechanism and the minimum energy path of vacancies, interstitials and an interstitial-vacancy pair in zinc oxide have been studied by the dimer method. The in-plane and out-of-plane migrations of zinc and oxygen vacancies are found to be anisotropic. The kick-out mechanism is energetically preferred to zinc and oxygen interstitials that can easily migrate through the ZnO crystal lattice. In addition, the migration process of an interstitial-vacancy pair as a complex of an octahedral oxygen interstitial and a zinc vacancy is dominated by an oxygen interstitial/zinc vacancy successive migration. The energy barriers indicate that the existence of oxygen interstitial in the defect pair can promote the mobility of zinc vacancy, whereas the migration of oxygen interstitial is slowed down due to the presence of zinc vacancy. In the end, we show a possible migration path of the interstitial-vacancy pair that can be dissociated through a set of displacement movements.

  20. Azo-functionalized microporous organic polymers: synthesis and applications in CO2 capture and conversion.

    PubMed

    Yang, Zhenzhen; Zhang, Hongye; Yu, Bo; Zhao, Yanfei; Ma, Zhishuang; Ji, Guipeng; Han, Buxing; Liu, Zhimin

    2015-07-25

    Azo-functionalized MOPs (Azo-MOPs) were synthesized via oxidative polymerization of aromatic amines catalyzed by t-BuOCl/NaI (25 °C, 1 h, yield: >95%), which displayed an excellent coordinating ability with a Ru complex. The resulting Ru-coordinated Azo-MOPs displayed high CO2 capacity and high performances for catalyzing the methylation of amines with CO2 under low pressure (0.5 MPa). PMID:26097913

  1. Zinc stable isotope fractionation upon accelerated oxidative weathering of sulfidic mine waste.

    PubMed

    Matthies, R; Krahé, L; Blowes, D W

    2014-07-15

    Accelerated oxidative weathering in a reaction cell (ASTM D 5744 standard protocol) was performed over a 33 week period on well characterized, sulfidic mine waste from the Kidd Creek Cu-Zn volcanogenic massive sulfide deposit, Canada. The cell leachate was monitored for physicochemical parameters, ion concentrations and stable isotope ratios of zinc. Filtered zinc concentrations (<0.45 ?m) in the leachate ranged between 4.5 mg L(-1) and 1.9 g L(-1)-potentially controlled by pH, mineral solubility kinetics and (de)sorption processes. The zinc stable isotope ratios varied mass-dependently within +0.1 and +0.52‰ relative to IRMM 3702, and were strongly dependent on the pH (rpH-d66Zn=0.65, p<0.005, n=31). At a pH below 5, zinc mobilization was governed by sphalerite oxidation and hydroxide dissolution-pointing to the isotope signature of sphalerite (+0.1 to +0.16‰). Desorption processes resulted in enrichment of (66)Zn in the leachate reaching a maximum offset of +0.32‰ compared to the proposed sphalerite isotope signature. Over a period characterized by pH=6.1 ± 0.6, isotope ratios were significantly more enriched in (66)Zn with an offset of ? 0.23‰ compared to sphalerite, suggesting that zinc release may have been derived from a second zinc source, such as carbonate minerals, which compose 8 wt.% of the tailings. This preliminary study confirms the benefit of applying zinc isotopes alongside standard monitoring parameters to track principal zinc sources and weathering processes in complex multi-phase matrices. PMID:24784733

  2. Magnetic Mn substituted cobalt zinc ferrite systems: Structural, electrical and magnetic properties and their role in photo-catalytic degradation of methyl orange azo dye

    NASA Astrophysics Data System (ADS)

    Bhukal, Santosh; Bansal, S.; Singhal, Sonal

    2014-07-01

    The present work focuses on the effect of replacement of Fe3+ ions by the Mn3+ ions in cobalt zinc ferrites (Co0.6Zn0.4MnxFe2-xO4 (0.2, 0.4, 0.6, 0.8 and 1.0) on the structural, magnetic, electrical and catalytic properties. Powder X-ray diffraction studies confirmed that all the samples possessed cubic spinel structure with Fd-3m space groups. The saturation magnetization was found to decrease with increase in Mn3+ ions concentration. The drift mobility of all compositions was found to decrease with increase in temperature which could be attributed to the semiconductor nature of nanoferrites. The photo-catalytic activity of all the nanoferrites was evaluated by the degradation of methyl orange dye and it was observed that the degradation of methyl orange dye was enhanced with increase in Mn3+ ions concentration from 0.2 to 1.0. This might be due to the octahedral site preference and higher redox potential of manganese ion as compared those of iron.

  3. Comparison of several advanced oxidation processes for the decolorization of Reactive Red 120 azo dye in aqueous solution

    Microsoft Academic Search

    Erdal Kusvuran; Osman Gulnaz; Sibel Irmak; Osman M. Atanur; H. Ibrahim Yavuz; Oktay Erbatur

    2004-01-01

    In this study UV\\/TiO2, electro-Fenton (EF), wet-air oxidation (WAO), and UV\\/electro-Fenton (UV\\/EF) advanced oxidation processes (AOPs) have been applied to degrade Reactive Red 120 (RR120) dye in aqueous solution. The most efficient method on decolorization and mineralization of RR120 was observed to be WAO process. Photocatalytic degradation of RR120 by UV\\/TiO2 have been studied at different pH values. At pH

  4. Leaching of oxidic zinc materials with chlorine and chlorine hydrate

    Microsoft Academic Search

    B. K. Thomas; D. J. Fray

    1981-01-01

    Low grade zinc ores and residues were leached in chlorine water and chlorine hydrate water mixtures. It was found that the rate of leaching Adrar ore and Electric Arc Furnace dust obeyed a shrinking core diffusion model, whereas, the rate of leaching of Turkish ore appeared to be controlled by a surface reaction. In all cases, lead leached with the

  5. Supercritical antisolvent precipitation of nanoparticles of a zinc oxide precursor

    Microsoft Academic Search

    E Reverchon; G Della Porta; D Sannino; P Ciambelli

    1999-01-01

    Supercritical antisolvent (SAS) precipitation has been applied to the production of zinc acetate with the aim of evaluating the applicability of this new process to the production of controlled size nanoparticles of catalyst precursors. SAS process is based on the large volumetric expansion of the liquid solvent induced by the fast diffusion of the antisolvent inside the liquid phase. The

  6. Zinc-catalyzed copolymerization of carbon dioxide and propylene oxide

    E-print Network

    Katsurao, Takumi

    1994-01-01

    dioxide has recently been paid attention in the field of extraction, separation, and reaction medium, its aptitude for both a reaction solvent and a reactant was examined in zinc glutarate-catalyzed reactions. As a result, it was proved that supercritical...

  7. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...substance identified generically as lithium salt of sulfophenyl azo phenyl azo...

  8. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...substance identified generically as lithium salt of sulfophenyl azo phenyl azo...

  9. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo disulfostilbene...substance identified generically as lithium salt of sulfophenyl azo phenyl azo...

  10. Role of iron surface oxidation layers in decomposition of azo-dye water pollutants in weak acidic solutions

    Microsoft Academic Search

    Jerzy A. Mielczarski; Gonzalo Montes Atenas; Ela Mielczarski

    2005-01-01

    While decomposition of water pollutants in the presence of metallic iron can be strongly influenced by the nature and structure of the iron surface layer, the composition and structure of the layer produced and transformed in the decomposition process, have been meagerly investigated. The studies presented here establish strong relationships between the composition and structure of the iron oxidized surface

  11. Investigation of zinc oxide doped with metal impurities for use as thin film conductive phosphors 

    E-print Network

    Evatt, Steven R.

    1994-01-01

    of a viable flat panel display, low voltage, conductive phosphors which emit blue, red, and green light will be required for the field emission technology. This thesis examines zinc oxide (ZnO) based thin ( ) phosphors for such an application. ZnO is a...

  12. Processing and Characterization of P-Type Doped Zinc Oxide Thin Films 

    E-print Network

    Myers, Michelle Anne

    2013-03-18

    Applications of zinc oxide (ZnO) for optoelectronic devices, including light emitting diodes, semiconductor lasers, and solar cells have not yet been realized due to the lack of high-quality p-type ZnO. In the research presented herein, pulsed laser...

  13. Zinc Oxide Nanowires Low-Temperature Wafer-Scale Production of

    E-print Network

    Yang, Peidong

    Zinc Oxide Nanowires Low-Temperature Wafer-Scale Production of ZnO Nanowire Arrays** Lori E. Greene aqueous conditions. We present data for arrays on four-inch (ca. 10 cm) silicon wafers and two) wafer to form a 50­200-nm thick film of crystal seeds. Between coatings, the wafer was annealed at 1508C

  14. Surface Plasmon Resonance (SPR) Electron and Energy Transfer in Noble Metal-Zinc Oxide Composite Nanocrystals

    E-print Network

    Kim, Tae-Geun

    Surface Plasmon Resonance (SPR) Electron and Energy Transfer in Noble Metal-Zinc Oxide Composite tagging, drug delivery, chemical sensors, catalysts, and photovoltaics.9­11 ZnO is a wide energy band gap is beneficial to light absorption/emission or electron transfer. Nanometer-scale noble metals have been

  15. Synthesis of carbon and zinc oxide nanotubes and their applications in electronic devices

    Microsoft Academic Search

    Kaikun Yang

    2010-01-01

    Nanostructured materials, including single and multiwalled carbon nanotubes (SWCNTs and MWCNTs), zinc oxide (ZnO) nanotubes (NTs) and graphene, have been successfully synthesized using chemical vapor deposition (CVD) or wet chemistry routines, and used to fabricate nanoelectronic and optoelectronic devices, including field effect transistors (FETs) and heterojunction solar cells. Both nanomaterials properties and devices performances have been characterized. Vertically aligned multiwalled

  16. Fabrication of Indium Gallium Zinc Oxide (IGZO) TFTs Using a Solution-Based Process

    Microsoft Academic Search

    Mi Sun Park; Doo Hyoung Lee; Eun Jin Bae; Dae-Hwan Kim; Jin Gyu Kang; Dae-Ho Son; Si Ok Ryu

    2010-01-01

    Highly transparent (?90% in the visible region) indium gallium zinc oxide (IGZO) thin films were deposited using a spin coating process with a newly developed precursor solution. Acetonitrile was used as the solvent in the preparation of the metal halide precursor solution for the deposition of the IGZO thin films. Ethylene glycol was added to the solvent at four different

  17. Hybrid p-type copper sulphide coated zinc oxide nanowire heterojunction device

    NASA Astrophysics Data System (ADS)

    Bu, Ian Y. Y.

    2014-11-01

    A novel heterojunction was formed between zinc oxide nanowires and copper sulphide. The proposed device was fabricated by a fully solution-based process that consists of hydrothermal growth method and chemical bath deposition. The optoelectronic properties of the proposed heterojunction were evaluated by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, UV-vis spectroscopy, photoluminescence measurements and current voltage characteristics.

  18. Vapor-phase growth of transparent zinc oxide ceramics with c -axis orientation

    SciTech Connect

    Noritake, F.; Yamamoto, N.; Horiguchi, Y. (Dept. of Research and Development, Lion Corporation, Tokyo, 132 (JP)); Fujitsu, S.; Koumoto, K. (Dept. of Industrial Chemistry, Faculty of Engineering, Univ. of Tokyo, Tokyo 113 (JP)); Yanagida, H. (Research Center for Advanced Science and Technology, Univ. of Tokyo, Tokyo 153 (JP))

    1991-01-01

    Large transparent specimens of polycrystalline zinc oxide with c-axis orientation have been prepared by the vapor transport method. Optical transmittance is 80% to 90% at 800 nm. X-ray diffraction peaks from faces other than (001) are negligible.

  19. Degradation of wastewaters containing organic dyes photocatalysed by zinc oxide: a review

    Microsoft Academic Search

    Sze-Mun Lam; Jin-Chung Sin; Ahmad Zuhairi Abdullah; Abdul Rahman Mohamed

    2012-01-01

    Organic dyes are one of the largest groups of pollutants discharged into wastewaters from textile and other industrial processes. Owing to the potential toxicity of the dyes and their visibility in surface waters, removal and degradation of them have attracted considerable attention worldwide. A wide range of approaches have been developed, amongst which the heterogeneous photocatalysis involving zinc oxide (ZnO)

  20. Preparation, characterization, and functional analysis of zinc oxide nanoparticle-coated cotton fabric for antibacterial efficacy

    Microsoft Academic Search

    Anita Asokan Subash; Koushik Venkatraman Chandramouli; T. Ramachandran; R. Rajendran; Mahalakshmi Muthusamy

    2012-01-01

    Nanotechnology is an emerging interdisciplinary technology and nanostructures capable of enhancing the physical properties of conventional textiles in areas such as antimicrobial properties, water repellence, soil resistance, antistatic, anti-infrared and flame-retardant properties, dye ability, color fastness, and strength of textile materials. The studies were carried out in order to fine tune the preparation of zinc oxide nanoparticles (NPs) for special

  1. Preparation, characterization, and functional analysis of zinc oxide nanoparticle-coated cotton fabric for antibacterial efficacy

    Microsoft Academic Search

    Anita Asokan Subash; Koushik Venkatraman Chandramouli; T. Ramachandran; R. Rajendran; Mahalakshmi Muthusamy

    2011-01-01

    Nanotechnology is an emerging interdisciplinary technology and nanostructures capable of enhancing the physical properties of conventional textiles in areas such as antimicrobial properties, water repellence, soil resistance, antistatic, anti-infrared and flame-retardant properties, dye ability, color fastness, and strength of textile materials. The studies were carried out in order to fine tune the preparation of zinc oxide nanoparticles (NPs) for special

  2. Subcooled flow boiling heat transfer of dilute alumina, zinc oxide, and diamond nanofluids at atmospheric pressure

    Microsoft Academic Search

    Sung Joong Kim; Tom McKrell; Jacopo Buongiorno; Lin-wen Hu

    2010-01-01

    A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In a previous paper, we reported on subcooled flow boiling CHF experiments with low concentrations of alumina, zinc oxide, and diamond nanoparticles in water (?0.1%

  3. Study on the bulk junction type organic solar cells with double zinc oxide layer

    Microsoft Academic Search

    Xiaohui Ju; Wei Feng; Varutt Kittichungchit; Tetsuro Hori; Hiroki Moritou; Akihiko Fujii; Masanori Ozaki

    2009-01-01

    The optical and photovoltaic properties of a photovoltaic cell with a structure of indium–tin oxide (ITO)\\/double ZnO\\/poly(3-hexylthiophene) (PAT6):PCBM\\/Ag have been investigated. The double layer ZnO was a composite of a sputtered ZnO layer and oriented zinc oxide nanopillars layer which was fabricated by a new method at low temperature (343 K). It is concluded that the double layer ZnO plays an

  4. Cobalt-phosphate-assisted photoelectrochemical water oxidation by arrays of molybdenum-doped zinc oxide nanorods.

    PubMed

    Lin, Yan-Gu; Hsu, Yu-Kuei; Chen, Ying-Chu; Lee, Bing-Wei; Hwang, Jih-Shang; Chen, Li-Chyong; Chen, Kuei-Hsien

    2014-09-01

    We report the first demonstration of cobalt phosphate (Co-Pi)-assisted molybdenum-doped zinc oxide nanorods (Zn(1-x)Mo(x)O NRs) as visible-light-sensitive photofunctional electrodes to fundamentally improve the performance of ZnO NRs for photoelectrochemical (PEC) water splitting. A maximum photoconversion efficiency as high as 1.05% was achieved, at a photocurrent density of 1.4?mA?cm(-2). More importantly, in addition to achieve the maximum incident photon to current conversion efficiency (IPCE) value of 86%, it could be noted that the IPCE of Zn(1-x)Mo(x)O photoanodes under monochromatic illumination (450?nm) is up to 12%. Our PEC performances are comparable to those of many oxide-based photoanodes in recent reports. The improvement in photoactivity of PEC water splitting may be attributed to the enhanced visible-light absorption, increased charge-carrier densities, and improved interfacial charge-transfer kinetics due to the combined effect of molybdenum incorporation and Co-Pi modification, contributing to photocatalysis. The new design of constructing highly photoactive Co-Pi-assisted Zn(1-x)Mo(x)O photoanodes enriches knowledge on doping and advances the development of high-efficiency photoelectrodes in the solar-hydrogen field. PMID:25044962

  5. Novel synthetic methodology for controlling the orientation of zinc oxide nanowires grown on silicon oxide substrates.

    PubMed

    Cho, Jinhyun; Salleh, Najah; Blanco, Carlos; Yang, Sungwoo; Lee, Chul-Jin; Kim, Young-Woo; Kim, Jungsang; Liu, Jie

    2014-04-01

    This study presents a simple method to reproducibly obtain well-aligned vertical ZnO nanowire arrays on silicon oxide (SiOx) substrates using seed crystals made from a mixture of ammonium hydroxide (NH4OH) and zinc acetate (Zn(O2CCH3)2) solution. In comparison, high levels of OH(-) concentration obtained using NaOH or KOH solutions lead to incorporation of Na or K atoms into the seed crystals, destroying the c-axis alignment of the seeds and resulting in the growth of misaligned nanowires. The use of NH4OH eliminates the metallic impurities and ensures aligned nanowire growth in a wide range of OH(-) concentrations in the seed solution. The difference of crystalline orientations between NH4OH- and NaOH-based seeds is directly observed by lattice-resolved images and electron diffraction patterns using a transmission electron microscope (TEM). This study obviously suggests that metallic impurities incorporated into the ZnO nanocrystal seeds are one of the factors that generates the misaligned ZnO nanowires. This method also enables the use of silicon oxide substrates for the growth of vertically aligned nanowires, making ZnO nanostructures compatible with widely used silicon fabrication technology. PMID:24584438

  6. Oxidation of 8-Oxo-7,8-dihydro-2?-deoxyguanosine by Oxyl Radicals Produced by Photolysis of Azo Compounds

    PubMed Central

    Shao, Jie; Geacintov, Nicholas E.; Shafirovich, Vladimir

    2010-01-01

    Oxidative damage to 8-oxo-7,8-dihydroguanine (8-oxoG) bases initiated by photolysis of the water-soluble radical generator 2,2?-azobis(2-amidinopropane) dihydrochloride (AAPH) has been investigated by laser kinetic spectroscopy. In neutral oxygenated aqueous solutions, 355 nm photolysis of AAPH initiates efficient one-electron oxidation of the 8-oxodG nucleosides directly monitored by the appearance of the 8-oxodG•+/8-oxodG(-H)• radicals at 325 nm. The reaction kinetics are consisted with a mechanism that includes the transformation of the 2-amidinoprop-2-peroxyl radicals (ROO•) derived from photolysis of AAPH to more reactive 2-amidinoprop-2-oxyl radicals (RO•), which directly react with the 8-oxoG bases. The major pathways for the formation of end products of 8-oxoG oxidation include the combination of the 8-oxodG•+/8-oxodG(-H)• radicals with superoxide (O2•?) and ROO• radicals in approximately 1:1 ratios, as demonstrated by experiments with Cu, Zn superoxide dismutase to form dehydroguanidinohydantoin (Ghox) derivatives. This mechanism was confirmed by analysis of the end products produced by the oxidation of two substrates: (1) the 8-oxoG derivative 2?,3?,5?-tri-O-acetylguanosine (tri-O-Ac-G), and (2) the 5?-d(CCATC[8-oxoG]CTACC) sequence. The major products isolated by HPLC and identified by mass spectrometry methods were the tri-O-Ac-Ghox and 5?-d(CCATC[Ghox]CTACC products. PMID:20408566

  7. Infrared spectroscopy of zinc oxide and magnesium nanostructures

    Microsoft Academic Search

    Win Maw Hlaing Oo

    2007-01-01

    Impurities in ZnO nanoparticles and Mg nanorods were investigated. ZnO nanoparticles were prepared by a reaction of zinc acetate and sodium hydrogen carbonate. The presence and source of CO2 impurities in ZnO nanoparticles were studied by infrared (IR) spectroscopy. Isotopic substitution was used to verify the vibrational frequency assignment. Isochronal annealing experiments were performed to study the formation and stability

  8. Leaching of oxidic zinc materials with chlorine and chlorine hydrate

    Microsoft Academic Search

    B. K. Thomas; D. J. Fray

    1981-01-01

    Low grade zinc ores and residues were leached in chlorine water and chlorine hydrate water mixtures. It was found that the\\u000a rate of leaching Adrar ore and Electric Arc Furnace dust obeyed a shrinking core diffusion model, whereas, the rate of leaching\\u000a of Turkish ore appeared to be controlled by a surface reaction. In all cases, lead leached with the

  9. Si/ZnO nanorods/Ag/AZO structures as promising photovoltaic plasmonic cells

    NASA Astrophysics Data System (ADS)

    Placzek-Popko, E.; Gwozdz, K.; Gumienny, Z.; Zielony, E.; Pietruszka, R.; Witkowski, B. S.; Wachnicki, ?.; Gieraltowska, S.; Godlewski, M.; Jacak, W.; Chang, Liann-Be

    2015-05-01

    The test structures for photovoltaic (PV) applications based on zinc oxide nanorods (NRs) that were grown using a low-temperature hydrothermal method on p-type silicon substrates (100) covered with Ag nanoparticles (NPs) were studied. The NPs of three different diameters, i.e., 5-10 nm, 20-30 nm, and 50-60 nm, were deposited using a sputtering method. The morphology and crystallinity of the structures were confirmed by scanning electron microscopy and Raman spectroscopy. It was found that the nanorods have a hexagonal wurtzite structure. An analysis of the Raman and photoluminescence spectra permitted the identification of the surface modes at 476 cm-1 and 561 cm-1. The presence of these modes is evidence of nanorods oriented along the wurtzite c-axis. The NRs with Ag NPs were covered with a ZnO:Al (AZO) layer that was grown using the low-temperature atomic layer deposition technique. The AZO layer served as a transparent ohmic contact to the ZnO nanorods. The applicability of the AZO layer for this purpose and the influence of the Ag nanoparticles on the effectiveness of light acquisition by such prepared PV cells were checked by reflectance and transmittance measurements of the AZO/glass and AZO/NPs/glass reference structures. Based on these studies, the high-energy transmittance edge was assigned to the ZnO energy gap, although it is blueshifted with respect to the bulk ZnO energy gap because of Al doping. It was also shown that the most optimal PV performance is obtained from a structure containing Ag nanoparticles with a diameter of 20-30 nm. This result is confirmed by the current-voltage measurements performed with 1-sun illumination. The structures show a plasmonic effect within the short wavelength range: the PV response for the structure with Ag nanoparticles is twice that of the structure without the nanoparticles. However, the influence of the Ag nanoparticle diameters on the plasmonic effect is ambiguous.

  10. Aluminum-doped zinc oxide (ZnO:Al) thin films deposited on glass substrates by chemical spray starting from zinc pentanedionate and aluminum chloride

    Microsoft Academic Search

    M. de la L. Olvera; A. Maldonado; J. Vega-Pérez; O. Solorza-Feria

    2010-01-01

    Aluminum-doped zinc oxide thin films (ZnO:Al) were deposited on sodalime glass substrates by the chemical spray technique, starting from zinc pentanedionate and aluminum chloride. The effect of the substrate temperature on the structural, morphological, optical, and electrical properties was studied. A constant [Al]\\/[Zn]=3at.% ratio was used. As the substrate temperature increases, the electrical resistance decreases, reaching a minimum value, in

  11. Surface morphology and electrical transport of rapid thermal annealed chromium-doped indium zinc oxides: The influence of zinc interstitials and out-diffusion

    SciTech Connect

    Hsu, C. Y., E-mail: cyhsu00@gmail.com [Physics Department, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China)

    2013-12-09

    We investigate the complex impedance (CI) spectra of chromium-doped indium zinc oxide (CIZO) films with different rapid thermal annealing (RTA) temperatures. The CI spectra drawn from the impedance contributions of Zn-O and In-O bondings in CIZO films were analyzed by two sets of parallel resistance and capacitance components in series. The result demonstrates that zinc interstitials controls electron concentration and transition of electrical transport from semiconducting to metallic. At higher RTA temperature, high-density zinc interstitial promotes Zn atom diffusion from the surface, modifying surface morphology.

  12. Radiation Stability of Zinc Oxide Pigment Modified by Zirconium Oxide and Aluminum Oxide Nanopowders

    SciTech Connect

    Mikhailov, M. M. [Tomsk State University of Control Systems and Radioelectronics, 40 Lenina Prospect, Tomsk, Russia 634050 (Russian Federation); Harbin Institute of Technology, Harbin (China); Neshchimenko, V. V. [Amur State University, Ignatyevskoye Shosse 21, Blagoveshchensk, Amur region, 675027 (Russian Federation); Li Chundong [Harbin Institute of Technology, Harbin (China)

    2009-01-05

    The effect on the reflective spectra of heat treatment and modification of ZnO pigments by 1-30 wt.%ZrO{sub 2} and Al{sub 2}O{sub 3} nanoparticles has been investigated before and after irradiation by 100 keV protons with a fluence of 5x10{sup 15} cm{sup -2}. It is established that with the optimum concentration of 5 wt.% nanoparticles and the temperature of 800 deg. C a 20% increase in the radiation stability is observed for the modified ZnO pigment in comparison with the not modified pigment. The decrease of absorption in the modified pigments is determined by the decrease of the intensity of the absorption bands of the zinc vacancies (V{sub zn}{sup -}), oxygen vacancies (V{sub o}{sup +}) and donor-acceptor couples (V{sub zn}-{sup -}Zn{sub i}{sup 0})

  13. Water oxidation catalysts and pH sensors based on azo-conjugated iridium/rhodium motifs.

    PubMed

    Yu, Wei-Bin; He, Qing-Ya; Shi, Hua-Tian; Pan, Yan; Wei, Xianwen

    2014-08-28

    Herein we report the molecular structures and electronic properties of ionic, hydrophobic half-sandwich complexes with formula [?(5)-Cp*Ir(L)(Cl)](OTf) (), [?(5)-Cp*Rh(L)(Cl)](OTf) (), [?(5)-Cp*Ir(L)(H2O)](OTf)2 () and [?(5)-Cp*Rh(L)(H2O)](OTf)2 (), where L is 1-(2-pyridylazo)-2-naphthol. The electrochemical properties of these complexes have been investigated, and they displayed good electronic properties for use as water oxidation catalysts. Interestingly, the color of their solutions is unambiguously transformed from brown to green at pH = 12; the color changes of , and are especially apparent. For this reason, their use as pH sensors for detecting solution pH values can be explored. PMID:24828473

  14. Bimetallic zinc complex--active species in coupling of terminal alkynes with aldehydes via nucleophilic addition/Oppenauer oxidation.

    PubMed

    Yuan, Jiwen; Wang, Jing; Zhang, Guanghui; Liu, Chao; Qi, Xiaotian; Lan, Yu; Miller, Jeffrey T; Kropf, A Jeremy; Bunel, Emilio E; Lei, Aiwen

    2015-01-11

    A mechanistic study on the zinc-promoted coupling between aldehydes and terminal alkynes via nucleophilic addition/Oppenauer oxidation using operando IR, XANES/EXAFS techniques and DFT calculations was demonstrated. It was determined that a bimetallic zinc complex was the active species. PMID:25413491

  15. Evaluation of growth and biochemical indicators of Salvinia natans exposed to zinc oxide nanoparticles and zinc accumulation in plants.

    PubMed

    Hu, Changwei; Liu, Xu; Li, Xiuling; Zhao, Yongjun

    2014-01-01

    The adverse effects of zinc oxide nanoparticles (ZnO NPs) with an average diameter of 25 nm on the aquatic plant Salvinia natans (L.) All. were determined. Growth, superoxide dismutase (SOD) activity, catalase (CAT) activity, peroxidase activity, and chlorophyll content of the plants were measured after 7 days of exposure to different concentrations of ZnO NPs (1 to 50 mg L(-1)). The particle distribution in the culture medium (without plants) during the first 24 h was determined using a Nanotrac 250 particle analyzer. We also investigated the zinc accumulation in leaves and roots of the plant after 7 days of exposure. Exposure to 50 mg L(-1) ZnO NPs significantly increased SOD and CAT activities (P??0.05). NPs completely precipitated at the bottom of the container at 8 h except for the portions of dissolution and aggregation on the roots. ZnO NPs at a concentration of 50 mg L(-1) can adversely affect S. natans, and their stress is affected by their aggregation and dissolution. PMID:23860598

  16. Paramagnetic dysprosium-doped zinc oxide thin films grown by pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    Lo, Fang-Yuh; Ting, Yi-Chieh; Chou, Kai-Chieh; Hsieh, Tsung-Chun; Ye, Cin-Wei; Hsu, Yung-Yuan; Chern, Ming-Yau; Liu, Hsiang-Lin

    2015-06-01

    Dysprosium(Dy)-doped zinc oxide (Dy:ZnO) thin films were fabricated on c-oriented sapphire substrate by pulsed-laser deposition with doping concentration ranging from 1 to 10 at. %. X-ray diffraction (XRD), Raman-scattering, optical transmission spectroscopy, and spectroscopic ellipsometry revealed incorporation of Dy into ZnO host matrix without secondary phase. Solubility limit of Dy in ZnO under our deposition condition was between 5 and 10 at. % according to XRD and Raman-scattering characteristics. Optical transmission spectroscopy and spectroscopic ellipsometry also showed increase in both transmittance in ultraviolet regime and band gap of Dy:ZnO with increasing Dy density. Zinc vacancies and zinc interstitials were identified by photoluminescence spectroscopy as the defects accompanied with Dy incorporation. Magnetic investigations with a superconducting quantum interference device showed paramagnetism without long-range order for all Dy:ZnO thin films, and a hint of antiferromagnetic alignment of Dy impurities was observed at highest doping concentration—indicating the overall contribution of zinc vacancies and zinc interstitials to magnetic interaction was either neutral or toward antiferromagnetic. From our investigations, Dy:ZnO thin films could be useful for spin alignment and magneto-optical applications.

  17. Kinetics of decolorization and mineralization of reactive azo dyes in aqueous solution by the UV\\/H 2O 2 oxidation

    Microsoft Academic Search

    Mariana Neamtu; Ilie Siminiceanu; Ayfer Yediler; Antonius Kettrup

    2002-01-01

    The photodegradation of three non hydrolysed reactive azo dyes (Reactive red 120, Reactive black 5, Reactive yellow 84) in aqueous solution was investigated in a laboratory-scale batch photoreactor equipped with an immersed low-pressure mercury lamp. Six different doses of hydrogen peroxide, at constant initial concentration of the substrate (100 mg\\/l) were used. The pseudo-first order rate constants have been calculated

  18. Influence of Roughness Surfaces on Third-Order Nonlinear-Optical Properties of Erbium-Doped Zinc Oxide Thin Films

    Microsoft Academic Search

    M. Alaoui Lamrani; M. El Jouad; M. Addou; T. El Habbani; N. Fellahi; K. Bahedi; M. Ebn Touhami; Z. Essaidi; Z. Sofiani; B. Sahraoui; A. Meghea; I. Rau

    2008-01-01

    Zinc oxide (ZnO) and erbium-doped zinc oxide (ZnO:Er) thin films were deposited on heated glass substrates using the spray pyrolysis technique. Third-order nonlinear-optical properties of the thin films have been investigated using the third harmonic generation (THG) at wavelength of 1064 nm in picosecond regime. The dependence of third-order nonlinear susceptibility and transmission characteristics on the thin films roughness has been

  19. Identification of intermediates and ecotoxicity assessment during the UV/H2O2 oxidation of azo dye Reactive Orange 16.

    PubMed

    Mitrovi?, Jelena Z; Radovi?, Miljana D; An?elkovi?, Tatjana D; Boji?, Danijela V; Boji?, Aleksandar Lj

    2014-01-01

    Degradation of azo dye Reactive Orange 16, a widely used textile dye, was carried out with UV light in the presence of H2O2. The experiments were conducted in the batch mode using low-pressure mercury lamps, emitting at 253.7 nm. Liquid-chromatography tandem mass spectrometry (LC/MS/MS) and high resolution mass spectrometry (FT-ICR) were employed in order to identify some of degradation products as well as to suggest possible degradation pathways. According to the mass spectrum characterization of RO16 dye and MS(n) fragmentation (up to MS(4)), its possible fragmentation pattern was proposed. The results revealed that degradation occurred mainly via hydroxylation, cleavage of the C?S bond between the aromatic ring and the sulfonate group, cleavage of the azo bond, cleavage of the C?N bond between azo group and naphthalene ring and aromatic ring opening. Toxicity test with marine photobacterium Vibrio Fisheri was performed to consider whether or not the UV/H2O2 treatment of RO16 dye results in the products with enhanced toxicity for aquatic life. PMID:24410680

  20. Conjugated phosphonic acid modified zinc oxide electron transport layers for improved performance in organic solar cells.

    PubMed

    Braid, Jennifer L; Koldemir, Unsal; Sellinger, Alan; Collins, Reuben T; Furtak, Thomas E; Olson, Dana C

    2014-11-12

    Phosphonic acid modification of zinc oxide (ZnO) electron transport layers in inverted P3HT:ICBA solar cells was studied to determine the effect of conjugated linkages between the aromatic and phosphonic acid attachment groups. For example, zinc oxide treated with 2,6-difluorophenylvinylphosphonic acid, having a conjugated vinyl group connecting the aromatic moiety to the phosphonic acid group, showed a 0.78 eV decrease in the effective work function versus unmodified ZnO, whereas nonconjugated 2,6-difluorophenylethylphosphonic acid resulted in a 0.57 eV decrease, as measured by Kelvin probe. This resulted in an average power conversion efficiency of 5.89% for conjugated 2,6-difluorophenyvinylphosphonic acid modified solar cells, an improvement over unmodified (5.24%) and nonconjugated phosphonic acid modified devices (5.64%), indicating the importance of the conjugated linkage. PMID:25329245

  1. Synthesis and dielectric properties of zinc oxide nanoparticles using a biotemplate

    SciTech Connect

    P, Sharmila P, E-mail: sharmilavishram@gmail.com [Sree Narayana College, Kollam, Kerala, India and T.K Madhva Memorial College, Nangiarkulungara, Alapuzha, Kerala (India); Tharayil, Nisha J., E-mail: nishajohntharayil@gmail.com [Sree Narayana College for Women Kollam, Kerala (India)

    2014-10-15

    Zinc Oxide nanoparticles are synthesized using DNA as capping agent. Zinc oxide nanoparticles are synthesized using DNA as a capping agent. Structural and morphological characterizations are done using SEM, FTIR and XRD. The particle size and lattice parameters are calculated from the diffraction data. The optical properties are studied using UV-Vis absorption spectroscopy and bandgap variation with temperature is determined. The dielectric property of nanoparticles is studied by varying temperature and frequency. The dielectric constant and dispersion parameters are found out. Method of Cole-Cole analysis is used to study the high temperature dispersion of relaxation time. The variation of both AC and DC conductivity are studied and activation energy calculated.

  2. Synthesis of highly crystalline Ga-doped zinc-oxide nanoparticles for hybrid polymer solar cells

    NASA Astrophysics Data System (ADS)

    Park, Hye-Jeong; Lee, Kang Hyuck; Sameera, Ivaturi; Kim, Sang-Woo

    2015-05-01

    Gallium (Ga)-doped zinc-oxide (ZnO) nanoparticles (NPs) were synthesized by using a polymer pyrolysis method. The smallest size of the obtained 4-mol% Ga-doped zinc-oxide (GZO) spherical NPs was approximately 10-15 nm, and the presence of Ga was confirmed by using X-ray photoelectron spectroscopy. To examine the role of GZO NPs, fabricated hybrid polymer solar cells (HPSCs) by using blends of a conjugated polymer poly (3-hexalthiophene) as an electron donor and crystalline GZO NPs as an electron acceptor. Significant improvements in the short-circuit current density and fill factor compared to these for the undoped ZnO (UZO) NPs were achieved by using the GZO NPs. This suggests that the GZO NPs have higher electron mobility than the UZO NPs and possess great potential for use as electron acceptor in HPSCs.

  3. Effect of Triaryl Phosphate, Zinc and Zinc Borate on Fire Properties of High Impact Polystyrene and High Impact Polystyrene-Polyphenylene Oxide Blend (Modified-Polyphenylene Oxide

    Microsoft Academic Search

    Ramazan Benrashid; Gordon L. Nelson; Donald J. Ferm

    1994-01-01

    Samples of m-PPO (virgin and flame retarded) and high impact polystyrene blended with zinc and zinc borate (2ZnO·3B2O3·3.5H 2O), were pre pared. The effect of triaryl phosphate on the flame retardancy of PPO-HIPS in conjunction with zinc and zinc borate was studied.For polystyrene zinc borate shows some reduction in smoke generation. Zinc, however does not show any effect on smoke

  4. Leaching kinetics of low grade zinc oxide ore in NH 3 NH 4 Cl-H 2 O system

    Microsoft Academic Search

    Rui-xiang Wang; Mo-tang Tang; Sheng-hai Yang; Wen-hai Zhagn; Chao-bo Tang; Jing He; Jian-guang Yang

    2008-01-01

    The leaching kinetics of low grade zinc oxide ore in NH3-NH4Cl-H2O system was studied. The effects of ore particle size, reaction temperature and the sum concentration of ammonium ion and\\u000a ammonia on the leaching efficiency of zinc were examined. The leaching kinetics of low-grade zinc oxide ore in NH3-NY4Cl-H2O system follows the kinetic law of shrinking-core model. The results show

  5. PREPARATION OF ZINC OXIDE NANOPARTICLE VIA UNIFORM PRECIPITATION METHOD AND ITS SURFACE MODIFICATION BY METHACRYLOXYPROPYLTRIMETHOXYSILANE

    Microsoft Academic Search

    Erjun Tang; Baoyong Tian; Erli Zheng; Cuiyan Fu; Guoxiang Cheng

    2008-01-01

    Zinc oxide nanoparticles were prepared by uniform precipitation using urea hydrolysis. The ZnO precursor was slowly deposited from aqueous solution. Anionic surfactant was added into solution to block ZnO crystal growth and its agglomeration. Then ZnO nanoparticles were synthesized by the calcination of the precursor at high temperature. Transmission electron microscope (TEM) observation and particle size analyzer demonstrated that the

  6. Hydrogenated aluminium-doped zinc oxide semiconductor thin films for polymeric light-emitting diodes

    Microsoft Academic Search

    X. T. Hao; F. R. Zhu; K. S. Ong; L. W. Tan

    2006-01-01

    Highly conducting transparent thin films of aluminium(Al)-doped zinc oxide (ZnO:Al) were deposited by a radio frequency magnetron-sputtering technique using an argon and hydrogen gas mixture at room temperature. Hydrogen serves as a shallow donor and plays a critical role in improving the Al doping efficiency to enhance the conductivity of thin films. The effect of hydrogen partial pressure on the

  7. Highly transparent and conducting zinc oxide films deposited by activated reactive evaporation

    Microsoft Academic Search

    W. S. Lau; S. J. Fonash

    1987-01-01

    Highly transparent and conducting undoped zinc oxide films have been obtained with a best resistivity of ˜1.1 × 10-3 Omega cm, a carrier density of ˜1.5 × 1020 cm-3 and a mobility of ˜38 cm2V-1s -1. These were produced by activated reactive evaporation at a deposition rate of 2 to 8Å\\/s with a substrate temperature 300°+ C) were always inferior

  8. Highly transparent and conducting zinc oxide films deposited by activated reactive evaporation

    Microsoft Academic Search

    W. S. Lau; S. J. Fonash

    1987-01-01

    Highly transparent and conducting undoped zinc oxide films have been obtained with a best resistivity of ?1.1 10-3\\u000a ? cm, a carrier density of ?1.5 1020 cm?3 and a mobility of ?38 cm2V?1s\\u000a ?1. These were produced by activated reactive evaporation at a deposition rate of 2 to 8\\/s with a substrate temperature ?200\\u000a C. The films deposited by this

  9. Mechanism of local stress release in armchair single-wall zinc oxide nanotube under tensile loading

    Microsoft Academic Search

    Wen-Jay Lee; Jee-Gong Chang; Shin-Pon Ju; Chia-Hung Lee

    The deformation mechanism of zinc oxide (ZnO) nanotube has been first examined by molecular dynamics. The result demonstrated\\u000a that ZnO nanotubes relax it excess strain via the phase transformation from an armchair structure to a fourfold-coordinated\\u000a structure, then to a zigzag structure, which is started by a slip deformation. In contrast to carbon, silicon carbide, and\\u000a boron nitride nanotubes, they

  10. Evaluation of the cytotoxic and inflammatory potential of differentially shaped zinc oxide nanoparticles

    Microsoft Academic Search

    Boon Chin Heng; Xinxin Zhao; Eng Chok Tan; Nurulain Khamis; Aarti Assodani; Sijing Xiong; Christiane Ruedl; Kee Woei Ng; Joachim Say-Chye Loo

    Zinc oxide (ZnO) nanoparticles have wide-ranging applications in a diverse array of industrial and consumer products, from\\u000a ceramic manufacture and paint formulation to sunscreens and haircare products. Hence, it is imperative to rigorously characterize\\u000a the health and safety aspects of human exposure to ZnO nanoparticles. This study therefore evaluated the cellular association,\\u000a cytotoxic and inflammatory potential of spherical and sheet-shaped

  11. FTIR spectroscopy of hydrogen, carbon monoxide, and methane adsorbed and co-adsorbed on zinc oxide

    Microsoft Academic Search

    D. Scarano; S Bertarione; G Spoto; A Zecchina; C Otero Areán

    2001-01-01

    Adsorption of dihydrogen, carbon monoxide and methane, and co-adsorption of H2\\/CO, H2\\/CH4 and CO\\/CH4 on zinc oxide was studied by means of Fourier transform infrared spectroscopy. Besides the already known dissociation of dihydrogen and molecular adsorption of CO, methane was found to be adsorbed molecularly on coordinatively unsaturated Zn2+ ions. Adsorption lowers the CH4 symmetry from Td to C3v, which

  12. Chemical enhancer induced changes in the mechanisms of transdermal delivery of zinc oxide nanoparticles

    Microsoft Academic Search

    Tsung-Rong Kuo; Chung-Long Wu; Chih-Ting Hsu; Wen Lo; Shu-Jen Chiang; Sung-Jan Lin; Chen-Yuan Dong; Chia-Chun Chen

    2009-01-01

    The overlapping wavelength of photoluminescence (PL) of zinc oxide nanoparticles (ZnO NPs) and autofluorescence (AF) from the stratum corneum (SC) has for a long time held back researchers from investigating the chemically enhanced penetration pathways of ZnO NPs into the SC lipids. However, the non-linear polarization effect of second harmonic generation (SHG) may be used for ZnO NPs to be

  13. Continuous synthesis of surface-modified zinc oxide nanoparticles in supercritical methanol

    Microsoft Academic Search

    Bambang Veriansyah; Jae-Duck Kim; Byoung Koun Min; Young Ho Shin; Youn-Woo Lee; Jaehoon Kim

    2010-01-01

    Continuous synthesis of surface-modified zinc oxide (ZnO) nanoparticles was examined using surface modifiers (oleic acid and decanoic acid) in supercritical methanol at 400°C, 30MPa and a residence time of ?40s. Wide angle X-ray diffraction (WAXD) analysis revealed that the surface-modified nanoparticles retained ZnO crystalline structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the surface modifiers changed

  14. Monitoring chemically enhanced transdermal delivery of zinc oxide nanoparticles by using multiphoton microscopy

    Microsoft Academic Search

    Wen Lo; Chih-Ting Hsu; Tsung-Rong Kuo; Chung-Long Wu; Shu-Jen Chiang; Sung-Jan Lin; Shean-Jen Chen; Chia-Chun Chen; Chen-Yuan Dong

    2010-01-01

    Zinc oxide nanoparticles (ZnO NPs) are commonly used in sunscreens to reduce the risk of skin cancer by blocking ultraviolet radiation. ZnO NPs absorption through the transdermal route may not cause high health risk as inhalation or ingestion. However, in practical usage of sunscreens and cosmetics, ZnO NPs are topically applied to a large area of skin with long periods

  15. Observation of an electromagnetically driven temperature wave in porous zinc oxide during microwave heating

    SciTech Connect

    Dadon, D.; Martin, L.P.; Rosen, M. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Material Science and Engineering; Gershon, D.; Carmel, Y.; Rybakov, K.I.; Birman, A.; Calame, J.; Levush, B. [Univ. of Maryland, College Park, MD (United States). Inst. for Plasma Research; Hutcheon, R. [Chalk River Labs., Ontario (Canada)

    1996-12-31

    Propagation of a sharp temperature wave was observed during microwave heating of porous zinc oxide in nitrogen and argon atmospheres. This wave initiated from the center of the sample and traveled at an average velocity of 0.2 cm/min towards its surface. This temperature wave was attributed to an anomalous peak in the imaginary part of the complex permittivity possibly caused by desorption of chemisorbed oxygen from the surfaces of ZnO crystallites.

  16. Synthesis and characterization of zinc oxide nanoparticles: application to textiles as UV-absorbers

    Microsoft Academic Search

    Alessio Becheri; Maximilian Dürr; Pierandrea Lo Nostro; Piero Baglioni

    2008-01-01

    We report the synthesis and characterization of nanosized zinc oxide particles and their application on cotton and wool fabrics\\u000a for UV shielding. The nanoparticles were produced in different conditions of temperature (90 or 150 °C) and reacting medium\\u000a (water or 1,2-ethanediol). A high temperature was necessary to obtain small monodispersed particles. Fourier transformed infrared\\u000a spectroscopy (FTIR), transmission electron microscopy (TEM), and

  17. Quantitative trait analysis of the development of pulmonary tolerance to inhaled zinc oxide in mice

    Microsoft Academic Search

    Scott C Wesselkamper; Lung Chi Chen; Terry Gordon

    2005-01-01

    BACKGROUND: Individuals may develop tolerance to the induction of adverse pulmonary effects following repeated exposures to inhaled toxicants. Previously, we demonstrated that genetic background plays an important role in the development of pulmonary tolerance to inhaled zinc oxide (ZnO) in inbred mouse strains, as assessed by polymorphonuclear leukocytes (PMNs), macrophages, and total protein in bronchoalveolar lavage (BAL) phenotypes. The BALB\\/cByJ

  18. High-Performance Chemical-Bath-Deposited Zinc Oxide Thin-Film Transistors

    Microsoft Academic Search

    David Redinger; Vivek Subramanian

    2007-01-01

    Solution-processed transparent zinc oxide (ZnO) transistors are demonstrated using a chemical bath deposition process for ZnO deposition. The process is glass compatible and amenable to producing fully transparent electronics. Mobility as high as 3.5 cm2\\/V ldr s with on-off ratios of ~105 is realized. The transparency of ZnO allows for complete coverage of the pixel by the pixel drive transistors;

  19. Zinc oxide nanowires in chemical bath on seeded substrates: Role of hexamine

    Microsoft Academic Search

    Abhilash Sugunan; Hemant C. Warad; Mats Boman; Joydeep Dutta

    2006-01-01

    We report a study of the role of hexamine in the seeded growth of zinc oxide (ZnO) nanowires by hydrothermal route. We show\\u000a that the growth can be made highly anisotropic (aspect ratio >150) with almost no detectable increase in diameter (with time\\u000a of hydrothermal growth) of the obtained nanowires. Results indicate that hexamine acts as a shape inducing molecule,

  20. Spectral Investigations of Chemical Bath Deposited Zinc Oxide Thin Films - Ammonia Gas Sensor

    Microsoft Academic Search

    P. Kathirvel; D. Manoharan; S. M. Mohan; S. Kumar

    Zinc oxide thin films have been deposited on glass substrates at various bath temperatures (40ºC, 60 ºC and 80 ºC) by simple chemical bath deposition technique. The structure of the deposited ZnO films was determined by powder X-ray diffraction and it exhibits hexagonal structure along with c-axis orientation. The optical absorbance of the deposited films was characterized by UV-VIS-NIR spectrometry.

  1. Tailoring of room temperature excitonic luminescence in sol–gel zinc oxide–silica nanocomposite films

    Microsoft Academic Search

    S. Chakrabarti; D Das; D Ganguli; S Chaudhuri

    2003-01-01

    Zinc oxide–silica (ZnO\\/SiO2=20:80, molar ratio) nanocomposites consisting of ZnO nanoparticles embedded in a dielectric matrix were prepared by a sol–gel technique (spin coating). Optical transmittance, Raman effect and photoluminescence measurements of the composites indicated effective capping of the ZnO nanoparticles (radii 1.4–1.5 nm) in the host showing practically no variation of particle size with the post-deposition-annealing treatments. The blue shift

  2. Non-volatile memory with zinc oxide nanoparticles embedded in a hybrid polymethylsilsesquioxane layer

    Microsoft Academic Search

    W. K. Lee; H. Y. Wong; K. C. Aw

    2011-01-01

    In this article the electrical characteristics of zinc oxide nanoparticles (ZnO NP) embedded in polymethylsilsesquioxane (PMSSQ) film have been studied. PMSSQ film with embedded ZnO NP was sandwiched between aluminium and ITO coated glass as a capacitor-based memory device. Charge transport mechanism in this device has been investigated. The device can be programmed and erased similar to a flash-memory. Programming

  3. Resistive Switching Characteristics of Sol–Gel Zinc Oxide Films for Flexible Memory Applications

    Microsoft Academic Search

    Sungho Kim; Hanul Moon; Dipti Gupta; Seunghyup Yoo; Yang-Kyu Choi

    2009-01-01

    Unipolar resistive switching devices are investigated for nonvolatile memory applications in a metal-insulator-metal structure in which the insulator layer is based on sol-gel-derived zinc oxide (ZnO) films prepared by a simple spin-coating process followed by thermal annealing. Fast programming ( les 50 ns) and a high off-to-on resistance ratio ( ges 104) is demonstrated. The influences on the switching behaviors

  4. Picosecond time-resolved photoluminescence of zinc oxide single crystals, films and nanoparticles

    Microsoft Academic Search

    John Henry Wilkinson IV

    2003-01-01

    Zinc oxide (ZnO) is a refractory semiconductor material whose band gap is both wide (3.39 eV) and direct. It is under consideration as a promising material for blue\\/uv semiconducting light emitting diodes (LEDs) and lasers. High purity macroscopic single crystals are available, along with epitaxial films grown by chemical vapor deposition, molecular beam epitaxy or pulsed-laser deposition. The exciton has

  5. Electrically conductive zinc oxide (ZnO) nanostructures prepared by solgel spin-coating

    Microsoft Academic Search

    M. H. Mamata; M. Rusop; Z. Zulkifli

    2010-01-01

    The electrically conductive zinc oxide (ZnO) nanostructures prepared by sol-gel spin coating are presented. This project has been focused on electrical, optical and structural properties of Al doped ZnO thin film. The effects of Al doping concentration at 0~5 at.% on the Al doped ZnO thin film properties have been investigated. This project involves 3 processes which are thin film

  6. Reduced Staphylococcus aureus proliferation and biofilm formation on zinc oxide nanoparticle PVC composite surfaces

    Microsoft Academic Search

    Justin T. Seil; Thomas J. Webster

    2011-01-01

    Conventional particulate zinc oxide (ZnO) is a known antibacterial agent. Studies have shown that reducing the size of ZnO particles to nanoscale dimensions further enhances their antibacterial properties. Polymers, like all biomaterials, run the risk of harboring bacteria which may produce an antibiotic-resistant biofilm. The addition of ZnO nanoparticles to form a polymer composite material may thus reduce undesirable bacteria

  7. Fabrication of zinc oxide\\/poly(styrene) grafted nanocomposite latex and its dispersion

    Microsoft Academic Search

    Erjun Tang; Hong Liu; Liming Sun; Erli Zheng; Guoxiang Cheng

    2007-01-01

    Zinc oxide nanoparticles, with an average size of about 40nm, were encapsulated by polystyrene using in situ emulsion polymerization in the presence of 3-methacryloxypropyltrimethoxysilane (MPTMS) as a coupling agent and polyoxyethylene nonylphenyl ether (OP-10) as a surfactant. Polymerization mechanism of nanocomposite latex was discussed. Transmission electron microscopy (TEM) proved the presence of ZnO nanoparticle appeared to be monodisperse in nanosize

  8. Electronic memory effects in diodes from a zinc oxide nanoparticle-polystyrene hybrid material

    Microsoft Academic Search

    Frank Verbakel; Stefan C. J. Meskers; René A. J. Janssen

    2006-01-01

    Current-voltage characteristics of diode structures with an active layer of a zinc oxide nanoparticle-polystyrene hybrid material (1:2 by weight) deposited by spin coating from solution were investigated. Aluminum and poly(3,4-ethylenedioxythiophene):polystyrene-sulfonate were used as electrodes. After a forming step, the conduction under reversed bias voltage can be raised or lowered in a gradual and reversible manner by applying forward and reverse

  9. Photocatalytic self-cleaning properties of cellulosic fibers modified by nano-sized zinc oxide

    Microsoft Academic Search

    Hadi Fallah Moafi; Abdollah Fallah Shojaie; Mohammad Ali Zanjanchi

    2011-01-01

    Nano-sized zinc oxide was synthesized and deposited onto cellulosic fibers using the sol–gel process at ambient temperature. The prepared materials were characterized using several techniques including scanning electron microscopy, transmission electron microscopy, diffuse reflectance spectroscopy, X-ray diffraction and thermogravimetric analysis. X-ray diffraction studies of the ZnO-coated fiber indicate formation of the hexagonal crystal phase which was satisfactory crystallized on the

  10. Zinc oxide nanoparticle decorated multi-walled carbon nanotubes and their optical properties

    Microsoft Academic Search

    C. S. Chen; X. H. Chen; B. Yi; T. G. Liu; W. H. Li; L. S. Xu; Z. Yang; H. Zhang; Y. G. Wang

    2006-01-01

    A simple and efficient approach is developed for the synthesis of single crystal zinc oxide (ZnO) nanoparticles on multi-walled carbon nanotubes (MWNT). Moreover, the effect of heat treatment on ZnO-coated MWNT is investigated. The results reveal that the MWNT are decorated by ZnO particles. The MWNT are continuously coated by ZnO nanoparticles at 450 and 600°C, and the average size

  11. Electrically Conductive Zinc Oxide (ZnO) Nanostructures Prepared by Sol-gel Spin-coating

    Microsoft Academic Search

    M. H. Mamat; A. S. Rodzi; M. Rusop

    2011-01-01

    The electrically conductive zinc oxide (ZnO) nanostructures prepared by sol-gel spin coating are presented. This project has been focused on electrical, optical and surface morphology properties of Al (aluminium) doped ZnO thin film. The effect of Al doping concentration at 0~5 at.% on the Al doped ZnO Thin film properties have been investigated. This project involves 3 processes which are

  12. Synthesis and characterization of zinc oxide fine particles coated with titania\\/PDMS hybrid

    Microsoft Academic Search

    Masato Nakade; Makoto Ogawa

    2007-01-01

    Zinc oxide nanoparticles were coated with titania\\/polydimethylsiloxane hybrid by co-hydrolysis and co-condensation of the\\u000a sols prepared from titanium tetraisopropoxide and methoxy-functionalized polydimethylsiloxane to synthesize a new class of\\u000a hierarchically designed composite materials. The successful formation of the shell, which is composed of titania\\/polydimethylsiloxane\\u000a hybrid, was evidenced by SEM, TEM, IR, EDS and zeta potential data. The hydrophobicity and the dispersibility

  13. Synthesis, characterization, and photocatalytic activities of titanate nanotubes surface-decorated by zinc oxide nanoparticles

    Microsoft Academic Search

    Li Shi Wang; Ming Wei Xiao; Xin Jian Huang; Yan Dan Wu

    2009-01-01

    Nanoscaled zinc oxide (ZnO) particles with different amounts are coated on titanate nanotubes (TNTs) by a facile chemical method at room temperature. The characterizations of XPS, TEM, XRD and UV–vis spectra confirm that pure hexagonal wurtzite ZnO nanoparticles with an average size of about 9nm are distributed on the surfaces of TNTs evenly and attached strongly. The photocatalytic activities of

  14. Electrically Conductive Zinc Oxide (ZnO) Nanostructures Prepared by Sol-gel Spin-coating

    Microsoft Academic Search

    M. H. Mamat; A. S. Rodzi; M. Rusop

    2011-01-01

    The electrically conductive zinc oxide (ZnO) nanostructures prepared by sol-gel spin coating are presented. This project has been focused on electrical, optical and surface morphology properties of Al (aluminium) doped ZnO thin film. The effect of Al doping concentration at 0?5 at.% on the Al doped ZnO Thin film properties have been investigated. This project involves 3 processes which are

  15. Effects of organic nucleating agents and zinc oxide nanoparticles on isotactic polypropylene crystallization

    Microsoft Academic Search

    Jianguo Tang; Yao Wang; Haiyan Liu; Laurence A. Belfiore

    2004-01-01

    Organic nucleating agents and inorganic nanoparticles, as well as their hybrid composites, affect the crystallization temperature and morphology of the monoclinic ?-form of isotactic polypropylene (iPP). Techniques such as differential scanning calorimetry, hot-stage optical microscopy with cross polars, wide angle X-ray diffraction, and transmission electron microscopy were employed. Nanoparticles of zinc oxide function as efficient supports for 1,3,5-benzene tricarboxylic-(N-2-methylcyclohexyl)triamine because

  16. Enhanced field emission characteristics of zinc oxide mixed carbon nano-tubes films

    Microsoft Academic Search

    J. Y. Pan; C. C. Zhu; Y. L. Gao

    2008-01-01

    A composite material of Zinc oxide and carbon nano-tubes (ZnO–CNTs) paste was synthesized by mixing multi-wall CNTs, ZnO nano-grains and organic vehicles. The microstructures and the morphologies of screen-printed films were characterized by field-emission scanning electron microscope. Results show that ZnO flakes geometrically matched with CNTs by filling into the interspaces of CNTs or directly covering upon CNTs. The field

  17. Well-crystallized zinc oxide quantum dots with narrow size distribution

    Microsoft Academic Search

    Keigo Suzuki; Masashi Inoguchi; Keisuke Kageyama; Hiroshi Takagi; Yukio Sakabe

    2009-01-01

    In this study, pulsed laser ablation, online annealing, and following size classification using a differential mobility analyzer\\u000a (DMA) were employed to fabricate quantum dots (QDs) of zinc oxide (ZnO). The irregularly shaped ZnO particles were obtained\\u000a at annealing temperature less than 873 K, which gradually transformed into spherical QDs with increasing the annealing temperature.\\u000a Finally, ZnO QDs with narrow size distribution

  18. The complex interface chemistry of thin-film silicon/zinc oxide solar cell structures.

    PubMed

    Gerlach, D; Wimmer, M; Wilks, R G; Félix, R; Kronast, F; Ruske, F; Bär, M

    2014-12-21

    The interface between solid-phase crystallized phosphorous-doped polycrystalline silicon (poly-Si(n(+))) and aluminum-doped zinc oxide (ZnO:Al) was investigated using spatially resolved photoelectron emission microscopy. We find the accumulation of aluminum in the proximity of the interface. Based on a detailed photoemission line analysis, we also suggest the formation of an interface species. Silicon suboxide and/or dehydrated hemimorphite have been identified as likely candidates. For each scenario a detailed chemical reaction pathway is suggested. The chemical instability of the poly-Si(n(+))/ZnO:Al interface is explained by the fact that SiO2 is more stable than ZnO and/or that H2 is released from the initially deposited a-Si:H during the crystallization process. As a result, Zn (a deep acceptor in silicon) is "liberated" close to the silicon/zinc oxide interface presenting the inherent risk of forming deep defects in the silicon absorber. These could act as recombination centers and thus limit the performance of silicon/zinc oxide based solar cells. Based on this insight some recommendations with respect to solar cell design, material selection, and process parameters are given for further knowledge-based thin-film silicon device optimization. PMID:25363298

  19. Weatherability and Leach Resistance of Wood Impregnated with Nano-Zinc Oxide

    PubMed Central

    2010-01-01

    Southern pine specimens vacuum-treated with nano-zinc oxide (nano-ZnO) dispersions were evaluated for leach resistance and UV protection. Virtually, no leaching occurred in any of the nano-ZnO–treated specimens in a laboratory leach test, even at the highest retention of 13 kg/m3. However, specimens treated with high concentrations of nano-ZnO showed 58–65% chemical depletion after 12 months of outdoor exposure. Protection from UV damage after 12 months exposure is visibly obvious on both exposed and unexposed surfaces compared to untreated controls. Graying was markedly diminished, although checking occurred in all specimens. Nano-zinc oxide treatment at a concentration of 2.5% or greater provided substantial resistance to water absorption following 12 months of outdoor exposure compared to untreated and unweathered southern pine. We conclude that nano-zinc oxide can be utilized in new wood preservative formulations to impart resistance to leaching, water absorption and UV damage of wood. PMID:20730119

  20. Synthesis and Characterization of Nanostructured Zinc Oxide and Tin Oxide for VOC Sensor Devices

    NASA Astrophysics Data System (ADS)

    Ahn, Hosang

    In this dissertation, nanostructured ZnO and SnOx with various forms of thin films, particles and rods were deposited and synthesized by combination of sputtering, thermolysis assisted chemical solution method, and/or dc applied electrodeposition. Different substrates such as alumina, silicon dioxide, and polyimide films were used to grow nanostructured materials in order to fabricate highly sensitive and selective VOC sensor devices. Synthesized ZnO and SnOx materials were characterized by FE-SEM, XRD, EDS, Raman spectroscopy and Keithley 2400 sourcemeter to examine the surface morphology, crystalline phase, atomic composition and electrical resistance change. Gas sensing properties of nanostructured metal oxides were studied as functions of the structural and compositional changes. Three different gases: acetone, ethanol, and ethylene, mixed with synthetic air were tested in a closed chamber by continuously flowing gases. SnO2 thin films were deposited by rf sputtering from a SnO 2 ceramic target under different argon-to-oxygen ratios to investigate the effects of oxygen stoichiometry on ethylene sensing properties. Thin film sensors exhibited higher sensitivity compared with bulk from SnO2 sensors. Post-annealing of the fabricated thin films influenced gas sensitivity while the control of argon-to-oxygen ratio during the film deposition did not affect the properties significantly due to the effective formation SnO2 by a post-annealing process. An ethylene sensing mechanism for the SnO 2 thin film sensor was also newly suggested. Significant compositional effects of tin oxide were investigated by sputter deposition from a metallic tin target. Post-annealing of the films resulted in SnO and/or SnO2 phases depending on annealing temperature. Combinatorial phases of SnOx, i.e. gradual distribution of SnO and SnO2 on the sample substrate, were fabricated by co-sputtering of tin metal and tin oxide ceramic targets. Gas sensing properties of the films were investigated with an emphasis on tin phases and microstructure. Although SnO is a p-type semiconductor and SnO2 is a n-type semiconductor, the data on sensitivity using three different gases were similar except for the direction of resistance changes during the detection of the gases. Such a combinatorial approach would enhance the selectivity of a VOC sensor by merging two different types of semiconducting materials. Geometric effects of the oxides on the gas sensing properties were investigated by constructing ZnO nanorods on ZnO thin film seed layers. A series of devices were prepared with seed layers of different thickness upon which nanorods with tuned density were grown. Quantitative analysis of the sensing mechanism shows that volumetric geometry of the nanorods such as diameter and length is a more critical factor than the thickness of the seed layer. In addition to control of the nanorod structure, the transition metal ions such as nickel, cobalt, and copper were doped into ZnO nanorods during electrodeposition. Such doping can provide the ability to operate at room temperature and to use flexible polymer substrates. Nickel was successfully doped in-situ into ZnO nanorods in aqueous solution. A doped concentration of 6% nickel revealed the most enhanced sensing property at room temperature under UV illumination. A mechanism is proposed to explain how the transition metal ions in zinc oxide play an important role in the gas sensitivity under UV illumination.

  1. Zinc Oxide Surge Arresters and HVDC 125kV-upgrade 500kV Converter Stations

    NASA Astrophysics Data System (ADS)

    Shirakawa, Shingo; Kobayashi, Takayuki; Matsushita, Yoshinao; Sakai, Takehisa; Suzuki, Hironori; Ozaki, Yuzo

    Gapless Metal (Zinc) Oxide Surge Arresters for a.c. systems contribute to the insulation co-ordination based on the suppression of lightning surges and switching surges. These gapless metal oxide surge arresters using ZnO elements are effective to HVDC systems. This paper describes basic characteristics of ZnO (zinc oxide) elements for d.c. systems and applications of gapless surge arresters to HVDC 125kV frequency converters, HVDC 250kV, upgrade HVDC 500kV converter stations, and HVDC 500kV cables of Japan through the experience of developments and applications of gapless metal oxide surge arresters.

  2. 40 CFR 721.2095 - Chromate(3-), bis 2-[[substituted-3-[(5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl) azo]phenyl]azo]substituted monocycle,...

  3. 40 CFR 721.2095 - Chromate(3-), bis 2-[[substituted-3-[(5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl) azo]phenyl]azo]substituted monocycle,...

  4. 40 CFR 721.2095 - Chromate(3-), bis 2-[[substituted-3-[(5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl) azo]phenyl]azo]substituted monocycle,...

  5. 40 CFR 721.2095 - Chromate(3-), bis 2-[[substituted-3-[(5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl) azo]phenyl]azo]substituted monocycle,...

  6. 40 CFR 721.2095 - Chromate(3-), bis 2-[[substituted-3-[(5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl)azo] phenyl]azo]substituted monocycle, trisodium...5-sulfo-1-naphthalenyl) azo]phenyl]azo]substituted monocycle,...

  7. Asymmetric alternating copolymerization of cyclohexene oxide and CO2 with dimeric zinc complexes.

    PubMed

    Nakano, Koji; Nozaki, Kyoko; Hiyama, Tamejiro

    2003-05-01

    Dimeric zinc complex 2a [ = Et(2)Zn(2)(1a)(2)] has been synthesized by the reaction of Et(2)Zn and (S)-diphenyl(pyrrolidin-2-yl)methanol (1a-H). X-ray crystallography revealed that the alkoxide ligand replaced one of the two ethyl groups of Et(2)Zn and formed a five-membered chelate ring through a Zn-N dative bond. Two zinc centers were bridged by oxygen atoms to form a Zn(2)O(2) four-membered ring with a syn relationship between the two ethyl groups on the zinc centers. Dimeric zinc complex 2a was an active catalyst for asymmetric alternating copolymerization of cyclohexene oxide and CO(2). An MALDI-TOF mass spectrum of the obtained copolymer showed that the copolymerization was initiated by the insertion of CO(2) into Zn-alkoxide to give [(S)-diphenyl(pyrroridin-2-ly)methoxy]-[C(=O)O-(1,2-cyclohexylene)-O](n)-H (copolymer I), including chiral ligand 1a as an initiating group. Complex 3a-OEt ( = EtZn(1a)(2)ZnOEt), in which an ethoxy group replaced one of the two ethyl groups in 2a, also polymerized cyclohexene oxide and CO(2) with higher catalytic activity and enantioselectivity than 2a and afforded EtO-[C(=O)O-(1,2-cyclohexylene)-O](n)-H ( = copolymer III), including an ethoxy group as an initiating group. Throughout the studies, dimeric zinc species are indicated to be the active species for the copolymerization. It is also depicted that the substituent on the aryl moiety in diaryl(pyrrolidin-2-yl)methanol 2b-e influenced the polymerization activity. PMID:12720465

  8. Synthesis and Characterization of Functional Nanostructured Zinc Oxide Thin Films

    E-print Network

    Chow, Lee

    -temperature thin film growth technique has been developed to fabricate a new generation of smart and functional nanostructured metal oxide thin film materials. This chemical synthetic route uses stable and inexpensive metal to 100 ppm ammonia at temperatures between 20 °C and 300 °C have been assessed. Introduction

  9. Bacitracin zinc overdose

    MedlinePLUS

    ... Small amounts of bacitracin zinc are dissolved in petroleum jelly to create antibiotic ointments. Bacitracin zinc overdose ... 1-800-222-1222. See also: Bacitracin overdose Petroleum jelly overdose Zinc oxide overdose

  10. Zinc oxide formation in galvanized metallic wire by simple selective growth method

    NASA Astrophysics Data System (ADS)

    Sivanantham, A.; Abinaya, C.; Vishnukanthan, V.; Jayabal, P.; Boobalan, K.; Mohanraj, S.; Mayandi, J.

    2015-06-01

    ZnO nanostructures were synthesized by a simple method of oxidizing metallic wire by direct electrical heating. A galvanized iron wire was used as the source of zinc. Several optical techniques were employed on the synthesized ZnO nanostructure such as photoluminescence, Raman and FTIR spectroscopy. The formation of ZnO nanostructures was confirmed from the spectra of different optical studies and also determined by XRD. SEM analysis shows the signature of nanorod formation on the surface of the wire. The oxidation state and ferromagnetic property of these oxidized metallic wires were discussed with the help of EPR spectrum. In summation to the properties studied, a growth mechanism was suggested based on the observations and method of the oxidation procedure.

  11. 40 CFR 721.10107 - Naphthalenedisulfonic acid, [amino-hydroxy-[(substituted)azo-sulfo-naphthaleneyl]azo]-hydroxy...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...methoxy-sulfophenyl)azo], metal salt (generic). 721.10107 Section 721...methoxy-sulfophenyl)azo], metal salt (generic). (a) Chemical substance...methoxy-sulfophenyl)azo], metal salt (PMN P-04-495) is subject to...

  12. 40 CFR 721.10107 - Naphthalenedisulfonic acid, [amino-hydroxy-[(substituted)azo-sulfo-naphthaleneyl]azo]-hydroxy...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...methoxy-sulfophenyl)azo], metal salt (generic). 721.10107 Section 721...methoxy-sulfophenyl)azo], metal salt (generic). (a) Chemical substance...methoxy-sulfophenyl)azo], metal salt (PMN P-04-495) is subject to...

  13. Acceptor conductivity in bulk zinc oxide (0001) crystals

    NASA Astrophysics Data System (ADS)

    Adekore, Bababunmi Tolu

    ZnO is a promising wide bandgap semiconductor. Its renowned and prominent properties as its bandgap of 3.37eV at 4.2K; its very high excitonic binding energy, 60meV; its high melting temperature, 2248K constitute the basis for the recently renewed and sustained scientific interests in the material. In addition to the foregoing, the availability of bulk substrates of industrially relevant sizes provides important opportunities such as homoepitaxial deposition of the material which is a technological asset in the production of efficient optoelectronic and electronic devices. The nemesis of wide bandgap materials cannot be more exemplified than in ZnO. The notorious limitation of asymmetric doping and the haunting plague of electrically active point defects dim the bright future of the material. In this case, the search for reliable and consistent acceptor conductivity in bulk substrates has been hitherto, unsuccessful. In the dissertation that now follows, our efforts have been concerted in the search for a reliable acceptor. We have carefully investigated the science of point defects in the material, especially those responsible for the high donor conductivity. We also investigated and herein report variety of techniques of introducing acceptors into the material. We employ the most relevant and informative characterization techniques in verifying both the intended conductivity and the response of intrinsic crystals to variation in temperature and strain. And finally we explain deviations, where they exist, from ideal acceptor characteristics. Our work on reliable acceptor has been articulated in four papers. The first establishing capacitance based methods of monitoring electrically active donor defects. The second investigates the nature of anion acceptors on the oxygen sublattice. A study similar to the preceding study was conducted for cation acceptors on the zinc sublattice and reported in the third paper. Finally, an analysis of the response of the crystal to hydrostatic strain and its recovery when such strain enforces a collapse of its crystallinity is reported in the fourth paper. For the sake of brevity and the need to be concise, our supplementary investigations on extrinsic donor conductivity is deferred to other journal publications.

  14. Proteus mirabilis alleviates zinc toxicity by preventing oxidative stress in maize (Zea mays) plants.

    PubMed

    Islam, Faisal; Yasmeen, Tahira; Riaz, Muhammad; Arif, Muhammad Saleem; Ali, Shafaqat; Raza, Syed Hammad

    2014-12-01

    Plant-associated bacteria can have beneficial effects on the growth and health of their host. However, the role of plant growth promoting bacteria (PGPR), under metal stress, has not been widely investigated. The present study investigated the possible mandatory role of plant growth promoting rhizobacteria in protecting plants from zinc (Zn) toxicity. The exposure of maize plants to 50µM zinc inhibited biomass production, decreased chlorophyll, total soluble protein and strongly increased accumulation of Zn in both root and shoot. Similarly, Zn enhanced hydrogen peroxide, electrolyte leakage and lipid peroxidation as indicated by malondaldehyde accumulation. Pre-soaking with novel Zn tolerant bacterial strain Proteus mirabilis (ZK1) isolated zinc (Zn) contaminated soil, alleviated the negative effect of Zn on growth and led to a decrease in oxidative injuries caused by Zn. Furthermore, strain ZK1 significantly enhanced the activities of catalase, guaiacol peroxidase, superoxide dismutase and ascorbic acid but lowered the Proline accumulation in Zn stressed plants. The results suggested that the inoculation of Zea mays plants with P. mirabilis during an earlier growth period could be related to its plant growth promoting activities and avoidance of cumulative damage upon exposure to Zn, thus reducing the negative consequences of oxidative stress caused by heavy metal toxicity. PMID:25240234

  15. Bio-fabrication of zinc oxide nanoparticles using leaf extract of Parthenium hysterophorus L. and its size-dependent antifungal activity against plant fungal pathogens.

    PubMed

    Rajiv, P; Rajeshwari, Sivaraj; Venckatesh, Rajendran

    2013-08-01

    The study reports the synthesis and characterization of zinc oxide nanoparticles from weed plant by a novel method. The aim of this work is to synthesize zinc oxide nanoparticles from Parthenium hysterophorus L. by inexpensive, ecofriendly and simple method. Highly stable, spherical and hexagonal zinc oxide nanoparticles were synthesized by using different concentrations of 50% and 25% parthenium leaf extracts. Both the concentrations of the leaf extract act as reducing and capping agent for conversion of nanoparticles. Formation of zinc oxide nanoparticles have been confirmed by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier trans-form infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis with energy dispersive X-ray analysis (EDX). SEM, TEM and EDX analysis reveals that spherical and hexagonal zinc oxide nanoparticle sizes were 27±5 nm and 84±2 nm respectively and chemical composition of zinc oxide were present. We synthesized different sized zinc oxide nanoparticles and explored the size-dependent antifungal activity against plant fungal pathogens. Highest zone of inhibition was observed in 25 ?g/ml of 27±5 nm size zinc oxide nanoparticles against Aspergillus flavus and Aspergillus niger. Parthenium mediated zinc oxide nanoparticles were synthesized and proved to be good antifungal agents and environment friendly. PMID:23686093

  16. Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

    SciTech Connect

    Zheng, Juanjuan; Zhang, Yu [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Xu, Wentao, E-mail: xuwentaoboy@sina.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Luo, YunBo [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Hao, Junran [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Shen, Xiao Li [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Yang, Xuan [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); Li, Xiaohong [The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China); Huang, Kunlun, E-mail: hkl009@163.com [Laboratory of Food Safety and Molecular Biology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083 (China); The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing 100083 (China)

    2013-04-15

    Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did not affect the OTA-induced decrease in the mitochondrial membrane potential (??{sub m}). Meanwhile, the addition of the zinc chelator N,N,N?,N?-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2?-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ? OTA decreased the intracellular zinc concentration. ? OTA induced the formation of 8-OHdG in HepG2 cells. ? It was testified for the first time that OTA induced DNA hypomethylation. ? Zinc protects against the oxidative damage and DNA damage induced by OTA in vitro.

  17. Chemical synthesis of zinc oxide nanorods for enhanced hydrogen gas sensing

    NASA Astrophysics Data System (ADS)

    Musarrat, Jabeen; Muhammad Azhar, Iqbal; R Vasant, Kumar; Mansoor, Ahmed; Muhammad Tayyeb, Javed

    2014-01-01

    Zinc oxide (ZnO) nanorods are prepared using equimolar solution of zinc nitrate ((Zn(NO3)2) and hexamethylenetetramine (C6H12N4) by the hydrothermal technique at 80 °C for 12 h. Epitaxial growth is explored by X-ray diffraction (XRD) patterns, revealing that the ZnO nanorods have a hexagonal (wurtzite) structure. Absorption spectra of ZnO are measured by UV—visible spectrometer. The surface morphology is investigated by field emission scanning electron microscopy (FESEM). The synthesized ZnO nanorods are used for detecting the 150 °C hydrogen gas with a concentration over 1000 ppm. The obtained results show a reversible response. The influence of operating temperature on hydrogen gas detecting characteristic of ZnO nanorods is also investigated.

  18. Observation of the amorphous zinc oxide recrystalline process by molecular dynamics simulation

    PubMed Central

    Lin, Ken-Huang; Sun, Shih-Jye; Ju, Shin-Pon; Tsai, Jen-Yu; Chen, Hsin-Tsung; Hsieh, Jin-Yuan

    2013-01-01

    The detailed structural variations of amorphous zinc oxide (ZnO) as well as wurtzite (B4) and zinc blende (B3) crystal structures during the temperature elevation process were observed by molecular dynamics simulation. The amorphous ZnO structure was first predicted through the simulated-annealing basin-hopping algorithm with the criterion to search for the least stable structure. The density and X-ray diffraction profiles of amorphous ZnO of the structure were in agreement with previous reports. The local structural transformation among different local structures and the recrystalline process of amorphous ZnO at higher temperatures are observed and can explain the structural transformation and recrystalline mechanism in a corresponding experiment [Bruncko et al., Thin Solid Films 520, 866-870 (2011)]. PMID:23509413

  19. Zinc stable isotope fractionation during its adsorption on oxides and hydroxides.

    PubMed

    Pokrovsky, O S; Viers, J; Freydier, R

    2005-11-01

    Adsorption of Zn on goethite, hematite, birnessite, pyrolusite, corundum, and gibbsite was studied using a batch adsorption technique as a function of pH, zinc concentration in solution, and time of exposure. Adsorption from 0.01 M NaNO3 solutions undersaturated with respect to zinc (hydr)oxide at 3MeOZn+ complexes, where Me=Fe, Mn, and Al, was used to describe the dependence of adsorption equilibria on aqueous solution composition in a wide range of pH and Zn concentration. The logarithms of surface stability constant for Zn interaction with metal oxy(hydr)oxides (>MeOH0+Zn2+-->MeOZn+) vary from -2.5 to 0.5. They are higher for oxy(hydr)oxides than for anhydrous oxides. Stable isotopes of zinc in several filtrates were measured using an ICP-MS Neptune multicollector which made it possible, for the first time, to assess the degree of isotopic fractionation between 66Zn and 64Zn during zinc adsorption on mineral surfaces. The isotopic offset between aqueous solution and mineral surfaces (Delta(66/64)Zn(soln/solid)=delta((66/64)Zn)(solution)-delta((66/64)Zn)(surface)) was found to be weakly dependent on percentage of adsorbed metal and equals 0.20+/-0.03, 0.17+/-0.06, -0.10+/-0.03, -0.10+/-0.09, and -0.13+/-0.12 per thousand for goethite, birnessite, pyrolusite, corundum, and Al(OH)3. For hematite, Delta(66/64)Zn varies from -0.61+/-0.10 per thousand at pH 5.5 to -0.02+/-0.09 per thousand at 5.8zinc stable isotopic fractionation induced by adsorption on most mineral surfaces does not exceed 0.2 per thousand. We do not observe any correlation between the sign and magnitude of isotopic offset and the chemical nature of solid phase (hydrous versus anhydrous minerals), zinc surface adsorption constants (surface complexation model of the present work), and coordination and first-neighbor distances of surface >MeOZn(H2O)(n) complexes (available literature data on X-ray absorption spectroscopy). Apparently, the fine structure of surface complexes and the position and bond strength for second neighbors of zinc are likely to control its isotopic fractionation during adsorption on mineral surfaces. Our results strongly suggest that inorganic processes controlling zinc isotope adsorption on soil and sediment minerals should be of second-order importance compared to biological factors. PMID:15963523

  20. Green luminescent center in undoped zinc oxide films deposited on silicon substrates

    NASA Astrophysics Data System (ADS)

    Lin, Bixia; Fu, Zhuxi; Jia, Yunbo

    2001-08-01

    The photoluminescence (PL) spectra of the undoped ZnO films deposited on Si substrates by dc reactive sputtering have been studied. There are two emission peaks, centered at 3.18 eV (UV) and 2.38 eV (green). The variation of these peak intensities and that of the I-V properties of the ZnO/Si heterojunctions were investigated at different annealing temperatures and atmospheres. The defect levels in ZnO films were also calculated using the method of full-potential linear muffin-tin orbital. It is concluded that the green emission corresponds to the local level composed by oxide antisite defect OZn rather than oxygen vacancy VO, zinc vacancy VZn, interstitial zinc Zni, and interstitial oxygen Oi.

  1. Oxidation reactivity of zinc-cysteine clusters in metallothionein.

    PubMed

    Kassim, Rima; Ramseyer, Christophe; Enescu, Mironel

    2013-03-01

    Evaluating the reactivity of the metal-thiolate clusters in metallothionein (MT) is a key step in understanding the biological functions of this protein. The effects of the metal clustering and protein environment on the thiolate reactivity with hydrogen peroxide (H(2)O(2)) were investigated by performing quantum theory calculations with chemical accuracy at two levels of complexity. At the first level, the reactivity with H(2)O(2) of a model system ([(Zn)(3)(MeS)(9)](3-), MeS is methanethiolate) of the ? domain cluster of MT was evaluated using density functional theory (DFT) with the mPW1PW91 functional. At the second level of complexity, the protein environment was included in the reactant system and the calculations were performed with the hybrid ONIOM method combining the DFT-mPW1PW91 and the semiempirical PM6 levels of theory. In these conditions, the energy barrier for the oxidation of the most reactive terminal thiolate was 21.5 kcal mol(-1). This is 3 kcal mol(-1) higher than that calculated for the terminal thiolate in the model system [(Zn)(3)(MeS)(9)](3-) and about 7 kcal mol(-1) higher than that obtained for the free thiolate. In spite of this rise of the energy barrier induced by the protein environment, the thiolate oxidation by H(2)O(2) is confirmed as a possible way for metal release from MT. On the other hand, the results suggest that the antioxidant role of MT in the living cell cannot be as important as that of glutathione (which bears a free thiol). PMID:23334196

  2. Metal Catalyst for Low-Temperature Growth of Controlled Zinc Oxide Nanowires on Arbitrary Substrates

    PubMed Central

    Kim, Baek Hyun; Kwon, Jae W.

    2014-01-01

    Zinc oxide nanowires generated by hydrothermal method present superior physical and chemical characteristics. Quality control of the growth has been very challenging and controlled growth is only achievable under very limited conditions using homogeneous seed layers with high temperature processes. Here we show the controlled ZnO nanowire growth on various organic and inorganic materials without the requirement of a homogeneous seed layer and a high temperature process. We also report the discovery of an important role of the electronegativity in the nanowire growth on arbitrary substrates. Using heterogeneous metal oxide interlayers with low-temperature hydrothermal methods, we demonstrate well-controlled ZnO nanowire arrays and single nanowires on flat or curved surfaces. A metal catalyst and heterogeneous metal oxide interlayers are found to determine lattice-match with ZnO and to largely influence the controlled alignment. These findings will contribute to the development of novel nanodevices using controlled nanowires. PMID:24625584

  3. Functional zinc oxide nanostructures for electronic and energy applications

    NASA Astrophysics Data System (ADS)

    Prasad, Abhishek

    ZnO has proven to be a multifunctional material with important nanotechnological applications. ZnO nanostructures can be grown in various forms such as nanowires, nanorods, nanobelts, nanocombs etc. In this work, ZnO nanostructures are grown in a double quartz tube configuration thermal Chemical Vapor Deposition (CVD) system. We focus on functionalized ZnO Nanostructures by controlling their structures and tuning their properties for various applications. The following topics have been investigated: (1) We have fabricated various ZnO nanostructures using a thermal CVD technique. The growth parameters were optimized and studied for different nanostructures. (2) We have studied the application of ZnO nanowires (ZnONWs) for field effect transistors (FETs). Unintentional n-type conductivity was observed in our FETs based on as-grown ZnO NWs. We have then shown for the first time that controlled incorporation of hydrogen into ZnO NWs can introduce p-type characters to the nanowires. We further found that the n-type behaviors remained, leading to the ambipolar behaviors of hydrogen incorporated ZnO NWs. Importantly, the detected p- and n- type behaviors are stable for longer than two years when devices were kept in ambient conditions. All these can be explained by an ab initio model of Zn vacancy-Hydrogen complexes, which can serve as the donor, acceptors, or green photoluminescence quencher, depend on the number of hydrogen atoms involved. (3) Next ZnONWs were tested for electron field emission. We focus on reducing the threshold field (Eth) of field emission from non-aligned ZnO NWs. As encouraged by our results on enhancing the conductivity of ZnO NWs by hydrogen annealing described in Chapter 3, we have studied the effect of hydrogen annealing for improving field emission behavior of our ZnO NWs. We found that optimally annealed ZnO NWs offered much lower threshold electric field and improved emission stability. We also studied field emission from ZnO NWs at moderate vacuum levels. We found that there exists a minimum Eth as we scale the threshold field with pressure. This behavior is explained by referring to Paschen's law.(4) We have studied the application of ZnO nanostructures for solar energy harvesting. First, as-grown and (CdSe) ZnS QDs decorated ZnO NBs and ZnONWs were tested for photocurrent generation. All these nanostructures offered fast response time to solar radiation. The decoration of QDs decreases the stable current level produced by ZnONWs but increases that generated by NBs. It is possible that NBs offer more stable surfaces for the attachment of QDs. In addition, our results suggests that performance degradation of solar cells made by growing ZnO NWs on ITO is due to the increase in resistance of ITO after the high temperature growth process. Hydrogen annealing also improve the efficiency of the solar cells by decreasing the resistance of ITO. Due to the issues on ITO, we use Ni foil as the growth substrates. Performance of solar cells made by growing ZnO NWs on Ni foils degraded after Hydrogen annealing at both low (300°C) and high (600°C) temperatures since annealing passivates native defects in ZnONWs and thus reduce the absorption of visible spectra from our solar simulator. Decoration of QDs improves the efficiency of such solar cells by increasing absorption of light in the visible region. Using a better electrolyte than phosphate buffer solution (PBS) such as KI also improves the solar cell efficiency. (5) Finally, we have attempted p-type doping of ZnO NWs using various growth precursors including phosphorus pentoxide, sodium fluoride, and zinc fluoride. We have also attempted to create p-type carriers via introducing interstitial fluorine by annealing ZnO nanostructures in diluted fluorine gas. In brief, we are unable to reproduce the growth of reported p-type ZnO nanostructures. However; we have identified the window of temperature and duration of post-growth annealing of ZnO NWs in dilute fluorine gas which leads to suppression of native defects. This is the first experimental effort on pos

  4. Synthesis and characterization of single-crystalline zinc tin oxide nanowires

    PubMed Central

    2014-01-01

    Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 ?m, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn?+?Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV. PMID:24872800

  5. Density Functional Theory Study of Atomic Layer Deposition of Zinc Oxide on Graphene.

    PubMed

    Ali, Amgad Ahmed; Hashim, Abdul Manaf

    2015-12-01

    The dissociation of zinc ions (Zn(2+)) from vapor-phase zinc acetylacetonate, Zn(C5H7O2)2, or Zn(acac)2 and its adsorption onto graphene oxide via atomic layer deposition (ALD) were studied using a quantum mechanics approach. Density functional theory (DFT) was used to obtain an approximate solution to the Schrödinger equation. The graphene oxide cluster model was used to represent the surface of the graphene film after pre-oxidation. In this study, the geometries of reactants, transition states, and products were optimized using the B3LYB/6-31G** level of theory or higher. Furthermore, the relative energies of the various intermediates and products in the gas-phase radical mechanism were calculated at the B3LYP/6-311++G** and MP2/6-311?+?G(2df,2p) levels of theory. Additionally, a molecular orbital (MO) analysis was performed for the products of the decomposition of the Zn(acac)2 complex to investigate the dissociation of Zn(2+) and the subsequent adsorption of H atoms on the C5H7O2 cluster to form acetylacetonate enol. The reaction energies were calculated, and the reaction mechanism was accordingly proposed. A simulation of infrared (IR) properties was performed using the same approach to support the proposed mechanism via a complete explanation of bond forming and breaking during each reaction step. PMID:26198282

  6. Synthesis and characterization of single-crystalline zinc tin oxide nanowires

    NASA Astrophysics Data System (ADS)

    Shi, Jen-Bin; Wu, Po-Feng; Lin, Hsien-Sheng; Lin, Ya-Ting; Lee, Hsuan-Wei; Kao, Chia-Tze; Liao, Wei-Hsiang; Young, San-Lin

    2014-05-01

    Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 ?m, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn + Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV.

  7. Synthesis and characterization of single-crystalline zinc tin oxide nanowires.

    PubMed

    Shi, Jen-Bin; Wu, Po-Feng; Lin, Hsien-Sheng; Lin, Ya-Ting; Lee, Hsuan-Wei; Kao, Chia-Tze; Liao, Wei-Hsiang; Young, San-Lin

    2014-01-01

    Crystalline zinc tin oxide (ZTO; zinc oxide with heavy tin doping of 33 at.%) nanowires were first synthesized using the electrodeposition and heat treatment method based on an anodic aluminum oxide (AAO) membrane, which has an average diameter of about 60 nm. According to the field emission scanning electron microscopy (FE-SEM) results, the synthesized ZTO nanowires are highly ordered and have high wire packing densities. The length of ZTO nanowires is about 4 ?m, and the aspect ratio is around 67. ZTO nanowires with a Zn/(Zn?+?Sn) atomic ratio of 0.67 (approximately 2/3) were observed from an energy dispersive spectrometer (EDS). X-ray diffraction (XRD) and corresponding selected area electron diffraction (SAED) patterns demonstrated that the ZTO nanowire is hexagonal single-crystalline. The study of ultraviolet/visible/near-infrared (UV/Vis/NIR) absorption showed that the ZTO nanowire is a wide-band semiconductor with a band gap energy of 3.7 eV. PMID:24872800

  8. Evaluation of zinc oxide nanoparticles toxicity on marine algae chlorella vulgaris through flow cytometric, cytotoxicity and oxidative stress analysis.

    PubMed

    Suman, T Y; Radhika Rajasree, S R; Kirubagaran, R

    2015-03-01

    The increasing industrial use of nanomaterials during the last decades poses a potential threat to the environment and in particular to organisms living in the aquatic environment. In the present study, the toxicity of zinc oxide nanoparticles (ZnO NPs) was investigated in Marine algae Chlorella vulgaris (C. vulgaris). High zinc dissociation from ZnONPs, releasing ionic zinc in seawater, is a potential route for zinc assimilation and ZnONPs toxicity. To examine the mechanism of toxicity, C. vulgaris were treated with 50mg/L, 100mg/L, 200mg/L and 300 mg/L ZnO NPs for 24h and 72h. The detailed cytotoxicity assay showed a substantial reduction in the viability dependent on dose and exposure. Further, flow cytometry revealed the significant reduction in C. vulgaris viable cells to higher ZnO NPs. Significant reductions in LDH level were noted for ZnO NPs at 300 mg/L concentration. The activity of antioxidant enzyme superoxide dismutase (SOD) significantly increased in the C. vulgaris exposed to 200mg/L and 300 mg/L ZnO NPs. The content of non-enzymatic antioxidant glutathione (GSH) significantly decreased in the groups with a ZnO NPs concentration of higher than 100mg/L. The level of lipid peroxidation (LPO) was found to increase as the ZnO NPs dose increased. The FT-IR analyses suggested surface chemical interaction between nanoparticles and algal cells. The substantial morphological changes and cell wall damage were confirmed through microscopic analyses (FESEM and CM). PMID:25483368

  9. Surface nanostructuring by ion-induced localized plasma expansion in zinc oxide

    SciTech Connect

    El-Said, A. S., E-mail: elsaid@kfupm.edu.sa, E-mail: a.s.el-said@hzdr.de [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), 01328 Dresden (Germany); Physics Department, Faculty of Science, Mansoura University, 35516 Mansoura (Egypt); Moslem, W. M. [Department of Physics, Faculty of Science, Port Said University, Port Said 42521 (Egypt); Centre for Theoretical Physics, British University in Egypt (BUE), El-Shorouk City, Cairo (Egypt); Djebli, M. [Theoretical Physics Laboratory, Faculty of Physics USTHB, B.P. 32 Bab Ezzour, 16079 Algiers (Algeria)

    2014-06-09

    Creation of hillock-like nanostructures on the surface of zinc oxide single crystals by irradiation with slow highly charged ions is reported. At constant kinetic energy, the nanostructures were only observed after irradiation with ions of potential energies above a threshold between 19.1?keV and 23.3?keV. The size of the nanostructures increases as a function of potential energy. A plasma expansion approach is used to explain the nanostructures creation. The calculations showed that the surface nanostructures became taller with the increase of ionic temperature. The influence of charged cluster formation and the relevance of their polarity are discussed.

  10. Preparation of surface modified zinc oxide nanoparticle with high capacity dye removal ability

    SciTech Connect

    Mahmoodi, Niyaz Mohammad, E-mail: nm_mahmoodi@yahoo.com [Department of Environmental Research, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of); Najafi, Farhood [Department of Resin and Additives, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of)] [Department of Resin and Additives, Institute for Color Science and Technology, Tehran (Iran, Islamic Republic of)

    2012-07-15

    Highlights: ? Amine-functionalized zinc oxide nanoparticle (AFZON) was synthesized. ? Isotherm and kinetics data followed Langmuir isotherm and pseudo-second order kinetic model, respectively. ? Q{sub 0} of ZON for AB25, DR23 and DR31 was 20, 12 and 15 mg/g, respectively. ? Q{sub 0} of AFZON for AB25, DR23 and DR31 was 1250, 1000 and 1429 mg/g, respectively. ? AFZON was regenerated at pH 12. -- Abstract: In this paper, the surface modification of zinc oxide nanoparticle (ZON) by amine functionalization was studied to prepare high capacity adsorbent. Dye removal ability of amine-functionalized zinc oxide nanoparticle (AFZON) and zinc oxide nanoparticle (ZON) was also investigated. The physical characteristics of AFZON were studied using Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Acid Blue 25 (AB25), Direct Red 23 (DR23) and Direct Red 31 (DR31) were used as model compounds. The effect of operational parameters such as dye concentration, adsorbent dosage, pH and salt on dye removal was evaluated. The isotherm and kinetic of dye adsorption were studied. The maximum dye adsorption capacity (Q{sub 0}) was 20 mg/g AB25, 12 mg/g DR23 and 15 mg/g DR31 for ZON and 1250 mg/g AB25, 1000 mg/g DR23 and 1429 mg/g DR31 for AFZON. It was found that dye adsorption followed Langmuir isotherm. Adsorption kinetic of dyes was found to conform to pseudo-second order kinetics. Dye desorption tests (adsorbent regeneration) showed that the maximum dye release of 90% AB25, 86% for DR23 and 90% for DR31 were achieved in aqueous solution at pH 12. Based on the data of the present investigation, it can be concluded that the AFZON being an adsorbent with high dye adsorption capacity might be a suitable alternative to remove dyes from colored aqueous solutions.

  11. Experimental confirmation of the predicted shallow donor hydrogen state in zinc oxide.

    PubMed

    Cox, S F; Davis, E A; Cottrell, S P; King, P J; Lord, J S; Gil, J M; Alberto, H V; Vilão, R C; Piroto Duarte, J; Ayres de Campos, N; Weidinger, A; Lichti, R L; Irvine, S J

    2001-03-19

    We confirm the recent prediction that interstitial protium may act as a shallow donor in zinc oxide, by direct spectroscopic observation of its muonium counterpart. On implantation into ZnO, positive muons--chemically analogous to protons in this context--form paramagnetic centers below about 40 K. The muon-electron contact hyperfine interaction, as well as the temperature and activation energy for ionization, imply a shallow level. Similar results for the cadmium chalcogenides suggest that such shallow donor states are generic to the II-VI compounds. The donor level depths should serve as a guide for the electrical activity of interstitial hydrogen. PMID:11289990

  12. Constrained, aqueous growth of three-dimensional single crystalline zinc oxide structures

    SciTech Connect

    Pooley, Kathryn J., E-mail: greenber@fas.harvard.edu; Joo, John H.; Hu, Evelyn L. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    2014-01-01

    We study low temperature (90?°C) aqueous growth of single crystal zinc oxide structures through patterned PMMA molds of different sizes, shapes, and orientations. We demonstrate the ability to create 3D shapes with smooth vertical sidewalls. Although the unconstrained growth is influenced by the hexagonal geometry of the underlying crystal structure, the ZnO is shown to conform exactly to any shape patterned. Using electron backscatter diffraction and scanning electron microscopy we show that the mold orientation, in conjunction with control of the growth rates of the c and m planes of the ZnO, is crucial in determining the final structure shape.

  13. Effects of Different Precursor's Concentration on the Properties of Zinc Oxide Thin Films

    SciTech Connect

    Malek, M. F.; Zakaria, N.; Sahdan, M. Z.; Mamat, M. H. [Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Khusaimi, Z. [NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); Rusop, M. [Faculty of Electrical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia); NANO-SciTech Centre, Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam, Selangor (Malaysia)

    2010-07-07

    Zinc oxide (ZnO) thin films were successfully grown on silicon substrate with different molarities, by a sol-gel method. In the process, the molarities were varied from 0.2-1.0 M and it was found that increasing in molarities had affected the structure of ZnO thin films. The properties of the thin films were characterized and studied by ultraviolet-visible spectroscopy (UV-Vis) and photoluminescence spectrometer (PL). It was found that the molarities affect the optical properties of the resultant ZnO thin films.

  14. Ultra Thin Ga-doped Transparent Conducting Zinc Oxide Films Fabricated by Pulsed Laser Deposition Method

    NASA Astrophysics Data System (ADS)

    Kaneda, Shinji; Aoki, Takanori; Matsushita, Tatsuhiko; Suzuki, Akio; Okuda, Masahiro

    Ultra-thin Ga2O3 doped zinc oxide transparent conduction films was deposited on glass substrates using pulsed laser deposition method by ArF excimer laser (?=193 nm) at the substrate temperature from 180 to 260 °C. The film thickness was changed from 40 to 110 nm-thick. The target containing 3 and 5 wt.% Ga2O3 were employed. As a result, resistivity of 2.69×10-4 ?·cm was obtained for the film with 40 nm-thick fabricated using the target containing 5 wt.% Ga2O3 at substrate temperature of 260°C.

  15. Laminates of zinc oxide and poly(amino acid) layers with enhanced mechanical performance

    NASA Astrophysics Data System (ADS)

    Lipowsky, Peter; Burghard, Žaklina; Jeurgens, Lars P. H.; Bill, Joachim; Aldinger, Fritz

    2007-08-01

    In order to improve the resistance of solution-derived zinc oxide thin films against mechanical stress, nanostructured composite systems of soft organic and brittle ZnO layers were prepared by a bio-inspired process. As the organic component, polyelectrolyte multilayers were prepared by dip-coating using polystyrene sulfonate and poly(amino acids). The organic-inorganic laminates have typical properties in common with nacre: they consist of nanocrystals in a matrix of biomolecules, they exhibit a texture and they proved to be harder than the monolithic mineral.

  16. Electronic memory effects in diodes from a zinc oxide nanoparticle-polystyrene hybrid material

    NASA Astrophysics Data System (ADS)

    Verbakel, Frank; Meskers, Stefan C. J.; Janssen, René A. J.

    2006-09-01

    Current-voltage characteristics of diode structures with an active layer of a zinc oxide nanoparticle-polystyrene hybrid material (1:2 by weight) deposited by spin coating from solution were investigated. Aluminum and poly(3,4-ethylenedioxythiophene):polystyrene-sulfonate were used as electrodes. After a forming step, the conduction under reversed bias voltage can be raised or lowered in a gradual and reversible manner by applying forward and reverse bias voltages, respectively. Electrically induced switching between states with high and lower conductivities is possible on a time scale of 100ms and the conduction levels remain stable for over 1h.

  17. Surfactant-modified nickel zinc iron oxide\\/polymer nanocomposites for radio frequency applications

    Microsoft Academic Search

    Ta-I. Yang; Rene N. C. Brown; Leo C. Kempel; Peter Kofinas

    2010-01-01

    Low loss, flexible, polymer nanocomposites with improved magneto-dielectric properties at radio frequencies (RF) were successfully\\u000a fabricated. Surfactant-modified nickel zinc iron oxide (NiZnFe2O4) nanoparticles with ferrimagnetic behavior at room temperature were synthesized by a seed-mediated growth method. The surfactant\\u000a prevented NiZnFe2O4 particle aggregation and provided compatibility with [styrene-b-ethylene\\/butylene-b-styrene] block copolymer matrices. NiZnFe2O4\\/polymer composites were prepared by a solution-casting method. Experimental results

  18. Cation-Mediated Effects on Zinc Oxide Films Formed by Chemical Bath Deposition

    Microsoft Academic Search

    Hua-Chi Cheng; Chia-Fu Chen; Chien-Yie Tsay

    2007-01-01

    Crystalline ZnO films with a densely packed morphology were grown on a silicon oxide (SiOx) glass substrate by chemical bath deposition (CBD) in an aqueous-solution bath containing magnesium nitrate [Mg(NO3)2\\\\cdot2H2O] used as a cation-mediation compound, zinc nitrate [Zn(NO3)2\\\\cdot6H2O], and dimethylamineborane (DMAB) at 65 °C. Grains of ZnO films grown in nonmediated solution preferentially grew on the (002) plane. In the

  19. Zinc oxide films prepared by sol–gel spin coating technique

    Microsoft Academic Search

    Sharul Ashikin Kamaruddin; Kah-Yoong Chan; Ho-Kwang Yow; Mohd Zainizan Sahdan; Hashim Saim; Dietmar Knipp

    2011-01-01

    Zinc oxide (ZnO) thin films and micro- and nanostructures are very promising candidates for novel applications in emerging\\u000a thin-film transistors, solar cells, sensors and optoelectronic devices. In this paper, a low-cost sol–gel spin coating technique\\u000a was used to fabricate ZnO films on glass substrates. The sol–gel fabrication process of the ZnO films is described. The influence\\u000a of precursor concentration on

  20. Zinc oxide integrated area efficient high output low power wavy channel thin film transistor

    SciTech Connect

    Hanna, A. N.; Ghoneim, M. T.; Bahabry, R. R.; Hussain, A. M.; Hussain, M. M., E-mail: muhammadmustafa.hussain@kaust.edu.sa [Integrated Nanotechnology Lab, Electrical Engineering, Computer Electrical Mathematical Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)

    2013-11-25

    We report an atomic layer deposition based zinc oxide channel material integrated thin film transistor using wavy channel architecture allowing expansion of the transistor width in the vertical direction using the fin type features. The experimental devices show area efficiency, higher normalized output current, and relatively lower power consumption compared to the planar architecture. This performance gain is attributed to the increased device width and an enhanced applied electric field due to the architecture when compared to a back gated planar device with the same process conditions.

  1. Analysis of indium zinc oxide thin films by laser-induced breakdown spectroscopy

    SciTech Connect

    Popescu, A. C. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France); National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); Beldjilali, S. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France); LPPMCA, Universite des Sciences et de la Technologie d'Oran, BP 1505 El Mnaouer, Oran (Algeria); Socol, G.; Mihailescu, I. N. [National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); Craciun, V. [National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); MAIC, University of Florida, Gainesville, FL 32611 (United States); Hermann, J. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France)

    2011-10-15

    We have performed spectroscopic analysis of the plasma generated by Nd:YAG ({lambda} = 266 nm) laser irradiation of thin indium zinc oxide films with variable In content deposited by combinatorial pulsed laser deposition on glass substrates. The samples were irradiated in 5 x 10{sup 4} Pa argon using laser pulses of 5 ns duration and 10 mJ energy. The plasma emission spectra were recorded with an Echelle spectrometer coupled to a gated detector with different delays with respect to the laser pulse. The relative concentrations of indium and zinc were evaluated by comparing the measured spectra to the spectral radiance computed for a plasma in local thermal equilibrium. Plasma temperature and electron density were deduced from the relative intensities and Stark broadening of spectral lines of atomic zinc. Analyses at different locations on the deposited thin films revealed that the In/(In + Zn) concentration ratio significantly varies over the sample surface, from 0.4 at the borders to about 0.5 in the center of the film. The results demonstrate that laser-induced breakdown spectroscopy allows for precise and fast characterization of thin films with variable composition.

  2. Study of zinc oxide epitaxial film growth and UV photodetectors

    NASA Astrophysics Data System (ADS)

    Nahhas, Ahmed Mohammed

    ZnO is a versatile material, and has been extensively studied for various applications such as varistors, transducers, transparent conducting electrodes, sensors, and catalysts. While polycrystalline ZnO is commonly used in these conventional applications, there has been a growing interest in obtaining single-crystalline ZnO films on various substrates. ZnO is a II-VI wide bandgap semiconductor with a relatively large exciton binding energy, and holds a potential for light emitting/detecting or nonlinear optical devices in the UV range. ZnO is isomorphic to wurtzite GaN with good lattice match, and therefore there has been a great deal of interest in using ZnO as a buffer layer or a substrate in growing high quality GaN films (or vice versa ZnO growth on GaN). In this study, we have investigated epitaxial growth of ZnO films on sapphire and silicon substrates. High quality epitaxial ZnO films were grown on sapphire (0001) single crystal substrates using a rf magnetron sputtering technique. X-ray diffraction analysis shows that the ZnO films are of a monocrystalline wurtzite structure with their epitaxial relationship of ZnO[0001]//sapphire[0001] along the growth direction and ZnO[112&barbelow;0]//sapphire[11&barbelow;00] along the in-plane direction. ZnO on Si also offers an interesting opportunity that the various functional properties of ZnO can be combined with the advanced Si electronics on the same substrate. Direct growth of epitaxial ZnO on Si, however, is known to be an extremely difficult task due to the oxidation problem during the nucleation stage of a ZnO growth process. We have overcome this problem by introducing an epitaxial GaN buffer layer, and have successfully grown epitaxial ZnO films on Si(111) substrates. X-ray diffraction analysis confirms an epitaxial relationship of ZnO[0001]//GaN[0001]//Si[111] along the growth direction and ZnO[112&barbelow;0]//GaN[112&barbelow;0]//Si[11&barbelow;0] along the in-plane direction. As an application of the epitaxial ZnO films grown with sputtering, we have developed the UV photoconductors, and characterized the UV detection properties. Ultra-high responsivity (of 104 A/W order) was observed with strong dependence on the illumination power. The high responsivity suggests an enhanced carrier lifetime in the photoconductor structure, which is attributed to the preferential capture of holes at surface states and the subsequent separation of photogenerated carriers by the space charge region formed near the film surface. The power dependence of responsivity is explained using a model that was developed based on the concept of the space charge region modulation by the photogenerated carriers and the resulting change in the effective carrier lifetime.

  3. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...azo(substituted phenyl)azo, sodium salt (generic name). 721.5930 Section...azo(substituted phenyl)azo, sodium salt (generic name). (a) Chemical substance...azo (substituted phenyl) azo, sodium salt (PMN P-95-274) is subject to...

  4. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...azo(substituted phenyl)azo, sodium salt (generic name). 721.5930 Section...azo(substituted phenyl)azo, sodium salt (generic name). (a) Chemical substance...azo (substituted phenyl) azo, sodium salt (PMN P-95-274) is subject to...

  5. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...azo(substituted phenyl)azo, sodium salt (generic name). 721.5930 Section...azo(substituted phenyl)azo, sodium salt (generic name). (a) Chemical substance...azo (substituted phenyl) azo, sodium salt (PMN P-95-274) is subject to...

  6. Effect of nitrogen doping on wetting and photoactive properties of laser processed zinc oxide-graphene oxide nanocomposite layers

    NASA Astrophysics Data System (ADS)

    György, E.; Pérez del Pino, A.; Logofatu, C.; Duta, A.; Isac, L.

    2014-07-01

    Zinc oxide-graphene oxide nanocomposite layers were submitted to laser irradiation in air or controlled nitrogen atmosphere using a frequency quadrupled Nd:YAG (? = 266 nm, ?FWHM ? 3 ns, ? = 10 Hz) laser source. The experiments were performed in air at atmospheric pressure or in nitrogen at a pressure of 2 × 104 Pa. The effect of the irradiation conditions, incident laser fluence value, and number of subsequent laser pulses on the surface morphology of the composite material was systematically investigated. The obtained results reveal that nitrogen incorporation improves significantly the wetting and photoactive properties of the laser processed layers. The kinetics of water contact angle variation when the samples are submitted to laser irradiation in nitrogen are faster than that of the samples irradiated in air, the surfaces becoming super-hydrophilic under UV light irradiation.

  7. Effect of nitrogen doping on wetting and photoactive properties of laser processed zinc oxide-graphene oxide nanocomposite layers

    SciTech Connect

    György, E., E-mail: egyorgy@icmab.es [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona (CSIC-ICMAB), Campus UAB, 08193 Bellaterra (Spain); National Institute for Lasers, Plasma and Radiation Physics, P. O. Box MG 36, 76900 Bucharest V (Romania); Pérez del Pino, A. [Consejo Superior de Investigaciones Cientificas, Instituto de Ciencia de Materiales de Barcelona (CSIC-ICMAB), Campus UAB, 08193 Bellaterra (Spain); Logofatu, C. [National Institute for Materials Physics, P. O. Box MG. 7, 77125 Bucharest (Romania); Duta, A.; Isac, L. [Transilvania University of Brasov, Research Centre for Renewable Energy Systems and Recycling, Eroilor 29, 500036, Brasov (Romania)

    2014-07-14

    Zinc oxide-graphene oxide nanocomposite layers were submitted to laser irradiation in air or controlled nitrogen atmosphere using a frequency quadrupled Nd:YAG (??=?266?nm, ?{sub FWHM}???3?ns, ??=?10?Hz) laser source. The experiments were performed in air at atmospheric pressure or in nitrogen at a pressure of 2?×?10{sup 4} Pa. The effect of the irradiation conditions, incident laser fluence value, and number of subsequent laser pulses on the surface morphology of the composite material was systematically investigated. The obtained results reveal that nitrogen incorporation improves significantly the wetting and photoactive properties of the laser processed layers. The kinetics of water contact angle variation when the samples are submitted to laser irradiation in nitrogen are faster than that of the samples irradiated in air, the surfaces becoming super-hydrophilic under UV light irradiation.

  8. Copolymerization of cyclohexene oxide with CO2 by using intramolecular dinuclear zinc catalysts.

    PubMed

    Xiao, Youli; Wang, Zheng; Ding, Kuiling

    2005-06-01

    The intramolecular dinuclear zinc complexes generated in situ from the reaction of multidentate semi-azacrown ether ligands with Et(2)Zn, followed by treatment with an alcohol additive, were found to promote the copolymerization of CO(2) and cyclohexene oxide (CHO) with completely alternating polycarbonate selectivity and high efficiency. With this type of novel initiator, the copolymerization could be accomplished under mild conditions at 1 atm pressure of CO(2), which represents a significant advantage over most catalytic systems developed for this reaction so far. The copolymerization reaction was demonstrated to be a living process as a result of the narrow polydispersities and the linear increase in the molecular weight with conversion of CHO. In addition, the solid-state structure of the dinuclear zinc complex was characterized by X-ray crystal structural analysis and can be considered as a model of the active catalyst. On the basis of the various efforts made to understand the mechanisms of the catalytic reaction, including MALDI-TOF mass analysis of the copolymers' end-groups, the effect of alcohol additives on the catalysis and CO(2) pressure on the conversion of CHO, as well as the kinetic data gained from in situ IR spectroscopy, a plausible catalytic cycle for the present reaction system is outlined. The copolymerization is initiated by the insertion of CO(2) into the Zn--OEt bond to afford a carbonate-ester-bridged complex. The dinuclear zinc structure of the catalyst remains intact throughout the copolymerization. The bridged zinc centers may have a synergistic effect on the copolymerization reaction; one zinc center could activate the epoxide through its coordination and the second zinc atom may be responsible for carbonate propagation by nucleophilic attack by the carbonate ester on the back side of the cis-epoxide ring to afford the carbonate. The mechanistic implication of this is particularly important for future research into the design of efficient and practical catalysts for the copolymerization of epoxides with CO(2.). PMID:15827981

  9. Post-Deposition Induced Conductivity in Pulsed Laser Irradiated Metal Doped Zinc Oxide Films

    SciTech Connect

    Wang, Lisa J.; Exarhos, Gregory J.

    2009-12-03

    The optical and electrical properties of doped solution-deposited and rf sputter-deposited thin metal oxide films were investigated following post deposition pulsed laser irradiation. Solution deposited films were annealed at 450 ºC. Following the heating regiment, the transparent metal oxide films were subjected to 355 nm pulsed Nd:YAG laser irradiation (4 nsec pulsewidth) at fluences between 5 and 150 mJ/cm2. Irradiation times at pulse frequencies of 30 Hz ranged from seconds to tens of minutes. Film densification, index change and a marked increase in conductivity were observed following irradiation in air and under vacuum of Al:ZnO (AZO), Ga:ZnO (GZO), and In:ZnO (IZO) films deposited on silica substrates. Despite the measured increase in conductivity, all films continued to show high transparency on the order of 90% at wavelengths from the band edge well into the near infrared region of the spectrum. Laser energies required for turning on the conductivity of these films varied depending upon the dopant. Irradiations in air yielded resistivity measurements on the order of 16 ?.cm. Resistivities of films irradiated under vacuum were on the order of 0.1 ?.cm. The increase in conductivity can be attributed to the formation of oxygen vacancies and subsequent promotion of free carriers into the conduction band. All irradiated films become insulating after around 24 hours. Oxygen atoms in air become reduced by electrons in the metal conduction band and diffuse into the vacancies in the lattice. The rate of this reduction process depends on the type of dopant. This work also sheds light on the damage threshold, correlating the optical properties with the presence of free carriers that have been introduced into the conduction band. All films were characterized by means of UV-VIS-NIR transmission spectroscopy, visible and UV Raman spectroscopy and Hall measurements. Analysis of interference fringes in measured transmission spectra allowed film density and refractive index to be evaluated while the Raman measurements showed an increase in LO mode intensity with respect to the TO mode intensity as the films became more conducting. Results of this study are not only important for the continued development of transparent conducting oxide films that find use in photovoltaic cells and solid state lighting modules, but also provide evidence for the role of free carriers in initiating the laser damage process in these wide bandgap metal oxide films.

  10. Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

    Microsoft Academic Search

    K. Bahedi; M. Addou; M. El Jouad; Z. Sofiani; M. Alaoui Lamrani; T. El Habbani; N. Fellahi; S. Bayoud; L. Dghoughi; B. Sahraoui; Z. Essaïdi

    2009-01-01

    Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500°C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG)

  11. Mixed metal oxides for dye-sensitized solar cell using zinc titanium layered double hydroxide as precursor

    NASA Astrophysics Data System (ADS)

    Liu, Jianqiang; Qin, Yaowei; Zhang, Liangji; Xiao, Hongdi; Song, Jianye; Liu, Dehe; Leng, Mingzhe; Hou, Wanguo; Du, Na

    2013-12-01

    Mixed metal oxides (MMO) are always obtained from layered double hydroxide (LDH) by thermal decomposition. In the present work, a zinc titanium LDH with the zinc titanium molar ratio of 4.25 was prepared by urea method and ZnO-based mixed oxides were obtained by calcining at or over 500°C. The MMO was used as electrodes for dye sensitized solar cell (DSSC). The cells constructed by films of prepared composite materials using a N719 as dye were prepared. The efficiency values of these cells are 0.691%, 0.572% and 0.302% with MMO prepared at 500, 600 and 700°C, respectively.

  12. Ex Vivo - Growth Response of Porcine Small Intestinal Bacterial Communities to Pharmacological Doses of Dietary Zinc Oxide

    PubMed Central

    Starke, Ingo C.; Zentek, Jürgen; Vahjen, Wilfried

    2013-01-01

    Piglets were fed diets containing 57 (low) or 2425 (high) mg zinc from analytical grade zinc oxide (ZnO) ·kg?1 feed. Digesta samples from the stomach and jejuna of 32, 39, 46 and 53 d old animals (n ?=?6 per group) were incubated in media containing 80, 40, 20 and 0 µg·mL?1 soluble zinc from ZnO. Turbidity was recorded for 16 h and growth parameters were calculated. Additionally, DNA extracts of selected samples were analyzed via qPCR for different bacterial groups. Samples from animals fed the low dietary zinc concentration always showed highest rate of growth and lowest lag times in media without added zinc. However, media supplemented with zinc displayed highest growth rates and lowest lag time in the high dietary zinc group. Specific growth rates and lag time showed significant differences on day 32 and 39 of age, but rarely on days 46 and 53 of age. Bacterial growth in digesta samples from the high dietary zinc group was less influenced by zinc and recovered growth more rapidly than in the low dietary zinc group. Specific growth rates and bacterial cell numbers from qPCR results showed that lactobacilli were most susceptible to zinc, while bifidobacteria, enterobacteria and enterococci exhibited increased growth rates in samples of animals from the high dietary zinc treatment. No treatment related differences were observed for clostridial cluster IV and the Bacteroides-Prevotella-Porphyromonas cluster. The diversity of enterobacteria after incubation was always higher in the high dietary zinc treatment or in medium supplemented with 80 µg·mL?1 soluble ZnO. This study has shown that a pharmacological dosage of ZnO leads to a reduced ex vivo- bacterial growth rate of bacteria from the stomach and jejunum of weaned piglets. In view of the rapid bacterial adaptation to dietary zinc, the administration of ZnO in feeds for weaned piglets might only be beneficial in a short period after weaning. PMID:23441186

  13. Role of quercetin and arginine in ameliorating nano zinc oxide-induced nephrotoxicity in rats

    PubMed Central

    2012-01-01

    Background Nanoparticles are small-scale substances (<100?nm) with unique properties. Therefore, nanoparticles pose complex health risk implications. The objective of this study was to detect whether treatment with quercetin (Qur) and/or arginine (Arg) ameliorated nephrotoxicity induced by two different doses of nano zinc oxide (n-ZnO) particles. Method ZnO nanoparticles were administered orally in two doses (either 600?mg or 1?g/Kg body weight/day for 5 conscutive days) to Wister albino rats. In order to detect the protective effects of the studied antioxidants against n-ZnO induced nepherotoxicity, different biochemical parameters were investigated. Moreover, histopathological examination of kidney tissue was performed. Results Nano zinc oxide-induced nephrotoxicity was confirmed by the elevation in serum inflammatory markers including: tumor necrosis factor alpha (TNF-?), interleukin-6 (IL-6); and C-reactive protein (CRP). Moreover, immunoglobulin (IGg), vascular endothelium growth factor (VEGF), and nitric oxide (NO) were significantly increased in rat serum. Serum urea and creatinine levels were also significantly increased in rats intoxicated with n-ZnO particles compared with the control group. Additionally, a significant decrease in the non-enzymatic antioxidant reduced glutathione (GSH) was shown in kidney tissues and serum glucose levels were increased. These biochemical findings were supported by a histopathological examination of kidney tissues, which showed that in the animals that received a high dose of n-ZnO, numerous kidney glomeruli underwent atrophy and fragmentation. Moreover, the renal tubules showed epithelial desquamation, degeneration and necrosis. Some renal tubules showed casts in their lumina. Severe congestion was also observed in renal interstitium. These effects were dose dependent. Cotreatment of rats with Qur and/or Arg along with n-ZnO significantly improved most of the deviated tested parameters. Conclusions The data show that Qur has a beneficial effect against n-ZnO oxidative stress and related vascular complications. Also, its combination with Arg proved to be even more effective in ameliorating nano zinc oxide nephrotoxicity. PMID:22551254

  14. Hydrogen plasma treatment for improved conductivity in amorphous aluminum doped zinc tin oxide thin films

    SciTech Connect

    Morales-Masis, M., E-mail: monica.moralesmasis@epfl.ch; Ding, L.; Dauzou, F. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Jeangros, Q. [Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Hessler-Wyser, A. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Interdisciplinary Centre for Electron Microscopy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Nicolay, S. [Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland); Ballif, C. [Photovoltaics and Thin-Film Electronics Laboratory (PVLab), Institute of Microengineering (IMT), Ecole Polytechnique Fédérale de Lausanne - EPFL, Rue de la Maladière 71b, CH-2002 Neuchatel (Switzerland); Centre Suisse d’Electronique et de Microtechnique (CSEM) SA, Rue Jaquet-Droz 1, CH-2002 Neuchatel (Switzerland)

    2014-09-01

    Improving the conductivity of earth-abundant transparent conductive oxides (TCOs) remains an important challenge that will facilitate the replacement of indium-based TCOs. Here, we show that a hydrogen (H{sub 2})-plasma post-deposition treatment improves the conductivity of amorphous aluminum-doped zinc tin oxide while retaining its low optical absorption. We found that the H{sub 2}-plasma treatment performed at a substrate temperature of 50?°C reduces the resistivity of the films by 57% and increases the absorptance by only 2%. Additionally, the low substrate temperature delays the known formation of tin particles with the plasma and it allows the application of the process to temperature-sensitive substrates.

  15. Significant improvement in electronic properties of transparent amorphous indium zinc oxide through yttrium doping

    NASA Astrophysics Data System (ADS)

    Sun, Jian; Yu, Zhigen; Huang, Yanhua; Xia, Yijie; Lai, Weng Soon; Gong, Hao

    2014-04-01

    One big challenge in transparent conducting oxides (TCOs) is to achieve high conductivity and mobility at a low processing temperature. Although optimized conductivity has been achieved in indium zinc oxide (IZO) without doping, it is still interesting to find whether doping can improve conductivity of IZO further. In this paper, we report a low processing temperature achievement of high conductivity and mobility of IZO through yttrium (Y) doping. We found that with different Y doping levels, room temperature fabricated amorphous IZO (a-IZO) samples can be controlled to exhibit either metallic or semiconductor characteristics. Y2O3 is demonstrated to be an effective doping source to achieve conductivity 300% higher than the non-doped IZO sample. Anomalously improved mobility of certain Y2O3-doped IZO samples compared with the non-doped IZO sample is found and analyzed. Besides, a low-temperature resistivity anomaly (semiconductor metal transition) phenomenon is observed and discussed.

  16. Dye sensitized solar cells using well-aligned zinc oxide nanotip arrays

    NASA Astrophysics Data System (ADS)

    Du Pasquier, Aurelien; Chen, Hanhong; Lu, Yicheng

    2006-12-01

    Well-aligned zinc oxide (ZnO) nanotip arrays were grown on fluorinated tin oxide coated glass using metal organic chemical vapor deposition. Dye (N719) sensitized photoelectrochemical cells comprising of ZnO nanotip arrays were fabricated and characterized. It is found that the power conversion efficiency of the cells increases with the length of the ZnO nanotips. The cells with 3.2?m ZnO nanotip array exhibited an incident photon-to-current conversion efficiency of 21.1% (at 550nm) and a power conversion efficiency of 0.55% under 1 sun irradiance. Light harvesting in ZnO nanotips also contributes to the photocurrent in the UV range.

  17. Characterizing the inhibitory action of zinc oxide nanoparticles on allergic-type mast cell activation.

    PubMed

    Feltis, B N; Elbaz, A; Wright, P F A; Mackay, G A; Turney, T W; Lopata, A L

    2015-08-01

    The development of nanoparticles (NPs) for commercial products is undergoing a dramatic expansion. Many sunscreens and cosmetics now use zinc oxide (ZnO) or titania (TiO2) NPs, which are effective ultraviolet (UV) filters. Zinc oxide topical creams are also used in mild anti-inflammatory treatments. In this study we evaluated the effect of size and dispersion state of ZnO and TiO2 NPs, compared to "bulk" ZnO, on mast cell degranulation and viability. ZnO and TiO2 NPs were characterized using dynamic light scattering and disc centrifugation. Rat basophilic leukaemia (RBL-2H3) cells and primary mouse bone marrow-derived mast cells (BMMCs) were exposed to ZnO and TiO2 NPs of different sizes (25-200nm) and surface coatings at concentrations from 1 to 200?g/mL. The effect of NPs on immunoglobulin E (IgE)-dependent mast cell degranulation was assessed by measuring release of both ?-hexosaminidase and histamine via colorimetric and ELISA assays. The intracellular level of Zn(2+) and Ca(2+) ions were measured using zinquin ethyl ester and Fluo-4 AM fluorescence probes, respectively. Cellular viability was determined using the soluble tetrazolium-based MTS colorimetric assay. Exposure of RBL-2H3 and primary mouse BMMC to ZnO NPs markedly inhibited both histamine and ?-hexosaminidase release. This effect was both particle size and dispersion dependent. In contrast, TiO2 NPs did not inhibit the allergic response. These effects were independent of cytotoxicity, which was observed only at high concentrations of ZnO NPs, and was not observed for TiO2 NPs. The inhibitory effects of ZnO NPs on mast cells were inversely proportional to particle size and dispersion status, and thus these NPs may have greater potential than "bulk" zinc in the inhibition of allergic responses. PMID:25771180

  18. Solvothermal synthesis of gallium-indium-zinc-oxide nanoparticles for electrolyte-gated transistors.

    PubMed

    Santos, Lídia; Nunes, Daniela; Calmeiro, Tomás; Branquinho, Rita; Salgueiro, Daniela; Barquinha, Pedro; Pereira, Luís; Martins, Rodrigo; Fortunato, Elvira

    2015-01-14

    Solution-processed field-effect transistors are strategic building blocks when considering low-cost sustainable flexible electronics. Nevertheless, some challenges (e.g., processing temperature, reliability, reproducibility in large areas, and cost effectiveness) are requirements that must be surpassed in order to achieve high-performance transistors. The present work reports electrolyte-gated transistors using as channel layer gallium-indium-zinc-oxide nanoparticles produced by solvothermal synthesis combined with a solid-state electrolyte based on aqueous dispersions of vinyl acetate stabilized with cellulose derivatives, acrylic acid ester in styrene and lithium perchlorate. The devices fabricated using this approach display a ION/IOFF up to 1 × 10(6), threshold voltage (VTh) of 0.3-1.9 V, and mobility up to 1 cm(2)/(V s), as a function of gallium-indium-zinc-oxide ink formulation and two different annealing temperatures. These results validates the usage of electrolyte-gated transistors as a viable and promising alternative for nanoparticle based semiconductor devices as the electrolyte improves the interface and promotes a more efficient step coverage of the channel layer, reducing the operating voltage when compared with conventional dielectrics gating. Moreover, it is shown that by controlling the applied gate potential, the operation mechanism of the electrolyte-gated transistors can be modified from electric double layer to electrochemical doping. PMID:25517251

  19. Barbiturase, a novel zinc-containing amidohydrolase involved in oxidative pyrimidine metabolism.

    PubMed

    Soong, Chee-Leong; Ogawa, Jun; Sakuradani, Eiji; Shimizu, Sakayu

    2002-03-01

    Barbiturase, which catalyzes the reversible amidohydrolysis of barbituric acid to ureidomalonic acid in the second step of oxidative pyrimidine degradation, was purified to homogeneity from Rhodococcus erythropolis JCM 3132. The characteristics and gene organization of barbiturase suggested that it is a novel zinc-containing amidohydrolase that should be grouped into a new family of the amidohydrolases superfamily. The amino acid sequence of barbiturase exhibited 48% identity with that of herbicide atrazine-decomposing cyanuric acid amidohydrolase but exhibited no significant homology to other proteins, indicating that cyanuric acid amidohydrolase may have evolved from barbiturase. A putative uracil phosphoribosyltransferase gene was found upstream of the barbiturase gene, suggesting mutual interaction between pyrimidine biosynthesis and oxidative degradation. Metal analysis with an inductively coupled radiofrequency plasma spectrophotometer revealed that barbiturase contains approximately 4.4 mol of zinc per mol of enzyme. The homotetrameric enzyme had K(m) and V(max) values of 1.0 mm and 2.5 micromol/min/mg of protein, respectively, for barbituric acid. The enzyme specifically acted on barbituric acid, and dihydro-l-orotate, alloxan, and cyanuric acid competitively inhibited its activity. The full-length gene encoding the barbiturase (bar) was cloned and overexpressed in Escherichia coli. The kinetic parameters and physicochemical properties of the cloned enzyme were apparently similar to those of the wild-type. PMID:11748240

  20. Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition.

    PubMed

    Waltz, Florian; Schwarz, Hans-Christoph; Schneider, Andreas M; Eiden, Stefanie; Behrens, Peter

    2015-01-01

    In this study we present a three-step process for the low-temperature chemical bath deposition of crystalline ZnO films on glass substrates. The process consists of a seeding step followed by two chemical bath deposition steps. In the second step (the first of the two bath deposition steps), a natural polysaccharide, namely hyaluronic acid, is used to manipulate the morphology of the films. Previous experiments revealed a strong influence of this polysaccharide on the formation of zinc oxide crystallites. The present work aims to transfer this gained knowledge to the formation of zinc oxide films. The influence of hyaluronic acid and the time of its addition on the morphology of the resulting ZnO film were investigated. By meticulous adjustment of the parameters in this step, the film morphology can be tailored to provide an optimal growth platform for the third step (a subsequent chemical bath deposition step). In this step, the film is covered by a dense layer of ZnO. This optimized procedure leads to ZnO films with a very high electrical conductivity, opening up interesting possibilities for applications of such films. The films were characterized by means of electron microscopy, X-ray diffraction and measurements of the electrical conductivity. PMID:25977851

  1. Synchrotron Speciation of Silver and Zinc Oxide Nanoparticles Aged in a Kaolin Suspension

    SciTech Connect

    Scheckel, Kirk G.; Luxton, Todd P.; El Badawy, Amro M.; Impellitteri, Christopher A.; Tolaymat, Thabet M. (EPA); (UCIN)

    2010-07-23

    Assessments of the environmental fate and mobility of nanoparticles must consider the behavior of nanoparticles in relevant environmental systems that may result in speciation changes over time. Environmental conditions may act on nanoparticles to change their size, shape, and surface chemistry. Changing these basic characteristics of nanoparticles may result in a final reaction product that is significantly different than the initial nanomaterial. As such, basing long-term risk and toxicity on the initial properties of a nanomaterial may lead to erroneous conclusions if nanoparticles change upon release to the environment. The influence of aging on the speciation and chemical stability of silver and zinc oxide nanoparticles in kaolin suspensions was examined in batch reactors for up to 18 months. Silver nanoparticles remained unchanged in sodium nitrate suspensions; however, silver chloride was identified with the metallic silver nanoparticles in sodium chloride suspensions and may be attributed to an in situ silver chloride surface coating. Zinc oxide nanoparticles were rapidly converted via destabilization/dissolution mechanisms to Zn{sup 2+} inner-sphere sorption complexes within 1 day of reaction and these sorption complexes were maintained through the 12 month aging processes. Chemical and physical alteration of nanomaterials in the environment must be examined to understand fate, mobility, and toxicology.

  2. Zinc-oxide nanorod/copper-oxide thin-film heterojunction for a nitrogen-monoxide gas sensor

    NASA Astrophysics Data System (ADS)

    Yoo, Hwansu; Kim, Hyojin; Kim, Dojin

    2014-11-01

    A novel p- n oxide heterojunction structure was fabricated by employing n-type zinc-oxide (ZnO) nanorods grown on an indium-tin-oxide-coated glass substrate by using the hydrothermal method and a p-type copper-oxide (CuO) thin film deposited onto the ZnO nanorod array by using the sputtering method. The crystallinities and microstructures of the heterojunction materials were examined by using X-ray diffraction and scanning electron microscopy. The observed current-voltage characteristics of the p - n oxide heterojunction showed a nonlinear diode-like rectifying behavior. The effects of an oxidizing or electron acceptor gas, such as nitrogen monoxide (NO), on the ZnO nanorod/CuO thin-film heterojunction were investigated to determine the potential applications of the fabricated material for use in gas sensors. The forward current of the p - n heterojunction was remarkably reduced when NO gas was introduced into dry air at temperatures from 100 to 250 °C. The NO gas response of the oxide heterojunction reached a maximum value at an operating temperature of 180 °C and linearly increased as the NO gas concentration was increased from 5 to 30 ppm. The sensitivity value was observed to be as high as 170% at 180 °C when biased at 2 V in the presence of 20-ppm NO. The ZnO nanorod/CuO thin-film heterojunction also exhibited a stable and repeatable response to NO gas. The experimental results suggest that the ZnO nanorod/CuO thin-film heterojunction structure may be a novel candidate for gas sensors.

  3. Reduction of azo dyes by desulfovibrio desulfuricans

    Microsoft Academic Search

    E. S. Yoo; J. Libra; U. Wiesmann

    2000-01-01

    Azo dyes are widely used in textile finishing, and have become of concern in wastewater treatment because of their color, bio-recalcitrance, and potential toxicity to animals and humans. Thus, wastewater with azo dyes must be decolorized and furthermore mineralized in appropriate systems combining biological and chemical processes. In this study, the potential for sulfate reducing bacteria (SRB) to decolorize azo

  4. Colorimetric cholesterol sensor based on peroxidase like activity of zinc oxide nanoparticles incorporated carbon nanotubes.

    PubMed

    Hayat, Akhtar; Haider, Waqar; Raza, Yousuf; Marty, Jean Louis

    2015-10-01

    A sensitive and selective colorimetric method based on the incorporation of zinc oxide nanoparticles (ZnO NPs) on the surface of carbon nanotubes (CNTs) was shown to posses synergistic peroxidase like activity for the detection of cholesterol. The proposed nanocomposite catalyzed the oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) in the presence of hydrogen peroxide (H2O2) to produce a green colored product which can be monitored at 405nm. H2O2 is the oxidative product of cholesterol in the presence of cholesterol oxidase. Therefore, the oxidation of cholesterol can be quantitatively related to the colorimetric response by combining these two reactions. Under the optimal experimental conditions, the colorimetric response was proportional to the concentration of cholesterol in the range of 0.5-500nmol/L, with a detection limit of 0.2nmol/L. The applicability of the proposed assays was demonstrated for the determination of cholesterol in milk powder samples with good recovery results. PMID:26078143

  5. Cardiorespiratory toxicity of environmentally relevant zinc oxide nanoparticles in the freshwater fish Catostomus commersonii.

    PubMed

    Bessemer, Robin Anne; Butler, Kathryn Marie Alison; Tunnah, Louise; Callaghan, Neal Ingraham; Rundle, Amanda; Currie, Suzanne; Dieni, Christopher Anthony; MacCormack, Tyson James

    2014-11-27

    Abstract The inhalation of zinc oxide engineered nanomaterials (ENMs) has been linked to cardiorespiratory dysfunction in mammalian models but the effects of aquatic ENM exposure on fish have not been fully investigated. Nano-zinc oxide (nZnO) is widely used in consumer products such as sunscreens and can make its way into aquatic ecosystems from domestic and commercial wastewater. This study examined the impact of an environmentally relevant nZnO formulation on cardiorespiratory function and energy metabolism in the white sucker (Catostomus commersonii), a freshwater teleost fish. Evidence of oxidative and cellular stress was present in gill tissue, including increases in malondialdehyde levels, heat shock protein (HSP) expression, and caspase 3/7 activity. Gill Na(+)/K(+)-ATPase activity was also higher by approximately three-fold in nZnO-treated fish, likely in response to increased epithelial permeability or structural remodeling. Despite evidence of toxicity in gill, plasma cortisol and lactate levels did not change in animals exposed to 1.0?mg?L(-1) nZnO. White suckers also exhibited a 35% decrease in heart rate during nZnO exposure, with no significant changes in resting oxygen consumption or tissue energy stores. Our results suggest that tissue damage or cellular stress resulting from nZnO exposure activates gill neuroepithelial cells, triggering a whole-animal hypoxic response. An increase in parasympathetic nervous signaling will decrease heart rate and may reduce energy demand, even in the face of an environmental toxicant. We have shown that acute exposure to nZnO is toxic to white suckers and that ENMs have the potential to negatively impact cardiorespiratory function in adult fish. PMID:25427894

  6. Intrinsic and interfacial effect of electrode metals on the resistive switching behaviors of zinc oxide films.

    PubMed

    Xue, W H; Xiao, W; Shang, J; Chen, X X; Zhu, X J; Pan, L; Tan, H W; Zhang, W B; Ji, Z H; Liu, G; Xu, X-H; Ding, J; Li, R-W

    2014-10-24

    Exploring the role of electrode metals on the resistive switching properties of metal electrode/oxide/metal electrode sandwiched structures provides not only essential information to understand the underlying switching mechanism of the devices, but also useful guidelines for the optimization of the switching performance. A systematic study has been performed to investigate the influence of electrodes on the resistive switching characteristics of zinc oxide (ZnO) films in this contribution, in terms of both the intrinsic and interfacial effects. It has been found that the low-resistance state resistances (?(LRS)) of all the investigated devices are below 50 ?, which can be attributed to the formation of highly conductive channels throughout the ZnO films. On the other hand, the high-resistance state resistances (?(HRS)) depend on the electronegativity and ionic size of the employed electrode metals. Devices with electrode metals of high electronegativity and large ionic size possess high ?(HRS) values, while those with electrode metals of low electronegativity and small ionic size carry low ?(HRS) values. A similar trend of the set voltages has also been observed, while the reset voltages are all distributed in a narrow range close to ±0.5 V. Moreover, the forming voltages of the switching devices strongly depend on the roughness of the metal/ZnO and/or ZnO/metal interface. The present work provides essential information for better understanding the switching mechanism of zinc oxide based devices, and benefits the rational selection of proper electrode metals for the device performance optimization. PMID:25274278

  7. Human Skin Penetration of Sunscreen Nanoparticles: In-vitro Assessment of a Novel Micronized Zinc Oxide Formulation

    Microsoft Academic Search

    Sheree E. Cross; Brian Innes; Michael S. Roberts; Takuya Tsuzuki; Terry A. Robertson; Paul McCormick

    2007-01-01

    The extent to which topically applied solid nanoparticles can penetrate the stratum corneum and access the underlying viable epidermis and the rest of the body is a great potential safety concern. Therefore, human epidermal penetration of a novel, transparent, nanoparticulate zinc oxide sunscreen formulation was determined using Franz-type diffusion cells, 24-hour exposure and an electron microscopy to verify the location

  8. Effects of undoped and manganese-doped zinc oxide nanoparticles on the colour fading of dyed polyester fabrics

    Microsoft Academic Search

    Lu Sun; John A. Rippon; Peter G. Cookson; Olga Koulaeva; Xungai Wang

    2009-01-01

    This paper describes the effects of applying coatings of an acrylic polymer containing nanoparticles of zinc oxide (ZnO) on the fading rate in artificial sunlight of polyester fabrics dyed with disperse dyes containing anthraquinone and benzopyran chromophores. Factors affecting the transparency and UV absorbance of the coatings are discussed. Removing the UV component of sunlight with ZnO nanoparticles markedly decreased

  9. Ultrasensitive diagnosis for an anthrax-protective antigen based on a polyvalent directed peptide polymer coupled to zinc oxide nanorods.

    PubMed

    Park, Hye-Yeon; Gedi, Vinayakumar; Kim, Joungmok; Park, Hae-Chul; Han, Sung-Hwan; Yoon, Moon-Young

    2011-12-01

    A flexible poly-D-lysine polymer conjugated with different target-binding peptides is demonstrated with an ultralow concentration detection limit compared to those of other conventional detection systems. This polyvalent directed peptide polymer (PDPP) exhibits increased binding affinity and detects anthrax protective antigen at low levels using a well-known zinc oxide nanorod detection system. PMID:21997757

  10. Room-temperature-operated sensitive hybrid gas sensor based on amorphous indium gallium zinc oxide thin-film transistors

    E-print Network

    . Sensitive vapor sensors are important for the development of noninvasive diagnostic breath analy- sis systemRoom-temperature-operated sensitive hybrid gas sensor based on amorphous indium gallium zinc oxide Institute of Physics. Related Articles Semiconductor core-shell quantum dot: A low temperature nano-sensor

  11. Room-temperature-operated sensitive hybrid gas sensor based on amorphous indium gallium zinc oxide thin-film transistors

    E-print Network

    . Sensitive vapor sensors are important for the development of noninvasive diagnostic breath analy- sis systemRoom-temperature-operated sensitive hybrid gas sensor based on amorphous indium gallium zinc oxide-film transistor TFT to form a hybrid sensor. The organic layer, served as a second gate, forms a p-n junction

  12. Antimicrobial Efficacy of Zinc Oxide Quantum Dots Against Listeria Monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc oxide quantum dots (ZnO QDs) in a powder form, a ZnO-polystyrene (PS) film form and a polyvinylprolidone capped ZnO (ZnO-PVP) gel form were prepared and their antibacterial activities against foodborne pathogenic Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7 in cul...

  13. Influence of the semiconductor thickness on the electrical properties of transparent TFTs based on indium zinc oxide

    Microsoft Academic Search

    P. Barquinha; A. Pimentel; A. Marques; L. Pereira; R. Martins; E. Fortunato

    2006-01-01

    Multicomponent amorphous oxides are starting to emerge as a class of appealing semiconductor materials for application in transparent electronics. In this work, a high performance bottom-gate n-type transparent thin-film transistors are reported, being the discussion primarily focused on the influence of the indium zinc oxide active layer thickness on the properties of the devices. For this purpose, transparent transistors with

  14. Preparation and characterization of copper nanoparticles\\/zinc oxide composite modified electrode and its application to glucose sensing

    Microsoft Academic Search

    S. Ashok Kumar; Hui-Wen Cheng; Shen-Ming Chen; Sea-Fue Wang

    2010-01-01

    We report a new method for selective detection of d(+)-glucose using a copper nanoparticles (Cu-NPs) attached zinc oxide (ZnO) film coated electrode. The ZnO and Cu-NPs were electrochemically deposited onto indium tin oxide (ITO) coated glass electrode and glassy carbon electrode (GCE) by layer-by-layer. In result, Cu-NPs\\/ZnO composite film topography was characterized by scanning electron microscopy (SEM) and atomic force

  15. Retinopathy Induced by Zinc Oxide Nanoparticles in Rats Assessed by Micro-computed Tomography and Histopathology

    PubMed Central

    Kwak, Kyung A; Kim, Tae Sung; Seok, Ji Hyeon; Roh, Hang Sik; Lee, Jong-Kwon; Jeong, Jayoung; Meang, Eun Ho; Hong, Jeong-sup; Lee, Yun Seok; Kang, Jin Seok

    2015-01-01

    Nanotechnology has advanced at an extremely rapid pace over the past several years in numerous fields of research. However, the uptake of nanoparticles (NPs) into the body after administration through various routes may pose a risk to human health. In this study, we investigated the potential ocular toxicity of 20-nm, negatively- charged zinc oxide (ZnO) NPs in rats using micro-computed tomography (micro-CT) and histopathological assessment. Animals were divided into four groups as control group, ZnO NPs treatment group (500 mg/kg/day), control recovery group, and ZnO NPs treatment and recovery group. Ocular samples were prepared from animals treated for 90 days (10 males and 10 females, respectively) and from recovery animals (5 males and 5 females, respectively) sacrificed at 14 days after final treatment and were compared to age-matched control animals. Micro-CT analyses represented the deposition and distribution of foreign materials in the eyes of rats treated with ZnO NPs, whereas control animals showed no such findings. X-ray fluorescence spectrometry and energy dispersive spectrometry showed the intraocular foreign materials as zinc in treated rats, whereas control animals showed no zinc signal. Histopathological examination revealed the retinopathy in the eyes of rats treated with ZnO NPs. Neuronal nuclei expression was decreased in neurons of the ganglion cell layer of animals treated with ZnO NPs compared to the control group. Taken together, treatment with 20-nm, negatively-charged ZnO NPs increased retinopathy, associated with local distribution of them in ocular lesions.

  16. Hydrogen sulfide adsorption on nano-sized zinc oxide/reduced graphite oxide composite at ambient condition

    NASA Astrophysics Data System (ADS)

    Song, Hoon Sub; Park, Moon Gyu; Kwon, Soon Jin; Yi, Kwang Bok; Croiset, Eric; Chen, Zhongwei; Nam, Sung Chan

    2013-07-01

    This paper presents new insights on the synthesis of nano-ZnO on reduced graphite oxide (rGO) composite via a microwave-assisted route and its use as a potential sorbent to adsorb hydrogen sulfide (H2S) at ambient conditions. Depending on the synthesis methods, the nano-sized ZnO on rGO presents different characteristics, in particular the degree of nano-ZnO dispersion on the surface of the rGO. Microwave-assisted reduction was able to offer a mild reduction to the oxygen-containing functional groups attached on the surface of graphite oxide (GO). Those oxygen-containing functional groups provide the bridge and the terminal groups between zinc oxide and the rGO surface. Because those functional groups act as anchor sites for metal ions, it was possible to achieve uniformly distributed nano-sized ZnO particles on the surface of the rGO sheets. In addition, they accelerate oxygen activation for H2S adsorption. H2S adsorption tests at ambient conditions were conducted. The 1-D carbon nanotubes (CNTs) had been used for reference in order to investigate the functionality of 2-D rGO substrate. Also, the effects of the different synthesis methods (microwave vs. reflux) were evaluated for H2S adsorption. The adsorption capacity increased dramatically for the microwave-assisted composite compared to the composite manufactured using the reflux method.

  17. Effects of physicochemical properties of zinc oxide nanoparticles on cellular uptake

    NASA Astrophysics Data System (ADS)

    Yu, J.; Baek, M.; Chung, H. E.; Choi, S. J.

    2011-07-01

    Zinc oxide (ZnO) nanoparticles have been used as a source of zinc, an essential trace element in food industry and also widely applied to various cosmetic products. However, there are few researches demonstrating that the cellular uptake behaviours of ZnO with respect to the physicochemical characteristics such as particle size and surface charge in human cells. In this study, we evaluated the cellular uptake of ZnO with two different sizes (20 and 70 nm) and different charges (positive and negative). Human lung epithelial cells were exposed to ZnO for a given time, and then the uptake amount of ZnO was measured with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The results showed that the smaller sized ZnO could more easily enter the cells than the larger sized ZnO. In terms of surface charge, positively charged ZnO showed high cellular uptake compared to ZnO with negative charge. The internalization pathway of positively charged ZnO nanoparticles was determined to be primarily related to the energy-dependent endocytosis. It is, therefore, concluded that the particle size and surface charge of ZnO nanoparticles are critical factors influencing on their cellular uptake. Understanding the cellular uptake behaviours of nanoparticles with respect to physicochemical properties may be important to predict their toxicity potential on human.

  18. Structure-property-composition relationships in doped zinc oxides: enhanced photocatalytic activity with rare Earth dopants.

    PubMed

    Goodall, Josephine B M; Illsley, Derek; Lines, Robert; Makwana, Neel M; Darr, Jawwad A

    2015-02-01

    In this paper, we demonstrate the use of continuous hydrothermal flow synthesis (CHFS) technology to rapidly produce a library of 56 crystalline (doped) zinc oxide nanopowders and two undoped samples, each with different particle properties. Each sample was produced in series from the mixing of an aqueous stream of basic zinc nitrate (and dopant ion or modifier) solution with a flow of superheated water (at 450 °C and 24.1 MPa), whereupon a crystalline nanoparticle slurry was rapidly formed. Each composition was collected in series, cleaned, freeze-dried, and then characterized using analytical methods, including powder X-ray diffraction, transmission electron microscopy, Brunauer-Emmett-Teller surface area measurement, X-ray photoelectron spectroscopy, and UV-vis spectrophotometry. Photocatalytic activity of the samples toward the decolorization of methylene blue dye was assessed, and the results revealed that transition metal dopants tended to reduce the photoactivity while rare earth ions, in general, increased the photocatalytic activity. In general, low dopant concentrations were more beneficial to having greater photodecolorization in all cases. PMID:25602735

  19. Fluorine-doped zinc oxide thin films: influence of precursor flow rate on violet luminescence

    NASA Astrophysics Data System (ADS)

    Muthukumar, Anusha; Dakshnamoorthy, Arivuoli

    2015-06-01

    Fluorine-doped zinc oxide (FZO) thin films were deposited by the aerosol-assisted chemical vapor deposition method with variable precursor flow rates (0.5-2.5 ml/min). X-ray diffraction patterns revealed the polycrystalline hexagonal wurtzite structure of the derived FZO nanocrystalline thin films. Extensive crystallinity analysis of the film deposited at 1 ml/min was done by grazing incidence X-ray diffraction. Field emission scanning electron microscope images apparent the gradual evolution from spherical grains and hexagonal platelet like surface morphology with increased flow rate. Optical transparency and photoluminescence (PL) are strongly influenced by flow rate. PL intensity and transparency increase with decreased flow rate. The optical bandgap was tuned significantly by increase in flow rate and especially tuned the PL emission from violet to UV. High intense violet PL observed at flow rate of 1 ml/min and radiative transition of electrons from zinc vacancies level to the conduction band were found. Crystallinity, growth rate and roughness increase with increased flow rate.

  20. A novel approach reveals that zinc oxide nanoparticles are bioavailable and toxic after dietary exposures

    USGS Publications Warehouse

    Croteau, M.-N.; Dybowska, A.D.; Luoma, S.N.; Valsami-Jones, E.

    2011-01-01

    If engineered nanomaterials are released into the environment, some are likely to end up associated with the food of animals due to aggregation and sorption processes. However, few studies have considered dietary exposure of nanomaterials. Here we show that zinc (Zn) from isotopically modified 67ZnO particles is efficiently assimilated by freshwater snails when ingested with food. The 67Zn from nano-sized 67ZnO appears as bioavailable as 67Zn internalized by diatoms. Apparent agglomeration of the zinc oxide (ZnO) particles did not reduce bioavailability, nor preclude toxicity. In the diet, ZnO nanoparticles damage digestion: snails ate less, defecated less and inefficiently processed the ingested food when exposed to high concentrations of ZnO. It was not clear whether the toxicity was due to the high Zn dose achieved with nanoparticles or to the ZnO nanoparticles themselves. Further study of exposure from nanoparticles in food would greatly benefit assessment of ecological and human health risks. ?? 2011 Informa UK, Ltd.

  1. Hydrothermal synthesis of nanostructured zinc oxide and study of their optical properties

    SciTech Connect

    Moulahi, A. [Laboratoire de Chimie de la Matiere Condensee IPEIT, Universite de Tunis, 2 rue Jawaher Lel Nehru 1008, B.P. 229 Montfleury, Tunis (Tunisia)] [Laboratoire de Chimie de la Matiere Condensee IPEIT, Universite de Tunis, 2 rue Jawaher Lel Nehru 1008, B.P. 229 Montfleury, Tunis (Tunisia); Sediri, F., E-mail: faouzi.sediri@ipeit.rnu.tn [Laboratoire de Chimie de la Matiere Condensee IPEIT, Universite de Tunis, 2 rue Jawaher Lel Nehru 1008, B.P. 229 Montfleury, Tunis (Tunisia); Faculte des Sciences de Tunis, Universite Tunis El Manar, 2092 El Manar, Tunis (Tunisia); Gharbi, N., E-mail: neji.gharbi@ipeit.rnu.tn [Laboratoire de Chimie de la Matiere Condensee IPEIT, Universite de Tunis, 2 rue Jawaher Lel Nehru 1008, B.P. 229 Montfleury, Tunis (Tunisia)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Nanostructured ZnO were successfully obtained by a hydrothermal route. Black-Right-Pointing-Pointer Inorganic precursor and molar ratio are key factors for morphology and particle size. Black-Right-Pointing-Pointer Optical properties were also studied. -- Abstract: Nanostructured ZnO (nanorods, nanoshuttles) have been synthesized by hydrothermal approach using ZnCl{sub 2} or Zn(NO{sub 3}){sub 2}{center_dot}6H{sub 2}O as zinc sources and cetyltrimethylammonium bromide as structure-directing agent. Techniques X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible absorption, Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy have been used to characterize the structure, morphology and composition of the nanostructured zinc oxide. The optical properties of the as-obtained materials were also studied and showing that it is possible to apply the ZnO nanoshuttles and nanorods on the UV filter, photocatalysis, and special optical devices.

  2. Chromium and Ruthenium-Doped Zinc Oxide Thin Films for Propane Sensing Applications

    PubMed Central

    Gómez-Pozos, Heberto; González-Vidal, José Luis; Torres, Gonzalo Alberto; Rodríguez-Baez, Jorge; Maldonado, Arturo; de la Luz Olvera, María; Acosta, Dwight Roberto; Avendaño-Alejo, Maximino; Castañeda, Luis

    2013-01-01

    Chromium and ruthenium-doped zinc oxide (ZnO:Cr) and (ZnO:Ru) thin solid films were deposited on soda-lime glass substrates by the sol-gel dip-coating method. A 0.6 M solution of zinc acetate dihydrate dissolved in 2-methoxyethanol and monoethanolamine was used as basic solution. Chromium (III) acetylacetonate and Ruthenium (III) trichloride were used as doping sources. The Ru incorporation and its distribution profile into the films were proved by the SIMS technique. The morphology and structure of the films were studied by SEM microscopy and X-ray diffraction measurements, respectively. The SEM images show porous surfaces covered by small grains with different grain size, depending on the doping element, and the immersions number into the doping solutions. The sensing properties of ZnO:Cr and ZnO:Ru films in a propane (C3H8) atmosphere, as a function of the immersions number in the doping solution, have been studied in the present work. The highest sensitivity values were obtained for films doped from five immersions, 5.8 and 900, for ZnO:Cr and ZnO:Ru films, respectively. In order to evidence the catalytic effect of the chromium (Cr) and ruthenium (Ru), the sensing characteristics of undoped ZnO films are reported as well. PMID:23482091

  3. Dissolution kinetics of macronutrient fertilizers coated with manufactured zinc oxide nanoparticles.

    PubMed

    Milani, Narges; McLaughlin, Mike J; Stacey, Samuel P; Kirby, Jason K; Hettiarachchi, Ganga M; Beak, Douglas G; Cornelis, Geert

    2012-04-25

    The solubility of Zn in Zn fertilizers plays an important role in the agronomic effectiveness of the fertilizer. On the basis of thermodynamics, zinc oxide (ZnO) nanoparticles (NPs) should dissolve faster and to a greater extent than bulk ZnO particles (equivalent spherical diameter >100 nm). These novel solubility features of ZnO NPs might be exploited to improve the efficiency of Zn fertilizers. In this study, we compared the Zn solubility and dissolution kinetics of ZnO nanoparticles and bulk ZnO particles coated onto two selected granular macronutrient fertilizers, urea and monoammonium phosphate (MAP). The main Zn species on coated MAP and urea granules were zinc ammonium phosphate and ZnO, respectively. Coated MAP granules showed greater Zn solubility and faster dissolution rates in sand columns compared to coated urea granules, which may be related to pH differences in the solution surrounding the fertilizer granules. The kinetics of Zn dissolution was not affected by the size of the ZnO particles applied for coating of either fertilizer type, possibly because solubility was controlled by formation of the same compounds irrespective of the size of the original ZnO particles used for coating. PMID:22480134

  4. Structural, optical and electrical properties of zinc oxide thin films deposited by a spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Aoun, Yacine; Benhaoua, Boubaker; Gasmi, Brahim; Benramache, Said

    2015-01-01

    Zinc oxide (ZnO) thin films were deposited on glass substrates by spray pyrolysis technique decomposition of zinc acetate dihydrate in an ethanol solution with 30 mL of deposition rate, the ZnO thin films were deposited at two different temperatures: 300 and 350 °C. The substrates were heated using the solar cells method. The substrate was R217102 glass, whose size was 30 × 17.5 × 1 mm3. The films exhibit a hexagonal wurtzite structure with a strong (002) preferred orientation. The higher value of crystallite size is attained for sprayed films at 350 °C, which is probably due to an improvement of the crystallinity of the films at this point. The average transmittance of obtain films is about 90%–95%, as measured by a UV—vis analyzer. The band gap energy varies from 3.265 to 3.294 eV for the deposited ZnO thin film at 300 and 350 °C, respectively. The electrical resistivity measured of our films are in the order 0.36 ?·cm.

  5. Transparent conductive indium zinc oxide films prepared by pulsed plasma deposition

    SciTech Connect

    Wan Runlai; Yang Ming; Zhou Qianfei; Zhang Qun [Department of Materials Science, Fudan University, Shanghai 200433 (China)

    2012-11-15

    Transparent conductive indium zinc oxide films were prepared by pulsed plasma deposition from a ceramic target (90 wt. % In{sub 2}O{sub 3} and 10 wt. % ZnO). The dependences of film properties upon the substrate temperature was investigated using characterization methods including x-ray diffraction, atomic force microscope, Hall measurement, ultraviolet-visible spectroscopy, and x-ray photoelectron spectroscopy. The films grown at room temperature had a rather smooth surface due to the amorphous structure, with a root mean square roughness of less than 1 nm. The atomic ratio of Zn/(Zn + In) in these films is 15.3 at. %, which is close to that in the target, and the chemical states of indium and zinc atoms were In{sup 3+} and Zn{sup 2+}, respectively. The films deposited on a substrate with a temperature of 200 Degree-Sign C exhibited polycrystalline structure and a preferred growth orientation along the (222) plane. Here the electrical properties were improved due to the better crystallinity, with the films exhibiting a minimum resistivity value of 4.2 Multiplication-Sign 10{sup -4}{Omega} cm, a maximum carrier mobility of 45 cm{sup 2} V{sup -1} s{sup -1}, and an optical transmittance over 80% in the visible region.

  6. Biokinetics of zinc oxide nanoparticles: toxicokinetics, biological fates, and protein interaction

    PubMed Central

    Choi, Soo-Jin; Choy, Jin-Ho

    2014-01-01

    Biokinetic studies of zinc oxide (ZnO) nanoparticles involve systematic and quantitative analyses of absorption, distribution, metabolism, and excretion in plasma and tissues of whole animals after exposure. A full understanding of the biokinetics provides basic information about nanoparticle entry into systemic circulation, target organs of accumulation and toxicity, and elimination time, which is important for predicting the long-term toxic potential of nanoparticles. Biokinetic behaviors can be dependent on physicochemical properties, dissolution property in biological fluids, and nanoparticle–protein interaction. Moreover, the determination of biological fates of ZnO nanoparticles in the systemic circulation and tissues is critical in interpreting biokinetic behaviors and predicting toxicity potential as well as mechanism. This review focuses on physicochemical factors affecting the biokinetics of ZnO nanoparticles, in concert with understanding bioavailable fates and their interaction with proteins. PMID:25565844

  7. Self-aligned coplanar amorphous indium zinc oxide thin-film transistors with high performance

    NASA Astrophysics Data System (ADS)

    Park, Jae Chul; Lee, Ho-Nyeon

    2015-01-01

    Self-aligned coplanar amorphous indium zinc oxide thin-film transistors (a-IZO TFTs) were fabricated. The a-IZO TFTs had a field-effect mobility of ?FE = 24.4 cm2 V-1 s-1, a subthreshold slope of 180 mV/dec, and an on/off ratio of 109. As the channel length decreased, the threshold voltage VTH shifted to more negative voltages, and ?FE increased due to the diffused carriers from the contact regions. The intrinsic field-effect mobility was estimated to be 15.05 cm2 V-1 s-1 in the linear mode and 13.28 cm2 V-1 s-1 in saturation mode. Under positive/negative bias-temperature-illumination stress, the shift in VTH was less than ±0.7 V after 11,000 s.

  8. Bidirectional reflectance measurement of zinc oxide in 0.25 to 2.5 microns spectrum

    NASA Technical Reports Server (NTRS)

    Scott, R. L., Jr.

    1974-01-01

    An experimental apparatus was designed and used to measure the bidirectional reflectance of zinc oxide in the spectrum 0.25 to 2.5 microns. The nonspecular reflectance is essentially Lambert for wavelengths above 0.40 microns with the most deviation occuring for large source zenith angles. Below 0.400 microns the nonspecular reflectance is greater than Lambert in all directions and is greatest in the forward and backscatter directions. The ratio of the specular component to the nonspecular component at a zenith of 0 degrees was found to increase with source zenith and wavelength for wavelengths above 0.400 microns. Below 0.400 microns this ratio increases as wavelengths decrease. The variation of bidirectional reflectance with wavelength was found to have the characteristics absorption for Zn0 for wavelength below 0.400 microns.

  9. Optical Kerr phase shift in a nanostructured nickel-doped zinc oxide thin solid film.

    PubMed

    Torres-Torres, C; Can-Uc, B A; Rangel-Rojo, R; Castañeda, L; Torres-Martínez, R; García-Gil, C I; Khomenko, A V

    2013-09-01

    The optical Kerr effect exhibited by a nickel doped zinc oxide thin solid film was explored with femto- and pico-second pulses using the z-scan method. The samples were prepared by the ultrasonic spray pyrolysis technique. Opposite signs for the value of the nonlinear refractive index were observed in the two experiments. Self-defocusing together with a two-photon absorption process was observed with 120 ps pulses at 1064 nm, while a dominantly self-focusing effect accompanied by saturated absorption was found for 80 fs pulses at 825 nm. Regarding the nanostructured morphology of the resulting film, we attribute the difference in the two ultrafast optical responses to the different physical mechanism responsible of energy transfer generated by multiphoton processes under electronic and thermal effects. PMID:24104010

  10. Superhydrophobic surfaces using selected zinc oxide microrod growth on ink-jetted patterns.

    PubMed

    Myint, Myo Tay Zar; Kitsomboonloha, Rungrot; Baruah, Sunandan; Dutta, Joydeep

    2011-02-15

    The synthesis and properties of superhydrophobic surfaces based on binary surface topography made of zinc oxide (ZnO) microrod-decorated micropatterns are reported. ZnO is intrinsically hydrophilic but can be utilized to create hydrophobic surfaces by creating artificial roughness via microstructuring. Micron scale patterns consisting of nanocrystalline ZnO seed particles were applied to glass substrates with a modified ink-jet printer. Microrods were then grown on the patterns by a hydrothermal process without any further chemical modification. Water contact angle (WCA)(1) up to 153° was achieved. Different micro array patterned surfaces with varying response of static contact angle or sessile droplet analysis are reported. PMID:21109250

  11. The E3 center in zinc oxide: Evidence for involvement of hydrogen

    SciTech Connect

    Hupfer, A.; Bhoodoo, C.; Vines, L.; Svensson, B. G. [Physics Department/Center for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, Oslo N-0316 (Norway)

    2014-03-03

    Proton implantation is shown to increase the concentration of the so called and commonly observed E3 defect level in zinc oxide (ZnO). Box and single profiles of protons with doses ranging from 6×10{sup 10}?cm{sup ?2} to 4.3×10{sup 12}?cm{sup ?2} were implanted into hydrothermally grown ZnO samples with original concentrations of E3 below 5×10{sup 14}?cm{sup ?3}. Capacitance-Voltage profiling and junction spectroscopy measurements showed that the charge carrier concentration and absolute concentration of E3 centers increase by more than one order of magnitude compared to the as-grown samples as well as control samples implanted with He ions. The results provide strong evidence for the involvement of H in the formation of the E3 center, and a complex involving interstitial H and an oxygen sub-lattice primary defect are discussed.

  12. Impact of temperature on zinc oxide particle size by using sol-gel process

    SciTech Connect

    Lee, Keanchuan, E-mail: lee.kc@petronas.com.my; Ching, Dennis Ling Chuan, E-mail: dennis.ling@petronas.com.my [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Saipolbahri, Zulhilmi Akmal bin, E-mail: zulhilmiakmal@gmail.com [Geoscience and Petroleum Engineering Department, Universiti Teknologi PETRONAS, 31750 Tronoh, Perak (Malaysia); Guan, Beh Hoe, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my; Soleimani, Hassan, E-mail: beh.hoeguan@petronas.com.my, E-mail: hassan.soleimani@petronas.com.my

    2014-10-24

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature.

  13. Photoluminescent zinc oxide polymer nanocomposites fabricated using picosecond laser ablation in an organic solvent

    NASA Astrophysics Data System (ADS)

    Wagener, Philipp; Faramarzi, Shamsolzaman; Schwenke, Andreas; Rosenfeld, Rupert; Barcikowski, Stephan

    2011-06-01

    Nanocomposites made of ZnO nanoparticles dispersed in thermoplastic polyurethane were synthesized using picosecond laser ablation of zinc in a polymer-doped solution of tetrahydrofuran. The pre-added polymer stabilizes the ZnO nanoparticles in situ during laser ablation by forming a polymer shell around the nanoparticles. This close-contact polymer shell has a layer thickness up to 30 nm. Analysis of ZnO polyurethane nanocomposites using optical spectroscopy, high resolution transmission electron microscopy and X-ray diffraction revealed that oxidized and crystalline ZnO nanoparticles were produced. Those nanocomposites showed a green photoluminescence emission centred at 538 nm after excitation at 350 nm, which should be attributed to oxygen defects generated during the laser formation mechanism of the monocrystalline nanoparticles. Further, the influence of pulse energy and polymer concentration on the production rate, laser fluence and energy-specific mass productivity was investigated.

  14. Impact of temperature on zinc oxide particle size by using sol-gel process

    NASA Astrophysics Data System (ADS)

    Lee, Keanchuan; Saipolbahri, Zulhilmi Akmal bin; Guan, Beh Hoe; Soleimani, Hassan; Ching, Dennis Ling Chuan

    2014-10-01

    Zinc oxide (ZnO) nanoparticles were prepared and synthesized via sol-gel method, by using citric acid as a precursor. The impact of annealing on the particle size was investigated. Based on the results from the Thermogravimetric Analysis (TGA), three different annealing temperature which is 500, 600 and 700 °C were chosen followed by the characterization of the ZnO nanoparticle by using Powder X-Ray Diffraction (PXRD), Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM). Results showed that the crystallite size estimated from PXRD increased with the annealing temperature which was hexagonal structure for ZnO. TEM further revealed the same tendency which the Zn NPs size also increased with the annealing temperature.

  15. Ultrasonic and dielectric characterization of microwave-sintered and conventionally sintered zinc oxide

    SciTech Connect

    Martin, L.P.; Dadon, D.; Rosen, M. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Materials Science and Engineering; Gershon, D.; Birman, A.; Levush, B.; Carmel, Y. [Univ. of Maryland, College Park, MD (United States). Lab. for Plasma Research

    1996-10-01

    Zinc oxide samples were prepared by microwave- and conventional-sintering processes using identical time-temperature profiles. Comparison of postsintering properties as a function of residual porosity over the range of 0%--35% indicated no significant difference in the ultrasonic velocity-porosity relations or the elastic moduli for the samples prepared by the two techniques. The real and imaginary parts of the permittivity of the samples processed by the two techniques were measured over a wide frequency range. In both cases, there was an increase in the measured permittivity values with decreasing porosity; however, the microwave-sintered samples had considerably higher values. Porosity levels were evaluated using bulk density measurements and scanning electron microscopy analysis. Significantly more densification was observed at intermediate temperatures for microwave sintering than for conventional sintering.

  16. Photoswitching in azobenzene self-assembled monolayers capped on zinc oxide: nanodots vs nanorods.

    PubMed

    Shah, Syed Mujtaba; Martini, Cyril; Ackermann, Jörg; Fages, Frédéric

    2012-02-01

    We report the synthesis and spectroscopic characterization of nanohybrid structures consisting of an azobenzene compound grafted on the surface of zinc oxide nanoparticles. Characteristic bathochromic shifts indicate that the azobenzene photochromic molecules self-assemble onto the surface of the nanocrystals. The extent of packing is dependent on the shape of the nanoparticle. ZnO nanorods, with flat facets, enable a tighter organization of the molecules in the self-assembled monolayer than in the case of nanodots that display a more curvated shape. Consistently, the efficiency of photochromic switching of the self-assembled monolayer on ZnO nanoparticles is also shown to be strongly affected by nanoparticle shape. PMID:22082797

  17. Electroluminescence from localized defects in zinc oxide: toward electrically driven single photon sources at room temperature.

    PubMed

    Choi, Sumin; Berhane, Amanuel M; Gentle, Angus; Ton-That, Cuong; Phillips, Matthew R; Aharonovich, Igor

    2015-03-18

    Single photon sources are required for a wide range of applications in quantum information science, quantum cryptography, and quantum communications. However, the majority of room temperature emitters to date are only excited optically, which limits their proper integration into scalable devices. In this work, we overcome this limitation and present room temperature electrically driven light emission from localized defects in zinc oxide (ZnO) nanoparticles and thin films. The devices emit in the red spectral range and show excellent rectifying behavior. The emission is stable over an extensive period of time, providing an important prerequisite for practical devices. Our results open possibilities for building new ZnO-based quantum integrated devices that incorporate solid-state single photon sources for quantum information technologies. PMID:25741632

  18. Zinc Oxide Thin Films Fabricated with Direct Current Magnetron Sputtering Deposition Technique

    SciTech Connect

    Hoon, Jian-Wei; Chan, Kah-Yoong; Krishnasamy, Jegenathan; Tou, Teck-Yong [Centre for Advanced Devices and Systems (CADS), Faculty of Engineering, Multimedia University, Selangor Darul Ehsan (Malaysia)

    2011-03-30

    Zinc oxide (ZnO) is a very promising material for emerging large area electronic applications including thin-film sensors, transistors and solar cells. We fabricated ZnO thin films by employing direct current (DC) magnetron sputtering deposition technique. ZnO films with different thicknesses ranging from 100 nm to 1020 nm were deposited on silicon (Si) substrate. The deposition pressure was varied from 12 mTorr to 25 mTorr. The influences of the film thickness and the deposition pressure on structural properties of the ZnO films were investigated using Mahr surface profilometer and atomic force microscopy (AFM). The experimental results reveal that the film thickness and the deposition pressure play significant role in the structural formation of the deposited ZnO thin films. ZnO films deposited on Si substrates are promising for variety of thin-film sensor applications.

  19. Improved stability of amorphous zinc tin oxide thin film transistors using molecular passivation

    NASA Astrophysics Data System (ADS)

    Rajachidambaram, M. S.; Pandey, A.; Vilayurganapathy, S.; Nachimuthu, P.; Thevuthasan, S.; Herman, G. S.

    2013-10-01

    The role of back channel surface chemistry on amorphous zinc tin oxide (ZTO) bottom gate thin film transistors (TFTs) has been characterized by positive bias-stress measurements and x-ray photoelectron spectroscopy. Positive bias-stress turn-on voltage shifts for ZTO-TFTs were significantly reduced by passivation of back channel surfaces with self-assembled monolayers of n-hexylphosphonic acid when compared to ZTO-TFTs with no passivation. These results indicate that adsorption of molecular species on the exposed back channel of ZTO-TFTs strongly influence observed turn-on voltage shifts, as opposed to charge injection into the dielectric or trapping due to oxygen vacancies.

  20. Characterization of Green-Emitting Translucent Zinc Oxide Ceramics Prepared Via Spark Plasma Sintering

    SciTech Connect

    Hong, Mei [University of California; DeVito, David M [ORNL; Howe, Jane Y [ORNL; Yang, Xiaocheng [West Virginia University; Giles, Nancy C. [Air Force Institute of Technology; Neal, John S [ORNL; Munir, Zuhair [University of California

    2011-01-01

    Translucent, green-emitting zinc oxide (ZnO) bodies, 19 mm in diameter and 0.72 mm in thickness, have been prepared via spark plasma sintering method. The consolidation of ZnO powders was investigated over the temperature range of 550-1050 C and the pressure range of 55-530 MPa. Samples sintered at temperatures >850 C and pressures of {approx}120 MPa were translucent and had densities of {approx}100%. Samples sintered at 950 C and 130 MPa showed a higher maximum transmittance than the samples sintered at higher or lower temperatures or pressures, with an excellent in-line transmission of 70% in the IR region around 2330 nm. The dense ZnO ceramics exhibited a strong green emission and a weak ultraviolet emission, and the relative intensity of the green emission increased with increasing sintering temperature.

  1. Temperature dependent current-voltage characteristics of zinc oxide nanowire/polypyrrole nanocomposite

    NASA Astrophysics Data System (ADS)

    Sameera, I.; Bhatia, Ravi; Prasad, V.; Menon, Reghu

    2014-12-01

    Temperature dependent current-voltage (I-V) measurements of electrochemically prepared zinc oxide nanowire/polypyrrole (ZnONW/PPy) nanocomposite yielded non-linear I-V characteristics at temperatures between 300 and 4.5 K. The low-field conductance (G) of the ZnONW/PPy film exhibits pronounced temperature dependence with room temperature conductance (G300K) ˜ 10-3 S and a conductance ratio (G300K/G4.5K) of ˜104, indicating dominance of significant temperature dependent charge transport processes. The conduction mechanism of the film is satisfactorily understood by extended fluctuation induced tunneling (FIT) model as the non-linear I-V characteristics fit fairly well to the extended FIT model. Further, the temperature dependence of G? obtained from fitting followed Sheng's model also.

  2. Low-Temperature, Aqueous-Solution-Processed Zinc Tin Oxide Thin Film Transistor

    NASA Astrophysics Data System (ADS)

    Park, Jee Ho; Choi, Won Jin; Oh, Jin Young; Chae, Soo Sang; Jang, Woo Soon; Jong Lee, Se; Song, Kie Moon; Baik, Hong Koo

    2011-07-01

    We fabricate solution-processed zinc tin oxide (ZTO) thin-film transistors (TFTs). The solution used is prepared by precipitating metal hydroxide using NaOH and dissolving it using NH4OH. The X-ray diffraction (XRD) data of the spin-coated ZTO film demonstrates an amorphous phase, and the atomic force microscopy (AFM) image shows a smooth surface. The device performance of solution-processed TFTs was analyzed as a function of annealing temperature. The fabricated TFTs were operated in the enhancement mode, and exhibited a carrier mobility of 3.03 cm2 V-1 s-1, a threshold voltage of 10.2 V, an on/off current ratio of 1.23×107, a subthreshold slope of 0.78 V/decade, and high transparency (with ˜90% transmittance) at a low annealing temperature of 300 °C.

  3. Effects of Hf incorporation on indium zinc oxide thin-film transistors using solution process

    NASA Astrophysics Data System (ADS)

    Li, Xifeng; Xin, Enlong; Zhang, Jianhua

    2015-01-01

    Thin-film transistors (TFTs) were fabricated by employing amorphous hafnium indium zinc oxide (HIZO) thin films as the active channel layer by the solution process. Thermogravimetry-differential thermal analysis, transmittance measurements, atomic force microscopy, scanning electron microscopy, x-ray diffraction, and Fourier transform infrared analysis were used to study the formation, structure, and optical properties of the HIZO films. The results showed that the addition of Hf to the IZO system resulted in suppression of carrier generation. The HIZO TFTs exhibited lower off-currents and higher onoff current ratios than IZO TFTs without Hf doping. HIZO TFTs with a Hf doping content of 5 at. % obtained a threshold voltage of 3.7 V, a mobility of 0.27 cm2 V-1 s-1, a subthreshold swing of 1.2 V/dec, and an on-off current ratio of 106.

  4. A benign hydrothermal synthesis of nanopencils-like zinc oxide nanoflowers

    NASA Astrophysics Data System (ADS)

    Akhoon, S. A.; Rubab, S.; Shah, M. A.

    2015-11-01

    Synthesis of zinc oxide (ZnO) nanoflowers and nanopencils is normally carried out with the help of structure-directing chemicals and templates. Besides releasing environmentally toxic substances, the use of these chemicals restricts the practical applications of nanostructures. In this paper, we report a typical template-free and environmentally benign synthesis of ZnO nanoflowers with nanopencils-like petals through a facile hydrothermal method. The as-synthesized ZnO nanoflowers were characterized using X-ray diffraction, field emission scanning electron microscopy, tunneling electron microscopy (TEM), high resolution TEM, and energy-dispersive X-ray spectroscopy techniques. The results reveal high quality and impurity-free hexagonal wurtzite phase ZnO nanoflowers of nanopencils-like petals having a length of 100-150 nm and a diameter of 45-60 nm.

  5. Reactive oxygen species-induced cytotoxic effects of zinc oxide nanoparticles in rat retinal ganglion cells.

    PubMed

    Guo, Dadong; Bi, Hongsheng; Liu, Bing; Wu, Qiuxin; Wang, Daoguang; Cui, Yan

    2013-03-01

    Recent studies have proved that zinc oxide (ZnO) nanoparticles can cause toxicity in different cell lines, oxidative stress is often hypothesized to be an important factor in cytotoxicity of ZnO nanoparticles. However, the mechanisms are incompletely understood. The present study aimed to investigate the role of oxidative stress in toxicity and possible involvement of mitochondria in the production of reactive oxygen species (ROS) upon exposure of retinal ganglion cells (RGC-5) to ZnO nanoparticles. In this study, the effects of ZnO nanoparticles on mitochondrial membrane potential and ROS levels involved in hydrogen peroxide and hydroxyl radical production were investigated via inverted fluorescence microscope and hydrogen peroxide and hydroxyl radical assay kits, respectively. Furthermore, the mRNA of caspase-12 and the protein secreted into culture supernatant were also determined by means of real-time quantitative PCR and ELISA techniques. Our studies indicate that ZnO nanoparticles could apparently decrease the mitochondrial membrane potential, increase the production of ROS and lead to the overexpression of caspase-12 in RGC-5 cells, suggesting that ZnO nanoparticle-induced toxicity via ROS overproduction will trigger endoplasmic reticulum stress, lead to the RGC-5 cell damage and finally induce apoptosis/necrosis, the overexpression of caspase-12 may be involved in cell death in RGC-5 cells. PMID:23232460

  6. Dopant induced bandgap narrowing in Y-doped zinc oxide nanostructures.

    PubMed

    Yogamalar, Rajeswari; Venkateswaran, Pedinti S; Benzigar, Mercy R; Ariga, Katsuhiko; Vinu, Ajayan; Bose, A Chandra

    2012-01-01

    In this report, hydrothermal synthesis and the absorption properties of the cubic shaped zinc oxide nanostructures doped with different amount of yttrium (Y) metal cation (0 to 15 at.%) are demonstrated. The structural and optical properties of chemically synthesized pure and Y doped ZnO powders are investigated by using powder X-ray diffraction (XRD), field emission scanning electron spectroscopy (FESEM) and transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) absorbance, photoluminescence (PL), and Fourier transform infra-red spectroscopy (FT-IR). It is found that the dopant ions stabilize in wurtzite hexagonal phase of ZnO upto the concentration of less than 6 at.%, which is mainly due to the fact that the ZnO lattice expands and the optical bandgap energy decreases at this level. Increasing the dopant concentration to greater than 6 at.% leads to a contraction of the lattice, which in turn produces a significant structural disorder evidenced by shift in the XRD peaks due to additional interstitial incorporation of Y. The vibrational modes of the metal oxide groups have been identified from the IR transmission spectra. The optical absorption results show that the optical bandgap energy of Y:ZnO nanocrystals is much less as compared to that of the pure bulk ZnO particles. Doping ZnO with trivalent Y produces excess number of electrons in the conduction band and thus, shifts the absorption edge and narrows down to 80 meV approximately. PL spectra are used to study the dependence of doping on the deep-level emission, which show an enhanced blue emission after Y doping. The existence of near band edge (NBE) emission and blue emission, related to zinc interstitials are observed in the luminescence spectra of Zn(1-x)Y(x)O nanostructures. PMID:22523948

  7. Metalloproteins and phytochelatin synthase may confer protection against zinc oxide nanoparticle induced toxicity in Caenorhabditis elegans.

    PubMed

    Polak, Natasa; Read, Daniel S; Jurkschat, Kerstin; Matzke, Marianne; Kelly, Frank J; Spurgeon, David J; Stürzenbaum, Stephen R

    2014-03-01

    Zinc oxide nanoparticles (ZnONPs) are used in large quantities by the cosmetic, food and textile industries. Here we exposed Caenorhabditis elegans wild-type and a metal sensitive triple knockout mutant (mtl-1;mtl-2;pcs-1) to ZnONPs (0-50mg/L) to study strain and exposure specific effects on transcription, reactive oxygen species generation, the biomolecular phenotype (measured by Raman microspectroscopy) and key endpoints of the nematode life cycle (growth, reproduction and lifespan). A significant dissolution effect was observed, where dissolved ZnO constituted over 50% of total Zn within a two day exposure to the test medium, suggesting that the nominal exposure to pure ZnONPs represents in vivo, at best, a mixture exposure of ionic zinc and nanoparticles. Nevertheless, the analyses provided evidence that the metallothioneins (mtl-1 and mtl-2), the phytochelatin synthase (pcs-1) and an apoptotic marker (cep-1) were transcriptionally activated. In addition, the DCFH-DA assay provided in vitro evidence of the oxidative potential of ZnONPs in the metal exposure sensitive triple mutant. Raman spectroscopy highlighted that the biomolecular phenotype changes significantly in the mtl-1;mtl-2;pcs-1 triple knockout worm upon ZnONP exposure, suggesting that these metalloproteins are instrumental in the protection against cytotoxic damage. Finally, ZnONP exposure was shown to decrease growth and development, reproductive capacity and lifespan, effects which were amplified in the triple knockout. By combining diverse toxicological strategies, we identified that individuals (genotypes) housing mutations in key metalloproteins and phytochelatin synthase are more susceptible to ZnONP exposure, which underlines their importance to minimize ZnONP induced toxicity. PMID:24333255

  8. Near net shape forming processes for chemically prepared zinc oxide varistors.

    SciTech Connect

    Lockwood, Steven John; Voigt, James A.; Tuttle, Bruce Andrew; Bell, Nelson Simmons

    2005-01-01

    Chemically prepared zinc oxide powders are fabricated for the production of high aspect ratio varistor components. Colloidal processing in water was performed to reduce agglomerates to primary particles, form a high solids loading slurry, and prevent dopant migration. The milled and dispersed powder exhibited a viscoelastic to elastic behavioral transition at a volume loading of 43-46%. The origin of this transition was studied using acoustic spectroscopy, zeta potential measurements and oscillatory rheology. The phenomenon occurs due to a volume fraction solids dependent reduction in the zeta potential of the solid phase. It is postulated to result from divalent ion binding within the polyelectrolyte dispersant chain, and was mitigated using a polyethylene glycol plasticizing additive. Chemically prepared zinc oxide powders were processed for the production of high aspect ratio varistor components. Near net shape casting methods including slip casting and agarose gelcasting were evaluated for effectiveness in achieving a uniform green microstructure achieving density values near the theoretical maximum during sintering. The structure of the green parts was examined by mercury porisimetry. Agarose gelcasting produced green parts with low solids loading values and did not achieve high fired density. Isopressing the agarose cast parts after drying raised the fired density to greater than 95%, but the parts exhibited catastrophic shorting during electrical testing. Slip casting produced high green density parts, which exhibited high fired density values. The electrical characteristics of slip cast parts are comparable with dry pressed powder compacts. Alternative methods for near net shape forming of ceramic dispersions were investigated for use with the chemically prepared ZnO material. Recommendations for further investigation to achieve a viable production process are presented.

  9. Growth of layered basic zinc acetate in methanolic solutions and its pyrolytic transformation into porous zinc oxide films.

    PubMed

    Hosono, Eiji; Fujihara, Shinobu; Kimura, Toshio; Imai, Hiroaki

    2004-04-15

    Layered basic zinc acetate (LBZA), Zn(5)(OH)(8)(CH(3)COO)(2).2H(2)O, was deposited on glass substrates by a chemical bath deposition (CBD) method using methanolic solutions of zinc acetate dihydrate. The substrates were put into bottles filled with the solutions and sealed up and were kept at 60 degrees C in a drying oven. Immersion time necessary for the deposition of LBZA films was typically more than 28 h. This was a key to inducing heterogeneous nucleation of LBZA through control over a degree of supersaturation in the evolution of a unique, nest-like morphology. Hydration water contained by zinc acetate dihydrate was quantitatively enough to promote hydrolysis of zinc acetate. The LBZA films were transformed into nanocrystalline, porous ZnO films without morphological deformation by heating at 150 degrees C in air. A mechanism of the formation of the nest-like morphology was discussed based on nonaqueous solution reactions, nucleation, and crystal growth during the CBD process. PMID:15028503

  10. Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating

    PubMed Central

    Abdullah, Wan Rafizah Wan; Zakaria, Azmi; Ghazali, Mohd Sabri Mohd

    2012-01-01

    High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr6O11) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr6O11 addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr6O11 from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, ?, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and ? lowering with increasing Pr6O11 content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary. PMID:22606043

  11. Synthesis mechanism of low-voltage praseodymium oxide doped zinc oxide varistor ceramics prepared through modified citrate gel coating.

    PubMed

    Abdullah, Wan Rafizah Wan; Zakaria, Azmi; Ghazali, Mohd Sabri Mohd

    2012-01-01

    High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr(6)O(11)) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr(6)O(11) addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr(6)O(11) from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, ?, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and ? lowering with increasing Pr(6)O(11) content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary. PMID:22606043

  12. On the possibility to grow zinc oxide-based transparent conducting oxide films by hot-wire chemical vapor deposition

    SciTech Connect

    Abrutis, Adulfas, E-mail: adulfas.abrutis@chf.vu.lt; Silimavicus, Laimis; Kubilius, Virgaudas; Murauskas, Tomas; Saltyte, Zita; Kuprenaite, Sabina; Plausinaitiene, Valentina [Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania)

    2014-03-15

    Hot-wire chemical vapor deposition (HW-CVD) was applied to grow zinc oxide (ZnO)-based transparent conducting oxide (TCO) films. Indium (In)-doped ZnO films were deposited using a cold wall pulsed liquid injection CVD system with three nichrome wires installed at a distance of 2?cm from the substrate holder. The wires were heated by an AC current in the range of 0–10 A. Zn and In 2,2,6,6-tetramethyl-3,5-heptanedionates dissolved in 1,2-dimethoxyethane were used as precursors. The hot wires had a marked effect on the growth rates of ZnO, In-doped ZnO, and In{sub 2}O{sub 3} films; at a current of 6–10 A, growth rates were increased by a factor of ?10–20 compared with those of traditional CVD at the same substrate temperature (400?°C). In-doped ZnO films with thickness of ?150?nm deposited on sapphire-R grown at a wire current of 9?A exhibited a resistivity of ?2?×?10{sup ?3} ?cm and transparency of >90% in the visible spectral range. These initial results reveal the potential of HW-CVD for the growth of TCOs.

  13. Synthesis, characterization and photo catalytic studies of the composites by tantalum oxide and zinc oxide nanorods

    NASA Astrophysics Data System (ADS)

    Chennakesavulu, K.; Reddy, M. Madhusudhana; Reddy, G. Ramanjaneya; Rabel, A. M.; Brijitta, J.; Vinita, V.; Sasipraba, T.; Sreeramulu, J.

    2015-07-01

    In-situ synthesis of ZnO:Ta2O5 composites in basic medium by using tantalum chloride and zinc chloride as precursors. The prepared composites were characterized by Fourier Transform Infrared spectroscopy (FTIR), confocal Raman spectroscopy, diffuse reflectance UV-Vis spectrophotometer (DRS), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, N2-sorption isotherms, Thermo Gravimetric Analysis (TGA), High Resolution Transmission Electron Microscope (HRTEM), X-ray Photoelectron Spectroscopy (XPS), and Field Emission Scanning Electron Microscopy (FESEM/EDS). The composite materials were used as photocatalyst in the degradation Rhodamine-B (RhB) dye under visible light irradiation. The catalytic activity and removal percentage of the dye was determined by the spectrophotometric method. This indicates the percentage of degradation was more for the ZnO:Ta2O5 composites. The kinetic parameter obeys pseudo-first order reaction. It may be due to fixed amount the catalysts and concentration of dye solution. The catalytic activity of the recycled ZnO:Ta2O5 catalyst was compared with fresh catalyst.

  14. Contacts on n-type germanium using variably doped zinc oxide and highly doped indium tin oxide interfacial layers

    NASA Astrophysics Data System (ADS)

    Paramahans Manik, Prashanth; Lodha, Saurabh

    2015-05-01

    The impact of varying interfacial layer (IL) doping on the performance of Ti/IL/n-Ge contacts is demonstrated using undoped ZnO, aluminum-doped ZnO (AZO), and O-vacancy-doped n+-ZnO ILs having similar conduction band offsets ?Ec with respect to Ti and Ge. Diode and transfer length method measurements show Fermi-level unpinning for all the ILs; however, the contact resistance and its dependence on the IL thickness decrease with increasing IL doping owing to the reduction in the tunneling resistance. The contact resistivity depends on the IL doping (NIL) as ? \\text{c-n + \\text{-ZnO}} < ? \\text{c-AZO} < ? \\text{c-ZnO} for N\\text{n + \\text{-ZnO}} > N\\text{AZO} > N\\text{ZnO}. Contacts using a highly doped, low ?Ec tin-doped In2O3 IL exhibit the lowest value, 1.4 × 10?7 ?·cm2.

  15. Physiological hepatic response to zinc oxide nanoparticle exposure in the white sucker, Catostomus commersonii.

    PubMed

    Dieni, Christopher Anthony; Callaghan, Neal Ingraham; Gormley, Patrick Thomas; Butler, Kathryn Marie Alison; Maccormack, Tyson James

    2014-05-01

    Liver toxicity of commercially relevant zinc oxide nanoparticles (nZnO) was assessed in a benthic freshwater cypriniform, the white sucker (Catostomus commersonii). Exposure to nZnO caused several changes in levels of liver enzyme activity, antioxidants, and lipid peroxidation end products consistent with an oxidative stress response. Aconitase activity decreased by ~65% but tended to be restored to original levels upon supplementation with Fe(2+), indicating oxidative inactivation of the 4Fe-4S cluster. Furthermore, glucose-6-phosphate dehydrogenase activity decreased by ~29%, and glutathione levels increased by ~56%. Taken together, these suggest that nZnO induces hepatic physiological stress. Each assay was then validated by using a single liver homogenate or plasma sample that was partitioned and treated with nZnO or Zn(2+), the breakdown product of nZnO. It was found that Zn(2+), but not nZnO, increased detected glutathione reductase activity by ~14% and decreased detected malondialdehyde by ~39%. This indicates that if appreciable nZnO dissolution occurs in liver samples during processing and assay, it may skew results, with implications not only for this study, but also for a wide range of nanotoxicology studies focusing on nZnO. Finally, in vitro incubations of cell-free rat blood plasma with nZnO failed to generate any significant increase in malondialdehyde or protein carbonyl levels, or any significant decrease in ferric reducing ability of plasma. This suggests that at the level tested, any oxidative stress caused by nZnO is the result of a coordinated physiological response by the liver. PMID:24704545

  16. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

  17. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

  18. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

  19. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

  20. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Substituted pyridine azo substituted phenyl. 721.8780 Section 721.8780 ...Substituted pyridine azo substituted phenyl. (a) Chemical substance and significant...as substituted pyridine azo substituted phenyl (PMNs P-96-767 and...

  1. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721...cyclic]azo]-substituted azo-, metal salt (generic). (a) Chemical substance...cyclic]azo]-substituted azo-, metal salt (PMN P-04-498) is subject to...

  2. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721...cyclic]azo]-substituted azo-, metal salt (generic). (a) Chemical substance...cyclic]azo]-substituted azo-, metal salt (PMN P-04-498) is subject to...

  3. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721...cyclic]azo]-substituted azo-, metal salt (generic). (a) Chemical substance...cyclic]azo]-substituted azo-, metal salt (PMN P-04-498) is subject to...

  4. Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes

    PubMed Central

    2010-01-01

    Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress. Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity. The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the pathogenesis of various neurological diseases, further insight into the contribution of zinc dynamics and metallothionein-3 function may help provide ways to effectively regulate these processes in brain cells. PMID:20974010

  5. Ultra-High Sensitivity Zinc Oxide Nanocombs for On-Chip Room Temperature Carbon Monoxide Sensing

    PubMed Central

    Pan, Xiaofang; Zhao, Xiaojin

    2015-01-01

    In this paper, we report an on-chip gas sensor based on novel zinc oxide (ZnO) nanocombs for carbon monoxide (CO) sensing. With ZnO gas sensing nanocombs fully integrated on a single silicon chip, the concept of low cost complementary-metal-oxide-semiconductor (CMOS) microsensor capable of on-chip gas sensing and processing is enabled. Compared with all previous implementations, the proposed ZnO nanocombs feature much larger effective sensing area and exhibit ultra-high sensitivity even at the room temperature. Specifically, at room temperature, we demonstrate peak sensitivities as high as 7.22 and 8.93 for CO concentrations of 250 ppm and 500 ppm, respectively. As a result, by operating the proposed ZnO-nanocomb-based gas sensor at the room temperature, the widely adopted power consuming heating components are completely removed. This leads to not only great power saving, but also full compatibility between the gas sensor and the on-chip circuitry in term of acceptable operating temperature. In addition, the reported fast response/recovery time of ~200 s/~50 s (250 ppm CO) makes it well suited to real-life applications. PMID:25894935

  6. Bio-inspired morphological evolution of zinc oxide nanostructures on a tunable enzyme platform.

    PubMed

    Murugappan, Gunavadhi; Parthasarathy, Meera

    2014-01-01

    Diamine oxidase is a copper-containing enzyme with interesting structural dynamics sensitive to environmental conditions. The present work explores the applicability of the system as a tunable platform for the shape and size selective synthesis of zinc oxide nanoparticles under ambient conditions. Significant changes in the nanoscale morphology of ZnO have been observed, using scanning electron microscopy, with respect to changes in pH and gas atmosphere of the medium. More specifically, hexagonal plates of nanoscale ZnO were formed at pH below the isoelectric point of the enzyme and spherical particles at alkaline pH. Interestingly the average particle size of ZnO nanostructures increases with increasing oxygen content at acidic pH while the opposite trend is noticed at alkaline pH. The observations are explained on the basis of changes in the enzyme's surface charge, conformation and redox potential using a combination of techniques like zeta potential measurements, FTIR spectroscopy, fluorescence spectroscopy, open circuit potential studies and cyclic voltammetry. Thus the present work demonstrates the applicability of an enzyme as a dynamic bio-template for the synthesis of a multitude of ZnO nanostructures which are expected to add newer insight into bottom-up fabrication of oxide nanostructures. PMID:24910331

  7. Enhancement of oxygen vacancies and solar photocatalytic activity of zinc oxide by incorporation of nonmetal

    NASA Astrophysics Data System (ADS)

    Patil, Ashokrao B.; Patil, Kashinath R.; Pardeshi, Satish K.

    2011-12-01

    B-doped ZnO and N-doped ZnO powders have been synthesized by mechanochemical method and characterized by TG-DTA, XRD, SEM-EDX, XPS, UV-visible and photoluminescence (PL) spectra. X-ray diffraction data suggests the hexagonal wurtzite structure for modified ZnO crystallites and the incorporation of nonmetal expands the lattice constants of ZnO. The room temperature PL spectra suggest more number of oxygen vacancies exist in nonmetal-doped ZnO than that of undoped zinc oxide. XPS analysis shows the substitution of some of the O atoms of ZnO by nonmetal atoms. Solar photocatalytic activity of B-doped ZnO, N-doped ZnO and undoped ZnO was compared by means of oxidative photocatalytic degradation (PCD) of Bisphenol A (BPA). B-doped ZnO showed better solar PCD efficiency as compare to N-doped ZnO and undoped ZnO. The PCD of BPA follows first order reaction kinetics. The detail mechanism of PCD of Bisphenol A was proposed with the identification of intermediates such as hydroquinone, benzene-1,2,4-triol and 4-(2-hydroxypropan-2-yl) phenol.

  8. Thin-Film Transistors Fabricated Using Sputter Deposition of Zinc Oxide

    NASA Astrophysics Data System (ADS)

    Xiao, Nan

    2013-01-01

    Development of thin film transistors (TFTs) with conventional channel layer materials, such as amorphous silicon (a-Si) and polysilicon (poly-Si), has been extensively investigated. A-Si TFT currently serves the large flat panel industry; however advanced display products are demanding better TFT performance because of the associated low electron mobility of a-Si. This has motivated interest in semiconducting metal oxides, such as Zinc Oxide (ZnO), for TFT backplanes. This work involves the fabrication and characterization of TFTs using ZnO deposited by sputtering. An overview of the process details and results from recently fabricated TFTs following a full-factorial designed experiment will be presented. Material characterization and analysis of electrical results will be described. The investigated process variables were the gate dielectric and ZnO sputtering process parameters including power density and oxygen partial pressure. Electrical results showed clear differences in treatment combinations, with certain I-V characteristics demonstrating superior performance to preliminary work. A study of device stability will also be discussed.

  9. Influence of surface properties of zinc oxide nanoparticles on their cytotoxicity.

    PubMed

    Altunbek, Mine; Baysal, Asl?; Çulha, Mustafa

    2014-09-01

    The toxicity of nanoparticles (NPs) depends on several factors including size, shape, surface properties and chemical nature of the NPs. The release of toxic ions due to the dissolution of NPs is another important factor. In addition, impurities or reaction products from synthesis procedures on the NP surfaces may contribute to the toxicity. Zinc oxide nanoparticles (ZnO NPs) are one of the unique NPs showing toxicity through all of these mentioned factors. In this study, we demonstrate that the treatment of the ZnO NPs with hydrogen peroxide (H2O2) alters the surface properties of the ZnO NPs by decomposing organic impurities remained from synthesis procedures. The changes on the surface chemistry and properties of the ZnO NPs influence their behavior in cell culture media and the NPs-cell interactions. Finally, a decrease in the cytotoxicity of H2O2 treated ZnO NPs is observed on HDF and A549 cells through the decrease of the membrane damage and oxidative stress. PMID:25042418

  10. Ecotoxicological effect of sublethal exposure to zinc oxide nanoparticles on freshwater snail Biomphalaria alexandrina.

    PubMed

    Fahmy, Sohair R; Abdel-Ghaffar, Fathy; Bakry, Fayez A; Sayed, Dawlat A

    2014-08-01

    Freshwater snails are used as sensitive biomarkers of aquatic ecosystem pollution. The potential impacts of zinc oxide nanoparticles (ZnONPs) on aquatic ecosystems have attracted special attention due to their unique properties. The present investigation was designed to evaluate the possible mechanisms of ecotoxicological effects of ZnONPs on freshwater snail Biomphalaria alexandrina. ZnONPs showed molluscicidal activity against B. alexandrina snails, and the LC50 was 145 ?g/ml. Two tested concentrations of ZnONPs were selected: The first concentration was equivalent to LC10 (7 ?g/ml), and the second was equivalent to LC25 (35 ?g/ml). Exposure to ZnONPs (7 and 35 ?g/ml) for three consecutive weeks significantly induced malondialdehyde and nitric oxide with concomitant decreases in glutathione and glutathione-S-transferase levels in hemolymph and soft tissues of treated snails. Moreover, ZnONPs elicited a significant decrease in total protein and albumin contents coinciding with enhancement of total lipids and cholesterol levels as well as activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hemolymph and soft tissues of treated snails. This study highlights the potential ecological implications of ZnONP release in aquatic environments and may serve to encourage regulatory agencies in Egypt to more carefully monitor and regulate the industrial use and disposal of ZnONPs. PMID:24736985

  11. Hydrogenated aluminium-doped zinc oxide semiconductor thin films for polymeric light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Hao, X. T.; Zhu, F. R.; Ong, K. S.; Tan, L. W.

    2006-01-01

    Highly conducting transparent thin films of aluminium(Al)-doped zinc oxide (ZnO:Al) were deposited by a radio frequency magnetron-sputtering technique using an argon and hydrogen gas mixture at room temperature. Hydrogen serves as a shallow donor and plays a critical role in improving the Al doping efficiency to enhance the conductivity of thin films. The effect of hydrogen partial pressure on the properties of ZnO:Al films was investigated in detail. Polycrystalline ZnO:Al films with a surface roughness of about 2 nm, conductivity of 1.97 × 103 S cm-1, transmittance of over 83% in the visible wavelength region and an optical band gap of 3.93 eV were achieved at a hydrogen partial pressure of 7.5 × 10-4 Pa. A ZnO:Al film with the desired properties was used as an anode contact in a bi-layer polymeric light-emitting diode. A polyethylene dioxythiophene-polystyrene sulfonate doped with poly(styrenesulfonic acid) (PEDOT: PSS) and phenyl-substituted poly(p-phenylene vinylene) (Ph-PPV) were employed as a hole transport layer and a light-emitting layer, respectively. The electro-luminescence performance of the aforementioned diode was studied and compared to a control device with an indium tin oxide anode.

  12. Effective contact resistance of zinc-tin oxide-based thin film transistors.

    PubMed

    Kang, Youjin; Han, Dongsuk; Park, Jaehyung; Shin, Sora; Choi, Duckkyun; Park, Jongwan

    2014-11-01

    We investigated different source/drain (S/D) electrode materials in thin-film transistors (TFTs) based on amorphous zinc-tin oxide (ZTO) semiconductors. The transfer length, channel conductance, and effective contact resistance between the S/D electrodes and the a-ZTO channel layer were examined. Total ON resistance (R(T)), transfer length (L(T)) and effective contact resistance (R(c-eff)) were extracted by the well-known transmission-line method (TLM) using a series of TFTs with different channel lengths. When the width of ZTO channel layer was fixed as 50 ?m, the lengths were varying from 10 to 50 ?m. The channel layer and S/D electrode were defined by lift-off process and for the S/D electrodes, indium-tin oxide (ITO), Cu, and Mo were used. The resistivity and work function values of electrode materials were considered when selected as candidates for S/D electrodes of ZTO-TFTs. The results showed that the ZTO-TFTs with Mo S/D electrodes had the lowest effective contact resistance indicating that ZTO-TFTs with Mo electrodes have better electrical performance compared to others. PMID:25958489

  13. X-ray absorption spectroscopy elucidates the impact of structural disorder on electron mobility in amorphous zinc-tin-oxide thin films

    E-print Network

    Siah, Sin Cheng

    We investigate the correlation between the atomic structures of amorphous zinc-tin-oxide (a-ZTO) thin films grown by atomic layer deposition (ALD) and their electronic transport properties. We perform synchrotron-based ...

  14. Salinity-dependent toxicities of zinc oxide nanoparticles to the marine diatom Thalassiosira pseudonana.

    PubMed

    Yung, Mana M N; Wong, Stella W Y; Kwok, Kevin W H; Liu, F Z; Leung, Y H; Chan, W T; Li, X Y; Djuriši?, A B; Leung, Kenneth M Y

    2015-08-01

    This study comprehensively investigated the influences of salinity, exposure concentration and time on the aggregate size, surface charge and dissolution of zinc oxide nanoparticles (ZnO-NPs; 20nm) in seawater, and examined the interacting effect of salinity and waterborne exposure of ZnO-NPs on the marine diatom Thalassiosira pseudonana for 96h. We found that aggregate sizes of ZnO-NPs significantly increased with increasing salinity, but generally decreased with increasing exposure concentration. Ion release decreased with increasing salinity, whereas the surface charge of the particles was not affected by salinity. The increased aggregate size and decreased ion release with increasing salinity, and consequently lower concentration of bioavailable zinc ions, resulted in decreased toxicity of ZnO-NPs at higher salinity in general in terms of growth inhibition (IC50) and chlorophyll fluorescence (EC50 - ?Po and EC50 - ?2). However, IC50s and EC50s of ZnO-NPs were smaller than those of Zn(2+) (from ZnO-NPs ultrafiltrate and ZnCl2), indicating that dissolved Zn(2+) can only partially explain the toxicity of ZnO-NPs. SEM images showed that ZnO-NPs attached on the diatom frustule surface, suggesting that the interaction between the nanoparticles and the cell surface may acerbate the toxicity of ZnO-NPs. Our results linked the physicochemical characteristics of ZnO-NPs in seawater with their toxicities to the marine diatom and highlighted the importance of salinity as an influential environmental factor governing the aggregation, dissolution and the toxicity of ZnO-NPs. PMID:26011135

  15. Microwave-assisted hydrothermal synthesis of zinc oxide particles starting from chloride precursor

    SciTech Connect

    Tseng, Chun-Chieh [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan, ROC (China)] [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan, ROC (China); Chou, Yu-Hsien [Nanopowder and Thin Film Technology Center, ITRI-South Industrial Technology Research Institute, Tainan 709, Taiwan, ROC (China)] [Nanopowder and Thin Film Technology Center, ITRI-South Industrial Technology Research Institute, Tainan 709, Taiwan, ROC (China); Liu, Chung-Ming [Department of Chemical and Material Engineering, LungHwa University of Science and Technology, Taoyuan 306, Taiwan, ROC (China)] [Department of Chemical and Material Engineering, LungHwa University of Science and Technology, Taoyuan 306, Taiwan, ROC (China); Liu, Yih-Ming [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan 335, Taiwan, ROC (China)] [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan 335, Taiwan, ROC (China); Ger, Ming-Der, E-mail: mingderger@gmail.com [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan 335, Taiwan, ROC (China)] [Department of Chemical and Materials Engineering, Chung Cheng Institute of Technology, National Defense University, Ta-His, Tao-Yuan 335, Taiwan, ROC (China); Shu, Youn-Yuen, E-mail: shuyy@nknucc.nknu.edu.tw [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan, ROC (China)] [Environmental Analysis Laboratory, Department of Chemistry, National Kaohsiung Normal University, Kaohsiung 802, Taiwan, ROC (China)

    2012-01-15

    Graphical abstract: Schematic of the mechanism for ZnO nanoparticles obtained by the calcination. Highlights: Black-Right-Pointing-Pointer Nanocrystalline ZnO particles were successfully prepared by a microwave-assisted method. Black-Right-Pointing-Pointer Sponge-like morphology of ZnO change to a net-like structure after thermal treatment. Black-Right-Pointing-Pointer The PL spectra exhibited a nearband-edge emission at 393 nm. -- Abstract: Zinc oxide (ZnO) was synthesized using a microwave assisted hydrothermal (MAH) process based on chloride/urea/water solution and under 800 W irradiation for 5 min. In the bath, Zn{sup 2+} ions reacted with the complex carbonate and hydroxide ions to form zinc carbonate hydroxide hydrate (Zn{sub 4}CO{sub 3}(OH){sub 6}{center_dot}H{sub 2}O), and the conversion from Zn{sub 4}CO{sub 3}(OH){sub 6}{center_dot}H{sub 2}O to ZnO was synchronously achieved by a MAH process. The as-prepared ZnO has a sponge-like morphology. However, the initial sponge-like morphology of ZnO could change to a net-like structure after thermal treatment, and compact nano-scale ZnO particles were finally obtained when the period of thermal treatment increased to 30 min. Pure ZnO nanoparticles was obtained from calcination of loose sponge-like ZnO particles at 500 Degree-Sign C. The analysis of optical properties of these ZnO nanoparticles showed that the intensity of 393 nm emission increased with the calcination temperature because the defects were reduced and the crystallinity was improved.

  16. Endoplasmic reticulum stress induced by zinc oxide nanoparticles is an earlier biomarker for nanotoxicological evaluation.

    PubMed

    Chen, Rui; Huo, Lingling; Shi, Xiaofei; Bai, Ru; Zhang, Zhenjiang; Zhao, Yuliang; Chang, Yanzhong; Chen, Chunying

    2014-03-25

    Zinc oxide nanoparticles (ZnO NPs) have been widely used in cosmetics and sunscreens, advanced textiles, self-charging and electronic devices; the potential for human exposure and the health impact at each stage of their manufacture and use are attracting great concerns. In addition to pulmonary damage, nanoparticle exposure is also strongly correlated with the increase in incidences of cardiovascular diseases; however, their toxic potential remains largely unclear. Herein, we investigated the cellular responses and endoplasmatic reticulum (ER) stress induced by ZnO NPs in human umbilical vein endothelial cells (HUVECs) in comparison with the Zn2+ ions and CeO2 NPs. We found that the dissolved zinc ion was the most significant factor for cytotoxicity in HUVECs. More importantly, ZnO NPs at noncytotoxic concentration, but not CeO2 NPs, can induce significant cellular ER stress response with higher expression of spliced xbp-1, chop, and caspase-12 at the mRNA level, and associated ER marker proteins including BiP, Chop, GADD34, p-PERK, p-eIF2?, and cleaved Caspase-12 at the protein levels. Moreover, ER stress was widely activated after treatment with ZnO NPs, while six of 84 marker genes significantly increased. ER stress response is a sensitive marker for checking the interruption of ER homeostasis by ZnO NPs. Furthermore, higher dosage of ZnO NPs (240 ?M) quickly rendered ER stress response before inducing apoptosis. These results demonstrate that ZnO NPs activate ER stress-responsive pathway and the ER stress response might be used as an earlier and sensitive end point for nanotoxicological study. PMID:24490819

  17. Fate of Zinc Oxide Nanoparticles Coated onto Macronutrient Fertilizers in an Alkaline Calcareous Soil.

    PubMed

    Milani, Narges; Hettiarachchi, Ganga M; Kirby, Jason K; Beak, Douglas G; Stacey, Samuel P; McLaughlin, Mike J

    2015-01-01

    Zinc oxide (ZnO) nanoparticles may provide a more soluble and plant available source of Zn in Zn fertilizers due to their greater reactivity compared to equivalent micron- or millimetre-sized (bulk) particles. However, the effect of soil on solubility, spatial distribution and speciation of ZnO nanoparticles has not yet been investigated. In this study, we examined the diffusion and solid phase speciation of Zn in an alkaline calcareous soil following application of nanoparticulate and bulk ZnO coated fertilizer products (monoammonium phosphate (MAP) and urea) using laboratory-based x-ray techniques and synchrotron-based ?-x-ray fluorescence (?-XRF) mapping and absorption fine structure spectroscopy (?-XAFS). Mapping of the soil-fertilizer reaction zones revealed that most of the applied Zn for all treatments remained on the coated fertilizer granule or close to the point of application after five weeks of incubation in soil. Zinc precipitated mainly as scholzite (CaZn2(PO4)2.2H2O) and zinc ammonium phosphate (Zn(NH4)PO4) species at the surface of MAP granules. These reactions reduced dissolution and diffusion of Zn from the MAP granules. Although Zn remained as zincite (ZnO) at the surface of urea granules, limited diffusion of Zn from ZnO-coated urea granules was also observed for both bulk and nanoparticulate ZnO treatments. This might be due to either the high pH of urea granules, which reduced solubility of Zn, or aggregation (due to high ionic strength) of released ZnO nanoparticles around the granule/point of application. The relative proportion of Zn(OH)2 and ZnCO3 species increased for all Zn treatments with increasing distance from coated MAP and urea granules in the calcareous soil. When coated on macronutrient fertilizers, Zn from ZnO nanoparticles (without surface modifiers) was not more mobile or diffusible compared to bulk forms of ZnO. The results also suggest that risk associated with the presence of ZnO NPs in calcareous soils would be the same as bulk sources of ZnO. PMID:25965385

  18. Effect of nano-zinc oxide on doxorubicin- induced oxidative stress and sperm disorders in adult male Wistar rats

    PubMed Central

    Badkoobeh, Puran; Parivar, Kazem; Kalantar, Seyed Mehdi; Hosseini, Seyed Davood; Salabat, Alireza

    2013-01-01

    Background: Doxorubicin (DOX), an anthracycline antibiotic, is a widely used anticancer agent. In spite of its high antitumor efficacy, the use of DOX in clinical chemotherapy is limited due to diverse toxicities, including gonadotoxicity. Objective: We investigated the protective effect of nano-zinc oxide (nZnO) as an established antioxidant on DOX-induced testicular disorders. Materials and Methods: In this experimental study 24 adult male Wistar rats were divided into four groups including one control and three experimentals (6 rats per group). They received saline (as control), DOX alone (6 mg/kg body weight, i.p.), nZnO alone (5 mg/kg body weight, i.p.), and nZnO followed by DOX. Animals were sacrificed 28 days after treatment and evaluations were made by sperm count and measuring sex hormone levels in plasma. Also total antioxidant power (TAP) and lipid peroxidation (LPO) in plasma were tested. Data was analyzed with SPSS-14 and one way ANOVA test. P<0.05 were considered to be statistically significant. Results: In the DOX-exposed rats significant differences were found compared with the control group (p=0.001) in plasma total antioxidant power (TAP) (425.50±32.33 vs. 493.33±18.54 mmol/mL), Lipid peroxidation (LPO) (3.70±0.44 vs. 2.78±0.68 ?mol/mL), plasma testosterone (3.38±0.69 vs. 5.40±0.89 ng/dl), LH (0.26±0.05 vs. 0.49±0.18 mlU/mL), sperm count (157.98±6.29 vs. 171.71±4.42×106/mL) and DNA damage (11.51±3.45 vs. 6.04±2.83%). Co-administration of nZnO significantly improved DOX-induced changes (p=0.013) in plasma TAP (471.83±14.51 mmol/mL), LPO (2.83±0.75 ?mol/mL), plasma testosterone (5.00±1.07 ng/dl), LH (0.52±0.08 mlU/mL), sperm count (169.13±5.01×106/mL) and DNA damage (7.00±1.67%). Conclusion: At the dose designed in the present investigation cytoprotective role of nano-zinc oxide through its antioxidant potential is illuminated in DOX-induced male gonadotoxicity. PMID:24639766

  19. Synthesis of Phytosteryl Esters by Using Alumina-Supported Zinc Oxide (ZnO\\/Al 2 O 3 ) from Esterification Production of Phytosterol with Fatty Acid

    Microsoft Academic Search

    Xianghe Meng; Qiuyue Pan; Tiankui Yang

    2011-01-01

    The feasibility of zinc oxide-catalyzed esterification of natural phytosterols with oleic acid was investigated well by a\\u000a chemical process. The influences of various reaction parameters were evaluated. Basic solid zinc oxide is the most desirable\\u000a catalyst due to its high selectivity (more than 90%), reusability, activity and less corrosivity, whereas sterol selectivity\\u000a with other catalysts, such as H2SO4, NaHSO4 and

  20. Facile preparation of monodispersed core\\/shell zinc oxide@polystyrene (ZnO@PS) nanoparticles via soapless seeded microemulsion polymerization

    Microsoft Academic Search

    Peng Liu

    2006-01-01

    Monodispersed core\\/shell zinc oxide@polystyrene (ZnO@PS) nanoparticles with chemical bonds between the inorganic core and the polymer shell were prepared successfully by the facile soapless microemulsion polymerization of styrene (St) with the oleic acid modified zinc oxide (OA-ZnO) nanoparticles as seeds, and potassium persulphate (KPS) as initiator in water. The products were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy

  1. Modification of phosphomolybdic acid and its compounds. Catalysts for the selective oxidation of methylacrolein to methacrylic acid. II. Systems modified by ammonium, vanadium, and zinc ions

    Microsoft Academic Search

    I. N. Staroverova; M. Yu. Kutyrev; B. V. Rozentuller

    1986-01-01

    X-ray diffraction and IR and ESR spectroscopy were used to study the structure of modified oxide catalysts for the selective oxidation of methylacrolein containing molybdenum, phosphorus, ammonium, vanadium, and zinc ions. (NHâ)PMoââOâânHâO is formed after roasting at 320degreeC upon using phosphomolybdic acid and ammonium carbonate or ammonium paramolybdate and ammonium phosphate. The introduction of vanadium and zinc during catalyst preparation

  2. Dispersion of Surface Modified Nanostructure Zinc Oxide in Optically Active Poly(Amide-Imide) Containing Pyromellitoyl-bis-L-isoleucine Segments: Nanocomposite Preparation and Morphological Investigation

    Microsoft Academic Search

    Shadpour Mallakpour; Mehdi Hatami

    2012-01-01

    Optically active zinc oxide\\/poly(amide-imide) (PAI) nanocomposites (NC)s were synthesized by using ultrasonic assisted technique. The polymers and zinc oxide (ZnO) nanoparticles were physically and\\/or chemically connected with each other through different kinds of interactions such as physical van der Waals forces, hydrogen bonding and\\/or covalent interactions. ZnO\\/PAI NCs were characterized by Fourier transform infrared spectra, X-ray diffraction patterns, and field

  3. Toll-like receptor 6 mediated inflammatory and functional responses of zinc oxide nanoparticles primed macrophages.

    PubMed

    Roy, Ruchi; Singh, Sunil K; Das, Mukul; Tripathi, Anurag; Dwivedi, Premendra D

    2014-07-01

    Macrophages are among the most sensitive immune cells because of their phagocytic activity and are prone to become dysfunctional or not able to perform properly if nanoparticle load increases. We have previously reported that zinc oxide nanoparticles (ZNPs) induce inflammatory responses in macrophages that contribute to their death. Recognition of ZNPs by pattern recognition receptors such as toll-like receptors (TLRs) might be a factor in the initiation of these responses in macrophages. Therefore, in this study we explored the role played by TLR6 and mitogen-activated protein kinase (MAPKs) pathways in the inflammatory responses of macrophages during ZNPs exposure. ZNPs-activated macrophages showed enhanced expression of activation and maturation markers (CD1d, MHC-II, CD86 and CD71). Among various TLRs screened, TLR6 emerged as the most potent activator for ZNPs-induced inflammatory responses. Downstream signalling proteins myeloid differentiation 88, interleukin-1 receptor associated kinase and tumour necrosis factor receptor-associated factor were also enhanced. On inhibiting MAPKs pathways individually, the inflammatory responses such as interleukin-1?, interleukin-6, tumour necrosis factor-?, cyclooxygenase-2 and inducible nitric oxide synthase were suppressed. TLR6 silencing significantly inhibited the pro-inflammatory cytokine levels, reactive nitrogen species generation and inducible nitric oxide synthase expression. Also, inhibition of MAPKs in the absence of TLR6 signalling validated the link between TLR6 and MAPKs in ZNPs-induced inflammatory responses. TLR6 was found to be co-localized with autophagosomes. Macrophages lacking TLR6 inhibited the autophagosome marker protein-microtubule-associated protein1 light chain 3-isoform II formation and phagocytosis. These results demonstrate that inflammatory responses caused by ZNPs-activated macrophages strongly depend on TLR6-mediated MAPK signalling. PMID:24593842

  4. Recovery of manganese oxides from spent alkaline and zinc-carbon batteries. An application as catalysts for VOCs elimination.

    PubMed

    Gallegos, María V; Falco, Lorena R; Peluso, Miguel A; Sambeth, Jorge E; Thomas, Horacio J

    2013-06-01

    Manganese, in the form of oxide, was recovered from spent alkaline and zinc-carbon batteries employing a biohydrometallurgy process, using a pilot plant consisting in: an air-lift bioreactor (containing an acid-reducing medium produced by an Acidithiobacillus thiooxidans bacteria immobilized on elemental sulfur); a leaching reactor (were battery powder is mixed with the acid-reducing medium) and a recovery reactor. Two different manganese oxides were recovered from the leachate liquor: one of them by electrolysis (EMO) and the other by a chemical precipitation with KMnO4 solution (CMO). The non-leached solid residue was also studied (RMO). The solids were compared with a MnOx synthesized in our laboratory. The characterization by XRD, FTIR and XPS reveal the presence of Mn2O3 in the EMO and the CMO samples, together with some Mn(4+) cations. In the solid not extracted by acidic leaching (RMO) the main phase detected was Mn3O4. The catalytic performance of the oxides was studied in the complete oxidation of ethanol and heptane. Complete conversion of ethanol occurs at 200°C, while heptane requires more than 400°C. The CMO has the highest oxide selectivity to CO2. The results show that manganese oxides obtained using spent alkaline and zinc-carbon batteries as raw materials, have an interesting performance as catalysts for elimination of VOCs. PMID:23562448

  5. The interaction of 193-nm excimer laser irradiation with single-crystal zinc oxide: Neutral atomic zinc and oxygen emission

    SciTech Connect

    Kahn, E. H. [Washington State University; Langford, S. C. [Washington State University; Dickinson, J. T. [Washington State University; Boatner, Lynn A [ORNL

    2013-01-01

    We report mass-resolved time-of-flight measurements of neutral particles from the surface of single-crystal ZnO during pulsed 193-nm irradiation at laser fluences below the threshold for avalanche breakdown. The major species emitted are atomic Zn and O. We examine the emissions of atomic Zn as a function of laser fluence and laser exposure. Defects at the ZnO surface appear necessary for the detection of these emissions. Our results suggest that the production of defects is necessary to explain intense sustained emissions at higher fluence. Rapid, clean surface etching and high atomic zinc kinetic energies seen at higher laser fluences are also discussed.

  6. Growth of Zinc oxide thin films on polar oxide surfaces by atomic layer deposition

    NASA Astrophysics Data System (ADS)

    Pradhan, Kallol

    Polar heterointerfaces of MgO(111) and the II-VI semiconductor ZnO are of technological interest for transparent conducting electrode applications. Growth and structure of thin films on polar surfaces can be different than on non-polar surfaces due to the large surface energy of polar surfaces. We have grown ZnO on unreconstructed MgO(111)-(1x1)-OH terminated and reconstructed MgO(111)-(?3x?3)R30° polar oxide surfaces using atomic layer deposition. A homemade UHV-interfaced viscous-flow atomic layer deposition (ALD) reactor with in-situ quartz crystal monitor was used to grow ZnO thin films on the MgO(111) substrates. Surface morphology studies revealed that the surface roughness increases with ZnO film thickness and that reconstructed MgO(111) is a better substrate for production of smooth ZnO films. Thin-film structural analysis revealed that ZnO thin films are polycrystalline, having the wurtzite structure, with preferential growth along the c-axis. ZnO grown on MgO(111)-(?3x?3)R30° substrates show strong preferential growth along the polar (002) direction. In contrast, growth along the non-polar (100) and (101) directions is also observed when grown on MgO(111)-(1x1) substrates. These observations indicate the crystal orientation during ALD ZnO growth depends not only on temperature but also on the surface terminations and symmetry of the substrates. We also investigated the growth of ALD ZnO on polar 6H-SiC(0001) substrates and non-polar MgO(100), alpha-Al2O3(0001) and oxidized Si(100). Our study revealed that, for non-polar substrates, ALD ZnO grows along the non-polar (100) and (101) directions along with the polar (002) direction. Highly c-axis-oriented ALD ZnO thin film growth on 6H-SiC(0001) indicates that lattice matched substrates favor growth of high-quality ALD ZnO. Finally, we investigated ZnO thin film growth on unreconstructed MgO(111)-(1x1)-OH terminated and reconstructed MgO(111)-(?3x?3)R30° polar oxide surfaces using pulsed-laser deposition (PLD). Structural studies revealed that surface termination affects the PLD ZnO growth similar to the way it affected ALD ZnO growth.

  7. Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

    NASA Astrophysics Data System (ADS)

    Bahedi, K.; Addou, M.; El Jouad, M.; Sofiani, Z.; Alaoui Lamrani, M.; El Habbani, T.; Fellahi, N.; Bayoud, S.; Dghoughi, L.; Sahraoui, B.; Essaïdi, Z.

    2009-02-01

    Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 °C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility ?(3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility ?(3) = 20.12 × 10 -12 (esu) of the studied films was found for the 3% doped sample.

  8. Organic light-emitting diode on indium zinc oxide film prepared by ion assisted deposition dc sputtering system

    Microsoft Academic Search

    W. J Lee; Y.-K Fang; J.-J Ho; C.-Y Chen; L.-H Chiou; S.-J Wang; F Dai; T Hsieh; R.-Y Tsai; D Huang; F. C Ho

    2002-01-01

    In this letter, high-quality indium zinc oxide (IZO) films (60–220 nm) were first grown on hardness poly-carbonate substrate by ion-assisted deposition (IAD) dc magnetron sputtering without a post deposition annealing treatment. The electrical, optical, and structural properties of these films were investigated as a function of film thickness. IAD dc magnetron sputtering provides very uniform IZO films with high transparency

  9. TOPICAL REVIEW: Zinc oxide nanorod based photonic devices: recent progress in growth, light emitting diodes and lasers

    Microsoft Academic Search

    M. Willander; O. Nur; Q. X. Zhao; L. L. Yang; M. Lorenz; B. Q. Cao; J. Zúñiga Pérez; C. Czekalla; M. Grundmann; A. Bakin; A. Behrends; M. Al-Suleiman; A. El-Shaer; A. Che Mofor; B. Postels; A. Waag; N. Boukos; A. Travlos; H. S. Kwack; J. Guinard; D. LeSi Dang

    2009-01-01

    Zinc oxide (ZnO), with its excellent luminescent properties and the ease of growth of its nanostructures, holds promise for the development of photonic devices. The recent advances in growth of ZnO nanorods are discussed. Results from both low temperature and high temperature growth approaches are presented. The techniques which are presented include metal-organic chemical vapour deposition (MOCVD), vapour phase epitaxy

  10. Physical properties of transparent conducting indium doped zinc oxide thin films deposited by pulsed DC magnetron sputtering

    Microsoft Academic Search

    Young Ran Park; Donggeun Jung; Ki-Chul Kim; Su Jeong Suh; Tae Seok Park; Young Sung Kim

    2009-01-01

    Transparent conducting In-doped (1at.%) zinc oxide (IZO) thin films are deposited on glass substrate by bipolar pulsed DC\\u000a magnetron sputtering. We have investigated the effect of pulse frequency on the physical properties of the IZO films. A highly\\u000a c-axis oriented IZO thin films were grown in perpendicular to the substrate. At optimal deposition conditions, IZO films with\\u000a a smoothest surface

  11. Kinetics of the absorption of hydrogen sulfide by high purity and doped high surface area zinc oxide

    Microsoft Academic Search

    J. Michael Davidson; Catriona H. Lawrie; Khalid Sohail

    1995-01-01

    Zinc oxide is used for removal of hydrogen sulfide from reformer feeds, synthesis gas, and natural gas before pipeline transmission. The stoichiometry and rate of the reaction of HâS (0.05--0.80% in Nâ) with high surface area ZnO have been studied at 273--318 K. Absorption of HâS by ZnO is not accompanied by evolution of the stoichiometric amount of HâO which

  12. Improved Inverted Organic Solar Cells With a Sol–Gel Derived Indium-Doped Zinc Oxide Buffer Layer

    Microsoft Academic Search

    Aung Ko Ko Kyaw; Xiaowei Sun; De Wei Zhao; Swee Tiam Tan; Yoga Divayana; Hilmi Volkan Demir

    2010-01-01

    We studied sol-gel derived indium-doped zinc oxide (IZO) with various indium contents as a functional buffer layer in inverted polymer:fullerene bulk-heterojunction solar cell. The short-circuit current density was observed to increase by doping indium in pure ZnO buffer layer. The maximum current density was obtained with a 1 at.% indium doping. Although the open-circuit voltage and fill factor reduced slightly,

  13. Evaluation of the Physical Stability of Zinc Oxide Suspensions Containing Sodium Poly(acrylate) and Sodium Dodecylsulfate

    Microsoft Academic Search

    Malika Chabni; Hadda Bougherra; Hakim Lounici; Toudert Ahmed-Zaïd; Jean-Paul Canselier; Joël Bertrand

    2011-01-01

    The physical stability of zinc oxide (ZnO) aqueous suspensions has been monitored during two months by different methods of investigation. The suspensions were formulated with ZnO at a fixed concentration (5 wt%), sodium poly-(acrylate), as a viscosifier, and sodium dodecylsulfate (SDS), as a wetting agent. The rheological study shows that the suspensions exhibit a non-Newtonian, most often shear-thinning behavior and their

  14. Measurement of the zinc oxide–molybdenum specific contact resistance for applications in Cu(In,Ga)Se 2-technology

    Microsoft Academic Search

    M. Oertel; S. Götz; J. Cieslak; J. Haarstrich; H. Metzner; W. Wesch

    2011-01-01

    We developed an improved measuring structure based on the transmission line model (TLM) which allows us to determine the specific contact resistance between rf-sputtered aluminum doped zinc oxide (ZnO:Al) and dc-sputtered molybdenum despite inhomogeneities in film thickness and conductivity which normally prevent an accurate determination of this value with the TLM. The improvement was achieved by an interchange between the

  15. Analysis of Tissue Reactions to Methacrylate Resin-based, Epoxy Resin-based, and Zinc Oxide–Eugenol Endodontic Sealers

    Microsoft Academic Search

    Roberta Kochenborger Scarparo; Fabiana Soares Grecca; Elaine Vianna Freitas Fachin

    2009-01-01

    The purpose of this study was to investigate the reaction of the subcutaneous connective tissue of rats to methacrylate resin-based sealer (EndoREZ), epoxy resin-based sealer (AH Plus), and zinc oxide–eugenol sealer (EndoFill). Polyethylene tubes containing the test materials were implanted in 18 rats. After 7, 30, and 60 days, tissues were collected for biopsy and fixed and processed for histologic

  16. Influence of the molar concentration and substrate temperature on fluorine-doped zinc oxide thin films chemically sprayed

    Microsoft Academic Search

    J. Rodríguez-Báez; A. Maldonado; G. Torres-Delgado; R. Castanedo-Pérez; M. de la L. Olvera

    2006-01-01

    The effect of both the molar concentration of the starting solution and the substrate temperature on the electrical, morphological, structural and optical properties of chemically sprayed fluorine-doped zinc oxide (ZnO:F) thin films deposited on glass substrates is analyzed in this work. All the starting solutions employed were aged for 10 days before the deposition. The results show that as the

  17. Composition and morphological characteristics of chemically sprayed fluorine-doped zinc oxide thin films deposited on Si(1 0 0)

    Microsoft Academic Search

    L. Castañeda; A. Maldonado; J. C. Cheang-Wong; M. Terrones; M. de la L. Olvera

    2007-01-01

    Fluorine-doped zinc oxide thin films (ZnO:F) were deposited on Si(100) substrates by the chemical spray technique (CST) from an aged-solution. The effect of the substrate temperature on the morphology and composition of the ZnO:F thin films was studied. The films were polycrystalline, with a preferential growth along the ZnO (002) plane, irrespective of the deposition temperature. The average crystal size

  18. Preparation, optical properties, magnetic properties and thermal stability of core–shell structure cobalt\\/zinc oxide nanocomposites

    Microsoft Academic Search

    Hari Bala; Wuyou Fu; Yanhui Yu; Haibin Yang; Yishun Zhang

    2009-01-01

    Cobalt nanoparticles coated with zinc oxide can form composite spheres with core–shell structure. This coating process was based on the use of silane coupling with agent 3-mercaptopropyltrimethoxysilane (HS-(CH2)3Si(OCH3)3, MPTS) as a primer to render the cobalt surface vitreophilic, thus it renders cobalt surface compatible with ZnO. X-ray photoelectron spectroscopy (XPS) was used to gain insight into the way in which

  19. Enhanced stability of zinc oxide-based hybrid polymer solar cells by manipulating ultraviolet light distribution in the active layer

    Microsoft Academic Search

    Shuyan Shao; Jian Liu; Baohua Zhang; Zhiyuan Xie; Lixiang Wang

    2011-01-01

    Polymer solar cells based on blends of conjugated polymer and zinc oxide (ZnO) nanoparticles degrade very fast under simulated solar light illumination due to the considerably increased photoconductivity of ZnO upon ultraviolet light exposure. It is reported that the stability of hybrid polymer solar cells with ZnO as electron acceptors is improved by using an optical layer to decrease ultraviolet

  20. Functionalization of direct-emulsion disperse-phase surface by zinc oxide nanoparticles using layer-by-layer electrostatic assembly

    Microsoft Academic Search

    O. A. Inozemtseva; T. A. Kolesnikova; D. A. Gorin; N. V. Shvyndina; V. Ya. Shklover

    2011-01-01

    Polyelectrolyte and nanocomposite (zinc oxide nanoparticles\\/polymer) coatings on the surface of a direct-emulsion disperse\\u000a phase containing fluorescent dye were obtained using layer-by-layer electrostatic assembly. The volume fraction of inorganic\\u000a nanoparticles was varied by changing the number of polymer layers in the coating. The loaded microcontainers were characterized\\u000a by fluorescence confocal and scanning electron microscopy (SEM). The parameters influencing the quality