Nanostructured zinc oxide platform for mycotoxin detection.

PubMed

Ansari, Anees A; Kaushik, Ajeet; Solanki, Pratima R; Malhotra, B D

2010-02-01

Nanostructured zinc oxide (Nano-ZnO) film has been deposited onto indium-tin-oxide (ITO) glass plate for co-immobilization of rabbit-immunoglubin antibodies (r-IgGs) and bovine serum albumin (BSA) for ochratoxin-A (OTA) detection. The results of X-ray diffraction (XRD) studies reveal the formation of Nano-ZnO with average particle size as ~5.0nm. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) techniques have been used to characterize Nano-ZnO/ITO electrode and BSA/r-IgGs/Nano-ZnO/ITO immunoelectrode. Electrochemical impedimetric response of BSA/r-IgGs/Nano-ZnO/ITO immunoelectrode obtained as a function of OTA concentration exhibits linearity as 0.006-0.01nM/dm(3), detection limit of 0.006nM/dm(3), response time as 25s and sensitivity of 189Omega/nM/dm(3)cm(-2) with a regression coefficient of 0.997. 2009 Elsevier B.V. All rights reserved.

Effects of Nano-zinc on Biochemical Parameters in Cadmium-Exposed Rats.

PubMed

Hejazy, Marzie; Koohi, Mohammad Kazem

2017-12-01

Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn 2+ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl 2 ) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl 2 (2-5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P < 0.05 was considered as statistically significant. The haematocrit (HCT) significantly increased and blood coagulation time significantly reduced in the nano-zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P < 0.05). It seems that in the oral administration of nano-zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.

Effect of Al2O3 insulator thickness on the structural integrity of amorphous indium-gallium-zinc-oxide based thin film transistors.

PubMed

Kim, Hak-Jun; Hwang, In-Ju; Kim, Youn-Jea

2014-12-01

The current transparent oxide semiconductors (TOSs) technology provides flexibility and high performance. In this study, multi-stack nano-layers of TOSs were designed for three-dimensional analysis of amorphous indium-gallium-zinc-oxide (a-IGZO) based thin film transistors (TFTs). In particular, the effects of torsional and compressive stresses on the nano-sized active layers such as the a-IGZO layer were investigated. Numerical simulations were carried out to investigate the structural integrity of a-IGZO based TFTs with three different thicknesses of the aluminum oxide (Al2O3) insulator (δ = 10, 20, and 30 nm), respectively, using a commercial code, COMSOL Multiphysics. The results are graphically depicted for operating conditions.

Zinc oxide nano-rods based glucose biosensor devices fabrication

NASA Astrophysics Data System (ADS)

Wahab, H. A.; Salama, A. A.; El Saeid, A. A.; Willander, M.; Nur, O.; Battisha, I. K.

2018-06-01

ZnO is distinguished multifunctional material that has wide applications in biochemical sensor devices. For extracellular measurements, Zinc oxide nano-rods will be deposited on conducting plastic substrate with annealing temperature 150 °C (ZNRP150) and silver wire with annealing temperature 250 °C (ZNRW250), for the extracellular glucose concentration determination with functionalized ZNR-coated biosensors. It was performed in phosphate buffer saline (PBS) over the range from 1 μM to 10 mM and on human blood plasma. The prepared samples crystal structure and surface morphologies were characterized by XRD and field emission scanning electron microscope FESEM respectively.

Characterization of Antimicrobial Poly (Lactic Acid)/Nano-Composite Films with Silver and Zinc Oxide Nanoparticles

PubMed Central

Chu, Zhuangzhuang; Zhao, Tianrui; Li, Lin; Fan, Jian; Qin, Yuyue

2017-01-01

Antimicrobial active films based on poly (lactic acid) (PLA) were prepared with nano-silver (nano-Ag) and nano-zinc oxide (nano-ZnO) using a solvent volatilizing method. The films were characterized for mechanical, structural, thermal, physical and antimicrobial properties. Scanning electron microscopy (SEM) images characterized the fracture morphology of the films with different contents of nano-Ag and nano-ZnO. The addition of nanoparticles into the pure PLA film decreased the tensile strength and elasticity modulus and increased the elongation of breaks—in other words, the flexibility and extensibility of these composites improved. According to the results of differential scanning calorimetry (DSC), the glass transition temperature of the PLA nano-composite films decreased, and the crystallinity of these films increased; a similar result was apparent from X-ray diffraction (XRD) analysis. The water vapor permeability (WVP) and opacity of the PLA nano-composite films augmented compared with pure PLA film. Incorporation of nanoparticles to the PLA films significantly improved the antimicrobial activity to inhibit the growth of Escherichia coli. The results indicated that PLA films with nanoparticles could be considered a potential environmental-friendly packaging material. PMID:28773018

Role of quercetin and arginine in ameliorating nano zinc oxide-induced nephrotoxicity in rats.

PubMed

Faddah, Laila M; Abdel Baky, Nayira A; Al-Rasheed, Nouf M; Al-Rasheed, Nawal M; Fatani, Amal J; Atteya, Muhammad

2012-05-02

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. 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. Nano zinc oxide-induced nephrotoxicity was confirmed by the elevation in serum inflammatory markers including: tumor necrosis factor alpha (TNF-α), 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. 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.

Effects of dietary zinc oxide nanoparticles on growth performance and antioxidative status in broilers.

PubMed

Zhao, Cui-Yan; Tan, Shu-Xian; Xiao, Xi-Yu; Qiu, Xian-Shuai; Pan, Jia-Qiang; Tang, Zhao-Xin

2014-09-01

Broilers in four groups were fed a basal diet supplemented with 60 mg/kg zinc oxide (60-ZnO; control), or 20, 60, or 100 mg/kg ZnO nanoparticles (20-, 60-, and 100-nano-ZnO, respectively). Compared with the controls, after 14 days, birds in the 20- and 60-nano-ZnO groups had significantly greater weight gains and better feed conversion ratios. However, the body weight of birds in the 100-nano-ZnO group was dramatically reduced after 28 days. Relative to the control group, the total antioxidant capability (T-AOC) in serum and liver tissue was significantly higher in the 20-nano-ZnO group at all time points and also significantly higher in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues on days 21 and 28. Compared with the controls, the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD) was significantly greater in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues after 21 days. Catalase activity in serum samples was significantly higher in the 20- and 60-nano-ZnO groups relative to the control and 100-nano-ZnO birds, but catalase activity in liver tissue was not affected by different nano-ZnO levels. Malondialdehyde content in serum and liver tissues was significantly reduced in the 20-, 60-, and 100-nano-ZnO groups compared with that in the control group at all time points except day 42. Taken together, our data indicate that appropriate concentration of dietary ZnO nanoparticles improves growth performance and antioxidative capabilities in broilers, and 20 mg/kg nano-ZnO is the optimal concentration.

Nano-zinc oxide incorporated graphene oxide/nanocellulose composite for the adsorption and photo catalytic degradation of ciprofloxacin hydrochloride from aqueous solutions.

PubMed

Anirudhan, T S; Deepa, J R

2017-03-15

Purpose of this study is to report the synthetic procedure of a novel photo catalyst, nano zinc oxide incorporated graphene oxide/nanocellulose (ZnO-GO/NC) for the effective adsorption and subsequent photo degradation of ciprofloxacin (CF), an antibiotic widely used in the poultry. Self cleaning property in cellulose was achieved by introducing a nano zinc oxide incorporated graphene oxide into nanocellulose (NC) matrix. By incorporating nano zinc oxide (ZnO) in graphene oxide (GO), band gap could be tuned to 2.4eV and after the composite formation with NC, the band gap was enhanced to 2.8eV which is in the visible region. Thus the degradation of the CF was achieved under the visible light. Photo degradation was due to electron hole interaction. The step wise modification in the synthesis ZnO-GO/NC was characterized using FT-IR, XRD, SEM, EDS, AFM, DRS-UV and BET N 2 adsorption isotherm techniques. The values of surface area, pore volume and pore radius were found to be 12.68m 2 /g, 0.026mL/g and 12.5nm, respectively. Efficiency in the adsorption process of CF onto ZnO-GO/NC was verified by batch adsorption technique. The optimum pH was found to be 5.5 and dose of the ZnO-GO/NC was optimized as 2.0g/L. Equilibrium was attained at 120min and the adsorption of drug followed second-order kinetics. Sips isotherm was the best fitted model and could explain the nature of interaction of CF with ZnO-GO/NC. The studies revealed that the degradation followed first-order kinetics and the optimum pH for the degradation process was found to be 6.0 and achieved a maximum degradation efficiency of 98.0%. The reusability of ZnO-GO/NC after five consecutive cycles indicated it to be a potential candidate for the removal and degradation of CF from aquatic environment. Copyright © 2016 Elsevier Inc. All rights reserved.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states

NASA Astrophysics Data System (ADS)

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-01

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states.

PubMed

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-27

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Subcutaneous Connective Tissue Reaction to a New Nano Zinc-Oxide Eugenol Sealer in Rat Model

PubMed Central

Omidi, Salma; Javidi, Maryam; Zarei, Mina; Mushakhian, Siavash; Jafarian, Amirhossein

2017-01-01

Introduction: The aim of this animal study was to evaluate the histological response of the new nano zinc-oxide eugenol (NZOE) sealer in comparison with Pulp Canal Sealer (ZOE based) and AH-26 (epoxy resin sealer). Methods and Materials: A total of 27 Wistar rats were used. Four polyethylene tubes were implanted in the back of each rat (three tubes containing the test materials and an empty tube as a control). Then, 9 animals were sacrificed at each interval of 15, 30 and 60 days, and the implants were removed with the surrounding tissues.Samples were evaluated for the presence of inflammatory cell (mononuclear cell), vascular changes, fibrous tissue formation and present of giant cell. Comparisons between groups and time-periods were performed using the Kruskal-Wallis and Mann-Whitney U non-parametric tests. The level of significance was set at 0.05. Results: No significant difference was observed in tissue reactions and biocompatibility pattern of three sealers during 3 experimental periods (P<0.05). In all groups the tissue behavior showed tendency to decrease the irritation effect over time. Conclusion: The new nano zinc-oxide eugenol sealer has histocompatibility properties comparable to conventional commercial sealers. PMID:28179927

Ultrasound-assisted synthesis of nano-structured Zinc(II)-based metal-organic frameworks as precursors for the synthesis of ZnO nano-structures.

PubMed

Bigdeli, Fahime; Ghasempour, Hosein; Azhdari Tehrani, Alireza; Morsali, Ali; Hosseini-Monfared, Hassan

2017-07-01

A 3D, porous Zn(II)-based metal-organic framework {[Zn 2 (oba) 2 (4-bpmn)]·(DMF) 1.5 } n (TMU-21), (4-bpmn=N,N'-Bis-pyridin-4-ylmethylene-naphtalene-1,5-diamine, H 2 oba=4,4'-oxybis(benzoic acid)) with nano-rods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure was prepared and characterized by scanning electron microscopy. Sonication time and concentration of initial reagents effects on the size and morphology of nano-structured MOFs were studied. Also {[Zn 2 (oba) 2 (4-bpmn)] (TMU-21) and {[Zn 2 (oba) 2 (4-bpmb)] (TMU-6), 4-bpmb=N,N'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) were easily prepared by mechanochemical synthesis. Nanostructures of Zinc(II) oxide were obtained by calcination of these compounds and their de-solvated analogue as activated MOFs, at 550°C under air atmosphere. As a result of that, different Nanostructures of Zinc(II) oxide were obtained. The ZnO nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and FT-IR spectroscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermal behaviour and corrosion resistance of nano-ZnO/polyurethane film

NASA Astrophysics Data System (ADS)

Virgawati, E.; Soegijono, B.

2018-03-01

Hybrid materials Nano-ZnO/polyurethane film was prepared with different zinc oxide (ZnO) content in polyurethane as a matrix. The film was deposited on low carbon steel plate using high volume low pressure (HVLP) method. To observe thermal behaviour of the film, the sample was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Fourier transform infrared spectroscopy (FTIR) was used to see whether any chemical reaction of ZnO in polyurethane occured. TGA and FTIR results showed that the decomposition temperature shifted to a higher point and the chemical reaction of zinc oxide in polyurethane occurred. The surface morphology changed and the corrosion resistance increased with an increase of ZnO content

Understanding and Quantifying the Reactivity of Energetic NanoParticles and NanoComposites

DTIC Science & Technology

2015-01-05

Aerosol Synthesis and Reactivity of Thin Oxide Shell Aluminum Nanoparticles via Fluorocarboxylic Acid Functional Coating, Particle & Particle...Received Paper 3.00 9.00 8.00 7.00 6.00 5.00 4.00 X. Ma and M.R. Zachariah. " Oxidation Anisotropy and Size Dependent Reaction Kinetics of Zinc ...in the reaction. Experiments also conducted for neat Al, CuO, Fe2O3 and ZnO powders show that the oxygen are produced by decomposition of oxidizer

Computational predictions of zinc oxide hollow structures

NASA Astrophysics Data System (ADS)

Tuoc, Vu Ngoc; Huan, Tran Doan; Thao, Nguyen Thi

2018-03-01

Nanoporous materials are emerging as potential candidates for a wide range of technological applications in environment, electronic, and optoelectronics, to name just a few. Within this active research area, experimental works are predominant while theoretical/computational prediction and study of these materials face some intrinsic challenges, one of them is how to predict porous structures. We propose a computationally and technically feasible approach for predicting zinc oxide structures with hollows at the nano scale. The designed zinc oxide hollow structures are studied with computations using the density functional tight binding and conventional density functional theory methods, revealing a variety of promising mechanical and electronic properties, which can potentially find future realistic applications.

Zinc oxide nanoparticles induce oxidative DNA damage and ROS-triggered mitochondria-mediated apoptosis in zebrafish embryos.

PubMed

Zhao, Xuesong; Ren, Xin; Zhu, Rong; Luo, Zhouying; Ren, Baixiang

2016-11-01

Zinc oxide nanoparticles (nano-ZnO) are one of the most important nanoparticles in the industry. The objectives of this study were (1) to investigate the effects of nano-ZnO on oxidative damage to DNA and on apoptosis in zebrafish (Danio rerio) embryos, and (2) to identify the underlying molecular mechanism affecting theapoptotic process. In addition to nano-ZnO, we also investigated the toxic effects of the Zn 2+ ion. Zebrafish embryos were exposed to 10, 30, 60, 90, or 120mg/L nano-ZnO for 96h postfertilization. Nano-ZnO (at concentrations between 10 and 120mg/L) significantly reduced the rate of embryo hatching. Embryos/larvae exposed to 120mg/L nano-ZnO had significantly higher heart rates. Increased heart rates could be a physiological mechanism compensating for body hypoxia. Embryos/larvae exposed to nano-ZnO exhibited oxidative stress, due to an excessive generation of reactive oxygen species (ROS). Oxidative stress was evidenced by increased levels of superoxide dismutase, by increased lipid peroxidation, and by increased expression of genes related to the antioxidant defense system (sod1, cat, gpx1a, and pparα), which were altered at different degrees. Upon exposure to nano-ZnO, the percentage of apoptotic cells increased in a dose-dependent manner (0.41% to 4.21%). In addition, altered transcriptional regulation of pro-apoptotic genes (bax, puma, and apaf-1) and anti-apoptotic genes (bcl-2) provided further evidence of the activation of apoptosis. In this study, exposure of zebrafish embryos to nano-ZnO triggered an excessive production of ROS, which was followed by several phenomena: the up-regulation of p53, a reduction in the bcl-2/bax ratio,a reduction in the mitochondrial membrane potential (ψ m ), the release of cytochrome c into the cytosolic fraction, and the activation of caspases 9 and 3. Collectively, our data imply that nano-ZnO induce an excessive production of ROS which then activate the apoptosis pathway mediated by mitochondria and caspases. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of nano-zinc oxide on nitrogenase activity in legumes: an interplay of concentration and exposure time

NASA Astrophysics Data System (ADS)

Kumar, Praveen; Burman, Uday; Santra, P.

2015-07-01

Experiments were carried out to study the effect of zinc oxide nanoparticles (nano-ZnO) on nitrogenase activity in legumes. In the first experiment, nodulated roots of cluster bean, moth bean, green gram and cowpea were dipped in Hoagland solution containing 1.5 and 10 μg mL-1 of nano-ZnO for 24 h. Nitrogenase activity in cluster bean, green gram and cowpea roots increased after dipping in solution containing 1.5 μg mL-1 nano-ZnO, but decreased in roots dipped in solution containing 10 μg mL-1 nano-ZnO. However, in moth bean roots, nitrogenase activity decreased after dipping in solution containing either concentration of nano-ZnO. In the second experiment, nodulated roots of green gram were dipped in Hoagland solution containing 1, 4, 6, 8 and 10 μg mL-1 nano-ZnO for 6-30 h before estimating nitrogenase activity. Results showed that an interactive effect of nano-ZnO concentration and exposure time influenced nitrogenase activity. The possible reasons behind this effect have been discussed. A model [ A = 3.44 + 0.46 t - 0.01 t 2 - 0.002 tc 2 ( R 2 = 0.81)] involving linear and power components was developed to simulate the response of nitrogenase activity in green gram roots to the concentration and exposure time of nano-ZnO.

Effect of zinc oxide nanoparticles on dielectric behavior of nematic liquid crystal

NASA Astrophysics Data System (ADS)

Sharma, Amit; Kumar, Pankaj; Malik, Praveen

2018-05-01

In this work, phase transition and dielectric behavior of nematic liquid crystal (NLC), E7 and zinc oxide (ZnO) nanoparticles (NPs) doped nematic liquid crystals are investigated. Effect of nano-particles dispersion is analyzed and compared with the dielectric behavior of E7 and E7-ZnO. Frequency dependent dielectric permittivity at various temperatures in nematic phase for E7 and E7-ZnO sample is also studied.

The effect of polymers onto the size of zinc layered hydroxide salt and its calcined product

NASA Astrophysics Data System (ADS)

Hussein, Mohd Zobir bin; Ghotbi, Mohammad Yeganeh; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

2009-02-01

Zinc hydroxide nitrate, a brucite-like layered material was synthesized using pH control method. Poly(vinyl alcohol) and poly(ethylene glycol) were used at various percentages as size decreasing agents during the synthesis of zinc hydroxide nitrate. SEM and PXRD showed the decrease of size and thickness of the resultant zinc hydroxide nitrates. TG and surface area data confirmed the decrease of the particle sizes, too. When zinc hydroxide nitrates were heat treated at 500 °C, the physical properties of nano zinc oxides obtained depended on the parent material, zinc hydroxide nitrate.

Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment.

PubMed

Leite-Silva, V R; Sanchez, W Y; Studier, H; Liu, D C; Mohammed, Y H; Holmes, A M; Ryan, E M; Haridass, I N; Chandrasekaran, N C; Becker, W; Grice, J E; Benson, H A E; Roberts, M S

2016-07-01

Public health concerns continue to exist over the safety of zinc oxide nanoparticles that are commonly used in sunscreen formulations. In this work, we assessed the effects of two conditions which may be encountered in everyday sunscreen use, occlusion and a compromised skin barrier, on the penetration and local toxicity of two topically applied zinc oxide nanoparticle products. Caprylic/capric triglyceride (CCT) suspensions of commercially used zinc oxide nanoparticles, either uncoated or with a silane coating, were applied to intact and barrier impaired skin of volunteers, without and with occlusion for a period of six hours. The exposure time was chosen to simulate normal in-use conditions. Multiphoton tomography with fluorescence lifetime imaging was used to noninvasively assess zinc oxide penetration and cellular metabolic changes that could be indicative of toxicity. We found that zinc oxide nanoparticles did not penetrate into the viable epidermis of intact or barrier impaired skin of volunteers, without or with occlusion. We also observed no apparent toxicity in the viable epidermis below the application sites. These findings were validated by ex vivo human skin studies in which zinc penetration was assessed by multiphoton tomography with fluorescence lifetime imaging as well as Zinpyr-1 staining and toxicity was assessed by MTS assays in zinc oxide treated skin cryosections. In conclusion, applications of zinc oxide nanoparticles under occlusive in-use conditions to volunteers are not associated with any measurable zinc oxide penetration into, or local toxicity in the viable epidermis below the application site. Copyright © 2016 Elsevier B.V. All rights reserved.

Zinc impregnated cellulose nanocomposites: Synthesis, characterization and applications

NASA Astrophysics Data System (ADS)

Ali, Attarad; Ambreen, Sidra; Maqbool, Qaisar; Naz, Sania; Shams, Muhammad Fahad; Ahmad, Madiha; Phull, Abdul Rehman; Zia, Muhammad

2016-11-01

Nanocomposite materials have broad applicability due to synergistic effect of combined components. In present investigation, cellulose isolated from citrus peel waste is used as a supporting material; impregnation of zinc oxide nanoparticles via co-precipitation method. The characterization of nano composite is carried out through Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and Thermo-gravimetric analysis (TGA) resulting less than 10 μm cellulose fiber and approx. 50 nm ZnO NPs. Zinc oxide impregnated cellulose (ZnO-Cel) exhibited significant bacterial devastation property when compared to ZnO NPs or Cellulose via disc diffusion and colony forming unit methods. In addition, the ZnO-Cel exhibited significant total antioxidant, and minor DPPH free radical scavenging and total reducing power activities. The nano composite also showed time dependent increase in photocatalytic by effectively degrading methylene blue dye up to 69.5% under sunlight irradiation within 90 min. The results suggest effective utilization of cellulose obtained from citrus waste and synthesis of pharmacologically important nano-composites that can be exploited in wound dressing; defence against microbial attack and healing due to antioxidative property, furthermore can also be used for waste water treatment.

Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities.

PubMed

Read, Daniel S; Matzke, Marianne; Gweon, Hyun S; Newbold, Lindsay K; Heggelund, Laura; Ortiz, Maria Diez; Lahive, Elma; Spurgeon, David; Svendsen, Claus

2016-03-01

Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities.

Comparison of porous and nano zinc oxide for replacing high-dose dietary regular zinc oxide in weaning piglets

PubMed Central

Long, Lina; Chen, Jiashun; Zhang, Yonggang; Liang, Xiao

2017-01-01

The aim of this study was to compare the effect of dietary supplementation with low dose of porous and nano zinc oxide (ZnO) on weaning piglets, and to evaluate the possibility of using them as an alternative to high dose of regular ZnO. Piglets were randomly allocated into four treatment groups fed with four diets: (1) basal diet (NC), (2) NC+ 3000 mg/kg ZnO (PC), (3) NC + 500 mg/kg porous ZnO (HiZ) and (4) NC + 500 mg/kg nano ZnO (ZNP). The result showed that piglets in HiZ group had less diarrhea than ZNP group (P < 0.05). Besides, there was no significant difference between PC, HiZ and ZNP groups in terms of serum malondialdeyhde (MDA) concentration and glutathione peroxidase (GSH-Px) activity (P > 0.05). Analysis of trace metal elements revealed that piglets fed with high dose of regular ZnO had the highest Zn level in kidney (P < 0.05), which may induce kidney stone formation. Additionally, a decrease in ileal crypt depth was observed in PC, HiZ and ZNP group, suggesting an effective protection against intestinal injury. Results of mRNA analysis in intestine showed that ZNP supplementation had better effects on up-regulated trefoil factor 3 (TFF3) and nuclear factor erythroid 2-related factor 2 (Nrf2) levels in duodenum and jejunum than HiZ did (P < 0.05), implying that nano ZnO may possess higher anti-inflammatory capacity than porous ZnO. In conclusion, dietary supplementation with low dose of porous and nano ZnO had similar (even better) effect on improving growth performance and intestinal morphology, reducing diarrhea and intestinal inflammatory as high dose of regular ZnO in weaning piglets. Compared with nano ZnO, porous ZnO had better performance on reducing diarrhea but less effect on up-regulation of intestinal TFF3 and Nrf2. PMID:28792520

Development of zinc oxide nanoparticle by sonochemical method and study of their physical and optical properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Samreen Heena, E-mail: samreen.heena.khan@gmail.com; Suriyaprabha, R.; Pathak, Bhawana, E-mail: bhawana.pathak@cug.ac.in

With the miniaturization of crystal size, the fraction of under-coordinated surface atoms becomes dominant, and hence, materials in the nano-regime behave very differently from the similar material in a bulk. Zinc oxide (ZnO), particularly, exhibits extraordinary properties such as a wide direct band gap (3.37 eV), large excitation binding energy (60 meV), low refractive index (1.9), stability to intense ultraviolet (UV) illumination, resistance to high-energy irradiation, and lower toxicity as compared to other semiconductors. This very property makes Zinc Oxide a potential candidate in many application fields, particularly as a prominent semiconductor. Zinc Oxide plays a significant role in manymore » technological advances with its application in semiconductor mediated photocatalytic processes and sensor, solar cells and others. In present study, Zinc Oxide (ZnO) has been synthesized using three different precursors by sonochemical method. Zinc Acetate Dihydrate, Zinc Nitrate Hexahydrate and Zinc Sulphate Heptahydrate used as a precursor for the synthesis process. The synthesized ZnO nanoparticle has been found under the range of ∼50 nm. Zinc oxide nanoparticles were characterized using different characterizing tools. The as-synthesized ZnO was characterized by Fourier Transform-Infrared Spectroscopy (FT-IR) for the determination of functional group; Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS) for Morphology and elemental detection respectively, Transmission Electron Microscopy for Particle size distribution and morphology and X-Ray Diffraction (XRD) for the confirmation of crystal structure of the nanomaterial. The optical properties of the ZnO were examined by UV-VIS spectroscopy equipped with Diffuse Reflectance spectroscopy (DRS) confirmed the optical band gap of ZnO-3 around 3.23 eV resembles with the band gap of bulk ZnO (3.37eV). The TEM micrograph of the as-synthesized material showed perfectly spherical shaped nanoparticle under the size range of 50nm. The XRD data showed that the ZnO-3 which was synthesized using Zinc Nitrate Hexahydrate as precursor showed the hexagonal wurtzite crystal structure. The XRD data obtained were compared with the JCPDS standard data. The precursor Zinc Nitrate Hexahydrate (ZnO-3) showed the good yield, monodispersity and size of nanoparticle under the range of 50 nm. The ZnO nanoparticles synthesize using different precursor was found effective in order of ZnO-3, followed by ZnO-1 & ZnO-2. The Synthesized ZnO has wider application in environmental remediation and clean-up as a potential nano-catalyst.« less

Near band edge emission characteristics of sputtered nano-crystalline ZnO films

NASA Astrophysics Data System (ADS)

Kunj, Saurabh; Sreenivas, K.

2016-05-01

Sputtered zinc oxide (ZnO) thin films deposited on unheated glass substrate under different sputtering gas mixtures (Ar+O2) have been investigated using X-ray diffraction and photo luminescence spectroscopy. Earlier reported studies on ZnO films prepared by different techniques exhibit either a sharp/broad near band edge (NBE) emission peak depending on the crystalline quality of the film. In the present study zinc oxide films, grown on unheated substrates, are seen to possess a preferred (002) orientation with a microstructure consisting of clustered nano-sized crystallites. The splitting in the near band edge emission (NBE) into three characteristic peaks is attributed to quantum confinement effect, and is observed specifically under an excitation of 270 nm. Deep level emission (DLE) in the range 400 to 700 nm is not observed indicating absence of deep level radiative defects.

Synthesis, characteristics and antimicrobial activity of ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Janaki, A. Chinnammal; Sailatha, E.; Gunasekaran, S.

2015-06-01

The utilization of various plant resources for the bio synthesis of metallic nano particles is called green technology and it does not utilize any harmful protocols. Present study focuses on the green synthesis of ZnO nano particles by Zinc Carbonate and utilizing the bio-components of powder extract of dry ginger rhizome (Zingiber officinale). The ZnO nano crystallites of average size range of 23-26 nm have been synthesized by rapid, simple and eco friendly method. Zinc oxide nano particles were characterized by using X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). FTIR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and the presence of ZnO bonding. Antimicrobial activity of ZnO nano particles was done by well diffusion method against pathogenic organisms like Klebsiella pneumonia, Staphylococcus aureus and Candida albicans and Penicillium notatum. It is observed that the ZnO synthesized in the process has the efficient antimicrobial activity.

High mobility and high stability glassy metal-oxynitride materials and devices

NASA Astrophysics Data System (ADS)

Lee, Eunha; Kim, Taeho; Benayad, Anass; Hur, Jihyun; Park, Gyeong-Su; Jeon, Sanghun

2016-04-01

In thin film technology, future semiconductor and display products with high performance, high density, large area, and ultra high definition with three-dimensional functionalities require high performance thin film transistors (TFTs) with high stability. Zinc oxynitride, a composite of zinc oxide and zinc nitride, has been conceded as a strong substitute to conventional semiconductor film such as silicon and indium gallium zinc oxide due to high mobility value. However, zinc oxynitride has been suffered from poor reproducibility due to relatively low binding energy of nitrogen with zinc, resulting in the instability of composition and its device performance. Here we performed post argon plasma process on zinc oxynitride film, forming nano-crystalline structure in stable amorphous matrix which hampers the reaction of oxygen with zinc. Therefore, material properties and device performance of zinc oxynitride are greatly enhanced, exhibiting robust compositional stability even exposure to air, uniform phase, high electron mobility, negligible fast transient charging and low noise characteristics. Furthermore, We expect high mobility and high stability zinc oxynitride customized by plasma process to be applicable to a broad range of semiconductor and display devices.

Synthesis of Nano-Zinc Oxide Loaded on Mesoporous Silica by Coordination Effect and Its Photocatalytic Degradation Property of Methyl Orange.

PubMed

Shen, Zhichuan; Zhou, Hongjun; Chen, Huayao; Xu, Hua; Feng, Chunhua; Zhou, Xinhua

2018-05-09

Salicylaldimine-modified mesoporous silica (Sal-MCM-3 and Sal-MCM-9) was prepared through a co-condensation method with different amounts of added salicylaldimine. With the coordination from the salicylaldimine, zinc ions were impregnated on Sal-MCM-3 and Sal-MCM-9. Then, Zn-Sal-MCM-3 and Zn-Sal-MCM-9 were calcined to obtain nano-zinc oxide loaded on mesoporous silica (ZnO-MCM-3 and ZnO-MCM-9). The material structures were systematically studied by Fourier transform infrared spectroscopy (FTIR), N₂ adsorption/desorption measurements, X-ray powder diffraction (XRD), zeta potential, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet diffused reflectance spectrum (UV-vis DRS), and thermogravimetry (TGA). Methyl orange (MO) was used to investigate the photocatalysis behavior of ZnO-MCM-3 and ZnO-MCM-9. The results confirmed that nano ZnO was loaded in the channels as well as the outside surface of mesoporous silica (MCM-41). The modification of salicylaldimine helped MCM-41 to load more nano ZnO on MCM-41. When the modification amount of salicylaldimine was one-ninth and one-third of the mass of the silicon source, respectively, the load of nano ZnO on ZnO-MCM-9 and ZnO-MCM-3 had atomic concentrations of 1.27 and 2.03, respectively. ZnO loaded on ZnO-MCM-9 had a wurtzite structure, while ZnO loaded on ZnO-MCM-3 was not in the same crystalline group. The blocking effect caused by nano ZnO in the channels reduced the orderliness of MCM-41. The photodegradation of MO can be divided in two processes, which are mainly controlled by the surface areas of ZnO-MCM and the loading amount of nano ZnO, respectively. The pseudo-first-order model was more suitable for the photodegradation process.

Carbon nanofibers wrapped with zinc oxide nano-flakes as promising electrode material for supercapacitors.

PubMed

Pant, Bishweshwar; Park, Mira; Ojha, Gunendra Prasad; Park, Juhyeong; Kuk, Yun-Su; Lee, Eun-Jung; Kim, Hak-Yong; Park, Soo-Jin

2018-07-15

A combination of electrospinning technique and hydrothermal process was carried out to fabricate zinc oxide nano-flakes wrapped carbon nanofibers (ZnO/CNFs) composite as an effective electrode material for supercapacitor. The morphology of the as-synthesized composite clearly revealed that the carbon nanofibers were successfully wrapped with ZnO nano-flakes. The electrochemical performance of the as-synthesized nanocomposite electrode was evaluated by the cyclic voltammetry (CV), galvanostatic charge-discharge (GDC), and electrochemical impedance spectroscopy (EIS), and compared with the pristine ZnO nanofibers. It was found that the composite exhibited a higher specific capacitance (260 F/g) as compared to pristine ZnO NFs (118 F/g) at the scan rate of 5 mV/s. Furthermore, the ZnO/CNFs composite also exhibited good capacity retention (73.33%). The obtained results indicated great potential applications of ZnO/CNFs composite in developing energy storage devices with high energy and power densities. The present work might provide a new route for utilizing ZnO based composites for energy storage applications. Copyright © 2018 Elsevier Inc. All rights reserved.

Synthesis of Ferrite Nickel Nano-particles and Its Role as a p-Dopant in the Improvement of Hole Injection of an Organic Light-Emitting Diode

NASA Astrophysics Data System (ADS)

Noori, Maryam; Jafari, Mohammad Reza; Hosseini, Sayed Mohsen; Shahedi, Zahra

2017-07-01

We fabricated an organometallic complex based on zinc ions using zinc complex as a fluorescent in organic light-emitting diodes (OLEDs). Also, the nano-particles of ferrite nickel were produced in a simple aqueous system prepared by mixing Ni (NO3)2, Fe (NO3)3 and deionized water solutions. The synthesized zinc bis (8-hydroxyquinoline) (Znq2) complex and NiFe2O4 nano-particles were characterized by using x-ray diffraction (XRD), ultraviolet-visible (UV-Vis), Fourier transform infrared spectroscopy (FT-IR) as well as photoluminescence spectroscopy analysis. Their energy level was also determined by some cyclic voltammetry (CV) measurements. The maximum green photoluminescence was observed at 565 nm. The nano-particles of ferrite nickel were utilized in preparation of OLEDs by blending of the magnetic nano-particles with PEDOT:PSS and Zn-complex solutions. The electrical and optical performance of prepared OLEDs with/without doped nano-particle was studied. The samples were configured into two structures: (1) Indium Tin Oxide (ITO)/ poly(3,4-ethylenedi-oxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/Znq2/(2-4-biphenylyl)-5-phenyl-oxadiazole (PBD)/aluminum (Al) and (2) ITO/PEDOT:PSS:NiFe2O4(NPs)/Znq2/PBD/Al. Obtained results showed that the current density and electroluminescence efficiency were increased and the turn-on voltage decreased (about 3 V) by using nano-particles into a PEDOT:PSS layer (Hole transport layer). Also, the electroluminescence efficiency was decreased by incorporating magnetic nano-particles into a Zn-complex layer (emissive layer). It was found that utilizing NiFe2O4 nano-particles caused an increase of hole-injection layer conductivity effectively and a decrease of the turn-on voltage.

Research on the Dielectric Properties of Nano-ZnO/Silicone Rubber Composites

NASA Astrophysics Data System (ADS)

Wang, Fei-feng; Yan, Dan-dan; Su, Yi; Lu, Yu-feng; Xia, Xiao-fei; Huang, Hui-min

2017-09-01

The samples of 1%, 2%, 3% and 4% Zinc Oxide (ZnO) nano-composite silicone rubber were prepared by mechanical method. The dielectric properties of each sample were measured by dielectric spectroscopy. The experimental results showed that the dielectric constant of the silicone rubber composite increases with the increase of the content of nano-ZnO. The breakdown test results showed that with the increase of the content of nano-ZnO, the breakdown strength of silicone rubber composites increased first and then decreased. The breakdown test results indicate that the nano-ZnO can reduce the breakdown strength of silicone rubber. The hydrophobic test results showed that nano-ZnO will reduce the hydrophobic of silicone rubber.

Structural and dielectric studies on Ag doped nano ZnSnO3

NASA Astrophysics Data System (ADS)

Deepa, K.; Angel, S. Lilly; Rajamanickam, N.; Jayakumar, K.; Ramachandran, K.

2018-04-01

Undoped and Ag-doped nano Zinc Stannate (ZSO) ternary oxide were prepared by co-precipitation method. The crystallographic, morphological and optical properties of the synthesized nanoparticles were studied using X-ray diffraction (XRD) and UV-Visible spectroscopy (UV-Vis) and Scanning electron microscopy (SEM). The electrical properties of the synthesized samples were studied by dielectric measurements. Higher concentration Ag doped ZSO nanoparticles exhibit higher dielectric constant at low frequency.

New possibility on InZnO nano thin film for green emissive optoelectronic devices

NASA Astrophysics Data System (ADS)

Sugumaran, Sathish; Noor Bin Ahmad, Mohd; Faizal Jamlos, Mohd; Bellan, Chandar Shekar; Chandran, Sharmila; Sivaraj, Manoj

2016-04-01

Indium zinc oxide (InZnO) nano thin film was prepared from InZnO nanoparticles (NPs) by thermal evaporation technique. Fourier transform infrared spectroscopy showed the presence of metal-oxide bond. X-ray diffraction pattern revealed the mixed phase structure. The presence of elements In, Zn and O were identified from energy dispersive X-ray analysis. Size of the NPs was found to be 171 and 263 nm by transmission electron microscopy. Scanning electron microscopy image showed the spherical shape uniform morphology with uniform distribution grains. Photoluminescence spectrum exhibited a broad green emission for InZnO nano thin film. The acquired results of structure, smooth morphology and photoluminescence property suggested that the InZnO nano thin film to be a promising material for room temperature green emissive optoelectronic, laser diodes, solar cells and other optical devices.

Solubility of nano-zinc oxide in environmentally and biologically important matrices

PubMed Central

Reed, Robert B.; Ladner, David A.; Higgins, Christopher P.; Westerhoff, Paul; Ranville, James F.

2011-01-01

Increasing manufacture and use of engineered nanoparticles (NPs) is leading to a greater probability for release of ENPs into the environment and exposure to organisms. In particular, zinc oxide (ZnO) is toxic, although it is unclear whether this toxicity is due to the zinc oxide nanoparticles (ZnO), dissolution to Zn2+, or some combination thereof. The goal of this study was to determine the relative solubilites of both commercially available and in-house synthesized ZnO in matrices used for environmental fate and transport or biological toxicity studies. Dissolution of ZnO was observed in nanopure water (7.18– 7.40 mg/L dissolved Zn, as measured by filtration) and Roswell Park Memorial Institute medium (RPMI-1640) (~5 mg/L), but much more dissolution was observed in Dulbecco’s Modified Eagle’s Medium (DMEM), where the dissolved Zn concentration exceeded 34 mg/L. Moderately hard water exhibited low zinc solubility, likely due to precipitation of a zinc carbonate solid phase. Precipitation of a zinc-containing solid phase in RPMI also appeared to limit zinc solubility. Equilibrium conditions with respect to ZnO solubility were not apparent in these matrices, even after more than 1,000 h of dissolution. These results suggest that solution chemistry exerts a strong influence on ZnO dissolution and can result in limits on zinc solubility due to precipitation of less soluble solid phases. PMID:21994124

Effect of CO on the field emission properties of tetrapod zinc oxide cathode.

PubMed

Wang, Jinchan; Zhang, Xiaobing; Lei, Wei; Mao, Fuming; Cui, Yunkang; Xiao, Mei

2012-08-01

Tetrapod zinc oxide (T-ZnO), being a kind of nano-material, has large specific surface area and surface binding energy, which will make it sensitive to the ambient gas condition. So the field emission properties will be influenced by the gas adsorption when being applied as the cathode materials of field emission devices. Carbon monoxide is the main residual gas in T-ZnO field emission devices. In this paper, carbon monoxide was introduced into a field emission device with T-ZnO emitters. The field emission currents of tetrapod ZnO were compared before and after exposure to CO.

Friction and wear behaviors and mechanisms of ZnO and graphite in Cu-based friction materials

NASA Astrophysics Data System (ADS)

Chen, Tianhua

2018-03-01

Based on powder metallurgy method, nanometer graphite reinforced copper matrix friction materials were prepared. The nanometer zinc oxide were obtained by the hydro-thermal synthesis. Nanoparticles on friction performances of copper-based materials was studied. The wear morphology were investigated by metallographic microscopes. Tribological performance were use the inertia friction and wear testing machine. Experimental results show that the friction factor of the friction material added by nanometer zinc oxide and nano graphite are high and stable, which has no obvious recession phenomenon with the increase of number of joint compared with not add nanoparticles of friction materials.

Development of biomimetic nanocomposites as bone extracellular matrix for human osteoblastic cells.

PubMed

Bhowmick, Arundhati; Mitra, Tapas; Gnanamani, Arumugam; Das, Manas; Kundu, Patit Paban

2016-05-05

Here, we have developed biomimetic nanocomposites containing chitosan, poly(vinyl alcohol) and nano-hydroxyapatite-zinc oxide as bone extracellular matrix for human osteoblastic cells and characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction. Scanning electron microscopy images revealed interconnected macroporous structures. Moreover, in this study, the problem related to fabricating a porous composite with good mechanical strength has been resolved by incorporating 5wt% of nano-hydroxyapatite-zinc oxide into chitosan-poly(vinyl alcohol) matrix; the present composite showed high tensile strength (20.25MPa) while maintaining appreciable porosity (65.25%). These values are similar to human cancellous bone. These nanocomposites also showed superior water uptake, antimicrobial and biodegradable properties than the previously reported results. Compatibility with human blood and pH was observed, indicating nontoxicity of these materials to the human body. Moreover, proliferation of osteoblastic MG-63 cells onto the nanocomposites was also observed without having any negative effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nano interfaced biosensor for detection of choline in triple negative breast cancer cells.

PubMed

Thiagarajan, Vignesh; Madhurantakam, Sasya; Sethuraman, Swaminathan; Balaguru Rayappan, John Bosco; Maheswari Krishnan, Uma

2016-01-15

Choline, a type of Vitamin B, is an important nutrient in the human body and is involved in key metabolic pathways. Abnormal levels of choline leads to diseased conditions. The levels of choline and its associated compounds are found to be elevated in triple negative breast cancer (TNBC) patients. The choline level ranges from 0.4 to 4.9mmol/kg in TNBC. Thus the detection of choline levels in cells can aid in diagnosing breast cancer. The present work aims to develop a nano-interfaced electrochemical biosensor for the rapid detection of choline in cancer cells. For electrochemical detection, glassy carbon electrode coated with a zinc oxide nano-interface was used as the working electrode. Zinc oxide synthesized by hydrothermal method was characterized using SEM and XRD. The choline oxidase (ChOx) enzyme was immobilized on the nano-interface by drop-casting. Choline oxidase (ChOx) converts choline to betaine and H2O2 in the presence of oxygen. The H2O2 produced was determined amperometrically. The amount of H2O2 produced is directly proportional to concentration of choline present. The sensitivity, selectivity, stability and concentration studies were carried out and quantification of choline in TNBC was also carried out. The results demonstrate that this biosensor has the potential to be developed as a clinical tool for breast cancer detection. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of Nitrogen Oxides on Elemental Mercury Removal by Nanosized Mineral Sulfide.

PubMed

Li, Hailong; Zhu, Lei; Wang, Jun; Li, Liqing; Lee, Po-Heng; Feng, Yong; Shih, Kaimin

2017-08-01

Because of its large surface area, nanosized zinc sulfide (Nano-ZnS) has been demonstrated in a previous study to be efficient for removal of elemental mercury (Hg 0 ) from coal combustion flue gas. The excellent mercury adsorption performance of Nano-ZnS was found to be insusceptible to water vapor, sulfur dioxide, and hydrogen chloride. However, nitrogen oxides (NO X ) apparently inhibited mercury removal by Nano-ZnS; this finding was unlike those of many studies on the promotional effect of NO X on Hg 0 removal by other sorbents. The negative effect of NO X on Hg 0 adsorption over Nano-ZnS was systematically investigated in this study. Two mechanisms were identified as primarily responsible for the inhibitive effect of NO X on Hg 0 adsorption over Nano-ZnS: (1) active sulfur sites on Nano-ZnS were oxidized to inactive sulfate by NO X ; and (2) the chemisorbed mercury, i.e., HgS, was reduced to Hg 0 by NO X . This new insight into the role of NO X in Hg 0 adsorption over Nano-ZnS can help to optimize operating conditions, maximize Hg 0 adsorption, and facilitate the application of Nano-ZnS as a superior alternative to activated carbon for Hg 0 removal using existing particulate matter control devices in power plants.

Entomotoxicity Assay of Silica, Zinc Oxide, Titanium Dioxide, Aluminium Oxide Nanoparticles on Lipaphis pseudobrassicae

NASA Astrophysics Data System (ADS)

Debnath, Nitai; Das, Sumistha; Brahmachary, R. L.; Chandra, Ramesh; Sudan, Sandeep; Goswami, Arunava

2010-10-01

High volume uses of conventional pesticides end up contaminating ground water and soil with highly toxic pesticide residues. Nano-pesticides and nano-encapsulated pesticides are expected to reduce the volume of application and slow down the fast release kinetics. Nature inspired Diatomaceous Earth (DE) were used to design and fabricate a variety of 15-50 nm size range hydrophilic, hydrophobic and lipophilic SiO2, ZnO, TiO2 (anatase and rutile) and Al2O3 (α and γ) nanoparticles (Nanocides). Mustard aphid (Lipaphis pseudobrassicae) causes devastations on oil producing mustard crops every year in Asia. Due to several distinct adaptations present in insects, tools of Genetics, Plant breeding, Biochemistry and Transgenic technology have not been so far effective. Nano Al2O3 and amorphous nano SiO2 were found to be highly effective and nano TiO2 was moderately effective against L. pseudobrassicae. But nano Al2O3 has deleterious effects on plant growth, whereas non crystalline nano SiO2 has no such adverse effect on plants. Here we present the first report showing that nanocides, especially nano SiO2 can be effectively used to control insect pests.

Soil pH effects on the comparative toxicity of dissolved zinc, non-nano and nano ZnO to the earthworm Eisenia fetida.

PubMed

Heggelund, Laura R; Diez-Ortiz, Maria; Lofts, Stephen; Lahive, Elma; Jurkschat, Kerstin; Wojnarowicz, Jacek; Cedergreen, Nina; Spurgeon, David; Svendsen, Claus

2014-08-01

To determine how soil properties influence nanoparticle (NP) fate, bioavailability and toxicity, this study compared the toxicity of nano zinc oxide (ZnO NPs), non-nano ZnO and ionic ZnCl2 to the earthworm Eisenia fetida in a natural soil at three pH levels. NP characterisation indicated that reaction with the soil media greatly controls ZnO properties. Three main conclusions were drawn. First that Zn toxicity, especially for reproduction, was influenced by pH for all Zn forms. This can be linked to the influence of pH on Zn dissolution. Secondly, that ZnO fate, toxicity and bioaccumulation were similar (including relationships with pH) for both ZnO forms, indicating the absence of NP-specific effects. Finally, earthworm Zn concentrations were higher in worms exposed to ZnO compared to ZnCl2, despite the greater toxicity of the ionic form. This observation suggests the importance of considering the relationship between uptake and toxicity in nanotoxicology studies.

Simulation, optimization and testing of a novel high spatial resolution X-ray imager based on Zinc Oxide nanowires in Anodic Aluminium Oxide membrane using Geant4

NASA Astrophysics Data System (ADS)

Esfandi, F.; Saramad, S.

2015-07-01

In this work, a new generation of scintillator based X-ray imagers based on ZnO nanowires in Anodized Aluminum Oxide (AAO) nanoporous template is characterized. The optical response of ordered ZnO nanowire arrays in porous AAO template under low energy X-ray illumination is simulated by the Geant4 Monte Carlo code and compared with experimental results. The results show that for 10 keV X-ray photons, by considering the light guiding properties of zinc oxide inside the AAO template and suitable selection of detector thickness and pore diameter, the spatial resolution less than one micrometer and the detector detection efficiency of 66% are accessible. This novel nano scintillator detector can have many advantages for medical applications in the future.

Synthesis of supported silver nano-spheres on zinc oxide nanorods for visible light photocatalytic applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saoud, Khaled; Alsoubaihi, Rola; Bensalah, Nasr

Highlights: • Synthesis of supported Ag NPs on ZnO nanorods using open vessel microwave reactor. • Use of the Ag/ZnO NPs as an efficient visible light photocatalyst. • Complete degradation of methylene blue in 1 h with 0.5 g/L Ag/ZnO NPs. - Abstract: We report the synthesis of silver (Ag) nano-spheres (NS) supported on zinc oxide (ZnO) nanorods through two step mechanism, using open vessel microwave reactor. Direct reduction of ZnO from zinc nitrates was followed by deposition precipitation of the silver on the ZnO nanorods. The supported Ag/ZnO nanoparticles were then characterized by electron microscopy, X-ray diffraction, FTIR, photoluminescencemore » and UV–vis spectroscopy. The visible light photocatalytic activity of Ag/ZnO system was investigated using a test contaminant, methylene blue (MB). Almost complete removal of MB in about 60 min for doses higher than 0.5 g/L of the Ag/ZnO photocatalyst was achieved. This significant improvement in the photocatalytic efficiency of Ag/ZnO photocatalyst under visible light irradiation can be attributed to the presence of Ag nanoparticles on the ZnO nanoparticles which greatly enhances absorption in the visible range of solar spectrum enabled by surface plasmon resonance effect from Ag nanoparticles.« less

Toxicity of Functional Nano-Micro Zinc Oxide Tetrapods: Impact of Cell Culture Conditions, Cellular Age and Material Properties

PubMed Central

Papavlassopoulos, Heike; Mishra, Yogendra K.; Kaps, Sören; Paulowicz, Ingo; Abdelaziz, Ramzy; Elbahri, Mady; Maser, Edmund; Adelung, Rainer; Röhl, Claudia

2014-01-01

With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development. PMID:24454775

ZnO nanoparticles via Moringa oleifera green synthesis: Physical properties & mechanism of formation

NASA Astrophysics Data System (ADS)

Matinise, N.; Fuku, X. G.; Kaviyarasu, K.; Mayedwa, N.; Maaza, M.

2017-06-01

The research work involves the development of better and reliable method for the bio-fabrication of Zinc oxide nanoparticles through green method using Moringa Oleifera extract as an effective chelating agent. The electrochemical activity, crystalline structure, morphology, isothermal behavior, chemical composition and optical properties of ZnO nanoparticles were studied using various characterization techniques i.e. Cyclic voltammetry (CV), X-ray powder diffraction (XRD), High resolution transmission electron microscopy (HRTEM), Selected area electron diffraction (SEAD), Differential scanning calorimetry/thermogravimetric analysis (DSC/TGA), Fourier Transform Infrared analysis (FTIR) and Ultraviolet spectroscopy studies (UV-vis). The electrochemical analysis proved that the ZnO nano has high electrochemical activity without any modifications and therefore are considered as a potential candidate in electrochemical applications. The XRD pattern confirmed the crystallinity and pure phase of the sample. DSC/TGA analysis of ZnO sample (before anneal) revealed three endothermic peaks around 140.8 °C, 223.7 °C and 389.5 °C. These endothermic peaks are attributed to the loss of volatile surfactant, conversion of zinc hydroxide to zinc oxide nanoparticles and transformation of zinc oxide into zinc nanoparticles. Mechanisms of formation of the ZnO nanoparticles via the chemical reaction of the Zinc nitrate precursor with the bioactive compounds of the Moringa oleifera are proposed for each of the major family compounds: Vitamins, Flavonoids, and Phenolic acids.

Bacterial toxicity comparison between nano- and micro-scaled oxide particles.

PubMed

Jiang, Wei; Mashayekhi, Hamid; Xing, Baoshan

2009-05-01

Toxicity of nano-scaled aluminum, silicon, titanium and zinc oxides to bacteria (Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens) was examined and compared to that of their respective bulk (micro-scaled) counterparts. All nanoparticles but titanium oxide showed higher toxicity (at 20 mg/L) than their bulk counterparts. Toxicity of released metal ions was differentiated from that of the oxide particles. ZnO was the most toxic among the three nanoparticles, causing 100% mortality to the three tested bacteria. Al(2)O(3) nanoparticles had a mortality rate of 57% to B. subtilis, 36% to E. coli, and 70% to P. fluorescens. SiO(2) nanoparticles killed 40% of B. subtilis, 58% of E. coli, and 70% of P. fluorescens. TEM images showed attachment of nanoparticles to the bacteria, suggesting that the toxicity was affected by bacterial attachment. Bacterial responses to nanoparticles were different from their bulk counterparts; hence nanoparticle toxicity mechanisms need to be studied thoroughly.

PLA coated paper containing active inorganic nanoparticles: Material characterization and fate of nanoparticles in the paper recycling process.

PubMed

Zhang, Hai; Bussini, Daniele; Hortal, Mercedes; Elegir, Graziano; Mendes, Joana; Jordá Beneyto, Maria

2016-06-01

For paper and paperboard packaging, recyclability plays an important role in conserving the resources and reducing the environmental impacts. Therefore, when it comes to the nano-enabled paper packaging material, the recyclability issue should be properly addressed. This study represents our first report on the fate of nanomaterials in paper recycling process. The packaging material of concern is a PLA (Polylactic Acid) coated paper incorporating zinc oxide nanoparticles in the coating layer. The material was characterised and assessed in a lab-scale paper recycling line. The recyclability test was based on a method adapted from ATICELCA MC501-13, which enabled to recover over 99% of the solids material. The mass balance result indicates that 86-91% zinc oxide nanoparticles ended up in the rejected material stream, mostly embedded within the polymer coating; whereas 7-16% nanoparticles ended up in the accepted material stream. Besides, the tensile strength of the recycled handsheets suggests that the nano-enabled coating had no negative impacts on the recovered fibre quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microstructure evolution of Al-doped zinc oxide films prepared by in-line reactive mid-frequency magnetron sputtering

NASA Astrophysics Data System (ADS)

Hong, R. J.; Jiang, X.

2006-07-01

Aluminium-doped zinc oxide (ZnO:Al or AZO) thin films were deposited on glass substrates by reactive mid-frequency (MF) magnetron sputtering from Zn/Al metallic targets. Strong (002) preferred orientation was detected by X-ray diffraction (XRD). It was observed by plan-view transmission electron microscopy (TEM) that an AZO film deposited at low substrate temperature was composed of irregular large grains; but the film prepared at high temperature was composed of moderate sized grains with a regular shape. A secondary phase of ZnO2 was also observed for the film deposited at low substrate temperature. The cross-sectional TEM study of the AZO film showed that prior to the well-aligned columnar growth an initial interfacial zone with nano crystallites were formed. The nano crystallites formed initially with a large tilt angle normal to the substrate surface and during the growth of the transition zone, the tilt angle decreased until it vanished. The evolution of the film structure is discussed in terms of evolutionary selection model and the dynamic deposition process.

A nanoscale bio-inspired light-harvesting system developed from self-assembled alkyl-functionalized metallochlorin nano-aggregates

NASA Astrophysics Data System (ADS)

Ocakoglu, Kasim; Joya, Khurram S.; Harputlu, Ersan; Tarnowska, Anna; Gryko, Daniel T.

2014-07-01

Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The transparent Zn-chlorin nano-aggregates inside the alkyl-TiO2 modified AAO nano-channels have a diameter of ~120 nm in a 60 μm length channel. UV-Vis studies and fluorescence emission spectra further confirm the formation of the supramolecular ZnChl aggregates from monomer molecules inside the alkyl-functionalized nano-channels. Our results prove that the novel and unique method can be used to produce efficient and stable light-harvesting assemblies for effective solar energy capture through transparent and stable nano-channel ceramic materials modified with bio-mimetic molecular self-assembled nano-aggregates.Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The transparent Zn-chlorin nano-aggregates inside the alkyl-TiO2 modified AAO nano-channels have a diameter of ~120 nm in a 60 μm length channel. UV-Vis studies and fluorescence emission spectra further confirm the formation of the supramolecular ZnChl aggregates from monomer molecules inside the alkyl-functionalized nano-channels. Our results prove that the novel and unique method can be used to produce efficient and stable light-harvesting assemblies for effective solar energy capture through transparent and stable nano-channel ceramic materials modified with bio-mimetic molecular self-assembled nano-aggregates. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01661k

A review on the application of inorganic nano-structured materials in the modification of textiles: focus on anti-microbial properties.

PubMed

Dastjerdi, Roya; Montazer, Majid

2010-08-01

Textiles can provide a suitable substrate to grow micro-organisms especially at appropriate humidity and temperature in contact to human body. Recently, increasing public concern about hygiene has been driving many investigations for anti-microbial modification of textiles. However, using many anti-microbial agents has been avoided because of their possible harmful or toxic effects. Application of inorganic nano-particles and their nano-composites would be a good alternative. This review paper has focused on the properties and applications of inorganic nano-structured materials with good anti-microbial activity potential for textile modification. The discussed nano-structured anti-microbial agents include TiO(2) nano-particles, metallic and non-metallic TiO(2) nano-composites, titania nanotubes (TNTs), silver nano-particles, silver-based nano-structured materials, gold nano-particles, zinc oxide nano-particles and nano-rods, copper nano-particles, carbon nanotubes (CNTs), nano-clay and its modified forms, gallium, liposomes loaded nano-particles, metallic and inorganic dendrimers nano-composite, nano-capsules and cyclodextrins containing nano-particles. This review is also concerned with the application methods for the modification of textiles using nano-structured materials. Copyright 2010 Elsevier B.V. All rights reserved.

Electrical properties of solution processed highly transparent ZnO TFT with organic gate dielectric

NASA Astrophysics Data System (ADS)

Pandya, Nirav C.; Joshi, Nikhil G.; Trivedi, U. N.; Joshi, U. S.

2013-02-01

All oxide thin film transistors (TFT) with zinc oxide active layer were fabricated by chemical solution deposition (CSD) using aqueous solutions on glass substrate. Thin film transistors (TFTs) with amorphous zinc oxide as channel layers and poly-vinyl alcohol as dielectric layers were fabricated at low temperatures by chemical solution deposition (CSD). Atomic force microscopy (AFM) confirmed nano grain size with fairly smooth surface topography. Very small leakage currents were achieved in the transfer curves, while soft saturation was observed in the output current voltage (I-V) characteristics of the device. Optical transmission of better than 87% in the visible region was estimated, which is better than the organic gate insulator based ZnO TFTs reported so far. Our results offer lot of promise to TFT based display and optoelectronics.

Organization of research team for nano-associated safety assessment in effort to study nanotoxicology of zinc oxide and silica nanoparticles

PubMed Central

Kim, Yu-Ri; Park, Sung Ha; Lee, Jong-Kwon; Jeong, Jayoung; Kim, Ja Hei; Meang, Eun-Ho; Yoon, Tae Hyun; Lim, Seok Tae; Oh, Jae-Min; An, Seong Soo A; Kim, Meyoung-Kon

2014-01-01

Currently, products made with nanomaterials are used widely, especially in biology, bio-technologies, and medical areas. However, limited investigations on potential toxicities of nanomaterials are available. Hence, diverse and systemic toxicological data with new methods for nanomaterials are needed. In order to investigate the nanotoxicology of nanoparticles (NPs), the Research Team for Nano-Associated Safety Assessment (RT-NASA) was organized in three parts and launched. Each part focused on different contents of research directions: investigators in part I were responsible for the efficient management and international cooperation on nano-safety studies; investigators in part II performed the toxicity evaluations on target organs such as assessment of genotoxicity, immunotoxicity, or skin penetration; and investigators in part III evaluated the toxicokinetics of NPs with newly developed techniques for toxicokinetic analyses and methods for estimating nanotoxicity. The RT-NASA study was carried out in six steps: need assessment, physicochemical property, toxicity evaluation, toxicokinetics, peer review, and risk communication. During the need assessment step, consumer responses were analyzed based on sex, age, education level, and household income. Different sizes of zinc oxide and silica NPs were purchased and coated with citrate, L-serine, and L-arginine in order to modify surface charges (eight different NPs), and each of the NPs were characterized by various techniques, for example, zeta potentials, scanning electron microscopy, and transmission electron microscopy. Evaluation of the “no observed adverse effect level” and systemic toxicities of all NPs were performed by thorough evaluation steps and the toxicokinetics step, which included in vivo studies with zinc oxide and silica NPs. A peer review committee was organized to evaluate and verify the reliability of toxicity tests, and the risk communication step was also needed to convey the current findings to academia, industry, and consumers. Several limitations were encountered in the RT-NASA project, and they are discussed for consideration for improvements in future studies. PMID:25565821

Organization of research team for nano-associated safety assessment in effort to study nanotoxicology of zinc oxide and silica nanoparticles.

PubMed

Kim, Yu-Ri; Park, Sung Ha; Lee, Jong-Kwon; Jeong, Jayoung; Kim, Ja Hei; Meang, Eun-Ho; Yoon, Tae Hyun; Lim, Seok Tae; Oh, Jae-Min; An, Seong Soo A; Kim, Meyoung-Kon

2014-01-01

Currently, products made with nanomaterials are used widely, especially in biology, bio-technologies, and medical areas. However, limited investigations on potential toxicities of nanomaterials are available. Hence, diverse and systemic toxicological data with new methods for nanomaterials are needed. In order to investigate the nanotoxicology of nanoparticles (NPs), the Research Team for Nano-Associated Safety Assessment (RT-NASA) was organized in three parts and launched. Each part focused on different contents of research directions: investigators in part I were responsible for the efficient management and international cooperation on nano-safety studies; investigators in part II performed the toxicity evaluations on target organs such as assessment of genotoxicity, immunotoxicity, or skin penetration; and investigators in part III evaluated the toxicokinetics of NPs with newly developed techniques for toxicokinetic analyses and methods for estimating nanotoxicity. The RT-NASA study was carried out in six steps: need assessment, physicochemical property, toxicity evaluation, toxicokinetics, peer review, and risk communication. During the need assessment step, consumer responses were analyzed based on sex, age, education level, and household income. Different sizes of zinc oxide and silica NPs were purchased and coated with citrate, L-serine, and L-arginine in order to modify surface charges (eight different NPs), and each of the NPs were characterized by various techniques, for example, zeta potentials, scanning electron microscopy, and transmission electron microscopy. Evaluation of the "no observed adverse effect level" and systemic toxicities of all NPs were performed by thorough evaluation steps and the toxicokinetics step, which included in vivo studies with zinc oxide and silica NPs. A peer review committee was organized to evaluate and verify the reliability of toxicity tests, and the risk communication step was also needed to convey the current findings to academia, industry, and consumers. Several limitations were encountered in the RT-NASA project, and they are discussed for consideration for improvements in future studies.

Synthesis, Dielectric, Electrical and Optical characterization of ZnO synthesized by chemical route using polymer precursors

NASA Astrophysics Data System (ADS)

Mishra, Raman; Bajpai, P. K.

2011-11-01

Nano-size ZnO (particle size 7.8 nm) have been prepared from a versatile, efficient and technically simple polymer matrix based precursor solution. The precursor solution constituted of zinc nitrates with polymer PVA in presence of mono-/disaccharides. Annealing the precursor mass at 900 °C single phase zinc oxide nano-particles are obtained. X-ray diffraction analysis confirms hexagonal crystal structure with lattice parameter a = b = 3.261 A0, c = 5.220 A0. The estimated average particle size obtained from XRD data is ≈7.8 nm. The impedance analysis reveals that the grain resistance decreases with increase in temperature as expected for a semi-conducting material. The relaxation is polydispersive and conduction is mainly through grains. Optical properties and AC/DC conduction activation energies are estimated from Arrhenius plots and conduction mechanism is discussed.

Orthophosphate modulates the phytotoxicity of nano-ZnO to Lemna minor (L.).

PubMed

Chen, Xiaolin; O'Halloran, John; Jansen, Marcel A K

2018-03-02

Because of their applications in large numbers of products, Zinc Oxide nanoparticles (nano-ZnO) will inevitably enter into the environment. Nano-ZnO released into the environment will be present in a complex matrix which can cause various chemical and physical transformations and modulate the biological reactivity of these particles. Due to their rapid growth and small size, Lemna minor is recommended by OECD for toxicological testing. Here, we tested how nano-ZnO reactivity is modulated by the suite of macro- and micronutrients that are present in Lemna minor growth media. Specifically, we measured ex situ Reactive Oxygen Species (ROS) formation by nano-ZnO, and subsequent in planta toxicity. The data show how orthophosphate can modulate both ex situ ROS formation, and in planta toxicity. This has ramifications for phytotoxicity testing, which is commonly performed under controlled conditions and on media containing orthophosphate.

Synthesis and characterization of porous metal oxides and desulfurization studies of sulfur containing compounds

NASA Astrophysics Data System (ADS)

Garces Trujillo, Hector Fabian

This thesis contains two parts: 1) synthesis and characterization of porous metal oxides that include zinc oxide and a porous mixed-valent manganese oxide with an amorphous structure (AMO) 2) the desulfurization studies for the removal of sulfur compounds. Zinc oxide with different nano-scale morphologies may result in various porosities with different adsorption capabilities. A tunable shape microwave synthesis of ZnO nano-spheres in a co-solvent mixture is presented. The ZnO nano-sphere material is investigated as a desulfurizing sorbent in a fixed bed reactor in the temperature range 200 to 400 °C and compared with ZnO nanorods and platelet-like morphologies. Fresh and sulfided materials were characterized by X-ray diffraction (XRD), BET specific surface area, pore volume, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (SEM/EDX), Raman spectroscopy, and thermogravimetric analysis (TGA). The tunable shape microwave synthesis of ZnO presents a high sulfur sorption capacity at temperatures as low as 200 °C which accounts for a three and four fold enhancement over the other preparations presented in this work, and reached 76 % of the theoretical sulfur capacity (TSC) at 300 °C. Another ZnO material with a bimodal micro- and mesopore size distribution investigated as a desulfurizing sorbent presents a sorption capacity that reaches 87% of the theoretical value for desulfurization at 400 °C at breakthrough time. A deactivation model that considers the activity of the solid reactant was used to fit the experimental data. Good agreement between the experimental breakthrough curves and the model predictions are obtained. Manganese oxides are a type of metal oxide materials commonly used in catalytic applications. Little is known about the adsorption capabilities for the removal of sulfur compounds. One of these manganese oxides; amorphous manganese oxide (AMO) is highly promising material for low temperature sorption processes. Amorphous manganese oxide (AMO) has been used in catalytic processes such as for the catalytic oxidation of benzyl alcohol, the preferential oxidation of CO, and for the capture of formate species. This chapter explores the possibility of using AMO in sorption processes for the removal of two contaminants; H 2S and COS in the temperature range 200 - 400 °C.

Micro-nano zinc oxide film fabricated by biomimetic mineralization: Designed architectures for SERS substrates

NASA Astrophysics Data System (ADS)

Lu, Fei; Guo, Yue; Wang, Yunxin; Song, Wei; Zhao, Bing

2018-05-01

In this study, we have investigated the effect of the surface morphologies of the zinc oxide (ZnO) substrates on surface enhanced Raman spectroscopy (SERS). During synthetic process, the self-assembly monolayers (SAMs) with different terminal groups are used as templates to induce the nucleation and growth of Zn(NO3)2·6H2O crystals, then different morphologies micro-nano ZnO powders are obtained by annealing Zn(NO3)2·6H2O crystals at 450 °C. The products obtained at different conditions are characterized by means of X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM) and Raman spectra. The as-prepared ZnO micro-sized particles have been used the efficient Surface enhanced Raman scattering (SERS) substrates, and the SERS signals of 4-mercaptopyridine (Mpy) probe molecules are much influenced by the morphologies of the ZnO structures. Results indicated that the more (0001) facets appear in the of ZnO morphology, the greater degree of charge-transfer (PCT) for the SERS enhancement on the surface of semiconductors is achieved. The chemical interaction between ZnO structures and Mpy molecules plays a very important role in the SERS enhancement.

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.

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken.

PubMed

Joshua, P Patric; Valli, C; Balakrishnan, V

2016-03-01

Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken. Nano form of zinc at 20, 40, 60 and 80 µg/egg, nano form of copper at 4, 8, 12 and 16 µg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 µg/egg were in ovo supplemented (18(th) day incubation, amniotic route) in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied. In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05) best feed efficiency for nano forms of zinc (2.16), copper (2.46) and selenium (2.51) were observed, when 40, 4 and 0.225 µg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 µg per egg which had significantly (p<0.05) highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments. Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18(th) day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability.

Effect of in ovo supplementation of nano forms of zinc, copper, and selenium on post-hatch performance of broiler chicken

PubMed Central

Joshua, P. Patric; Valli, C.; Balakrishnan, V.

2016-01-01

Background and Aim: Nanoparticles can bypass conventional physiological ways of nutrient distribution and transport across tissue and cell membranes, as well as protect compounds against destruction prior to reaching their targets. In ovo administration of nanoparticles, may be seen as a new method of nano-nutrition, providing embryos with an additional quantity of nutrients. The aim of the study is to examine the effect of in ovo supplementation of nano forms of zinc, copper and selenium on the hatchability and post hatch performance of broiler chicken. Materials and Methods: Nano form of zinc at 20, 40, 60 and 80 µg/egg, nano form of copper at 4, 8, 12 and 16 µg/egg and nano form of selenium at 0.075, 0.15, 0.225 and 0.3 µg/egg were in ovo supplemented (18th day incubation, amniotic route) in fertile broiler eggs. Control group in ovo fed with normal saline alone was also maintained. Each treatment had thirty replicates. Parameters such as hatchability, hatch weight and post hatch performance were studied. Results: In ovo feeding of nano minerals were not harmful to the developing embryo and did not influence the hatchability. Significantly (p<0.05) best feed efficiency for nano forms of zinc (2.16), copper (2.46) and selenium (2.51) were observed, when 40, 4 and 0.225 µg/egg respectively were in ovo supplemented. Except in nano form of copper at 12 µg per egg which had significantly (p<0.05) highest breast muscle percentage there was no distinct trend to indicate that dressing percentage or breast muscle yield was influenced in other treatments. Conclusion: Nano forms of zinc, copper and selenium can be prepared at laboratory conditions. In ovo feeding of nano forms of zinc, copper and selenium at 18th day of incubation through amniotic route does not harm the developing embryo, does not affect hatchability. PMID:27057113

Novel polyoxometalate silica nano-sized spheres: efficient catalysts for olefin oxidation and the deep desulfurization process.

PubMed

Nogueira, Lucie S; Ribeiro, Susana; Granadeiro, Carlos M; Pereira, Eulália; Feio, Gabriel; Cunha-Silva, Luís; Balula, Salete S

2014-07-07

A novel method to prepare silica nano-sized particles incorporating polyoxometalates was developed leading to a new efficient heterogeneous oxidative catalyst. Zinc-substituted polyoxotungstate [PW11Zn(H2O)O39](5-) (PW11Zn) was encapsulated into silica nanoparticles using a cross-linked organic-inorganic core, performed through successive spontaneous reactions in water. The potassium salt of PW11Zn and the composite formed, PW11Zn-APTES@SiO2, were characterized by a myriad of solid-state methods such as FT-IR, FT-Raman, (31)P and (13)C CP/MAS solid-state NMR, elemental analysis and SEM-EDS, confirming the integrity of the PW11Zn structure immobilized in the silica nanoparticles. The new composite has shown to be a versatile catalyst for the oxidation of olefins and also to catalyze the desulfurization of a model oil using H2O2 as the oxidant and acetonitrile as the solvent. The novel composite material was capable of being recycled without significant loss of activity and maintaining its structural stability for consecutive desulfurization and olefin oxidative cycles.

Application of short-term inhalation studies to assess the inhalation toxicity of nanomaterials

PubMed Central

2014-01-01

Background A standard short-term inhalation study (STIS) was applied for hazard assessment of 13 metal oxide nanomaterials and micron-scale zinc oxide. Methods Rats were exposed to test material aerosols (ranging from 0.5 to 50 mg/m3) for five consecutive days with 14- or 21-day post-exposure observation. Bronchoalveolar lavage fluid (BALF) and histopathological sections of the entire respiratory tract were examined. Pulmonary deposition and clearance and test material translocation into extra-pulmonary organs were assessed. Results Inhaled nanomaterials were found in the lung, in alveolar macrophages, and in the draining lymph nodes. Polyacrylate-coated silica was also found in the spleen, and both zinc oxides elicited olfactory epithelium necrosis. None of the other nanomaterials was recorded in extra-pulmonary organs. Eight nanomaterials did not elicit pulmonary effects, and their no observed adverse effect concentrations (NOAECs) were at least 10 mg/m3. Five materials (coated nano-TiO2, both ZnO, both CeO2) evoked concentration-dependent transient pulmonary inflammation. Most effects were at least partially reversible during the post-exposure period. Based on the NOAECs that were derived from quantitative parameters, with BALF polymorphonuclear (PMN) neutrophil counts and total protein concentration being most sensitive, or from the severity of histopathological findings, the materials were ranked by increasing toxic potency into 3 grades: lower toxic potency: BaSO4; SiO2.acrylate (by local NOAEC); SiO2.PEG; SiO2.phosphate; SiO2.amino; nano-ZrO2; ZrO2.TODA; ZrO2.acrylate; medium toxic potency: SiO2.naked; higher toxic potency: coated nano-TiO2; nano-CeO2; Al-doped nano-CeO2; micron-scale ZnO; coated nano-ZnO (and SiO2.acrylate by systemic no observed effect concentration (NOEC)). Conclusion The STIS revealed the type of effects of 13 nanomaterials, and micron-scale ZnO, information on their toxic potency, and the location and reversibility of effects. Assessment of lung burden and material translocation provided preliminary biokinetic information. Based upon the study results, the STIS protocol was re-assessed and preliminary suggestions regarding the grouping of nanomaterials for safety assessment were spelled out. PMID:24708749

Wood surface modification by in-situ sol-gel deposition of hybrid inorganic-organic thin films

Treesearch

Mandla A. Tshabalala; Li-Piin Sung

2007-01-01

Interest in the use of nanoparticles of iron, titanium, aluminum, and zinc oxides in transparent coatings for wood is increasing. Such nano-composite coatings have the potential of not only preserving the natural color of the wood, but also stabilizing the wood surface against the combined degradative effects of sunlight and moisture. The nanoparticles can be used as...

Dietary ZnO nanoparticles alters intestinal microbiota and inflammation response in weaned piglets

PubMed Central

Xia, Tian; Lai, Wenqing; Han, Miaomiao; Han, Meng; Ma, Xi; Zhang, Liying

2017-01-01

The present study was carried out to determine whether low dose of zinc oxide nanoparticles (Nano-ZnO) could serve as a potential substitute of pharmacological dose of traditional ZnO in weaned piglets. 180 crossbred weaning piglets were randomly assigned to 3 treatments. Experimental animals were fed basal diet supplemented with 0 mg Zn/kg (Control), 600 mg Zn/kg (Nano-ZnO) and 2000 mg Zn/kg (ZnO) for 14 days. On day 14 after weaning, the piglets fed Nano-ZnO did not differ from those fed traditional ZnO in growth performance and jejunal morphology, while Nano-ZnO treatment could significantly alleviate the incidence of diarrhea (P < 0.05). In jejunum, the mRNA expressions of intestinal antioxidant enzymes and tight junction proteins were increased (P < 0.05) in Nano-ZnO treatment. In ileum, the expression levels of IFN-γ, IL-1β, TNF-α and NF-κB were decreased (P < 0.05). Gene sequencing analysis of 16S rRNA revealed that dietary Nano-ZnO increased the bacterial richness and diversity in ileum, while decreased both of them in cecum and colon. Specifically, the relative abundances of Streptococcus in ileum, Lactobacillus in colon were increased, while the relative abundances of Lactobacillus in ileum, Oscillospira and Prevotella in colon were decreased (P < 0.05). In conclusion, our data reveal that low dose of Nano-ZnO (600 mg Zn/kg) can effectively reduce piglet diarrhea incidence, similar to high dose of traditional ZnO (2000 mg Zn/kg), which may be mediated by improving intestinal microbiota and inflammation response in piglets, and help to reduce zinc environmental pollution. PMID:29029398

Effective mobility enhancement of amorphous In-Ga-Zn-O thin-film transistors by holographically generated periodic conductor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeong, Jaewook; Kim, Joonwoo; Jeong, Soon Moon

In this study, we demonstrate a mobility enhancement structure for fully transparent amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) by embedding a holographically generated periodic nano-conductor in the back-channel regions. The intrinsic field-effect mobility was enhanced up to 2 times compared to that of a reference sample. The enhancement originated from a decrease in the effective channel length due to the highly conductive nano-conductor region. By combining conventional and holographic lithography, the performance of the a-IGZO TFT can be effectively improved without varying the composition of the channel layer.

Effective mobility enhancement of amorphous In-Ga-Zn-O thin-film transistors by holographically generated periodic conductor

NASA Astrophysics Data System (ADS)

Jeong, Jaewook; Kim, Joonwoo; Kim, Donghyun; Jeon, Heonsu; Jeong, Soon Moon; Hong, Yongtaek

2016-08-01

In this study, we demonstrate a mobility enhancement structure for fully transparent amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs) by embedding a holographically generated periodic nano-conductor in the back-channel regions. The intrinsic field-effect mobility was enhanced up to 2 times compared to that of a reference sample. The enhancement originated from a decrease in the effective channel length due to the highly conductive nano-conductor region. By combining conventional and holographic lithography, the performance of the a-IGZO TFT can be effectively improved without varying the composition of the channel layer.

3D highly oriented nanoparticulate and microparticulate array ofmetal oxide materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vayssieres, Lionel; Guo, Jinghua; Nordgren, Joseph

2006-09-15

Advanced nano and micro particulate thin films of 3d transition and post-transition metal oxides consisting of nanorods and microrods with parallel and perpendicular orientation with respect to the substrate normal, have been successfully grown onto various substrates by heteronucleation, without template and/or surfactant, from the aqueous condensation of solution of metal salts or metal complexes (aqueous chemical growth). Three-dimensional arrays of iron oxide nanorods and zinc oxide nanorods with parallel and perpendicular orientation are presented as well as the oxygen K-edge polarization dependent x-ray absorption spectroscopy (XAS) study of anisotropic perpendicularly oriented microrod array of ZnO performed at synchrotron radiationmore » source facility.« less

The influence of chain rigidity and the degree of sulfonation on the morphology of block copolymers as nano reactor

NASA Astrophysics Data System (ADS)

Hong, K.; Zhang, X.

2005-03-01

Polyelectrolyte block copolymer was used to form an ordered domain of ionic block as a ``nanoreactor'' due to its ability to bind oppositely charged metal ion, Zn^2+, Fe^2+ etc. The purpose of our research is to investigate the controllability of the size and morphology of domains (inorganic nano particles) by changing backbone stiffness, the charge density and the volume fraction of ionic block. Poly(styrene sulfonate) (PSS), which backbone is flexible, and poly(cyclohexadiene sulfonate) (PCHDS), which backbone is ``semiflexible'', were used as ionic blocks. We synthesized PtBS-PSS and PS-PCHDS with various degree of sulfonation and the volume fraction. Zinc oxide (ZnO) nano particles successfully formed in the ionic domain of microphase separated block copolymers. We used SANS to characterize the morphology of block copolymers and TEM for block copolymer containing ZnO nano particles. Our experimental results show that the chemistry of ``sulfonation'' of block copolymers can be successfully used to synthesize nano composite materials.

The toxicity of zinc oxide nanoparticles to Lemna minor (L.) is predominantly caused by dissolved Zn.

PubMed

Chen, Xiaolin; O'Halloran, John; Jansen, Marcel A K

2016-05-01

Nano-ZnO particles have been reported to be toxic to many aquatic organisms, although it is debated whether this is caused by nanoparticles per sé, or rather dissolved Zn. This study investigated the role of dissolved Zn in nano-ZnO toxicity to Lemna minor. The technical approach was based on modulating nano-ZnO dissolution by either modifying the pH of the growth medium and/or surface coating of nano-ZnO, and measuring resulting impacts on L. minor growth and physiology. Results show rapid and total dissolution of nano-ZnO in the medium (pH 4.5). Quantitatively similar toxic effects were found when L. minor was exposed to nano-ZnO or the "dissolved Zn equivalent of dissolved nano-ZnO". The conclusion that nano-ZnO toxicity is primarily caused by dissolved Zn was further supported by the observation that phytotoxicity was absent on medium with higher pH-values (>7), where dissolution of nano-ZnO almost ceased. Similarly, the reduced toxicity of coated nano-ZnO, which displays a slower Zn dissolution, is also consistent with a major role for dissolved Zn in nano-ZnO toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of zinc oxide nano-microtetrapods for biomolecule sensing applications

NASA Astrophysics Data System (ADS)

Zhao, Wei; Zhao, Yichen; Karlsson, Mikael; Wang, Qin; Toprak, Muhammet S.

2015-12-01

Zinc oxide tetrapods (ZnO-Ts) were synthesized by flame transport synthesis using Zn microparticles. This work herein reports a systematical study on the structural, optical and electrochemical properties of the ZnO-Ts. The morphology of the ZnO-Ts was confirmed by scanning electron microscopy (SEM) as joint structures of four nano-microstructured legs, of which the diameter of each leg is 0.7-2.2 μm in average from the tip to the stem. The ZnO-Ts were dispersed in glucose solution to study the luminescence as well as photocatalytic activity in a mimicked biological environment. The photoluminescence (PL) intensity in the ultraviolet (UV) region quenches with linear dependence to increased glucose concentration up to 4 mM. The ZnO-Ts were also attached with glucose oxidase (GOx) and over coated with a thin film of Nafion to form active layers for electrochemical glucose sensing. The attachment of GOx and coating of Nafion were confirmed by infrared spectroscopy (FT-IR). Furthermore, the current response of the active layers based on ZnO-Ts was investigated by cyclic voltammetry (CV) in various glucose concentrations. Stable current response of glucose was detected with linear dependence to glucose concentration up to 12 mM, which confirms the potential of ZnO-Ts for biomolecule sensing applications.

Construction of Zinc Oxide into Different Morphological Structures to Be Utilized as Antimicrobial Agent against Multidrug Resistant Bacteria

PubMed Central

Elkady, M. F.; Shokry Hassan, H.; Hafez, Elsayed E.; Fouad, Ahmed

2015-01-01

Nano-ZnO has been successfully implemented in particles, rods, and tubes nanostructures via sol-gel and hydrothermal techniques. The variation of the different preparation parameters such as reaction temperature, time, and stabilizer agents was optimized to attain different morphological structures. The influence of the microwave annealing process on ZnO crystallinity, surface area, and morphological structure was monitored using XRD, BET, and SEM techniques, respectively. The antimicrobial activity of zinc oxide produced in nanotubes structure was examined against four different multidrug resistant bacteria: Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) strains. The activity of produced nano-ZnO was determined by disc diffusion technique and the results revealed that ZnO nanotubes recorded high activity against the studied strains due to their high surface area equivalent to 17.8 m2/g. The minimum inhibitory concentration (MIC) of ZnO nanotubes showed that the low concentrations of ZnO nanotubes could be a substitution for the commercial antibiotics when approached in suitable formula. Although the annealing process of ZnO improves the degree of material crystallinity, however, it declines its surface area and consequently its antimicrobial activity. PMID:26451136

Aminolysis of polyethylene terephthalate surface along with in situ synthesis and stabilizing ZnO nanoparticles using triethanolamine optimized with response surface methodology.

PubMed

Poortavasoly, Hajar; Montazer, Majid; Harifi, Tina

2016-01-01

This research concerned the simultaneous polyester surface modification and synthesis of zinc oxide nano-reactors to develop durable photo-bio-active fabric with variable hydrophobicity/hydrophilicity under sunlight. For this purpose, triethanolamine (TEA) was applied as a stabilizer and pH adjusting chemical for the aminolysis of polyester surface and enhancing the surface reactivity along with synthesis and deposition of ZnO nanoparticles on the fabric. Therefore, TEA played a crucial role in providing the alkaline condition for the preparation of zinc oxide nanoparticles and acting as stabilizer controlling the size of the prepared nanoparticles. The stain-photodegradability regarded as self-cleaning efficiency, wettability and weight change under the process was optimized based on zinc acetate and TEA concentrations, using central composite design (CCD). Findings also suggested the potential of the prepared fabric in inhibiting Staphylococcus aureus and Escherichia coli bacteria growth with greater than 99.99% antibacterial efficiency. Besides, the proposed treatment had no detrimental effect on tensile strength and hand feeling of the polyester fabric. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization and Influence of Green Synthesis of Nano-Sized Zinc Complex with 5-Aminolevulinic Acid on Bioactive Compounds of Aniseed.

PubMed

Tavallali, Vahid; Rahmati, Sadegh; Rowshan, Vahid

2017-11-01

A new water soluble zinc-aminolevulinic acid nano complex (n[Zn(ALA) 2 ]), which was characterized by TEM, IR, and EDX spectra, has been prepared via sonochemical method under green conditions in water. In the current study, the effectiveness of foliar Zn amendment using synthetic Zn-ALA nano complex, as a new introduced Zn-fertilizer here, was evaluated. As the model plant, Pimpinella anisum, the most valuable spice and medicinal plant grown in warm regions, was used. By using zinc nano complex, further twenty compounds were obtained in the essential oil of anise plants. Application of 0.2% (w/v) Zn-ALA nano complex increased the levels of (E)-anethole, β-bisabolene, germacrene D, methyl chavicol, and α-zingiberene in the essential oil. Nano Zn complex at the rate of 0.2% induced considerable high phenolic compounds and zinc content of shoots and seeds. Chlorogenic acid had the highest level between four detected phenolic compounds. The maximum antioxidant activity was monitored through the application of Zn nano complex. According to the results, nanoscale nutrients can be provided with further decreased doses for medicinal plants. Using Zn-ALA nano complex is a new and efficient method to improve the pharmaceutical and food properties of anise plants. © 2017 Wiley-VHCA AG, Zurich, Switzerland.

One-pot green synthesis of zinc oxide nano rice and its application as sonocatalyst for degradation of organic dye and synthesis of 2-benzimidazole derivatives

NASA Astrophysics Data System (ADS)

Paul, Bappi; Vadivel, Sethumathavan; Dhar, Siddhartha Sankar; Debbarma, Shyama; Kumaravel, M.

2017-05-01

In this paper, we report novel and green approach for one-pot biosynthesis of zinc oxide (ZnO) nanoparticles (NPs). Highly stable and hexagonal phase ZnO nanoparticles were synthesized using seeds extract from the tender pods of Parkia roxburghii and characterized by XRD, FT-IR, EDX, TEM, and N2 adsorption-desorption (BET) studies. The present method of synthesis of ZnO NPs is very efficient and cost effective. The powder XRD pattern furnished evidence for the formation of hexagonal close packing structure of ZnO NPs having average crystallite size 25.6 nm. The TEM image reveals rice shapes ZnO NPs are with an average diameter of 40-60 nm. The as-synthesized ZnO NPs has proved to be an excellent sonocatalysts for degradation of organic dye and synthesis of 2-benzimidazole derivatives.

Non-Enzymatic Glucose Sensor Composed of Carbon-Coated Nano-Zinc Oxide

PubMed Central

Chung, Ren-Jei; Wang, An-Ni; Liao, Qing-Liang; Chuang, Kai-Yu

2017-01-01

Nowadays glucose detection is of great importance in the fields of biological, environmental, and clinical analyzes. In this research, we report a zinc oxide (ZnO) nanorod powder surface-coated with carbon material for non-enzymatic glucose sensor applications through a hydrothermal process and chemical vapor deposition method. A series of tests, including crystallinity analysis, microstructure observation, and electrochemical property investigations were carried out. For the cyclic voltammetric (CV) glucose detection, the low detection limit of 1 mM with a linear range from 0.1 mM to 10 mM was attained. The sensitivity was 2.97 μA/cm2mM, which is the most optimized ever reported. With such good analytical performance from a simple process, it is believed that the nanocomposites composed of ZnO nanorod powder surface-coated with carbon material are promising for the development of cost-effective non-enzymatic electrochemical glucose biosensors with high sensitivity. PMID:28336869

The neglected nano-specific toxicity of ZnO nanoparticles in the yeast Saccharomyces cerevisiae

PubMed Central

Zhang, Weicheng; Bao, Shaopan; Fang, Tao

2016-01-01

Nanoparticles (NPs) with unique physicochemical properties induce nano-specific (excess) toxicity in organisms compared with their bulk counterparts. Evaluation and consideration of nano-specific toxicity are meaningful for the safe design and environmental risk assessment of NPs. However, ZnO NPs have been reported to lack excess toxicity for diverse organisms. In the present study, the nano-specific toxicity of ZnO NPs was evaluated in the yeast Saccharomyces cerevisiae. Nano-specific toxicity of ZnO NPs was not observed in the wild type yeast. However, the ZnO NPs induced very similar nano-specific toxicities in the three mutants with comparable log Te (particle) values (0.64 vs 0.65 vs 0.62), suggesting that the mutants were more sensitive and specific for the NPs’ nano-specific toxicity. The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles. Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles. The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants. The log Te (particle) was a useful parameter for evaluation of NPs nano-specific toxicity, whereas log Te (ion) efficiently determined the NPs toxicity associated with released ions. PMID:27094203

A nanoscale bio-inspired light-harvesting system developed from self-assembled alkyl-functionalized metallochlorin nano-aggregates.

PubMed

Ocakoglu, Kasim; Joya, Khurram S; Harputlu, Ersan; Tarnowska, Anna; Gryko, Daniel T

2014-08-21

Self-assembled supramolecular organization of nano-structured biomimetic light-harvesting modules inside solid-state nano-templates can be exploited to develop excellent light-harvesting materials for artificial photosynthetic devices. We present here a hybrid light-harvesting system mimicking the chlorosomal structures of the natural photosynthetic system using synthetic zinc chlorin units (ZnChl-C6, ZnChl-C12 and ZnChl-C18) that are self-aggregated inside the anodic aluminum oxide (AAO) nano-channel membranes. AAO nano-templates were modified with a TiO2 matrix and functionalized with long hydrophobic chains to facilitate the formation of supramolecular Zn-chlorin aggregates. The transparent Zn-chlorin nano-aggregates inside the alkyl-TiO2 modified AAO nano-channels have a diameter of ∼120 nm in a 60 μm length channel. UV-Vis studies and fluorescence emission spectra further confirm the formation of the supramolecular ZnChl aggregates from monomer molecules inside the alkyl-functionalized nano-channels. Our results prove that the novel and unique method can be used to produce efficient and stable light-harvesting assemblies for effective solar energy capture through transparent and stable nano-channel ceramic materials modified with bio-mimetic molecular self-assembled nano-aggregates.

The neglected nano-specific toxicity of ZnO nanoparticles in the yeast Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Zhang, Weicheng; Bao, Shaopan; Fang, Tao

2016-04-01

Nanoparticles (NPs) with unique physicochemical properties induce nano-specific (excess) toxicity in organisms compared with their bulk counterparts. Evaluation and consideration of nano-specific toxicity are meaningful for the safe design and environmental risk assessment of NPs. However, ZnO NPs have been reported to lack excess toxicity for diverse organisms. In the present study, the nano-specific toxicity of ZnO NPs was evaluated in the yeast Saccharomyces cerevisiae. Nano-specific toxicity of ZnO NPs was not observed in the wild type yeast. However, the ZnO NPs induced very similar nano-specific toxicities in the three mutants with comparable log Te (particle) values (0.64 vs 0.65 vs 0.62), suggesting that the mutants were more sensitive and specific for the NPs’ nano-specific toxicity. The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles. Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles. The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants. The log Te (particle) was a useful parameter for evaluation of NPs nano-specific toxicity, whereas log Te (ion) efficiently determined the NPs toxicity associated with released ions.

The neglected nano-specific toxicity of ZnO nanoparticles in the yeast Saccharomyces cerevisiae.

PubMed

Zhang, Weicheng; Bao, Shaopan; Fang, Tao

2016-04-20

Nanoparticles (NPs) with unique physicochemical properties induce nano-specific (excess) toxicity in organisms compared with their bulk counterparts. Evaluation and consideration of nano-specific toxicity are meaningful for the safe design and environmental risk assessment of NPs. However, ZnO NPs have been reported to lack excess toxicity for diverse organisms. In the present study, the nano-specific toxicity of ZnO NPs was evaluated in the yeast Saccharomyces cerevisiae. Nano-specific toxicity of ZnO NPs was not observed in the wild type yeast. However, the ZnO NPs induced very similar nano-specific toxicities in the three mutants with comparable log Te ((particle)) values (0.64 vs 0.65 vs 0.62), suggesting that the mutants were more sensitive and specific for the NPs' nano-specific toxicity. The toxic effects in the yeast were slightly attributable to dissolved zinc ions from the ZnO (nano or bulk) particles. Oxidative damage and mechanical damage contributed to the toxic effect of the ZnO particles. The mechanism of mechanical damage is proposed to be an inherent characteristic underlying the nano-specific toxicity in the mutants. The log Te ((particle)) was a useful parameter for evaluation of NPs nano-specific toxicity, whereas log Te ((ion)) efficiently determined the NPs toxicity associated with released ions.

Design of nanostructured-based glucose biosensors

NASA Astrophysics Data System (ADS)

Komirisetty, Archana; Williams, Frances; Pradhan, Aswini; Konda, Rajini B.; Dondapati, Hareesh; Samantaray, Diptirani

2012-04-01

This paper presents the design of glucose sensors that will be integrated with advanced nano-materials, bio-coatings and electronics to create novel devices that are highly sensitive, inexpensive, accurate, and reliable. In the work presented, a glucose biosensor and its fabrication process flow have been designed. The device is based on electrochemical sensing using a working electrode with bio-functionalized zinc oxide (ZnO) nano-rods. Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability which are very crucial parameters to achieve high sensitivity. Amperometric enzyme electrodes based on glucose oxidase (GOx) are used due to their stability and high selectivity to glucose. The device also consists of silicon dioxide and titanium layers as well as platinum working and counter electrodes and a silver/silver chloride reference electrode. Currently, the biosensors are being fabricated using the process flow developed. Once completed, the sensors will be bio-functionalized and tested to characterize their performance, including their sensitivity and stability.

Pure and zinc doped nano-hydroxyapatite: Synthesis, characterization, antimicrobial and hemolytic studies

NASA Astrophysics Data System (ADS)

Tank, Kashmira P.; Chudasama, Kiran S.; Thaker, Vrinda S.; Joshi, Mihir J.

2014-09-01

The structural, antimicrobial, and hemolytic properties and bioactivity have been studied of pure hydroxyapatite (HAP) and zinc doped hydroxyapatite (Zn-HAP) nano-particles for their medical applications. Pure HAP and Zn-HAP nano-particles were synthesized by the surfactant mediated approach. The doping of zinc was estimated by EDAX. The average particle size was determined by applying Scherrer's formula to powdered XRD patterns. The nano-particle morphology was studied by TEM and the presence of various functional groups was identified by FTIR spectroscopy. Good antimicrobial activity of nano-HAP and nano-Zn-HAP was found against five organisms, viz., Pseudomonas aeruginosa and Shigella flexneri as Gram negative as well as Micrococcus luteus, Staphylococcous aureus and Bacillus cereus as Gram positive. The ability of new apatite formation on the surface of pure and doped HAP samples was studied by using Simulated Body Fluid (SBF) in vitro. Hemolytic study indicated that all samples were non-hemolytic and suggesting potential application as bone implant material.

Synthesis of nano-sized ZnO particles by co-precipitation method with variation of heating time

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purwaningsih, S. Y., E-mail: sriyanisaputri@gmail.com; Pratapa, S.; Triwikantoro

Zinc oxide powders have been synthesized by a co-precipitation method at low temperature (85 °C), using zinc acetate dihydrate, ammonia, hydrochloric acid solutions as the reactants. A number of process parameters such as reaction temperature, solution basicity or pH and heating time are the main factors affecting the morphology and physical properties of the ZnO nanostructures. In this work the effect of heating time on the morphology and particles size were studied. The as-synthesized ZnO powders were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The samples were also analyzed using Fourier transform infrared (FTIR). Rietveld refinementmore » of XRD data confirms that ZnO crystallizes in the hexagonal wurtzite structure with high degree of purity and the (101) plane predominant. The XRD results show that the average crystallite sizes were about 66, 27 and 12 nm for 3, 4 and 5 h of heating times, respectively. The XRD analysis indicated that a fraction of nano-sized ZnO powders were in the form of aggregates, which was also verified by TEM image. The TEM photograph demonstrated that the nano-sized ZnO particles were a pseudo-spherical shape.« less

Toxicity of ZnO nanoparticles to Escherichia coli: mechanism and the influence of medium components.

PubMed

Li, Mei; Zhu, Lizhong; Lin, Daohui

2011-03-01

Water chemistry can be a major factor regulating the toxicity mechanism of ZnO nanoparticles (nano-ZnO) in water. The effect of five commonly used aqueous media with various chemical properties on the toxicity of nano-ZnO to Escherichia coli O111 (E. coli) was investigated, including ultrapure water, 0.85% NaCl, phosphate-buffered saline (PBS), minimal Davis (MD), and Luria-Bertani (LB). Combined results of physicochemical characterization and antibacterial tests of nano-ZnO in the five media suggest that the toxicity of nano-ZnO is mainly due to the free zinc ions and labile zinc complexes. The toxicity of nano-ZnO in the five media deceased as follows: ultrapure water > NaCl > MD > LB > PBS. The generation of precipitates (Zn(3)(PO(4))(2) in PBS) and zinc complexes (of zinc with citrate and amino acids in MD and LB, respectively) dramatically decreased the concentration of Zn(2+) ions, resulting in the lower toxicity in these media. Additionally, the isotonic and rich nutrient conditions improved the tolerance of E. coli to toxicants. Considering the dramatic difference of the toxicity of nano-ZnO in various aqueous media, the effect of water chemistry on the physicochemical properties of nanoparticles should be paid more attention in future nanotoxicity evaluations.

SEM-EDX, water absorption, and wetting capability studies on evaluation of the influence of nano-zinc oxide as additive to paraloid B72 solutions used for wooden artifacts consolidation.

PubMed

Tuduce Traistaru, Ana-Adriana; Crina Anca Sandu, Irina; Cristina Timar, Maria; Lucia Dumitrescu, Georgeta; Sandu, Ion

2013-02-01

Consolidation of frail, degraded wood is a key issue of wooden cultural heritage conservation. Paraloid B72 is one of the most often used consolidant in conservation practice. The present research aimed at formulating stable consolidation solutions of Paraloid B72 with ZnO nano-additives and at determining the influence of these additives on the penetration pathways, retention of the consolidation material into wood and on the water behavior of the treated wood. The experiments were performed on sound samples of aspen (Populus tremula). The addition of nano-ZnO slightly increased the uptake and retention of the consolidant within the wooden structure and led to hydrophobic surfaces. However, the influence of nano-ZnO additives to the water absorption was not conclusive. Scanning Electron Microscope coupled with an EDX Detector investigation proved vessels, fibers, and interconnecting pits as main pathways of consolidant penetration into the wooden structure as well as the presence and distribution of nano-ZnO. Copyright © 2012 Wiley Periodicals, Inc.

The antimicrobial sensitivity of Streptococcus mutans and Streptococcus sangius to colloidal solutions of different nanoparticles applied as mouthwashes

PubMed Central

Ahrari, Farzaneh; Eslami, Neda; Rajabi, Omid; Ghazvini, Kiarash; Barati, Sahar

2015-01-01

Background: Metal nanoparticles have been recently applied in dentistry because of their antibacterial properties. This study aimed to evaluate antibacterial effects of colloidal solutions containing zinc oxide (ZnO), copper oxide (CuO), titanium dioxide (TiO2) and silver (Ag) nanoparticles on Streptococcus mutans and Streptococcus sangius and compare the results with those of chlorhexidine and sodium fluoride mouthrinses. Materials and Methods: After adding nanoparticles to a water-based solution, six groups were prepared. Groups I to IV included colloidal solutions containing nanoZnO, nanoCuO, nanoTiO2 and nanoAg, respectively. Groups V and VI consisted of 2.0% sodium fluoride and 0.2% chlorhexidine mouthwashes, respectively as controls. We used serial dilution method to find minimum inhibitory concentrations (MICs) and with subcultures obtained minimum bactericidal concentrations (MBCs) of the solutions against S. mutans and S. sangius. The data were analyzed by analysis of variance and Duncan test and P < 0.05 was considered as significant. Results: The sodium fluoride mouthrinse did not show any antibacterial effect. The nanoTiO2-containing solution had the lowest MIC against both microorganisms and also displayed the lowest MBC against S. mutans (P < 0.05). The colloidal solutions containing nanoTiO2 and nanoZnO showed the lowest MBC against S. sangius (P < 0.05). On the other hand, chlorhexidine showed the highest MIC and MBC against both streptococci (P < 0.05). Conclusion: The nanoTiO2-containing mouthwash proved to be an effective antimicrobial agent and thus it can be considered as an alternative to chlorhexidine or sodium fluoride mouthrinses in the oral cavity provided the lack of cytotoxic and genotoxic effects on biologic tissues. PMID:25709674

Antagonistic effect of nano-ZnO and cetyltrimethyl ammonium chloride on the growth of Chlorella vulgaris: Dissolution and accumulation of nano-ZnO.

PubMed

Liu, Na; Wang, Yipeng; Ge, Fei; Liu, Shixiang; Xiao, Huaixian

2018-04-01

The interaction of nanoparticles with coexisting chemicals affects the fate and transport of nanoparticles, as well as their combined effects on aquatic organisms. Here, we evaluated the joint effect of ZnO nanoparticle (nano-ZnO) and cetyltrimethyl ammonium chloride (CTAC) on the growth of Chlorella vulgaris and explored the possible mechanism. Results showed that an antagonistic effect of nano-ZnO and CTAC (0.1, 0.2 and 0.3 mg L -1 ) was found because CTAC stop nano-ZnO being broken down into solution zinc ions (Zn 2+ ). In the presence of CTAC, the zinc (including nano-ZnO and released Zn 2+ ) showed a higher adsorption on bound extracellular polymeric substances (B-EPS) but lower accumulation in the algal cells. Moreover, we directly demonstrated that nano-ZnO was adsorbed on the algal B-EPS and entered into the algal cells by transmission electron microscope coupled with energy dispersive X-ray (TEM-EDX). Hence, these results suggested that the combined system of nano-ZnO and CTAC exhibited an antagonistic effect due to the inhibition of CTAC on dissolution of nano-ZnO and accumulation of the zinc in the algal cells. Copyright © 2017. Published by Elsevier Ltd.

Highly efficient inverted organic light emitting diodes by inserting a zinc oxide/polyethyleneimine (ZnO:PEI) nano-composite interfacial layer

NASA Astrophysics Data System (ADS)

Kaçar, Rifat; Pıravadılı Mucur, Selin; Yıldız, Fikret; Dabak, Salih; Tekin, Emine

2017-06-01

The electrode/organic interface is one of the key factors in attaining superior device performance in organic electronics, and inserting a tailor-made layer can dramatically modify its properties. The use of nano-composite (NC) materials leads to many advantages by combining materials with the objective of obtaining a desirable combination of properties. In this context, zinc oxide/polyethyleneimine (ZnO:PEI) NC film was incorporated as an interfacial layer into inverted bottom-emission organic light emitting diodes (IBOLEDs) and fully optimized. For orange-red emissive MEH-PPV based IBOLEDs, a high power efficiency of 6.1 lm W-1 at a luminance of 1000 cd m-2 has been achieved. Notably, the external quantum efficiency (EQE) increased from 0.1 to 4.8% and the current efficiency (CE) increased from 0.2 to 8.7 cd A-1 with rise in luminance (L) from 1000 to above 10 000 cd m-2 levels when compared to that of pristine ZnO-based devices. An identical device architecture containing a ZnO:PEI NC layer has also been used to successfully fabricate green and blue emissive IBOLEDs. The significant enhancement in the inverted device performance, in terms of luminance and efficiency, is attributed to a good energy-level alignment between the cathode/organic interface which leads to effective carrier balance, resulting in efficient radiative-recombination.

Antibacterial activity and biocompatibility of three-dimensional nanostructured porous granules of hydroxyapatite and zinc oxide nanoparticles—an in vitro and in vivo study

NASA Astrophysics Data System (ADS)

Grenho, L.; Salgado, C. L.; Fernandes, M. H.; Monteiro, F. J.; Ferraz, M. P.

2015-08-01

Ceramic scaffolds are widely studied in the bone tissue engineering field due to their potential in regenerative medicine. However, adhesion of microorganisms on biomaterials with subsequent formation of antibiotic-resistant biofilms is a critical factor in implant-related infections. Therefore, new strategies are needed to address this problem. In the present study, three-dimensional and interconnected porous granules of nanostructured hydroxyapatite (nanoHA) incorporated with different amounts of zinc oxide (ZnO) nanoparticles were produced using a simple polymer sponge replication method. As in vitro experiments, granules were exposed to Staphylococcus aureus and Staphylococcus epidermidis and, after 24 h, the planktonic and sessile populations were assessed. Cytocompatibility towards osteoblast-like cells (MG63 cell line) was also evaluated for a period of 1 and 3 days, through resazurin assay and imaging flow cytometry analysis. As in vivo experiments, nanoHA porous granules with and without ZnO nanoparticles were implanted into the subcutaneous tissue in rats and their inflammatory response after 3, 7 and 30 days was examined, as well as their antibacterial activity after 1 and 3 days of S. aureus inoculation. The developed composites proved to be especially effective at reducing bacterial activity in vitro and in vivo for a weight percentage of 2% ZnO, with a low cell growth inhibition in vitro and no differences in the connective tissue growth and inflammatory response in vivo. Altogether, these results suggest that nanoHA-ZnO porous granules have a great potential to be used in orthopaedic and dental applications as a template for bone regeneration and, simultaneously, to restrain biomaterial-associated infections.

Towards lightweight and flexible high performance nanocrystalline silicon solar cells through light trapping and transport layers

NASA Astrophysics Data System (ADS)

Gray, Zachary R.

This thesis investigates ways to enhance the efficiency of thin film solar cells through the application of both novel nano-element array light trapping architectures and nickel oxide hole transport/electron blocking layers. Experimental results independently demonstrate a 22% enhancement in short circuit current density (JSC) resulting from a nano-element array light trapping architecture and a ˜23% enhancement in fill factor (FF) and ˜16% enhancement in open circuit voltage (VOC) resulting from a nickel oxide transport layer. In each case, the overall efficiency of the device employing the light trapping or transport layer was superior to that of the corresponding control device. Since the efficiency of a solar cell scales with the product of JSC, FF, and VOC, it follows that the results of this thesis suggest high performance thin film solar cells can be realized in the event light trapping architectures and transport layers can be simultaneously optimized. The realizations of these performance enhancements stem from extensive process optimization for numerous light trapping and transport layer fabrication approaches. These approaches were guided by numerical modeling techniques which will also be discussed. Key developments in this thesis include (1) the fabrication of nano-element topographies conducive to light trapping using various fabrication approaches, (2) the deposition of defect free nc-Si:H onto structured topographies by switching from SiH4 to SiF 4 PECVD gas chemistry, and (3) the development of the atomic layer deposition (ALD) growth conditions for NiO. Keywords: light trapping, nano-element array, hole transport layer, electron blocking layer, nickel oxide, nanocrystalline silicon, aluminum doped zinc oxide, atomic layer deposition, plasma enhanced chemical vapor deposition, electron beam lithography, ANSYS HFSS.

Nano ZnO-activated carbon composite electrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Selvakumar, M.; Krishna Bhat, D.; Manish Aggarwal, A.; Prahladh Iyer, S.; Sravani, G.

2010-05-01

A symmetrical (p/p) supercapacitor has been fabricated by making use of nanostructured zinc oxide (ZnO)-activated carbon (AC) composite electrodes for the first time. The composites have been characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction analysis (XRD). Electrochemical properties of the prepared nanocomposite electrodes and the supercapacitor have been studied using cyclic voltammetry (CV) and AC impedance spectroscopy in 0.1 M Na 2SO 4 as electrolyte. The ZnO-AC nanocomposite electrode showed a specific capacitance of 160 F/g for 1:1 composition. The specific capacitance of the electrodes decreased with increase in zinc oxide content. Galvanostatic charge-discharge measurements have been done at various current densities, namely 2, 4, 6 and 7 mA/cm 2. It has been found that the cells have excellent electrochemical reversibility and capacitive characteristics in 0.1 M Na 2SO 4 electrolyte. It has also been observed that the specific capacitance is constant up to 500 cycles at all current densities.

Effect of solvent volume on the physical properties of aluminium doped nanocrystalline zinc oxide thin films deposited using a simplified spray pyrolysis technique

NASA Astrophysics Data System (ADS)

Jabena Begum, N.; Mohan, R.; Ravichandran, K.

2013-01-01

Aluminium doped zinc oxide (AZO) thin films were deposited by employing a low cost and simplified spray technique using a perfume atomizer from starting solutions having different volumes (10, 20, … , 50 mL) of solvent. The effect of solvent volume on the structural, electrical, optical, photoluminescence (PL) and surface morphological properties was studied. The electrical resistivity of the AZO films is remarkably influenced by the variation in the solvent volume. The X-ray diffraction profiles clearly showed that all the films have preferential orientation along the (0 0 2) plane irrespective of the solvent volume. The crystallite size was found to be in the nano range of 35-46 nm. The optical transmittance in the visible region is desirably high (>85%). The AFM images show columnar morphology with varying grain size. The PL studies revealed that the AZO film deposited from 50 mL of solvent volume has good quality with lesser defect density.

Spontaneous polarization induced electric field in zinc oxide nanowires and nanostars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farid, S., E-mail: sfarid3@uic.edu; Choi, M.; Datta, D.

We report on the detection mechanism of spontaneous polarization using electrostatic force microscopy in zinc oxide nanowires and nanostars grown by vapor-liquid-solid technique. Optical and structural properties are investigated in detail to understand the complex ZnO nanostructures comprehensively. Calculations are carried out to estimate the electric field from the change in interleave amplitude induced by the electrostatic force due to the spontaneous polarization effects. Attraction of the probe between the tip and the sample varies for different structures with a stronger attraction for nanostars as compared to nanowires. Strength of electric field is dependent on the orientation of nanowires andmore » nanostars c-axis with measured magnitude of electric field to be ∼10{sup 7 }V/m and 10{sup 8 }V/m respectively. This technique presents a unique detection mechanism of built-in spontaneous polarization and electric field from polar ZnO nanowires with applications in voltage gated ion channels, nano-bio interfaces, optoelectronic and photonic devices.« less

Evaluation of nano-ZnOs as a novel Zn source for marine fish: importance of digestive physiology.

PubMed

Wang, Jian; Wang, Aili; Wang, Wen-Xiong

2017-10-01

Waterborne nanotoxicology of zinc oxide nanoparticles (nano-ZnOs) has been extensively studied over the past decade, whereas their potential dietary toxicity and applications were seldom investigated. In the present study, we systematically investigated both short-term bioavailability and chronic effects of nano-ZnOs to two marine fish (marine medaka Oryzias melastigma and red drum Sciaenops ocellatus). At normal supplementary level (80 mg Zn/kg), red drum (with a stomach) had similar assimilation efficiencies of nano-ZnOs and ZnCl 2 . Correspondingly, in vitro digestion experiments showed the continuous dissolution of nano-ZnOs in acid environment. In contrast, nano-ZnOs were more bioavailable than ZnCl 2 to medaka (stomach-less) at 80 mg Zn/kg supplementary level. There results were further validated by using bulk-ZnOs. Chronic dietary exposure to nano-ZnOs (80 mg/kg) significantly enhanced the antioxidative defenses in medaka, with no negative effect on fish growth. Beneficial effects disappeared in the high dietary nano-ZnOs (300 mg/kg) treatment. For the first time, we provided direct evidence that nano-ZnOs was more bioavailable than ZnCl 2 and bulk-ZnOs to stomach-less fish at normal dietary Zn inclusion level (<80 mg/kg), with potential benefits on antioxidative defenses. It is also necessary to pay attention to the dietary nano-ZnOs toxicity on stomach-less fish due to the presence of real 'nano-effects.'

Zinc oxide tetrapods inhibit herpes simplex virus infection of cultured corneas

PubMed Central

Duggal, Neil; Jaishankar, Dinesh; Yadavalli, Tejabhiram; Hadigal, Satvik; Mishra, Yogendra Kumar; Adelung, Rainer

2017-01-01

Purpose Infection of the human cornea by herpes simplex virus type-1 (HSV-1) can cause significant vision loss. The purpose of this study was to develop an ex vivo model to visualize viral growth and spread in the cornea. The model was also used to analyze cytokine production and study the antiviral effects of zinc oxide tetrapods. Methods A β-galactosidase-expressing recombinant virus, HSV-1(KOS)tk12, was used to demonstrate the ability of the virus to enter and develop blue plaques on human corneal epithelial (HCE) cells and corneal tissues. Freshly obtained porcine corneas were cultured and then scratched before infection with HSV-1(KOS)tk12. The blue plaques on the corneas were imaged using a stereomicroscope. Western blot analysis for HSV-1 proteins was performed to verify HSV-1 infection of the cornea. Using the ex vivo model, zinc oxide tetrapods were tested for their anti-HSV-1 potential, and a cytokine profile was developed to assess the effects of the treatment. Results Cultured corneas and the use of β-galactosidase-expressing HSV-1(KOS)tk12 virus can provide an attractive ex vivo model to visualize and study HSV-1 entry and spread of the infection in tissues. We found that unlike cultured HCE cells, which demonstrated nearly 100% infectivity, HSV-1 infection of the cultured cornea was more restrictive and took longer to develop. We also found that the zinc oxide tetrapod–shaped nano- and microstructures inhibited HSV infection of the cultured cells, as well as the cultured corneas. The cytokine profile of the infected samples was consistent with previous studies of HSV-1 corneal infection. Conclusions The ability to visualize HSV-1 growth and spread in corneal tissues can provide new details about HSV-1 infection of the cornea and the efficacy of new cornea-specific antiviral drug candidates. The ex vivo model also demonstrates antiviral effects of zinc oxide tetrapods and adequately portrays the drug delivery issues that cornea-specific treatments face. PMID:28275313

Nanoparticulate zinc oxide as a coating material for orthopedic and dental implants.

PubMed

Memarzadeh, Kaveh; Sharili, Amir S; Huang, Jie; Rawlinson, Simon C F; Allaker, Robert P

2015-03-01

Orthopedic and dental implants are prone to infection. In this study, we describe a novel system using zinc oxide nanoparticles (nZnO) as a coating material to inhibit bacterial adhesion and promote osteoblast growth. Electrohydrodynamic atomisation (EHDA) was employed to deposit mixtures of nZnO and nanohydroxyapatite (nHA) onto the surface of glass substrates. Nano-coated substrates were exposed to Staphylococcus aureus suspended in buffered saline or bovine serum to determine antimicrobial activity. Our results indicate that 100% nZnO and 75% nZnO/25% nHA composite-coated substrates have significant antimicrobial activity. Furthermore, osteoblast function was explored by exposing cells to nZnO. UMR-106 cells exposed to nZnO supernatants showed minimal toxicity. Similarly, MG-63 cells cultured on nZnO substrates did not show release of TNF-α and IL-6 cytokines. These results were reinforced by both proliferation and differentiation studies which revealed that a substrate coated with exclusively nZnO is more efficient than composite surface coatings. Finally, electron and light microscopy, together with immunofluorescence staining, revealed that all cell types tested, including human mesenchymal cell (hMSC), were able to maintain normal cell morphology when adhered onto the surface of the nano-coated substrates. Collectively, these findings indicate that nZnO can, on its own, provide an optimal coating for future bone implants that are both antimicrobial and biocompatible. © 2014 Wiley Periodicals, Inc.

Protective effect of quercetin and/or l-arginine against nano-zinc oxide-induced cardiotoxicity in rats

NASA Astrophysics Data System (ADS)

Faddah, L. M.; Baky, Nayira A. Abdel; Mohamed, Azza M.; Al-Rasheed, Nouf M.; Al-Rasheed, Nawal M.

2013-04-01

The aim of this study was to investigate the protective role of quercetin and/or l-arginine against the cardiotoxic potency of zinc oxide nanoparticle (ZnO-NP)-induced cardiac infarction. ZnO-NPs (50 nm) were administered orally at either 600 mg or 1 g/kg body weight for 5 consecutive days. The results revealed that co-administration of quercetin and/or l-arginine (each 200 mg/kg body weight) daily for 3 weeks to rats intoxicated by either of the two doses markedly ameliorated increases in serum markers of cardiac infarction, including troponin T, creatine kinase-MB, and myoglobin, as well as increases in proinflammatory biomarkers, including tumor necrosis factor-α, interleukin-6, and C-reactive protein, compared with intoxicated, untreated rats. Each agent alone or in combination also successfully modulated the alterations in serum vascular endothelial growth factor, cardiac calcium concentration, and oxidative DNA damage as well as the increase in the apoptosis marker caspase 3 of cardiac tissue in response to ZnO-NP toxicity. In conclusion, early treatment with quercetin and l-arginine may protect cardiac tissue from infarction induced by the toxic effects of ZnO-NPs.

Zinc oxide nanostructures and its nano-compounds for efficient visible light photo-catalytic processes

NASA Astrophysics Data System (ADS)

Adam, Rania E.; Alnoor, Hatim; Elhag, Sami; Nur, Omer; Willander, Magnus

2017-02-01

Zinc oxide (ZnO) in its nanostructure form is a promising material for visible light emission/absorption and utilization in different energy efficient photocatalytic processes. We will first present our recent results on the effect of varying the molar ratio of the synthesis nutrients on visible light emission. Further we will use the optimized conditions from the molar ration experiments to vary the synthesis processing parameters like stirring time etc. and the effect of all these parameters in order to optimize the efficiency and control the emission spectrum are investigated using different complementary techniques. Cathodoluminescence (CL) is combined with photoluminescence (PL) and electroluminescence (EL) as the techniques to investigate and optimizes visible light emission from ZnO/GaN light emitting diodes. We will then show and discuss our recent finding of the use of high quality ZnO nanoparticles (NPs) for efficient photo-degradation of toxic dyes using the visible spectra, namely with a wavelength up to 800 nm. In the end, we show how ZnO nanorods (NRs) are used as the first template to be transferred to bismuth zinc vanadate (BiZn2VO6). The BiZn2VO6 is then used to demonstrate efficient and cost effective hydrogen production through photoelectrochemical water splitting using solar radiation.

Selenium Nanoparticles Induce the Chemo-Sensitivity of Fluorouracil Nanoparticles in Breast and Colon Cancer Cells.

PubMed

Abd-Rabou, Ahmed A; Shalby, Aziza B; Ahmed, Hanaa H

2018-05-11

Drug resistance is a major challenge of breast and colon cancer therapies leading to treatment failure. The main objective of the current study is to investigate whether selenium nanoparticles (nano-Se) can induce the chemo-sensitivity of 5-fluorouracil (FU)-encapsulated poly (D, L-lactide-co-glycolide) nanoparticles (nano-FU) in breast and colon cancer cell lines. Nano-Se and nano-FU were synthesized and characterized, then applied individually or in combination upon MCF7, MDA-MB-231, HCT 116, and Caco-2 cancerous cell lines. Cytotoxicity, cellular glucose uptake, and apoptosis, as well as malondialdehyde (MDA), nitric oxide (NO), and zinc (Zn) levels, were investigated upon the different treatments. We have resulted that nano-FU induced cell death in MCF7 and Caco-2 more effectively than MDA-MB-231 and HCT 116 cell lines. Moreover, nano-FU plus nano-Se potentiate MCF7 and Caco-2 chemo-sensitivity were higher than MDA-MB-231 and HCT 116 cancerous cell lines. It is relevant to note that Se and FU nano-formulations inhibited cancer cell bioenergetics via glucose uptake slight blockage. Furthermore, nano-FU increased the levels of NO and MDA in media over cancer cells, while their combinations with nano-Se rebalance the redox status with Zn increment. We noticed that MCF7 cell line is sensitive, while MDA-MB-231 cell line is resistant to Se and nano-Se. This novel approach could be of great potential to enhance the chemo-sensitivity in breast and colon cancer cells.

Erbium-doped zinc-oxide waveguide amplifiers for hybrid photonic integrated circuits

NASA Astrophysics Data System (ADS)

O'Neal, Lawrence; Anthony, Deion; Bonner, Carl; Geddis, Demetris

2016-02-01

CMOS logic circuits have entered the sub-100nm regime, and research is on-going to investigate the quantum effects that are apparent at this dimension. To avoid some of the constraints imposed by fabrication, entropy, energy, and interference considerations for nano-scale devices, many have begun designing hybrid and/or photonic integrated circuits. These circuits consist of transistors, light emitters, photodetectors, and electrical and optical waveguides. As attenuation is a limiting factor in any communications system, it is advantageous to integrate a signal amplifier. There are numerous examples of electrical amplifiers, but in order to take advantage of the benefits provided by optically integrated systems, optical amplifiers are necessary. The erbium doped fiber amplifier is an example of an optical amplifier which is commercially available now, but the distance between the amplifier and the device benefitting from amplification can be decreased and provide greater functionality by providing local, on-chip amplification. Zinc oxide is an attractive material due to its electrical and optical properties. Its wide bandgap (≍3.4 eV) and high refractive index (≍2) make it an excellent choice for integrated optics systems. Moreover, erbium doped zinc oxide (Er:ZnO) is a suitable candidate for optical waveguide amplifiers because of its compatibility with semiconductor processing technology, 1.54 μm luminescence, transparency, low resistivity, and amplification characteristics. This research presents the characterization of radio frequency magnetron sputtered Er:ZnO, the design and fabrication of integrated waveguide amplifiers, and device analysis.

Hybrid Energy Cell with Hierarchical Nano/Micro-Architectured Polymer Film to Harvest Mechanical, Solar, and Wind Energies Individually/Simultaneously.

PubMed

Dudem, Bhaskar; Ko, Yeong Hwan; Leem, Jung Woo; Lim, Joo Ho; Yu, Jae Su

2016-11-09

We report the creation of hybrid energy cells based on hierarchical nano/micro-architectured polydimethylsiloxane (HNMA-PDMS) films with multifunctionality to simultaneously harvest mechanical, solar, and wind energies. These films consist of nano/micro dual-scale architectures (i.e., nanonipples on inverted micropyramidal arrays) on the PDMS surface. The HNMA-PDMS is replicable by facile and cost-effective soft imprint lithography using a nanoporous anodic alumina oxide film formed on the micropyramidal-structured silicon substrate. The HNMA-PDMS film plays multifunctional roles as a triboelectric layer in nanogenerators and an antireflection layer for dye-sensitized solar cells (DSSCs), as well as a self-cleaning surface. This film is employed in triboelectric nanogenerator (TENG) devices, fabricated by laminating it on indium-tin oxide-coated polyethylene terephthalate (ITO/PET) as a bottom electrode. The large effective contact area that emerged from the densely packed hierarchical nano/micro-architectures of the PDMS film leads to the enhancement of TENG device performance. Moreover, the HNMA-PDMS/ITO/PET, with a high transmittance of >90%, also results in highly transparent TENG devices. By placing the HNMA-PDMS/ITO/PET, where the ITO/PET is coated with zinc oxide nanowires, as the top glass substrate of DSSCs, the device is able to add the functionality of TENG devices, thus creating a hybrid energy cell. The hybrid energy cell can successfully convert mechanical, solar, and wind energies into electricity, simultaneously or independently. To specify the device performance, the effects of external pushing frequency and load resistance on the output of TENG devices are also analyzed, including the photovoltaic performance of the hybrid energy cells.

Band gap and conductivity variations of ZnO nano structured thin films annealed under Vacuum

NASA Astrophysics Data System (ADS)

Vattappalam, Sunil C.; Thomas, Deepu; T, Raju Mathew; Augustine, Simon; Mathew, Sunny

2015-02-01

Zinc Oxide thin films were prepared by Successive Ionic layer adsorption and reaction technique(SILAR). The samples were annealed under vacuum and conductivity of the samples were taken at different temperatures. UV Spectrograph of the samples were taken and the band gap of each sample was found from the data. All the results were compared with that of the sample annealed under air. It was observed that the band gap decreases and concequently conductivity of the samples increases when the samples are annealed under vacuum.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boppana, Venkata Bharat Ram; Hould, Nathan D.; Lobo, Raul F., E-mail: lobo@udel.ed

We report the first instance of a hydrothermal synthesis of zinc germanate (Zn{sub 2}GeO{sub 4}) nano-materials having a variety of morphologies and photochemical properties in surfactant, template and catalyst-free conditions. A systematic variation of synthesis conditions and detailed characterization using X-ray diffraction, ultraviolet-visible diffuse reflectance spectroscopy, Raman spectroscopy, electron microscopy, X-ray photoelectron spectroscopy and small angle X-ray scattering led to a better understanding of the growth of these particles from solution. At 140 {sup o}C, the zinc germanate particle morphology changes with pH from flower-shaped at pH 6.0, to poly-disperse nano-rods at pH 10 when the Zn to Ge ratiomore » in the synthesis solution is 2. When the Zn to Ge ratio is reduced to 1.25, mono-disperse nano-rods could be prepared at pH 7.5. Nanorod formation is also independent of the addition of cetyltrimethylammonium bromide (CTAB), in contrast to previous reports. Photocatalytic tests show that Zn{sub 2}GeO{sub 4} nano-rods (by weight) and flower shaped (by surface area) are the most active for methylene blue dye degradation among the synthesized zinc germanate materials. -- Graphical abstract: Zinc germanate materials were synthesized possessing unique morphologies dependent on the hydrothermal synthesis conditions in the absence of surfactant, catalyst or template. These novel materials are characterized and evaluated for their photocatalytic activities. Display Omitted highlights: > Zinc germanate synthesized hydrothermally (surfactant free) with unique morphologies. > Flower-shaped, nano-rods, globular particles obtained dependent on synthesis pH. > At 140 {sup o}C, they possess the rhombohedral crystal irrespective of synthesis conditions. > They are photocatalytically active for the degradation of methylene blue. > Potential applications could be photocatalytic water splitting and CO{sub 2} reduction.« less

ZnO Nano-Rod Devices for Intradermal Delivery and Immunization

PubMed Central

Nayak, Tapas R.; Wang, Hao; Pant, Aakansha; Zheng, Minrui; Junginger, Hans; Goh, Wei Jiang; Lee, Choon Keong; Zou, Shui; Alonso, Sylvie; Czarny, Bertrand; Storm, Gert; Sow, Chorng Haur; Lee, Chengkuo; Pastorin, Giorgia

2017-01-01

Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO) nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods’ length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30–35 µm and diameters of 200–300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC) absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA) antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery. PMID:28617335

ZnO Nano-Rod Devices for Intradermal Delivery and Immunization.

PubMed

Nayak, Tapas R; Wang, Hao; Pant, Aakansha; Zheng, Minrui; Junginger, Hans; Goh, Wei Jiang; Lee, Choon Keong; Zou, Shui; Alonso, Sylvie; Czarny, Bertrand; Storm, Gert; Sow, Chorng Haur; Lee, Chengkuo; Pastorin, Giorgia

2017-06-15

Intradermal delivery of antigens for vaccination is a very attractive approach since the skin provides a rich network of antigen presenting cells, which aid in stimulating an immune response. Numerous intradermal techniques have been developed to enhance penetration across the skin. However, these methods are invasive and/or affect the skin integrity. Hence, our group has devised zinc oxide (ZnO) nano-rods for non-destructive drug delivery. Chemical vapour deposition was used to fabricate aligned nano-rods on ZnO pre-coated silicon chips. The nano-rods' length and diameter were found to depend on the temperature, time, quality of sputtered silicon chips, etc. Vertically aligned ZnO nano-rods with lengths of 30-35 µm and diameters of 200-300 nm were selected for in vitro human skin permeation studies using Franz cells with Albumin-fluorescein isothiocyanate (FITC) absorbed on the nano-rods. Fluorescence and confocal studies on the skin samples showed FITC penetration through the skin along the channels formed by the nano-rods. Bradford protein assay on the collected fluid samples indicated a significant quantity of Albumin-FITC in the first 12 h. Low antibody titres were observed with immunisation on Balb/c mice with ovalbumin (OVA) antigen coated on the nano-rod chips. Nonetheless, due to the reduced dimensions of the nano-rods, our device offers the additional advantage of excluding the simultaneous entrance of microbial pathogens. Taken together, these results showed that ZnO nano-rods hold the potential for a safe, non-invasive, and painless intradermal drug delivery.

Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

NASA Astrophysics Data System (ADS)

Espitia, Paula Judith Perez; Soares, Nilda de Fátima Ferreira; Teófilo, Reinaldo F.; Vitor, Débora M.; Coimbra, Jane Sélia dos Reis; de Andrade, Nélio José; de Sousa, Frederico B.; Sinisterra, Rubén D.; Medeiros, Eber Antonio Alves

2013-01-01

Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na4P2O7), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

Preparation and characterization of zinc sulphide nanocomposites based on acrylonitrile butadiene rubber

NASA Astrophysics Data System (ADS)

Ramesan, M. T.; Nihmath, A.; Francis, Joseph

2013-06-01

Rubber composite based on acrylonitrile butadiene rubber (NBR) reinforced with nano zinc sulphide (ZnS) have been prepared via vulcanization process and characterized by several techniques. Processing characteristics such as scorch time, optimum cure time decreases with increase in concentration of nano filler in acrylonitrile butadiene rubber. Mechanical properties such as tensile and tear strength increases with increase in concentration of nano filler up to 7 phr of loading thereafter the value decreases, whereas hardness, and flame resistance increases with the dosage of fillers. These enhanced properties are due to the homogenous dispersion of nano fillers in NBR matrix, which is evidenced from the structure that evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Study of the effect of ZnO film on some properties of clear and color window glass

NASA Astrophysics Data System (ADS)

Hamead, Alaa A. Abdul; Ahmed, Sura S.; Khdheer, Mena F.

2018-05-01

In the current research, a samples of transparent color and colorless window glass were prepared, (includes metal transition oxides) for construction applications. A nano-film layer of zinc oxide ZnO was deposited by spray pyrolysis technique for use in sustainability applications prepared. Structural properties (x-ray diffraction XRD, scanning electron microscopy SEM and atomic force microscopy AFM), and thermal properties, as well as optical properties and the effect of weathering conditions on applied film on clear and colored glass were examined. The results showed that the deposition film had a thickness of less than 90nm and that it was crystallized with high optical transparently, that was not significantly affected after deposited the ZnO nano film. While thermal insulation decreased significantly after deposition, and the effect of the weather conditions was very low as the ZnO coating was not affected, as the thermal insulation did not change after exposure to accelerated air conditions. Make it suitable in glass applications for buildings in vertical construction.

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

2015-01-01

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.

Acute and Cumulative Effects of Unmodified 50-nm Nano-ZnO on Mice.

PubMed

Kong, Tao; Zhang, Shu-Hui; Zhang, Ji-Liang; Hao, Xue-Qin; Yang, Fan; Zhang, Cai; Yang, Zi-Jun; Zhang, Meng-Yu; Wang, Jie

2018-01-02

Nanometer zinc oxide (nano-ZnO) is widely used in diverse industrial and agricultural fields. Due to the extensive contact humans have with these particles, it is crucial to understand the potential effects that nano-ZnO have on human health. Currently, information related to the toxicity and mechanisms of nano-ZnO is limited. The aim of the present study was to investigate acute and cumulative toxic effects of 50-nm unmodified ZnO in mice. This investigation will seek to establish median lethal dose (LD50), a cumulative coefficient, and target organs. The acute and cumulative toxicity was investigated by Karber's method and via a dose-increasing method, respectively. During the experiment, clinical signs, mortality, body weights, hematology, serum biochemistry, gross pathology, organ weight, and histopathology were examined. The LD50 was 5177-mg/kg·bw; the 95% confidence limits for the LD50 were 5116-5238-mg/kg·bw. It could be concluded that the liver, kidney, lung, and gastrointestinal tract were target organs for the 50-nm nano-ZnO acute oral treatment. The cumulative coefficient (K) was 1.9 which indicated that the cumulative toxicity was apparent. The results also indicated that the liver, kidney, lung, and pancrea were target organs for 50-nm nano-ZnO cumulative oral exposure and might be target organs for subchronic and chronic toxicity of oral administered 50-nm ZnO.

Synthesis, characterization, antimicrobial activity and mechanism of a novel hydroxyapatite whisker/nano zinc oxide biomaterial.

PubMed

Yu, Jian; Zhang, Wenyun; Li, Yang; Wang, Gang; Yang, Lidou; Jin, Jianfeng; Chen, Qinghua; Huang, Minghua

2014-12-23

Postoperative infections remain a risk factor that leads to failures in oral and maxillofacial artificial bone transplantation. This study aimed to synthesize and evaluate a novel hydroxyapatite whisker (HAPw) / nano zinc oxide (n-ZnO) antimicrobial bone restorative biomaterial. A scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD) were employed to characterize and analyze the material. Antibacterial capabilities against Staphylococcus aureus, Escherichia coli, Candida albicans and Streptococcus mutans were determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), and kinetic growth inhibition assays were performed under darkness and simulated solar irradiation. The mode of antibiotic action was observed by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). The MIC and MBC were 0.078-1.250 mg ml(-1) and 0.156-2.500 mg ml(-1), respectively. The inhibitory function on the growth of the microorganisms was achieved even under darkness, with gram-positive bacteria found to be more sensitive than gram-negative, and enhanced antimicrobial activity was exhibited under simulated solar excitation compared to darkness. TEM and CLSM images revealed a certain level of bacterial cell membrane destruction after treatment with 1 mg ml(-1) of the material for 12 h, causing the leakage of intracellular contents and bacteria death. These results suggest favorable antibiotic properties and a probable mechanism of the biomaterial for the first time, and further studies are needed to determine its potential application as a postoperative anti-inflammation method in bone transplantation.

Dead end1 is an essential partner of NANOS2 for selective binding of target RNAs in male germ cell development.

PubMed

Suzuki, Atsushi; Niimi, Yuki; Shinmyozu, Kaori; Zhou, Zhi; Kiso, Makoto; Saga, Yumiko

2016-01-01

RNA-binding proteins (RBPs) play important roles for generating various cell types in many developmental processes, including eggs and sperms. Nanos is widely known as an evolutionarily conserved RNA-binding protein implicated in germ cell development. Mouse NANOS2 interacts directly with the CCR4-NOT (CNOT) deadenylase complex, resulting in the suppression of specific RNAs. However, the mechanisms involved in target specificity remain elusive. We show that another RBP, Dead end1 (DND1), directly interacts with NANOS2 to load unique RNAs into the CNOT complex. This interaction is mediated by the zinc finger domain of NANOS2, which is essential for its association with target RNAs. In addition, the conditional deletion of DND1 causes the disruption of male germ cell differentiation similar to that observed in Nanos2-KO mice. Thus, DND1 is an essential partner for NANOS2 that leads to the degradation of specific RNAs. We also present the first evidence that the zinc finger domain of Nanos acts as a protein-interacting domain for another RBP, providing a novel insight into Nanos-mediated germ cell development. © 2015 The Authors.

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Manganese phosphate (dibasic). Manganese sulfate. Manganous oxide. Zinc Zinc acetate. Zinc carbonate. Zinc chloride. Zinc oxide. Zinc sulfate. ... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper...

21 CFR 582.80 - Trace minerals added to animal feeds.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Manganese phosphate (dibasic). Manganese sulfate. Manganous oxide. Zinc Zinc acetate. Zinc carbonate. Zinc chloride. Zinc oxide. Zinc sulfate. ... Cobalt Cobalt acetate. Cobalt carbonate. Cobalt chloride. Cobalt oxide. Cobalt sulfate. Copper Copper...

NanoE-Tox: New and in-depth database concerning ecotoxicity of nanomaterials.

PubMed

Juganson, Katre; Ivask, Angela; Blinova, Irina; Mortimer, Monika; Kahru, Anne

2015-01-01

The increasing production and use of engineered nanomaterials (ENMs) inevitably results in their higher concentrations in the environment. This may lead to undesirable environmental effects and thus warrants risk assessment. The ecotoxicity testing of a wide variety of ENMs rapidly evolving in the market is costly but also ethically questionable when bioassays with vertebrates are conducted. Therefore, alternative methods, e.g., models for predicting toxicity mechanisms of ENMs based on their physico-chemical properties (e.g., quantitative (nano)structure-activity relationships, QSARs/QNARs), should be developed. While the development of such models relies on good-quality experimental toxicity data, most of the available data in the literature even for the same test species are highly variable. In order to map and analyse the state of the art of the existing nanoecotoxicological information suitable for QNARs, we created a database NanoE-Tox that is available as Supporting Information File 1. The database is based on existing literature on ecotoxicology of eight ENMs with different chemical composition: carbon nanotubes (CNTs), fullerenes, silver (Ag), titanium dioxide (TiO2), zinc oxide (ZnO), cerium dioxide (CeO2), copper oxide (CuO), and iron oxide (FeO x ; Fe2O3, Fe3O4). Altogether, NanoE-Tox database consolidates data from 224 articles and lists altogether 1,518 toxicity values (EC50/LC50/NOEC) with corresponding test conditions and physico-chemical parameters of the ENMs as well as reported toxicity mechanisms and uptake of ENMs in the organisms. 35% of the data in NanoE-Tox concerns ecotoxicity of Ag NPs, followed by TiO2 (22%), CeO2 (13%), and ZnO (10%). Most of the data originates from studies with crustaceans (26%), bacteria (17%), fish (13%), and algae (11%). Based on the median toxicity values of the most sensitive organism (data derived from three or more articles) the toxicity order was as follows: Ag > ZnO > CuO > CeO2 > CNTs > TiO2 > FeO x . We believe NanoE-Tox database contains valuable information for ENM environmental hazard estimation and development of models for predicting toxic potential of ENMs.

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.

Zinc oxide varistors and/or resistors

DOEpatents

Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

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.

Objective Molecular Dynamics with Self-consistent Charge Density Functional Tight-Binding (SCC-DFTB) Method

NASA Astrophysics Data System (ADS)

Dumitrica, Traian; Hourahine, Ben; Aradi, Balint; Frauenheim, Thomas

We discus the coupling of the objective boundary conditions into the SCC density functional-based tight binding code DFTB+. The implementation is enabled by a generalization to the helical case of the classical Ewald method, specifically by Ewald-like formulas that do not rely on a unit cell with translational symmetry. The robustness of the method in addressing complex hetero-nuclear nano- and bio-fibrous systems is demonstrated with illustrative simulations on a helical boron nitride nanotube, a screw dislocated zinc oxide nanowire, and an ideal double-strand DNA. Work supported by NSF CMMI 1332228.

Selective Sensitization of Zinc Finger Protein Oxidation by Reactive Oxygen Species through Arsenic Binding*

PubMed Central

Zhou, Xixi; Cooper, Karen L.; Sun, Xi; Liu, Ke J.; Hudson, Laurie G.

2015-01-01

Cysteine oxidation induced by reactive oxygen species (ROS) on redox-sensitive targets such as zinc finger proteins plays a critical role in redox signaling and subsequent biological outcomes. We found that arsenic exposure led to oxidation of certain zinc finger proteins based on arsenic interaction with zinc finger motifs. Analysis of zinc finger proteins isolated from arsenic-exposed cells and zinc finger peptides by mass spectrometry demonstrated preferential oxidation of C3H1 and C4 zinc finger configurations. C2H2 zinc finger proteins that do not bind arsenic were not oxidized by arsenic-generated ROS in the cellular environment. The findings suggest that selectivity in arsenic binding to zinc fingers with three or more cysteines defines the target proteins for oxidation by ROS. This represents a novel mechanism of selective protein oxidation and demonstrates how an environmental factor may sensitize certain target proteins for oxidation, thus altering the oxidation profile and redox regulation. PMID:26063799

Fabrication and Characterization of Fully Transparent ZnO Thin-Film Transistors and Self-Switching Nano-Diodes

NASA Astrophysics Data System (ADS)

Sun, Y.; Ashida, K.; Sasaki, S.; Koyama, M.; Maemoto, T.; Sasa, S.; Kasai, S.; Iñiguez-de-la-Torre, I.; González, T.

2015-10-01

Fully transparent zinc oxide (ZnO) based thin-film transistors (TFTs) and a new type of rectifiers calls self-switching nano-diodes (SSDs) were fabricated on glass substrates at room temperature by using low resistivity and transparent conducting Al- doped ZnO (AZO) thin-films. The deposition conditions of AZO thin-films were optimized with pulsed laser deposition (PLD). AZO thin-films on glass substrates were characterized and the transparency of 80% and resistivity with 1.6*10-3 Ωcm were obtained of 50 nm thickness. Transparent ZnO-TFTs were fabricated on glass substrates by using AZO thin-films as electrodes. A ZnO-TFT with 2 μm long gate device exhibits a transconductance of 400 μS/mm and an ON/OFF ratio of 2.8*107. Transparent ZnO-SSDs were also fabricated by using ZnO based materials and clear diode-like characteristics were observed.

Hydroquinone-ZnO nano-laminate deposited by molecular-atomic layer deposition

NASA Astrophysics Data System (ADS)

Huang, Jie; Lucero, Antonio T.; Cheng, Lanxia; Hwang, Hyeon Jun; Ha, Min-Woo; Kim, Jiyoung

2015-03-01

In this study, we have deposited organic-inorganic hybrid semiconducting hydroquinone (HQ)/zinc oxide (ZnO) superlattices using molecular-atomic layer deposition, which enables accurate control of film thickness, excellent uniformity, and sharp interfaces at a low deposition temperature (150 °C). Self-limiting growth of organic layers is observed for the HQ precursor on ZnO surface. Nano-laminates were prepared by varying the number of HQ to ZnO cycles in order to investigate the physical and electrical effects of different HQ to ZnO ratios. It is indicated that the addition of HQ layer results in enhanced mobility and reduced carrier concentration. The highest Hall mobility of approximately 2.3 cm2/V.s and the lowest n-type carrier concentration of approximately 1.0 × 1018/cm3 were achieved with the organic-inorganic superlattice deposited with a ratio of 10 ZnO cycles to 1 HQ cycle. This study offers an approach to tune the electrical transport characteristics of ALD ZnO matrix thin films using an organic dopant. Moreover, with organic embedment, this nano-laminate material may be useful for flexible electronics.

Consumer exposures to laser printer-emitted engineered nanoparticles: A case study of life-cycle implications from nano-enabled products.

PubMed

Pirela, Sandra V; Sotiriou, Georgios A; Bello, Dhimiter; Shafer, Martin; Bunker, Kristin Lee; Castranova, Vincent; Thomas, Treye; Demokritou, Philip

2015-01-01

It is well established that printers emit nanoparticles during their operation. To-date, however, the physicochemical and toxicological characterization of "real world" printer-emitted nanoparticles (PEPs) remains incomplete, hampering proper risk assessment efforts. Here, we investigate our earlier hypothesis that engineered nanomaterials (ENMs) are used in toners and ENMs are released during printing (consumer use). Furthermore, we conduct a detailed physicochemical and morphological characterization of PEPs in support of ongoing toxicological assessment. A comprehensive suite of state of the art analytical methods and tools was employed for the physicochemical and morphological characterization of 11 toners widely utilized in printers from major printer manufacturers and their PEPs. We confirmed that a number of ENMs incorporated into toner formulations (e.g. silica, alumina, titania, iron oxide, zinc oxide, copper oxide, cerium oxide, carbon black among others) and released into the air during printing. All evaluated toners contained large amounts of organic carbon (OC, 42-89%), metals/metal oxides (1-33%), and some elemental carbon (EC, 0.33-12%). The PEPs possess a composition similar to that of toner and contained 50-90% OC, 0.001-0.5% EC and 1-3% metals. While the chemistry of the PEPs generally reflected that of their toners, considerable differences are documented indicative of potential transformations taking place during consumer use (printing). We conclude that: (i) Routine incorporation of ENMs in toners classifies them as nano-enabled products (NEPs); (ii) These ENMs become airborne during printing; (iii) The chemistry of PEPs is complex and it reflects that of the toner and paper. This work highlights the importance of understanding life-cycle (LC) nano-EHS implications of NEPs and assessing real world exposures and associated toxicological properties rather than focusing on "raw" materials used in the synthesis of an NEP.

Consumer exposures to laser printer-emitted engineered nanoparticles: A case study of life-cycle implications from nano-enabled products

PubMed Central

Pirela, Sandra V.; Sotiriou, Georgios A.; Bello, Dhimiter; Shafer, Martin; Bunker, Kristin Lee; Castranova, Vincent; Thomas, Treye; Demokritou, Philip

2015-01-01

It is well established that printers emit nanoparticles during their operation. To-date, however, the physicochemical and toxicological characterization of “real world” printer-emitted nanoparticles (PEPs) remains incomplete, hampering proper risk assessment efforts. Here, we investigate our earlier hypothesis that engineered nanomaterials (ENMs) are used in toners and ENMs are released during printing (consumer use). Furthermore, we conduct a detailed physicochemical and morphological characterization of PEPs in support of ongoing toxicological assessment. A comprehensive suite of state of the art analytical methods and tools was employed for the physicochemical and morphological characterization of 11 toners widely utilized in printers from major printer manufacturers and their PEPs. We confirmed that a number of ENMs incorporated into toner formulations (e.g., silica, alumina, titania, iron oxide, zinc oxide, copper oxide, cerium oxide, carbon black among others) and released into the air during printing. All evaluated toners contained large amounts of organic carbon (OC, 42–89%), metals/metal oxides (1–33%), and some elemental carbon (EC, 0.33–12%). The PEPs possess a composition similar to that of toner and contained 50–90% OC, 0.001–0.5% EC and 1–3% metals. While the chemistry of the PEPs generally reflected that of their toners, considerable differences are documented indicative of potential transformations taking place during consumer use (printing). We conclude that: (i) Routine incorporation of ENMs in toners classifies them as nano-enabled products (NEPs); (ii) These ENMs become airborne during printing; (iii) The chemistry of PEPs is complex and it reflects that of the toner and paper. This work highlights the importance of understanding life-cycle (LC) nano-EHS implications of NEPs and assessing real world exposures and associated toxicological properties rather than focusing on “raw” materials used in the synthesis of an NEP. PMID:25387251

Fabrication of visible light-triggered photocatalytic materials from the coupling of n-type zinc oxide and p-type copper oxide

NASA Astrophysics Data System (ADS)

Gorospe, A. B.; Herrera, M. U.

2017-04-01

Coupling of copper oxide (CuO) and zinc oxide (ZnO) was done by chemical precipitation method. In this method, copper sulfate pentahydrate and zinc sulfate heptahydrate salt precursors were separately dissolved in distilled water; then were mixed together. The copper sulfate-zinc sulfate solution was then combined with a sodium hydroxide solution. The precipitates were collected and washed in distilled water and ethanol several times, then filtered and dried. The dried sample was grounded, and then undergone heat treatment. After heating, the sample was grounded again. Zinc oxide powder and copper oxide powder were also fabricated using chemical precipitation method. X-Ray Diffraction measurements of the coupled CuO/ZnO powder showed the presence of CuO and ZnO in the fabricated sample. Furthermore, other peaks shown by XRD were also identified corresponding to copper, copper (II) oxide, copper sulfate and zinc sulfate. Results of the photocatalytic activity investigation show that the sample exhibited superior photocatalytic degradation of methyl orange under visible light illumination compared to copper oxide powder and zinc oxide powder. This may be attributed to the lower energy gap at the copper oxide-zinc oxide interface, compared to zinc oxide, allowing visible light to trigger its photocatalytic activity.

Quantum dots conjugated zinc oxide nanosheets: Impeder of microbial growth and biofilm

NASA Astrophysics Data System (ADS)

Patil, Rajendra; Gholap, Haribhau; Warule, Sambhaji; Banpurkar, Arun; Kulkarni, Gauri; Gade, Wasudeo

2015-01-01

The grieving problem of the 21st century has been the antimicrobial resistance in pathogenic microorganisms to conventional antibiotics. Therefore, developments of novel antibacterial materials which effectively inhibit or kill such resistant microorganisms have become the need of the hour. In the present study, we communicate the synthesis of quantum dots conjugated zinc oxide nanostructures (ZnO/CdTe) as an impeder of microbial growth and biofilm. The as-synthesized nanostructures were characterized by X-ray diffraction, ultraviolet-visible spectroscopy, photoluminescence spectroscopy, field emission scanning electron microscopy and high resolution transmission electron microscopy. The growth impedance property of ZnO and ZnO/CdTe on Gram positive organism, Bacillus subtilis NCIM 2063 and Gram negative, Escherichia coli NCIM 2931 and biofilm impedance activity in Pseudomonas aeruginosa O1 was found to occur due to photocatalytical action on the cell biofilm surfaces. The impedance in microbial growth and biofilm formation was further supported by ruptured appearances of cells and dettrered biofilm under field emission scanning electron and confocal laser scanning microscope. The ZnO/CdTe nanostructures array synthesized by hydrothermal method has an advantage of low growth temperature, and opportunity to fabricate inexpensive material for nano-biotechnological applications.

The Effect of UV Aging on Antimicrobial and Mechanical Properties of PLA Films with Incorporated Zinc Oxide Nanoparticles

PubMed Central

Mizielińska, Małgorzata; Kowalska, Urszula; Jarosz, Michał; Sumińska, Patrycja; Landercy, Nicolas; Duquesne, Emmanuel

2018-01-01

The aim of this study was to examine the influence of accelerated UV-aging on the activity against chosen microorganisms and the mechanical properties of poly-lactic acid (PLA) films enhanced with ZnO nanoparticles. The pure PLA films and tri-layered PLAZnO1%/PLA/PLAZnO1% films of 150 µm thickness were extruded. The samples were treated with UV-A and Q-SUN irradiation. After irradiation the antimicrobial activity and mechanical properties of the films were analyzed. The results of the study demonstrated that PLA films did not inhibit the growth of Staphylococcus aureus, Bacillus cereus, Escherichia coli, Bacillus atrophaeus, and Candida albicans cells. PLA films with incorporated zinc oxide nanoparticles decreased the number of analyzed microorganisms. Accelerated UV aging had no negative effect on the activity of the film containing nano-ZnO against Gram-positive bacteria, but it influenced the activity against Gram-negative cells and C. albicans. Q-SUN irradiation decreased the antimicrobial effect of films with incorporated nanoparticles against B. cereus. UV-A and Q-UV irradiation did not influence the mechanical properties of PLA films containing incorporated ZnO nanoparticles. PMID:29670066

The Effect of UV Aging on Antimicrobial and Mechanical Properties of PLA Films with Incorporated Zinc Oxide Nanoparticles.

PubMed

Mizielińska, Małgorzata; Kowalska, Urszula; Jarosz, Michał; Sumińska, Patrycja; Landercy, Nicolas; Duquesne, Emmanuel

2018-04-18

The aim of this study was to examine the influence of accelerated UV-aging on the activity against chosen microorganisms and the mechanical properties of poly-lactic acid (PLA) films enhanced with ZnO nanoparticles. The pure PLA films and tri-layered PLAZnO1%/PLA/PLAZnO1% films of 150 µm thickness were extruded. The samples were treated with UV-A and Q-SUN irradiation. After irradiation the antimicrobial activity and mechanical properties of the films were analyzed. The results of the study demonstrated that PLA films did not inhibit the growth of Staphylococcus aureus , Bacillus cereus , Escherichia coli , Bacillus atrophaeus , and Candida albicans cells. PLA films with incorporated zinc oxide nanoparticles decreased the number of analyzed microorganisms. Accelerated UV aging had no negative effect on the activity of the film containing nano-ZnO against Gram-positive bacteria, but it influenced the activity against Gram-negative cells and C. albicans . Q-SUN irradiation decreased the antimicrobial effect of films with incorporated nanoparticles against B. cereus . UV-A and Q-UV irradiation did not influence the mechanical properties of PLA films containing incorporated ZnO nanoparticles.

Toxic behavior of silver and zinc oxide nanoparticles on environmental microorganisms.

PubMed

Dhas, Sindhu Priya; Shiny, Punalur John; Khan, Sudheer; Mukherjee, Amitava; Chandrasekaran, Natrajan

2014-09-01

Silver and zinc oxide nanoparticles (Ag and ZnO NPs) are widely used as antimicrobial agents. However, their potential toxicological impact on environmental microorganisms is largely unexplored. The aim of this work was to investigate the sensitivity and adaptability of five bacterial species isolated from sewage towards Ag and ZnO NPs. The bacterial species were exposed to increasing concentration of nanoparticles and the growth inhibitory effect, exopolysaccharides (EPSs) and extracellular proteins (ECPs) productions were determined. The involvement of surface charge in nanoparticles toxicity was also determined. The bacterial species were constantly exposed to nanoparticles to determine the adaptation behavior toward nanoparticles. The nanoparticles exhibited remarkable growth inhibitory effect on tested bacterial species. The toxicity of nanoparticles was found to be strongly dependent on surface charge effects. Though, these organisms are highly sensitive to Ag and ZnO NPs, the continuous exposure to these nanoparticles leads to moderate adaptation of bacterial species and the adapted bacterial species convert the highly toxic nano form to less toxic microform. Finally we predict that the continuing applications of nanoparticles in consumer products may lead to the development of nanoparticles resistant bacterial strains in future. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process for preparing zinc oxide-based sorbents

DOEpatents

Gangwal, Santosh Kumar [Cary, NC; Turk, Brian Scott [Durham, NC; Gupta, Raghubir Prasad [Durham, NC

2011-06-07

The disclosure relates to zinc oxide-based sorbents, and processes for preparing and using them. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise 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.2O.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, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

In-situ sonosynthesis of nano N-doped ZnO on wool producing fabric with photo and bio activities, cell viability and enhanced mechanical properties.

PubMed

Behzadnia, Amir; Montazer, Majid; Rad, Mahnaz Mahmoudi

2015-08-01

Here, a simple processing route is introduced for preparation of N-doped nano structure ZnO at 75-80°C using in-situ sonosynthesis method through hydrolysis of zinc acetate at pH≈9-10 adjusting with ammonia. Synthesis and fabrication of nano N-doped ZnO were carried out on the wool fabric through impregnation of the fabric in ultrasound bath using different concentrations of zinc acetate followed by curing. The antibacterial and antifungal activities of the treated fabrics were assessed against two common pathogenic bacteria including Escherichia coli, Staphylococcus aureus and the diploid fungus namely Candida albicans. The photo-catalytic activity of nano N-doped ZnO particles on the wool fabric was determined by degradation of Methylene Blue under daylight irradiation. Increasing zinc acetate and prolonged sonication time led to higher photo-catalytic activity as more dye stain degraded from the stained treated fabric under daylight. Higher photo-catalytic activity was observed on the nano N-doped ZnO sonotreated wool fabric having more hydrophilicity. Finally, the treatment indicated no negative effect on the fabric safety while reduced alkaline solubility and yellowness even enhanced the fabric tensile strength. The response surface methodology was also utilized to optimize the wool fabric treatment conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

SILAR controlled CdSe nanoparticles sensitized ZnO nanorods photoanode for solar cell application: Electrolyte effect.

PubMed

Nikam, Pratibha R; Baviskar, Prashant K; Majumder, Sutripto; Sali, Jaydeep V; Sankapal, Babasaheb R

2018-08-15

Controlled growth of different sizes of cadmium selenide (CdSe) nanoparticles over well aligned ZnO nanorods have been performed using successive ionic layer adsorption and reaction (SILAR) technique at room temperature (27 °C) in order to form nano heterostructure solar cells. Deposition of compact layer of zinc oxide (ZnO) by SILAR technique on fluorine doped tin oxide (FTO) coated glass substrate followed by growth of vertically aligned ZnO nanorods array using chemical bath deposition (CBD) at low temperature (<100 °C). Different characterization techniques viz. X-ray diffractometer, UV-Vis spectrophotometer, field emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy have been used to know the structural, optical, morphological and compositional properties of synthesized nano heterostructure. The photovoltaic performance of the cells with variation in SILAR cycles for CdSe and with use of different electrolytes have been recorded as J-V characteristics and the maximum conversion efficiency of 0.63% have been attained with ferro/ferri cyanide electrolyte for 12 cycles CdSe coating over 1-D ZnO nanorods. Copyright © 2018 Elsevier Inc. All rights reserved.

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Zinc and the modulation of redox homeostasis

PubMed Central

Oteiza, Patricia I.

2012-01-01

Zinc, a redox inactive metal, has been long viewed as a component of the antioxidant network, and growing evidence points to its involvement in redox-regulated signaling. These actions are exerted through several mechanisms based on the unique chemical and functional properties of zinc. Overall, zinc contributes to maintain the cell redox balance through different mechanisms including: i) the regulation of oxidant production and metal-induced oxidative damage; ii) the dynamic association of zinc with sulfur in protein cysteine clusters, from which the metal can be released by nitric oxide, peroxides, oxidized glutathione and other thiol oxidant species; iii) zinc-mediated induction of the zinc-binding protein metallothionein, which releases the metal under oxidative conditions and act per se scavenging oxidants; iv) the involvement of zinc in the regulation of glutathione metabolism and of the overall protein thiol redox status; and v) a direct or indirect regulation of redox signaling. Findings of oxidative stress, altered redox signaling, and associated cell/tissue disfunction in cell and animal models of zinc deficiency, stress the relevant role of zinc in the preservation of cell redox homeostasis. However, while the participation of zinc in antioxidant protection, redox sensing, and redox-regulated signaling is accepted, the involved molecules, targets and mechanisms are still partially known and the subject of active research. PMID:22960578

3-D matrix template-assisted growth of oriented oxide nanowire arrays using glancing angle pulsed laser deposition

NASA Astrophysics Data System (ADS)

Wright, N.; Mateo-Feliciano, D.; Ostoski, A.; Mukherjee, P.; Witanachchi, S.

Nanosphere lithography is a combination of different methods to nanofabrication. In this work nanosphere lithography is used to study the growth of Zinc Oxide Nano-columns (ZnO NCs) on different diameter Silica Nanosphere (SNS) self-assembled templates. ZnO NCs are promising building blocks for many existing and emerging optical, electrical, and piezoelectric devices, specifically, the seeded growth of other oxide materials. Recently, reports have shown a ferroelectric phase of zinc stannate (ZnSnO3) and while lead zirconium titanate oxide (PZT) has been the main material of interest in ferroelectric and piezoelectric applications, the toxicity of lead has been of great concern. The possibility of developing lead free piezoelectric materials is of great interest in the ferroelectric community. Langmuir-Blodgett method was used to construct a self-assembled monolayer of SNSs on silicon substrates. Oriented ZnO NCs were grown on top of the spheres using the glancing angle pulsed laser deposition technique. Columns were formed in a spatially ordered closed-packed hexagonal configuration. Growth of ZnO NCs was studied as function of ambient Oxygen pressure with SNS size ranging from 250-1000 nm. Cross-sectional Scanning Electron Microscopy and X-ray diffraction (XRD) were used to study the template structure. Relative aspect ratios were studied and showed tunability of column dimensions with sphere size. XRD revealed ZnO NC arrays were c-axis oriented with hexagonal wurtzite structure.

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.

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

DOEpatents

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

2010-03-23

Zinc oxide-based sorbents, and processes for preparing and using them are provided. The sorbents are preferably used to remove one or more reduced sulfur species from gas streams. The sorbents comprise 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.2O.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, comprising a precipitated zinc oxide precursor and a precipitated aluminum oxide precursor, to the two-phase, active zinc oxide containing component.

Effect of zinc-borate glass addition on the thermal properties of the cordierite/Al2O3 composites containing nano-sized spinel crystal.

PubMed

Jo, Sinae; Kang, Seunggu

2013-11-01

Low-melting zinc-borate glass was added to the cordierite/Al2O3 composite in order to improve the sintering facility of Al2O3 and formation of nano-sized spinel crystal of high thermal conductivity. Increasing the ZnO/B2O3 ratio in the zinc-borate glass increased the ZnAl2O4 spinel and decreased the Al4B2O9 crystal peak intensities in X-ray diffraction pattern. The XRD peak intensities of the ZnAl2O4 spinel and Al4B2O9 crystals in the specimen containing 10 wt% zinc-borate glass (10G series) are higher than that of the specimen containing 5 wt% zinc-borate glass (5G series). The microstructures of most 10G series specimens had the flower-shaped crystal which was composed of 50 nm wide and 250 nm long needle-like crystals and identified as ZnAl2O4 spinel phase. The thermal conductivity of the 10G series specimen was higher than that of the 5G series in any ZnO/B2O3 ratio due to the formation of plenty of nano-sized ZnAl2O4 spinel of high thermal conductivity. Particularly, the thermal conductivity of the cordierite/Al2O3 composite containing 10 wt% zinc-borate glass of ZnO/B2O3 weight ratio = 1.5 was 3.8 W/Km which is much higher than that of the published value (3.0 W/Km).

Degradation of lindane by a novel embedded bio-nano hybrid system in aqueous environment.

PubMed

Salam, Jaseetha Abdul; Das, Nilanjana

2015-03-01

The objective of this study was to evaluate the effect of an embedded bio-nano hybrid system using nanoscale zinc oxide (n-ZnO) and lindane-degrading yeast Candida VITJzN04 for lindane degradation. Nano-embedding of the yeast was done with chemically synthesized n-ZnO particles (50 mg/mL) and was visualized by atomic force microscope (AFM) and scanning electron microscope (SEM). Nanoparticles were embedded substantially on the surfaces of the yeast cells and translocated into the cell cytoplasm without causing any lethal effect to the cell until 50 mg/mL. Lindane (600 mg/L) degradation was studied both in the individual and hybrid system. Rapid reductive-dechlorination of lindane was attained with n-ZnO under illuminated conditions, with the generation of chlorobenzene and benzene as dechlorination products. The bio-nano hybrid was found to be more effective compared to the native yeasts for lindane degradation and resulted in complete removal within 3 days. The kinetic data analysis implied that the half-life of lindane was 9 h for bio-nano hybrid and 28 h for Candida VITJzN04. The enhanced lindane degradation by bio-nano hybrid might be due to increased porosity and permeability of the yeast cell membrane, facilitating the easy entry of lindane into cell cytoplasm and n-ZnO-mediated dechlorination. To the best of our knowledge, this report, for the first time, suggests the use of n-ZnO-mediated dechlorination of lindane and the novel bio-nano hybrid system that reduces the half-life to one third of the time taken by the yeast alone. The embedded bio-nano hybrid system may be exploited as an effective remediation tool for the treatment of lindane-contaminated wastewaters.

Incorporation of zinc oxide nanoparticles into chitosan-collagen 3D porous scaffolds: Effect on morphology, mechanical properties and cytocompatibility of 3D porous scaffolds.

PubMed

Ullah, Saleem; Zainol, Ismail; Idrus, Ruszymah Hj

2017-11-01

The zinc oxide nanoparticles (particles size <50nm) incorporated into chitosan-collagen 3D porous scaffolds and investigated the effect of zinc oxide nanoparticles incorporation on microstructure, mechanical properties, biodegradation and cytocompatibility of 3D porous scaffolds. The 0.5%, 1.0%, 2.0% and 4.0% zinc oxide nanoparticles chitosan-collagen 3D porous scaffolds were fabricated via freeze-drying technique. The zinc oxide nanoparticles incorporation effects consisting in chitosan-collagen 3D porous scaffolds were investigated by mechanical and swelling tests, and effect on the morphology of scaffolds examined microscopically. The biodegradation and cytocompatibility tests were used to investigate the effects of zinc oxide nanoparticles incorporation on the ability of scaffolds to use for tissue engineering application. The mean pore size and swelling ratio of scaffolds were decreased upon incorporation of zinc oxide nanoparticles however, the porosity, tensile modulus and biodegradation rate were increased upon incorporation of zinc oxide nanoparticles. In vitro culture of human fibroblasts and keratinocytes showed that the zinc oxide nanoparticles facilitated cell adhesion, proliferation and infiltration of chitosan-collagen 3D porous scaffolds. It was found that the zinc oxide nanoparticles incorporation enhanced porosity, tensile modulus and cytocompatibility of chitosan-collagen 3D porous scaffolds. Copyright © 2017 Elsevier B.V. All rights reserved.

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways.

PubMed

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-06-27

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use.

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways

PubMed Central

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-01-01

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use. PMID:28487501

21 CFR 182.8991 - Zinc oxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use...

21 CFR 182.8991 - Zinc oxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used in...

21 CFR 582.5991 - Zinc oxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally...

21 CFR 182.8991 - Zinc oxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used in...

21 CFR 582.5991 - Zinc oxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally...

Recent Progress in Photocatalysis Mediated by Colloidal II-VI Nanocrystals

PubMed Central

Wilker, Molly B; Schnitzenbaumer, Kyle J; Dukovic, Gordana

2012-01-01

The use of photoexcited electrons and holes in semiconductor nanocrystals as reduction and oxidation reagents is an intriguing way of harvesting photon energy to drive chemical reactions. This review focuses on recent research efforts to understand and control the photocatalytic processes mediated by colloidal II-VI nanocrystalline materials, such as cadmium and zinc chalcogenides. First, we highlight how nanocrystal properties govern the rates and efficiencies of charge-transfer processes relevant to photocatalysis. We then describe the use of nanocrystal catalyst heterostructures for fuel-forming reactions, most commonly H2 generation. Finally, we review the use of nanocrystal photocatalysis as a synthetic tool for metal–semiconductor nano-heterostructures. PMID:24115781

Enhancement of a-IGZO TFT Device Performance Using a Clean Interface Process via Etch-Stopper Nano-layers

NASA Astrophysics Data System (ADS)

Chung, Jae-Moon; Zhang, Xiaokun; Shang, Fei; Kim, Ji-Hoon; Wang, Xiao-Lin; Liu, Shuai; Yang, Baoguo; Xiang, Yong

2018-05-01

To overcome the technological and economic obstacles of amorphous indium-gallium-zinc-oxide (a-IGZO)-based display backplane for industrial production, a clean etch-stopper (CL-ES) process is developed to fabricate a-IGZO-based thin film transistor (TFT) with improved uniformity and reproducibility on 8.5th generation glass substrates (2200 mm × 2500 mm). Compared with a-IGZO-based TFT with back-channel-etched (BCE) structure, a newly formed ES nano-layer ( 100 nm) and a simultaneous etching of a-IGZO nano-layer (30 nm) and source-drain electrode layer are firstly introduced to a-IGZO-based TFT device with CL-ES structure to improve the uniformity and stability of device for large-area display. The saturation electron mobility of 8.05 cm2/V s and the V th uniformity of 0.72 V are realized on the a-IGZO-based TFT device with CL-ES structure. In the negative bias temperature illumination stress and positive bias thermal stress reliability testing under a ± 30 V bias for 3600 s, the measured V th shift of CL-ES-structured device significantly decreased to - 0.51 and + 1.94 V, which are much lower than that of BCE-structured device (- 3.88 V, + 5.58 V). The electrical performance of the a-IGZO-based TFT device with CL-ES structure implies that the economic transfer from a silicon-based TFT process to the metal oxide semiconductor-based process for LCD fabrication is highly feasible.

21 CFR 73.2991 - Zinc oxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in identity and specifications to the requirements of § 73.1991...

Electrocontact material based on silver dispersion-strengthened by nickel, titanium, and zinc oxides

NASA Astrophysics Data System (ADS)

Zeer, G. M.; Zelenkova, E. G.; Belousov, O. V.; Beletskii, V. V.; Nikolaev, S. V.; Ledyaeva, O. N.

2017-09-01

Samples of a composite electrocontact material based on silver strengthened by the dispersed phases of zinc and titanium oxides have been investigated by the electron microscopy and energy dispersive X-ray spectroscopy. A uniform distribution of the oxide phases containing 2 wt % zinc oxide in the initial charge has been revealed. The increase in the amount of zinc oxide leads to an increase of the size of the oxide phases. It has been shown that at the zinc oxide content of 2 wt %, the minimum wear is observed in the process of electroerosion tests; at 3 wt %, an overheating and welding of the contacts are observed.

Enhanced antimicrobial activity in biosynthesized ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Kumari, Niraj; Kumari, Priti; Jha, Anal K.; Prasad, K.

2018-05-01

Biological synthesis of different metallic and/or oxide nanoparticles and their applications especially in agriculture and biomedical sciences are gaining prominence nowadays due to their handy and reproducible synthetic protocols which are cost-effective and eco-friendly. In this work, green synthesis of zinc oxide nanoparticles (ZnO NPs) using the alcoholic extract of Azadirachta indica as a reducing and stabilizing agent has been presented. Formation of ZnO NPs was confirmed by X-ray diffraction, scanning and transmission electron microscopy techniques. The phytochemicals responsible for nano-transformation were principally alkaloids, flavanoids, terpenoids, tannins and organic acids present in the Azadirachta indica leaves. The synthesized ZnO NPs were used for antimicrobial assays by disc diffusion method against Staphylococcus aureus and Candida albicans. Results showed that ZnO NPs may act as antimicrobial agent especially against skin infections.

Time-resolved fluorescence and ultrafast energy transfer in a zinc (hydr)oxide-graphite oxide mesoporous composite

NASA Astrophysics Data System (ADS)

Secor, Jeff; Narinesingh, Veeshan; Seredych, Mykola; Giannakoudakis, Dimitrios A.; Bandosz, Teresa; Alfano, Robert R.

2015-01-01

Ultrafast energy decay kinetics of a zinc (hydr)oxide-graphite oxide (GO) composite is studied via time-resolved fluorescence spectroscopy. The time-resolved emission is spectrally decomposed into emission regions originating from the zinc (hydr)oxide optical gap, surface, and defect states of the composite material. The radiative lifetime of deep red emission becomes an order of magnitude longer than that of GO alone while the radiative lifetime of the zinc optical gap is shortened in the composite. An energy transfer scheme from the zinc (hydr)oxide to GO is considered.

Characteristic of nanoparticles generated from different nano-powders by using different dispersion methods

NASA Astrophysics Data System (ADS)

Tsai, Chuen-Jinn; Lin, Guan-Yu; Liu, Chun-Nan; He, Chi-En; Chen, Chun-Wan

2012-03-01

A standard rotating drum with a modified sampling train (RD), a vortex shaker (VS), and a SSPD (small-scale powder disperser) were used to investigate the emission characteristics of nano-powders, including nano-titanium dioxide (nano-TiO2, primary diameter: 21 nm), nano-zinc oxide (nano-ZnO, primary diameter: 30-50 nm), and nano-silicon dioxide (nano-SiO2, primary diameter: 10-30 nm). A TSI SMPS (scanning mobility particle sizer), a TSI APS (aerodynamic particle sizer), and a MSP MOUDI (micro-orifice uniform deposit impactor) were used to measure the number and mass distributions of generated particles. Significant differences in specific number and mass concentration or distributions were found among different methods and nano-powders with the most specific number and mass concentration and the smallest particles being generated by the most energetic SSPD, followed by VS and RD. Near uni-modal number or mass distributions were observed for the SSPD while bi-modal number or mass distributions existed for nano-powders except nano-SiO2 which also exhibited bimodal mass distributions. The 30-min average results showed that the mass median aerodynamic diameter (MMAD) and number median diameter (NMD) of the SSPD ranged 1.1-2.1 μm and 166-261 nm, respectively, for all three nano-powders, which were smaller than those of the VS (MMAD: 3.3-6.0 μm and NMD: 156-462 nm), and the RD (MMAD: 5.2-11.2 μm and NMD: 198-479 nm). For nano-particles (electric mobility diameter < 100 nm), specific mass concentrations were nearly negligible for all three nano-powders and test methods. Specific number concentrations of nano-particles were low for the RD tester but were elevated when more energetic VS and SSPD testers were used. The quantitative size and concentration data obtained in this study is useful to elucidate the field emission and personal exposure data in the future provided that particle loss in the generation system is carefully assessed.

Morphological Control of Metal Oxide-Doped Zinc Oxide and Application to Cosmetics

NASA Astrophysics Data System (ADS)

Goto, Takehiro; Yin, Shu; Sato, Tsugio; Tanaka, Takumi

2012-06-01

Zinc oxide shows excellent transparency and ultraviolet radiation shielding ability, and is used for various cosmetics.1-3 However, it possesses high catalytic activity and lower dispersibility. Therefore, spherical particles of zinc oxide have been synthesized by soft solution reaction using zinc nitrate, ethylene glycol, sodium hydroxide and triethanolamine as starting materials. After dissolving these compounds in water, the solution was heated at 90°C for 1 h to form almost mono-dispersed spherical zinc oxide particles. The particle size changed depending on zinc ion concentration, ethylene glycol concentration and so on. Furthermore, with doping some metal ions, the phtocatalytic activity could be decreased. The obtained monodispersed metal ion-doped spherical zinc oxides showed excellent UV shielding ability and low photocatalytic activity. Therefore, they are expected to be used as cosmetics ingredients.

21 CFR 73.2991 - Zinc oxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in...

21 CFR 73.2991 - Zinc oxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in...

21 CFR 73.1991 - Zinc oxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc oxide is a white or yellow-white amorphous...

21 CFR 73.1991 - Zinc oxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc oxide is a white or yellow-white amorphous...

21 CFR 73.1991 - Zinc oxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc oxide is a white or yellow-white amorphous...

Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach.

PubMed

Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; Van Dorsselaer, Alain; Rabilloud, Thierry

2014-06-07

Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.

Sorption, dissolution and pH determine the long-term equilibration and toxicity of coated and uncoated ZnO nanoparticles in soil.

PubMed

Waalewijn-Kool, Pauline L; Diez Ortiz, Maria; van Straalen, Nico M; van Gestel, Cornelis A M

2013-07-01

To assess the effect of long-term dissolution on bioavailability and toxicity, triethoxyoctylsilane coated and uncoated zinc oxide nanoparticles (ZnO-NP), non-nano ZnO and ZnCl2 were equilibrated in natural soil for up to twelve months. Zn concentrations in pore water increased with time for all ZnO forms but peaked at intermediate concentrations of ZnO-NP and non-nano ZnO, while for coated ZnO-NP such a clear peak only was seen after 12 months. Dose-related increases in soil pH may explain decreased soluble Zn levels due to fixation of Zn released from ZnO at higher soil concentrations. At T = 0 uncoated ZnO-NP and non-nano ZnO were equally toxic to the springtail Folsomia candida, but not as toxic as coated ZnO-NP, and ZnCl2 being most toxic. After three months equilibration toxicity to F. candida was already reduced for all Zn forms, except for coated ZnO-NP which showed reduced toxicity only after 12 months equilibration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

PubMed Central

Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

2014-01-01

The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

Development of Electrodeposited Zn/nano-TiO2 Composite Coatings with Enhanced Corrosion Performance

NASA Astrophysics Data System (ADS)

Benea, L.; Dănăilă, E.

2017-06-01

Pure zinc coatings have been found ineffective when are used in aggressive environments such as those which contain chlorides or industrial pollutants [1]. In this paper, Zn/nano-TiO2 composite coatings with various contents of TiO2 nanoparticles (diameter size of 10 nm) were prepared on low-carbon steel by electro-codeposition technique. The deposition was carried out at different cathodic potentials ranging from -1600 mV to -2100 mV for different deposition times between 5-15 min. Pure Zn coatings were also produced under the same experimental conditions for comparison. Present work aims to investigate the effects of selected electrodeposition parameters (cathodic potential, TiO2 nanoparticle concentration in the plating bath and electrodeposition time) on the corrosion behavior of electrodeposited Zn/nano-TiO2 composite obtained. The corrosion experiments were performed in natural seawater, using electrochemical methods such as open circuit potential, potentiodynamic polarization and linear polarization resistance. The results showed that the inclusion of TiO2 nanoparticles into zinc matrix lead to an improved corrosion resistance comparatively with pure zinc coatings obtained under similar conditions.

Regeneration of zinc halide catalyst used in the hydrocracking of polynuclear hydrocarbons

DOEpatents

Gorin, Everett

1978-01-01

Improved recovery of spent molten zinc halide hydro-cracking catalyst is achieved in the oxidative vapor phase regeneration thereof by selective treatment of the zinc oxide carried over by the effluent vapors from the regeneration zone with hydrogen halide gas under conditions favoring the reaction of the zinc oxide with the hydrogen halide, whereby regenerated zinc halide is recovered in a solids-free state with little loss of zinc values.

21 CFR 73.1991 - Zinc oxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... amounts consistent with good manufacturing practice. (d) Labeling. The color additive and any mixtues... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc...). It is principally composed of Zn. (2) Color additive mixtures for drug use made with zinc oxide may...

Nano-micro structured superhydrophobic zinc coating on steel for prevention of corrosion and ice adhesion.

PubMed

Brassard, J D; Sarkar, D K; Perron, J; Audibert-Hayet, A; Melot, D

2015-06-01

Thin films of zinc have been deposited on steel substrates by electrodeposition process and further functionalized with ultra-thin films of commercial silicone rubber, in order to obtain superhydrophobic properties. Morphological feature, by scanning electron microscope (SEM), shows that the electrodeposited zinc films are composed of micro-nano rough patterns. Furthermore, chemical compositions of these films have been analyzed by X-ray diffraction (XRD) and infra-red (IRRAS). An optimum electrodeposition condition, based on electrical potential and deposition time, has been obtained which provides superhydrophobic properties with a water contact angle of 155±1°. The corrosion resistance properties, in artificial seawater, of the superhydrophobic zinc coated steel are found to be superior to bare steel. Similarly, the measured ice adhesion strength on superhydrophobic surfaces, using the centrifugal adhesion test (CAT), is found to be 6.3 times lower as compared to bare steel. This coating has promising applications in offshore environment, to mitigate corrosion and reduce ice adhesion. Copyright © 2014 Elsevier Inc. All rights reserved.

Design Concepts, Fabrication and Advanced Characterization Methods of Innovative Piezoelectric Sensors Based on ZnO Nanowires.

PubMed

Araneo, Rodolfo; Rinaldi, Antonio; Notargiacomo, Andrea; Bini, Fabiano; Pea, Marialilia; Celozzi, Salvatore; Marinozzi, Franco; Lovat, Giampiero

2014-12-08

Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct bandgap, piezoelectricity, pyroelectricity and biocompatibility. Most applications are based on the cooperative and average response of a large number of ZnO micro/nanostructures. However, in order to assess the quality of the materials and their performance, it is fundamental to characterize and then accurately model the specific electrical and piezoelectric properties of single ZnO structures. In this paper, we report on focused ion beam machined high aspect ratio nanowires and their mechanical and electrical (by means of conductive atomic force microscopy) characterization. Then, we investigate the suitability of new power-law design concepts to accurately model the relevant electrical and mechanical size-effects, whose existence has been emphasized in recent reviews.

Remarkably High Mobility Thin-Film Transistor on Flexible Substrate by Novel Passivation Material.

PubMed

Shih, Cheng Wei; Chin, Albert

2017-04-25

High mobility thin-film transistor (TFT) is crucial for future high resolution and fast response flexible display. Remarkably high performance TFT, made at room temperature on flexible substrate, is achieved with record high field-effect mobility (μ FE ) of 345 cm 2 /Vs, small sub-threshold slope (SS) of 103 mV/dec, high on-current/off-current (I ON /I OFF ) of 7 × 10 6 , and a low drain-voltage (V D ) of 2 V for low power operation. The achieved mobility is the best reported data among flexible electronic devices, which is reached by novel HfLaO passivation material on nano-crystalline zinc-oxide (ZnO) TFT to improve both I ON and I OFF . From X-ray photoelectron spectroscopy (XPS) analysis, the non-passivated device has high OH-bonding intensity in nano-crystalline ZnO, which damage the crystallinity, create charged scattering centers, and form potential barriers to degrade mobility.

Design Concepts, Fabrication and Advanced Characterization Methods of Innovative Piezoelectric Sensors Based on ZnO Nanowires

PubMed Central

Araneo, Rodolfo; Rinaldi, Antonio; Notargiacomo, Andrea; Bini, Fabiano; Pea, Marialilia; Celozzi, Salvatore; Marinozzi, Franco; Lovat, Giampiero

2014-01-01

Micro- and nano-scale materials and systems based on zinc oxide are expected to explode in their applications in the electronics and photonics, including nano-arrays of addressable optoelectronic devices and sensors, due to their outstanding properties, including semiconductivity and the presence of a direct bandgap, piezoelectricity, pyroelectricity and biocompatibility. Most applications are based on the cooperative and average response of a large number of ZnO micro/nanostructures. However, in order to assess the quality of the materials and their performance, it is fundamental to characterize and then accurately model the specific electrical and piezoelectric properties of single ZnO structures. In this paper, we report on focused ion beam machined high aspect ratio nanowires and their mechanical and electrical (by means of conductive atomic force microscopy) characterization. Then, we investigate the suitability of new power-law design concepts to accurately model the relevant electrical and mechanical size-effects, whose existence has been emphasized in recent reviews. PMID:25494351

Zinc oxide overdose

MedlinePlus

Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

Critical Role of Zinc as Either an Antioxidant or a Prooxidant in Cellular Systems

PubMed Central

2018-01-01

Zinc is recognized as an essential trace metal required for human health; its deficiency is strongly associated with neuronal and immune system defects. Although zinc is a redox-inert metal, it functions as an antioxidant through the catalytic action of copper/zinc-superoxide dismutase, stabilization of membrane structure, protection of the protein sulfhydryl groups, and upregulation of the expression of metallothionein, which possesses a metal-binding capacity and also exhibits antioxidant functions. In addition, zinc suppresses anti-inflammatory responses that would otherwise augment oxidative stress. The actions of zinc are not straightforward owing to its numerous roles in biological systems. It has been shown that zinc deficiency and zinc excess cause cellular oxidative stress. To gain insights into the dual action of zinc, as either an antioxidant or a prooxidant, and the conditions under which each role is performed, the oxidative stresses that occur in zinc deficiency and zinc overload in conjunction with the intracellular regulation of free zinc are summarized. Additionally, the regulatory role of zinc in mitochondrial homeostasis and its impact on oxidative stress are briefly addressed. PMID:29743987

Synergistic effect of Chitosan-Zinc Oxide Hybrid Nanoparticles on antibiofouling and water disinfection of mixed matrix polyethersulfone nanocomposite membranes.

PubMed

Munnawar, Iqra; Iqbal, Sadia S; Anwar, Muhammad N; Batool, Mehwish; Tariq, Sheraz; Faitma, Nosheen; Khan, Asim L; Khan, Asad U; Nazar, Umair; Jamil, Tahir; Ahmad, Nasir M

2017-11-01

Antifouling polyethersulfone (PES) membranes for water disinfection were fabricated by incorporating varying concentrations of carbohydrate polymer chitosan and Zinc oxide hybrid nanoparticles (CS-ZnO HNPS). The CS-ZnO HNPS were prepared using chemical precipitation method and were characterized using SEM, XRD and FTIR. The membranes were then fabricated by incorporating nanoparticles of CS-ZnO HNPS with three different concentrations of 5%, 10% and 15% w/w in the casting solution of PES through phase inversion method. The influence of nano-sized CS-ZnO HNPS on the properties of PES was characterized to study morphology, contact angle, water retention, surface roughness and permeability flux. The membranes with the maximum concentrations of 15% HNPS resulted in larger mean pore sizes and lowest contact angle value as compare to the pristine PES membrane. The prepared membranes exhibited significant water permeability, hydrophilicity and prevention against microbial fouling. The prepared membranes were observed to have significant antibacterial as well as antifungal properties due to the synergistic effect of chitosan and ZnO against both bacteria of the type of S. Aureus, B. Cereus, E. coli, and fungi such as S. typhi, A. fumigatus and F. solani. Copyright © 2017. Published by Elsevier Ltd.

Physical and mechanical properties of hybrid montmorillonite/zinc oxide reinforced carboxymethyl cellulose nanocomposites.

PubMed

Zahedi, Younes; Fathi-Achachlouei, Bahram; Yousefi, Ali Reza

2018-03-01

In this research, a novel carboxymethyl cellulose (CMC)-based nanocomposite films containing sodium montmorillonite (MMT) (5%wt) and zinc oxide (ZnO) (1, 2, 3 and 4%wt) nanoparticles (NPs) were fabricated via casting method. The results revealed that addition of NPs decreased water vapor permeability of the films by about 53%, while moisture content, density and glass transition temperature increased. The nanomaterials enhanced resistance of the nanocomposites against tensile stress at the expense of elongation at break. Nano-ZnO was very effective than nanoclay in UV-light blocking (99% vs. 60%) associated with sacrificing the films transparency. Formation of hydrogen bonds between the hydroxyl groups of CMC and MMT was evidenced by FTIR spectroscopy. According to the XRD analysis, clay nanolayers formed an exfoliated structure in the nanocomposites, whereas ZnO NPs raised crystallinity. SEM micrographs showed well-dispersed MMT and ZnO NPs through the films surface. Antibacterial test showed that vulnerability of Gram-positive S. aureus toward ZnO NPs was more than that of Gram-negative E. Coli. In conclusion, simultaneous incorporation of MMT and ZnO NPs improved the functional characteristics of CMC film and extended the potential for food packaging applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Microbundles of zinc oxide nanorods: Assembly in ionic liquid [EMIM]{sup +}[BF{sub 4}]{sup -}, photoluminescence and photocatalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Li; Xu Shenzhi; Li Huijun

2011-03-15

A simple, efficient and low-temperature approach for the assembly of hierarchical Zinc oxide (ZnO) microstructures in ionic liquid [EMIM]{sup +}[BF{sub 4}]{sup -} is reported. The as-obtained ZnO superstructures are composed of microbundles of nanorods from the center points, with the diameter and length in the range of 100-150 nm and 2-4 {mu}m, which have been characterized by X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy. The ZnO microstructures exhibit significant defect-related green-yellow emission and high photodegradation of dye Methyl Orange (5x10{sup -5} mol/L) under UV excitation within 80 min. -- Graphical abstract: Easy formation of microbundles of ZnOmore » nanorods were accomplished in low temperature with [EMIM]{sup +}[BF{sub 4}]{sup -} (1-ethyl-3-methylimidazolium tetrafluoroborate) ionic liquid, which exhibit significant green-yellow photoluminescence property and high photodegradation of Methyl Orange dye. Display Omitted Research highlights: {yields} Ionic liquid assisted solid-state route was introduced into synthesis of ZnO nanorods. {yields} The distinctive microbundles ZnO nanorod assembles was evidenced by SEM and TEM. {yields} ZnO nano-material exhibited high efficiency in photodegradation of Methyl Orange.« less

Green synthesised zinc oxide nanostructures through Periploca aphylla extract shows tremendous antibacterial potential against multidrug resistant pathogens.

PubMed

Abbas, Fazal; Maqbool, Qaisar; Nazar, Mudassar; Jabeen, Nyla; Hussain, Syed Zaheer; Anwaar, Sadaf; Mehmood, Nasir; Sheikh, Muhammad Saleem; Hussain, Talib; Iftikhar, Sidra

2017-12-01

To grapple with multidrug resistant bacterial infections, implementations of antibacterial nanomedicines have gained prime attention of the researchers across the globe. Nowadays, zinc oxide (ZnO) at nano-scale has emerged as a promising antibacterial therapeutic agent. Keeping this in view, ZnO nanostructures (ZnO-NS) have been synthesised through reduction by P. aphylla aqueous extract without the utilisation of any acid or base. Structural examinations via scanning electron microscopy (SEM) and X-ray diffraction have revealed pure phase morphology with highly homogenised average particle size of 18 nm. SEM findings were further supplemented by transmission electron microscopy examinations. The characteristic Zn-O peak has been observed around 363 nm using ultra-violet-visible spectroscopy. Fourier-transform infrared spectroscopy examination has also confirmed the formation of ZnO-NS through detection of Zn-O bond vibration frequencies. To check the superior antibacterial activity of ZnO-NS, the authors' team has performed disc diffusion assay and colony forming unit testing against multidrug resistant E. coli, S. marcescens and E. cloacae . Furthermore, protein kinase inhibition assay and cytotoxicity examinations have revealed that green fabricated ZnO-NS are non-hazardous, economical, environmental friendly and possess tremendous potential to treat lethal infections caused by multidrug resistant pathogens.

Facile fabrication and characterization of chitosan-based zinc oxide nanoparticles and evaluation of their antimicrobial and antibiofilm activity

NASA Astrophysics Data System (ADS)

Dhillon, Gurpreet Singh; Kaur, Surinder; Brar, Satinder Kaur

2014-06-01

The present investigation deals with the facile synthesis and characterization of chitosan (CTS)-based zinc oxide (ZnO) nanoparticles (NPs) and their antimicrobial activities against pathogenic microorganisms. ZnO-CTS NPs were synthesized through two different methods: nano spray drying and precipitation, using various organic compounds (citric acid, glycerol, starch and whey powder) as stabilizers. Both the synthesis methods were simple and were devoid of any chemical usage. The detailed characterization of the NPs was carried out using UV-Vis spectroscopy, dynamic light scattering particle size analysis, zeta potential measurements and scanning electron microscopy, which confirmed the fabrication of NPs with different shapes and sizes. Antimicrobial assay of synthesized ZnO-CTS NPs was carried out against different pathogenic microbial strains ( Candida albicans, Micrococcus luteus and Staphylococcus aureus). The significant ( p < 0.05) inhibition of growth was observed for both M. luteus and S. aureus with ZnO-CTS NPs (with a concentration ranging from 0.625 to 0.156 mg/ml) as compared to control treatment. ZnO-CTS NPs also showed significant biofilm inhibition activity ( p < 0.05) against M. luteus and S. aureus. The study demonstrated the potential of ZnO-CTS NPs as antimicrobial and antibiofilm agents.

Microwave assisted facile hydrothermal synthesis and characterization of zinc oxide flower grown on graphene oxide sheets for enhanced photodegradation of dyes

NASA Astrophysics Data System (ADS)

Kashinath, L.; Namratha, K.; Byrappa, K.

2015-12-01

Microwave assisted hydrothermal process of synthesis of ZnO-GO nanocomposite by using ZnCl2 and NaOH as precursors is being reported first time. In this investigation, a novel route to study on synthesis, interaction, kinetics and mechanism of hybrid zinc oxide-graphene oxide (ZnO-GO) nanocomposite using microwave assisted facile hydrothermal method has been reported. The results shows that the ZnO-GO nanocomposite exhibits an enhancement and acts as stable photo-response degradation performance of Brilliant Yellow under the UV light radiation better than pure GO and ZnO nanoparticles. The microwave exposure played a vital role in the synthesis process, it facilitates with well define crystalline structure, porosity and fine morphology of ZnO/GO nanocomposite. Different molar concentrations of ZnO precursors doped to GO sheets were been synthesized, characterized and their photodegradation performances were investigated. The optical studies by UV-vis and Photo Luminescence shows an increase in band gap of nanocomposite, which added an advantage in photodegradation performance. The in situ flower like ZnO nano particles are were densely decorated and anchored on the surfaces of graphene oxide sheets which aids in the enhancement of the surface area, adsorption, mass transfer of dyes and evolution of oxygen species. The nanocomposite having high surface area and micro/mesoporous in nature. This structure and morphology supports significantly in increasing photo catalytic performance legitimate to the efficient photosensitized electron injection and repressed electron recombination due to electron transfer process with GO as electron collector and transporter dependent on the proportion of GO in ZnO/GO composite.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron

PubMed Central

Rosado, Jorge L.; Díaz, Margarita; Muñoz, Elsa; Westcott, Jamie L.; González, Karla E.; Krebs, Nancy F.; Caamaño, María C.; Hambidge, Michael

2013-01-01

Background Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. Objective To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. Methods A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. Results The mean (± SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 ± 0.07, 0.36 ± 0.05, and 0.37 ± 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 ± 0.04, 0.33 ± 0.02, and 0.32 ± 0.05, respectively) and similar amounts of zinc absorbed (4.8 ± 0.7, 4.5 ± 0.3, and 4.8 ± 0.7 mg/day, respectively). Conclusions Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour. PMID:23424892

Characteristics of phase-change materials containing oxide nano-additives for thermal storage.

PubMed

Teng, Tun-Ping; Yu, Chao-Chieh

2012-11-06

In this study, the authors report the production of nanocomposite-enhanced phase-change materials (NEPCMs) using the direct-synthesis method by mixing paraffin with alumina (Al2O3), titania (TiO2), silica (SiO2), and zinc oxide (ZnO) as the experimental samples. Al2O3, TiO2, SiO2, and ZnO were dispersed into three concentrations of 1.0, 2.0, and 3.0 wt.%. Through heat conduction and differential scanning calorimeter experiments to evaluate the effects of varying concentrations of the nano-additives on the heat conduction performance and thermal storage characteristics of NEPCMs, their feasibility for use in thermal storage was determined. The experimental results demonstrate that TiO2 is more effective than the other additives in enhancing both the heat conduction and thermal storage performance of paraffin for most of the experimental parameters. Furthermore, TiO2 reduces the melting onset temperature and increases the solidification onset temperature of paraffin. This allows the phase-change heat to be applicable to a wider temperature range, and the highest decreased ratio of phase-change heat is only 0.46%, compared to that of paraffin. Therefore, this study demonstrates that TiO2, added to paraffin to form NEPCMs, has significant potential for enhancing the thermal storage characteristics of paraffin.

SIMS depth profiling of rubber-tyre cord bonding layers prepared using 64Zn depleted ZnO

NASA Astrophysics Data System (ADS)

Fulton, W. S.; Sykes, D. E.; Smith, G. C.

2006-07-01

Zinc oxide and copper/zinc sulphide layers are formed during vulcanisation and moulding of rubber to brass-coated steel tyre reinforcing cords. Previous studies have described how zinc diffuses through the rubber-brass interface to form zinc sulphide, and combines with oxygen to create zinc oxide during dezincification. The zinc is usually assumed to originate in the brass of the tyre cord, however, zinc oxide is also present in the rubber formulation. We reveal how zinc from these sources is distributed within the interfacial bonding layers, before and after heat and humidity ageing. Zinc oxide produced using 64Zn-isotope depleted zinc was mixed in the rubber formulation in place of the natural ZnO and the zinc isotope ratios within the interfacial layers were followed by secondary ion mass spectroscopy (SIMS) depth profiling. Variations in the relative ratios of the zinc isotopes during depth profiling were measured for unaged, heat-aged and humidity-aged wire samples and in each case a relatively large proportion of the zinc incorporated into the interfacial layer as zinc sulphide was shown to have originated from ZnO in the rubber compound.

Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saeednia, S., E-mail: sami_saeednia@yahoo.com; Iranmanesh, P.; Ardakani, M. Hatefi

Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM),more » X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.« less

The Preparation, Characterization, Mechanical and Antibacterial Properties of GO-ZnO Nanocomposites with a Poly(l-lactide)-Modified Surface

PubMed Central

Yuan, Mingwei; Xiong, Chengdong; Jiang, Lin; Li, Hongli

2018-01-01

Graphene oxide (GO) was employed for the preparation of GO-zinc oxide (ZnO). The hydroxyl group on the surface was exploited to trigger the l-lactide ring-opening polymerization. A composite material with poly(l-lactide) (PLLA) chains grafted to the GO-ZnO surface, GO-ZnO-PLLA, was prepared. The results demonstrated that the employed method allowed one-step, rapid grafting of PLLA to the GO-ZnO surface. The chemical structure of the GO surface was altered by improved dispersion of GO-ZnO in organic solvents, thus enhancing the GO-ZnO dispersion in the PLLA matrix and the interface bonding with PLLA. Subsequently, composite films, GO-ZnO-PLLA and GO-ZnO-PLLA/PLLA, were prepared. The changes in interface properties and mechanical properties were studied. Furthermore, the antibacterial performance of nano-ZnO was investigated. PMID:29473891

Mechanical properties of bioplastics cassava starch film with Zinc Oxide nanofiller as reinforcement

NASA Astrophysics Data System (ADS)

Harunsyah; Yunus, M.; Fauzan, Reza

2017-06-01

This study focuses on investigating the influence of zinc oxide nanofiller on the mechanical properties of bioplastic cassava starch films. Bioplastic cassava starch film-based zinc oxide reinforced composite biopolymeric films were prepared by casting technique. The content of zinc oxide in the bioplastic films was varied from 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) by weight of starch. Surface morphologies of the composites bioplastic films were examined by scanning electron microscope (SEM).The result showed that the Tensile strength (TS) was improved significantly with the additional of zinc oxide but the elongation at break (EB %) of the composites was decreased. The maximum tensile strength obtained was 22.30 kgf / mm on the additional of zinc oxide by 0.6% and plastilizer by 25%. Based on data of FTIR, the produced film plastic did not change the group function and it can be concluded that theinteraction in film plastic produced was only a physical interaction. Biodegradable plastic film based on cassava starch-zinc oxide and plasticizer glycerol showed that interesting mechanical properties being transparent, clear, homogeneous, flexible, and easily handled.

Improved synthesis of fine zinc borate particles using seed crystals

NASA Astrophysics Data System (ADS)

Gürhan, Deniz; Çakal, Gaye Ö.; Eroğlu, İnci; Özkar, Saim

2009-03-01

Zinc borate is a flame retardant additive used in polymers, wood applications and textile products. There are different types of zinc borate having different chemical compositions and structures. In this study, the production of zinc borate having the molecular formula of 2ZnO·3B 2O 3·3.5H 2O was reexamined by studying the effects of reaction parameters on the properties of product as well as the reaction kinetics. Production of zinc borate from the reaction of boric acid and zinc oxide in the presence of seed crystals was performed in a continuously stirred, temperature-controlled batch reactor having a volume of 1.5 L. Samples taken in regular time intervals during the experiments were analyzed for the concentration of zinc oxide and boron oxide in the solid as well as for the conversion of zinc oxide to zinc borate versus time. The zinc borate production reaction was fit to the logistic model. The reaction rate, reaction completion time, composition and particle size distribution of zinc borate product were determined by varying the following parameters: the boric acid to zinc oxide ratio (H 3BO 3:ZnO=3:1, 3.5:1, 5:1 and 7:1), the particle size of zinc oxide (10 and 25 μm), stirring rate (275, 400, 800 and 1600 rpm), temperature (75, 85 and 95 °C) and the size of seed crystals (10 and 2 μm). The products were also analyzed for particle size distribution. The experimental results showed that the reaction rate increases with the increase in H 3BO 3:ZnO ratio, particle size of zinc oxide, stirring rate and temperature. Concomitantly, the reaction completion time is decreased by increasing the H 3BO 3:ZnO ratio, stirring rate and temperature. The average particle sizes of the zinc borate products are in the range 4.3-16.6 μm (wet dispersion analysis).

Influence of sodium nitrite on protein oxidation and nitrosation of sausages subjected to processing and storage.

PubMed

Feng, Xianchao; Li, Chenyi; Jia, Xu; Guo, Yan; Lei, Na; Hackman, Robert M; Chen, Lin; Zhou, Guanghong

2016-06-01

The influence of NaNO2 content on protein oxidation and nitrosation was investigated in cooked sausages at different concentrations (0, 50, 100, 200 and 400 mg NaNO2/kg). Dependent on concentration, NaNO2 had both anti- and pro-oxidant effects on protein oxidation. The antioxidant effects of NaNO2 on the protein oxidation were evidenced by significantly lower carbonyl contents, higher free amines and lower surface hydrophobicities. The pro-oxidant effects of NaNO2 on protein oxidation resulted in a decrease of sulfhydryls and an increase of disulfide bonds. NaNO2 also improved the protein nitrosation inducing the formation of 3-nitrotyrosine (3-NT). Moreover, 3-NT had significant correlations with parameters of protein oxidation, indicating that 3-NT may be a possible marker for protein oxidation. Results of this study contribute to an understanding of the impact of NaNO2 on food quality and help to identify optimal formulations of cured meat products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification, characterization and functional analysis of regulatory region of nanos gene from half-smooth tongue sole (Cynoglossus semilaevis).

PubMed

Huang, Jinqiang; Li, Yongjuan; Shao, Changwei; Wang, Na; Chen, Songlin

2017-06-20

The nanos gene encodes an RNA-binding zinc finger protein, which is required in the development and maintenance of germ cells. However, there is very limited information about nanos in flatfish, which impedes its application in fish breeding. In this study, we report the molecular cloning, characterization and functional analysis of the 3'-untranslated region of the nanos gene (Csnanos) from half-smooth tongue sole (Cynoglossus semilaevis), which is an economically important flatfish in China. The 1233-bp cDNA sequence, 1709-bp genomic sequence and flanking sequences (2.8-kb 5'- and 1.6-kb 3'-flanking regions) of Csnanos were cloned and characterized. Sequence analysis revealed that CsNanos shares low homology with Nanos in other species, but the zinc finger domain of CsNanos is highly similar. Phylogenetic analysis indicated that CsNanos belongs to the Nanos2 subfamily. Csnanos expression was widely detected in various tissues, but the expression level was higher in testis and ovary. During early development and sex differentiation, Csnanos expression exhibited a clear sexually dimorphic pattern, suggesting its different roles in the migration and differentiation of primordial germ cells (PGCs). Higher expression levels of Csnanos mRNA in normal females and males than in neomales indicated that the nanos gene may play key roles in maintaining the differentiation of gonad. Moreover, medaka PGCs were successfully labeled by the microinjection of synthesized mRNA consisting of green fluorescence protein and the 3'-untranslated region of Csnanos. These findings provide new insights into nanos gene expression and function, and lay the foundation for further study of PGC development and applications in tongue sole breeding. Copyright © 2017 Elsevier B.V. All rights reserved.

Prediction Surface Morphology of Nanostructure Fabricated by Nano-Oxidation Technology.

PubMed

Huang, Jen-Ching; Chang, Ho; Kuo, Chin-Guo; Li, Jeen-Fong; You, Yong-Chin

2015-12-04

Atomic force microscopy (AFM) was used for visualization of a nano-oxidation technique performed on diamond-like carbon (DLC) thin film. Experiments of the nano-oxidation technique of the DLC thin film include those on nano-oxidation points and nano-oxidation lines. The feature sizes of the DLC thin film, including surface morphology, depth, and width, were explored after application of a nano-oxidation technique to the DLC thin film under different process parameters. A databank for process parameters and feature sizes of thin films was then established, and multiple regression analysis (MRA) and a back-propagation neural network (BPN) were used to carry out the algorithm. The algorithmic results are compared with the feature sizes acquired from experiments, thus obtaining a prediction model of the nano-oxidation technique of the DLC thin film. The comparative results show that the prediction accuracy of BPN is superior to that of MRA. When the BPN algorithm is used to predict nano-point machining, the mean absolute percentage errors (MAPE) of depth, left side, and right side are 8.02%, 9.68%, and 7.34%, respectively. When nano-line machining is being predicted, the MAPEs of depth, left side, and right side are 4.96%, 8.09%, and 6.77%, respectively. The obtained data can also be used to predict cross-sectional morphology in the DLC thin film treated with a nano-oxidation process.

A review of zinc oxide mineral beneficiation using flotation method.

PubMed

Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

2014-04-01

In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy. Copyright © 2013 Elsevier B.V. All rights reserved.

Attrition resistant, zinc titanate-containing, reduced sulfur sorbents and methods of use thereof

DOEpatents

Vierheilig, Albert A.; Gupta, Raghubir P.; Turk, Brian S.

2006-06-27

Reduced sulfur gas species (e.g., H.sub.2S, COS and CS.sub.2) are removed from a gas stream by compositions wherein a zinc titanate ingredient is associated with a metal oxide-aluminate phase material in the same particle species. Nonlimiting examples of metal oxides comprising the compositions include magnesium oxide, zinc oxide, calcium oxide, nickel oxide, etc.

Sulfur-Doped Zinc Oxide (ZnO) Nanostars: Synthesis and Simulation of Growth Mechanism

DTIC Science & Technology

2011-10-01

Zinc Oxide ( ZnO ) Nanostars: Synthesis and Simulation of Growth Mechanism Jinhyun Cho1, Qiubao Lin2,3, Sungwoo...characterization, and ab initio simulations of star-shaped hexagonal zinc oxide ( ZnO ) nanowires. The ZnO nanostructures were synthesized by a low...Introduction Zinc oxide ( ZnO ) is a wide bandgap (3.37 eV), Ⅱ–Ⅵ semiconductor of great interest for optoelectronic applications [1–3]. Its

21 CFR 582.5991 - Zinc oxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5991 Zinc oxide. (a) Product. Zinc...

21 CFR 582.5991 - Zinc oxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5991 Zinc oxide. (a) Product. Zinc...

Analysis of Zinc Oxide Thin Films Synthesized by Sol-Gel via Spin Coating

NASA Astrophysics Data System (ADS)

Wolgamott, Jon Carl

Transparent conductive oxides are gaining an increasingly important role in optoelectronic devices such as solar cells. Doped zinc oxide is a candidate as a low cost and nontoxic alternative to tin doped indium oxide. Lab results have shown that both n-type and p-type zinc oxide can be created on a small scale. This can allow zinc oxide to be used as either an electrode as well as a buffer layer to increase efficiency and protect the active layer in solar cells. Sol-gel synthesis is emerging as a low temperature, low cost, and resource efficient alternative to producing transparent conducting oxides such as zinc oxide. For sol-gel derived zinc oxide thin films to reach their potential, research in this topic must continue to optimize the known processing parameters and expand to new parameters to tighten control and create novel processing techniques that improve performance. The processing parameters of drying and annealing temperatures as well as cooling rate were analyzed to see their effect on the structure of the prepared zinc oxide thin films. There were also preliminary tests done to modify the sol-gel process to include silver as a dopant to produce a p-type thin film. The results from this work show that the pre- and post- heating temperatures as well as the cooling rate all play their own unique role in the crystallization of the film. Results from silver doping show that more work needs to be done to create a sol-gel derived p-type zinc oxide thin film.

Zinc and redox signaling: perturbations associated with cardiovascular disease and diabetes mellitus.

PubMed

Foster, Meika; Samman, Samir

2010-11-15

Cellular signal transduction pathways are influenced by the zinc and redox status of the cell. Numerous chronic diseases, including cardiovascular disease (CVD) and diabetes mellitus (DM), have been associated with impaired zinc utilization and increased oxidative stress. In humans, mutations in the MT-1A and ZnT8 genes, both of which are involved in the maintenance of zinc homeostasis, have been linked with DM development. Changes in levels of intracellular free zinc may exacerbate oxidative stress in CVD and DM by impacting glutathione homeostasis, nitric oxide signaling, and nuclear factor-kappa B-dependent cellular processes. Zinc ions have been shown to influence insulin and leptin signaling via the phosphoinositide 3′-kinase/Akt pathway, potentially linking an imbalance of zinc at the cellular level to insulin resistance and dyslipidemia. The oxidative modification of cysteine residues in zinc coordination sites in proteins has been implicated in cellular signaling and regulatory pathways. Despite the many interactions between zinc and cellular stress responses, studies investigating the potential therapeutic benefit of zinc supplementation in the prevention and treatment of oxidative stress-related chronic disease in humans are few and inconsistent. Further well-designed randomized controlled trials are needed to determine the effects of zinc supplementation in populations at various stages of CVD and DM progression.

40 CFR 63.11167 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... melt cadmium or produce cadmium oxide from the cadmium recovered in the zinc production process... engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc... Sources-Zinc, Cadmium, and Beryllium Other Requirements and Information § 63.11167 What definitions apply...

Influence of ZnO nanostructures in liquid crystal interfaces for bistable switching applications

NASA Astrophysics Data System (ADS)

Pal, Kaushik; Zhan, Bihong; Madhu Mohan, M. L. N.; Schirhagl, Romana; Wang, Guoping

2015-12-01

The controlled fabrication of nanometer-scale objects is without doubt one of the central issues in current science and technology. In this article, we exhibit a simple, one-step bench top synthesis of zinc oxide nano-tetrapods and nano-spheres which were tailored by the facial growth of nano-wires (diameter ≈ 24 nm; length ≈ 118 nm) and nano-cubes (≈395 nm edge) to nano-sphere (diameter ≈ 585 nm) appeaded. The possibilities of inexpensive, simple solvo-chemical synthesis of nanostructures were considered. In this article, a successful attempt has been made that ZnO nano-structures dispersed on well aligned hydrogen bonded liquid crystals (HBLC) comprising azelaic acid (AC) with p-n-alkyloxy benzoic acid (nBAO) by varying the respective alkyloxy carbon number (n = 5). The dispersion of nanomaterials with HBLC is an effective route to enhance the existing functionalities. A series of these composite materials were analyzed by polarizing optical microscope's electro-optical switching. An interesting feature of AC + nBAO is the inducement of tilted smectic G phase with increasing carbon chain length. Phase diagrams of the above hybrid ZnO nanomaterial influenced LC complex and pure LC were constructed and compared. The switching times, the contrast ratio and spontaneous polarization of the nanostructures-HBLC composite film were carried out by systematic investigation. The sample preparation parameters, such as the curing time and curing intensity were optimized. The critical applied voltage to achieve the switching bi-stability of our device is only 4.5 V, which is approximately twice its threshold voltage for Freedericksz transition. This performance puts the hybrid structure at the top level in the state of the art in application oriented research in optics of liquid crystalline composite materials.

The viability of MCM-41 as separator in secondary alkaline cells

NASA Astrophysics Data System (ADS)

Meskon, S. R.; Othman, R.; Ani, M. H.

2018-01-01

The viability of MCM-41 membrane as a separator material in secondary alkaline cell is investigated. The inorganic membrane was employed in an alkaline nickel-zinc system. MCM-41 mesoporous material consists of arrays of hexagonal nano-pore channels. The membrane was synthesized using sol-gel route from parent solution comprising of quarternary ammonium surfactant, cethyltrimethylammonium bromide C16H33(CH3)3NBr (CTAB), hydrochloric acid (HCl), deionized water (H2O), ethanol (C2H5OH), and tetraethylortosilicate (TEOS). Both the anodic zinc/zinc oxide and cathodic nickel hydroxide electrodeposited film were coated with MCM-41 membrane. The Ni/MCM-41/Zn alkaline cell was then subjected to 100-cycle durability test and the structural stability of MCM-41 separator throughout the progression of the charge-discharge cycles is studied. X-ray diffraction (XRD) analysis on the dismantled cell shows that MCM-41 began to transform to lamellar MCM-50 on the 5th cycle and transformed almost completely on the 25th cycle. The phase transformation of MCM-41 hexagonal structure into gel-like MCM-50 prevents the mesoporous cell separator from diminished in the caustic alkaline surround. This work has hence demonstrated MCM-41 membrane is viable to be employed in secondary alkaline cells.

Zinc and Carbonate Co-Substituted Nano-Hydroxyapatite

NASA Astrophysics Data System (ADS)

Girija, E. K.; Kumar, G. Suresh; Thamizhavel, A.

2011-07-01

Synthesis of Zn or CO32- substituted nano-hydroxyapatite (HA) and its physico-chemical properties have been well documented. However, the effects of the simultaneous substitution of Zn and CO32- in nano-HA have not been reported. In the present study, Zn and CO32- substitutions in nano HA independently and concurrently have been done by wet precipitation method and characterized by XRD and FT-IR for its phase purity and chemical homogeneity. Further modulations of the bioactivity and thermal stability of HA due to the substitutions have been studied.

System for trapping and storing gases for subsequent chemical reduction to solids

DOEpatents

Vogel, John S [San Jose, CA; Ognibene, Ted J [Oakland, CA; Bench, Graham S [Livermore, CA; Peaslee, Graham F [Holland, MI

2009-11-03

A system for quantitatively reducing oxide gases. A pre-selected amount of zinc is provided in a vial. A tube is provided in the vial. The zinc and the tube are separated. A pre-selected amount of a catalyst is provided in the tube. Oxide gases are injected into the vial. The vial, tube, zinc, catalyst, and the oxide gases are cryogenically cooled. At least a portion of the vial, tube, zinc, catalyst, and oxide gases are heated.

Radiopacifier Particle Size Impacts the Physical Properties of Tricalcium Silicate–based Cements

PubMed Central

Saghiri, Mohammad Ali; Gutmann, James L.; Orangi, Jafar; Asatourian, Armen; Sheibani, Nader

2016-01-01

Introduction The aim of this study was to evaluate the impact of radiopaque additive, bismuth oxide, particle size on the physical properties, and radiopacity of tricalcium silicate–based cements. Methods Six types of tricalcium silicate cement (CSC) including CSC without bismuth oxide, CSC + 10% (wt%) regular bismuth oxide (particle size 10 μm), CSC + 20% regular bismuth oxide (simulating white mineral trioxide aggregate [WMTA]) as a control, CSC + 10% nano bismuth oxide (particle size 50–80 nm), CSC + 20% nano-size bismuth oxide, and nano WMTA (a nano modification of WMTA comprising nanoparticles in the range of 40–100 nm) were prepared. Twenty-four samples from each group were divided into 4 groups and subjected to push-out, surface microhardness, radiopacity, and compressive strength tests. Data were analyzed by 1-way analysis of variance with the post hoc Tukey test. Results The push-out and compressive strength of CSC without bismuth oxide and CSC with 10% and 20% nano bismuth oxide were significantly higher than CSC with 10% or 20% regular bismuth oxide (P < .05). The surface micro-hardness of CSC without bismuth oxide and CSC with 10% regular bismuth oxide had the lowest values (P < .05). The lowest radiopacity values were seen in CSC without bismuth oxide and CSC with 10% nano bismuth oxide (P < .05). Nano WMTA samples showed the highest values for all tested properties (P < .05) except for radiopacity. Conclusions The addition of 20% nano bismuth oxide enhanced the physical properties of CSC without any significant changes in radiopacity. Regular particle-size bismuth oxide reduced the physical properties of CSC material for tested parameters. PMID:25492489

Nanoscale lamellar photoconductor hybrids and methods of making same

DOEpatents

Stupp, Samuel I; Goldberger, Josh; Sofos, Marina

2013-02-05

An article of manufacture and methods of making same. In one embodiment, the article of manufacture has a plurality of zinc oxide layers substantially in parallel, wherein each zinc oxide layer has a thickness d.sub.1, and a plurality of organic molecule layers substantially in parallel, wherein each organic molecule layer has a thickness d.sub.2 and a plurality of molecules with a functional group that is bindable to zinc ions, wherein for every pair of neighboring zinc oxide layers, one of the plurality of organic molecule layers is positioned in between the pair of neighboring zinc oxide layers to allow the functional groups of the plurality of organic molecules to bind to zinc ions in the neighboring zinc oxide layers to form a lamellar hybrid structure with a geometric periodicity d.sub.1+d.sub.2, and wherein d.sub.1 and d.sub.2 satisfy the relationship of d.sub.1.ltoreq.d.sub.2.ltoreq.3d.sub.1.

Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor.

PubMed

Low, Sze Shin; Tan, Michelle T T; Loh, Hwei-San; Khiew, Poi Sim; Chiu, Wee Siong

2016-01-15

Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM(-1) with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P < 0.05) and efficient than the conventional agarose gel electrophoresis. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluating the Microshear Bond Strength and Microleakage of Flowable Composites Containing Zinc Oxide Nano-particles.

PubMed

Teymoornezhad, Koorosh; Alaghehmand, Homayoun; Daryakenari, Ghazaleh; Khafri, Soraya; Tabari, Mitra

2016-11-01

Preventive resin restorations (PRR) are the conservative choice for the most common carious lesions in children. Thus, new age flowable resin composites with higher filler content are readily used. The aim of this study was to evaluate the microshear bond strength and microleakage of two flowable resin composites containing different percentages of nano zinc oxide (NZnO) particles, which have proven to have antimicrobial properties. This experimental in-vitro study was carried out in the Dental Material Research Center of Babol University of Medical Sciences in 2015. One nanohybrid and one nanofill flowable resin composite were chosen and modified with the incorporation of 1% and 3% Wt NZnO particles. Six groups (n=10, 0%, 1%, and 3%) of resin composite sticks on dental enamel (2×2mm) were prepared to be placed in the microtensile tester. The microshear bond strength magnitude (MPa) was recorded at the point of failure. A class I box (3×0.8×1 mm) was prepared on 60 premolars and filled using the resin composites (6 groups, n=10). The specimens were immersed in a 5% basic fuschin solution and sectioned bucco-lingually to view the microleakage using a stereomicroscope. One-way ANOVA and Tukey tests for microshear and Wilcoxon and Kruskal-Wallis tests for microleakage were used to analyze the data in the IBM SPSS Statistics version 22 software. The bond strength of the 3% clearfill group significantly decreased while no significant change occurred in the bond strength in other groups. The Z-350 group had significantly lower microleakage as nanoparticles increased. No significant difference was observed in the clearfill group. Up to 3% Wt incorporation of NZnO particles will not diversely alter the bond strength, but it will be beneficial in providing antimicrobial effects with lower microleakage rates.

Supercritical Fluid Synthesis and Tribological Applications of Silver Nanoparticle-decorated Graphene in Engine Oil Nanofluid.

PubMed

Meng, Yuan; Su, Fenghua; Chen, Yangzhi

2016-08-04

Silver nanoparticle-decorated graphene nanocomposites were synthesized by a facile chemical reduction approach with the assistance of supercritical CO2 (ScCO2). The silver nanoparticles with diameters of 2-16 nm are uniformly distributed and firmly anchored on graphene nanosheets. The tribological properties of the as-synthesized nanocomposites as lubricant additives in engine oil were investigated by a four-ball tribometer. The engine oil with 0.06~0.10 wt.% Sc-Ag/GN nanocomposites displays remarkable lubricating performance, superior than the pure engine oil, the engine oil containing zinc dialkyl dithiophosphate (ZDDP), as well as the oil dispersed with the single nanomaterial of graphene oxides (GOs) and nano-Ag particles alone. The remarkable lubricating behaviors of Sc-Ag/GN probably derive from the synergistic interactions of nano-Ag and graphene in the nanocomposite and the action of the formed protective film on the contact balls. The anchored nano-Ag particles on graphene expand the interlamination spaces of graphene nanosheets and can prevent them from restacking during the rubbing process, resulting in the full play of lubricating activity of graphene. The formed protective film on the friction pairs significantly reduces the surface roughness of the sliding balls and hence preventing them from direct interaction during the sliding process.

Supercritical Fluid Synthesis and Tribological Applications of Silver Nanoparticle-decorated Graphene in Engine Oil Nanofluid

NASA Astrophysics Data System (ADS)

Meng, Yuan; Su, Fenghua; Chen, Yangzhi

2016-08-01

Silver nanoparticle-decorated graphene nanocomposites were synthesized by a facile chemical reduction approach with the assistance of supercritical CO2 (ScCO2). The silver nanoparticles with diameters of 2-16 nm are uniformly distributed and firmly anchored on graphene nanosheets. The tribological properties of the as-synthesized nanocomposites as lubricant additives in engine oil were investigated by a four-ball tribometer. The engine oil with 0.06~0.10 wt.% Sc-Ag/GN nanocomposites displays remarkable lubricating performance, superior than the pure engine oil, the engine oil containing zinc dialkyl dithiophosphate (ZDDP), as well as the oil dispersed with the single nanomaterial of graphene oxides (GOs) and nano-Ag particles alone. The remarkable lubricating behaviors of Sc-Ag/GN probably derive from the synergistic interactions of nano-Ag and graphene in the nanocomposite and the action of the formed protective film on the contact balls. The anchored nano-Ag particles on graphene expand the interlamination spaces of graphene nanosheets and can prevent them from restacking during the rubbing process, resulting in the full play of lubricating activity of graphene. The formed protective film on the friction pairs significantly reduces the surface roughness of the sliding balls and hence preventing them from direct interaction during the sliding process.

IR-Spectroscopic Study on the Interface of Cu-Based Methanol Synthesis Catalysts: Evidence for the Formation of a ZnO Overlayer

DOE PAGES

Schumann, Julia; Kröhnert, Jutta; Frei, Elias; ...

2017-08-28

Carbon monoxide was applied as probe molecule to compare the surface of a ZnO-containing (Cu/ZnO:Al) and a ZnO-free (Cu/MgO) methanol synthesis catalyst (copper content 70 atomic %) after reduction in hydrogen at 523 K by DRIFT spectroscopy. Nano-structured, mainly metallic copper was detected on the surface of the Cu/MgO catalyst. In contrast, the high energy of the main peak in the spectrum of CO adsorbed on reduced Cu/ZnO:Al (2125 cm -1) proves that metallic copper is largely absent on the surface of this catalyst. The band is assigned to Zn δ+–CO. The presence of not completely reduced Cu δ+–CO speciesmore » cannot be excluded. The results are interpreted in terms of a partial coverage of the copper nano-particles in the Cu/ZnO:Al catalyst by a thin layer of metastable, defective zinc oxide. Minor contributions in the spectrum at 2090 and 2112 cm -1 due to nano-structured Cu 0–CO and CO adsorbed on highly defective Cu 0, respectively, indicate that the coverage of metallic copper is not complete.« less

Optimised synthesis of ZnO-nano-fertiliser through green chemistry: boosted growth dynamics of economically important L. esculentum.

PubMed

Jabeen, Nyla; Maqbool, Qaisar; Bibi, Tahira; Nazar, Mudassar; Hussain, Syed Z; Hussain, Talib; Jan, Tariq; Ahmad, Ishaq; Maaza, Malik; Anwaar, Sadaf

2018-06-01

Mounting-up economic losses to annual crops yield due to micronutrient deficiency, fertiliser inefficiency and increasing microbial invasions (e.g. Xanthomonas cempestri attack on tomatoes) are needed to be solved via nano-biotechnology. So keeping this in view, the authors' current study presents the new horizon in the field of nano-fertiliser with highly nutritive and preservative effect of green fabricated zinc oxide-nanostructures (ZnO-NSs) during Lycopersicum esculentum (tomato) growth dynamics. ZnO-NS prepared via green chemistry possesses highly homogenous crystalline structures well-characterised through ultraviolet and visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscope. The ZnO-NS average size was found as small as 18 nm having a crystallite size of 5 nm. L. esculentum were grown in different concentrations of ZnO-NS to examine the different morphological parameters includes time of seed germination, germination percentage, the number of plant leaves, the height of the plant, average number of branches, days count for flowering and fruiting time period along with fruit quantity. Promising results clearly predict that bio-fabricated ZnO-NS at optimum concentration resulted as growth booster and dramatically triggered the plant yield.

IR-Spectroscopic Study on the Interface of Cu-Based Methanol Synthesis Catalysts: Evidence for the Formation of a ZnO Overlayer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schumann, Julia; Kröhnert, Jutta; Frei, Elias

Carbon monoxide was applied as probe molecule to compare the surface of a ZnO-containing (Cu/ZnO:Al) and a ZnO-free (Cu/MgO) methanol synthesis catalyst (copper content 70 atomic %) after reduction in hydrogen at 523 K by DRIFT spectroscopy. Nano-structured, mainly metallic copper was detected on the surface of the Cu/MgO catalyst. In contrast, the high energy of the main peak in the spectrum of CO adsorbed on reduced Cu/ZnO:Al (2125 cm -1) proves that metallic copper is largely absent on the surface of this catalyst. The band is assigned to Zn δ+–CO. The presence of not completely reduced Cu δ+–CO speciesmore » cannot be excluded. The results are interpreted in terms of a partial coverage of the copper nano-particles in the Cu/ZnO:Al catalyst by a thin layer of metastable, defective zinc oxide. Minor contributions in the spectrum at 2090 and 2112 cm -1 due to nano-structured Cu 0–CO and CO adsorbed on highly defective Cu 0, respectively, indicate that the coverage of metallic copper is not complete.« less

Supercritical Fluid Synthesis and Tribological Applications of Silver Nanoparticle-decorated Graphene in Engine Oil Nanofluid

PubMed Central

Meng, Yuan; Su, Fenghua; Chen, Yangzhi

2016-01-01

Silver nanoparticle-decorated graphene nanocomposites were synthesized by a facile chemical reduction approach with the assistance of supercritical CO2 (ScCO2). The silver nanoparticles with diameters of 2–16 nm are uniformly distributed and firmly anchored on graphene nanosheets. The tribological properties of the as-synthesized nanocomposites as lubricant additives in engine oil were investigated by a four-ball tribometer. The engine oil with 0.06~0.10 wt.% Sc-Ag/GN nanocomposites displays remarkable lubricating performance, superior than the pure engine oil, the engine oil containing zinc dialkyl dithiophosphate (ZDDP), as well as the oil dispersed with the single nanomaterial of graphene oxides (GOs) and nano-Ag particles alone. The remarkable lubricating behaviors of Sc-Ag/GN probably derive from the synergistic interactions of nano-Ag and graphene in the nanocomposite and the action of the formed protective film on the contact balls. The anchored nano-Ag particles on graphene expand the interlamination spaces of graphene nanosheets and can prevent them from restacking during the rubbing process, resulting in the full play of lubricating activity of graphene. The formed protective film on the friction pairs significantly reduces the surface roughness of the sliding balls and hence preventing them from direct interaction during the sliding process. PMID:27488733

Topical zinc oxide vs. salicylic acid-lactic acid combination in the treatment of warts.

PubMed

Khattar, Joe A; Musharrafieh, Umayya M; Tamim, Hala; Hamadeh, Ghassan N

2007-04-01

Warts are a common dermatologic problem. Treatment is painful, prolonged, and can cause scarring. To evaluate topical zinc oxide for the treatment of warts. This was a randomized, double-blind controlled trial of 44 patients. Twenty-two patients were given topical zinc oxide 20% ointment, and the other 22 received salicylic acid 15% + lactic acid 15% ointment twice daily. All patients were followed up for 3 months or until cure, whichever occurred first. All patients were observed for side-effects. Sixteen patients in the zinc group and 19 in the salicylic acid-lactic acid group completed the study. In the zinc oxide-treated group, 50% of the patients showed complete cure and 18.7% failed to respond, compared with 42% and 26%, respectively, in the salicylic acid-lactic acid-treated group. No patients developed serious side-effects. Topical zinc oxide is an efficacious, painless, and safe therapeutic option for wart treatment.

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

2006-02-02

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.

Nano/microstructure and optical properties of ZnO particles precipitated from zinc acetylacetonate

NASA Astrophysics Data System (ADS)

Petrović, Željka; Ristić, Mira; Musić, Svetozar; Fabián, Martin

2015-06-01

The influence of experimental conditions on the nano/microstructure and optical properties of ZnO particles produced by rapid hydrolysis of zinc acetylacetonate, followed by aging of the precipitation system at 160 °C, was investigated. Samples were characterized by XRD, FE scanning electron microscopy (FE-SEM), FT-IR, UV/Vis/NIR and photoluminescence (PL) spectroscopies. XRD patterns of all samples were assigned to the hexagonal ZnO phase (wurtzite-type), as well as the corresponding FT-IR spectra. FE-SEM inspection showed a high dependence of the ZnO nano/microstructure on the chemical composition of the reaction mixture and autoclaving time after the rapid hydrolysis of zinc acetylacetonate. Microstructural differences were noticed between C2H5OH/H2O and H2O media, as well as under the influence of NH4OH addition. Measurements of nanocrystallite sizes showed no significant preferential orientation in the (1 0 0) and (0 0 2) directions relative to the (1 0 1) and (1 1 0) directions. Somewhat smaller crystallite sizes were noticed for ZnO samples synthesized by adding the NH4OH solution. Dissolution/recrystallization of ZnO particles played an important role in the formation of different ZnO nano/microstructures. The band gap values for prepared ZnO samples were calculated on the basis of recorded UV/Vis spectra. PL spectra were recorded for ZnO samples in powder form and their suspensions in pure ethanol. Noticed differences are discussed.

Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis.

PubMed

Taranath, Tarikere C; Patil, Bheemanagouda N

2016-06-01

The present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis. The formation of zinc oxide nanoparticles was confirmed with UV-visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique. The UV-visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL. Phytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease. Copyright © 2016 Asian-African Society for Mycobacteriology. Published by Elsevier Ltd. All rights reserved.

Zinc oxide crystal whiskers as a novel sorbent for solid-phase extraction of flavonoids.

PubMed

Wang, Licheng; Shangguan, Yangnan; Hou, Xiudan; Jia, Yong; Liu, Shujuan; Sun, Yingxin; Guo, Yong

2017-08-15

As a novel solid-phase extraction material, zinc oxide crystal whiskers were used to extract flavonoid compounds and showed good extraction abilities. X-ray diffraction, scanning electron microscopy with energy dispersive X-ray spectroscopy and surface area/pore volume characterized the sorbent. The zinc oxide was packed into a solid-phase extraction micro-column and its extraction ability was evaluated by four model flavonoid compounds. The sample loading and elution parameters were optimized and the zinc oxide based analytical method for flavonoids was established. It showed that the method has wide linearities from 1 to 150μg/L and low limits of detection at 0.25μg/L. The relative standard deviations of a single column repeatability and column to column reproducibility were less than 6.8% and 10.6%. Several real samples were analyzed by the established method and satisfactory results were obtained. The interactions between flavonoids and zinc oxide were calculated and proved to be from the Van der Waals' forces between the 4p and 5d orbitals from zinc atom and the neighboring π orbitals from flavonoid phenyl groups. Moreover, the zinc oxide crystal whiskers showed good stability and could be reused more than 50 times under the operation conditions. This work proves that the zinc oxide crystal whiskers are a good candidate for flavonoids enrichment. Copyright © 2017. Published by Elsevier B.V.

ZnO nanoparticle catalysts for use in biodiesel production and method of making

DOEpatents

Yan, Shuli; Salley, Steven O; Ng, K. Y. Simon

2014-11-25

A method of forming a biodiesel product and a heterogeneous catalyst system used to form said product that has a high tolerance for the presence of water and free fatty acids (FFA) in the oil feedstock is disclosed. This catalyst system may simultaneously catalyze both the esterification of FAA and the transesterification of triglycerides present in the oil feedstock. The catalyst system is comprised of a mixture of zinc oxide and a second metal oxide. The zinc oxide includes a mixture of amorphous zinc oxide and zinc oxide nanocrystals, the zinc nanocrystals having a mean grain size between about 20 and 80 nanometers with at least one of the nanocrystals including a mesopore having a diameter of about 5 to 15 nanometers. Preferably, the second metal oxide is a lanthanum oxide, the lanthanum oxide being selected as one from the group of La.sub.2CO.sub.5, LaOOH, and combinations or mixtures thereof.

21 CFR 73.1991 - Zinc oxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... coloring externally applied drugs. (b) Specifications. Zinc oxide shall conform to the following...

21 CFR 73.2991 - Zinc oxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The... (a)(1) and (b). (b) Uses and restrictions. Zinc oxide may be safely used in cosmetics, including cosmetics intended for use in the area of the eye, in amounts consistent with good manufacturing practice...

Hydrothermal synthesis of zinc oxide nanoparticles using rice as soft biotemplate.

PubMed

Ramimoghadam, Donya; Bin Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin

2013-01-01

Rice as a renewable, abundant bio-resource with unique characteristics can be used as a bio-template to synthesize various functional nanomaterials. Therefore, the effect of uncooked rice flour as bio-template on physico-chemical properties, especially the morphology of zinc oxide nanostructures was investigated in this study. The ZnO particles were synthesized through hydrothermal-biotemplate method using zinc acetate-sodium hydroxide and uncooked rice flour at various ratios as precursors at 120°C for 18 hours. The results indicate that rice as a bio-template can be used to modify the shape and size of zinc oxide particles. Different morphologies, namely flake-, flower-, rose-, star- and rod-like structures were obtained with particle size at micro- and nanometer range. Pore size and texture of the resulting zinc oxide particles were found to be template-dependent and the resulting specific surface area enhanced compared to the zinc oxide synthesized without rice under the same conditions. However, optical property particularly the band gap energy is generally quite similar. Pure zinc oxide crystals were successfully synthesized using rice flour as biotemplate at various ratios of zinc salt to rice. The size- and shape-controlled capability of rice to assemble the ZnO particles can be employed for further useful practical applications.

New insights into the adsorption of 3-(trimethoxysilyl)propylmethacrylate on hydroxylated ZnO nanopowders.

PubMed

Bressy, Christine; Ngo, Van Giang; Ziarelli, Fabio; Margaillan, André

2012-02-14

Functionalization of zinc oxide (ZnO) nano-objects by silane grafting is an attractive method to provide nanostructured materials with a variety of surface properties. Active hydroxyl groups on the oxide surface are one of the causes governing the interfacial bond strength in nanohybrid particles. Here, "as-prepared" and commercially available zinc oxide nanopowders with a wide range of surface hydroxyl density were functionalized by a well-known polymerizable silane coupling agent, i.e., 3-(trimethoxysilyl)propylmethacrylate (MPS). Fourier transform infrared (FTIR) and solid-state (13)C and (29)Si nuclear magnetic resonance (NMR) spectroscopic investigations demonstrated that the silane coupling agent was fully hydrolyzed and linked to the hydroxyl groups already present on the particle surface through covalent and hydrogen bonds. Due to a basic catalyzed condensation of MPS with water, a siloxane layer was shown to be anchored to the nanoparticles through mono- and tridentate structures. Quantitative investigations were performed by thermogravimetric (TGA) and elemental analyses. The amount of silane linked to ZnO particles was shown to be affected by the amount of isolated hydroxyl groups available to react on the particle surface. For as-prepared ZnO nanoparticles, the number of isolated and available hydroxyl groups per square nanometer was up to 3 times higher than the one found on commercially available ZnO nanoparticles, leading to higher amounts of polymerizable silane agent linked to the surface. The MPS molecules were shown to be mainly oriented perpendicular to the oxide surface for all the as-prepared ZnO nanoparticles, whereas a parallel orientation was found for the preheated commercially ZnO nanopowders. In addition, ZnO nanoparticles were shown to be hydrophobized by the MPS treatment with water contact angles higher than 60°.

Comparative studies on acid leaching of zinc waste materials

NASA Astrophysics Data System (ADS)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

NASA Astrophysics Data System (ADS)

Luthra, Deepali; Kumar, Sacheen

2018-05-01

Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

Cadmium-free junction fabrication process for CuInSe.sub.2 thin film solar cells

DOEpatents

Ramanathan, Kannan V.; Contreras, Miguel A.; Bhattacharya, Raghu N.; Keane, James; Noufi, Rommel

1999-01-01

The present invention provides an economical, simple, dry and controllable semiconductor layer junction forming process to make cadmium free high efficiency photovoltaic cells having a first layer comprised primarily of copper indium diselenide having a thin doped copper indium diselenide n-type region, generated by thermal diffusion with a group II(b) element such as zinc, and a halide, such as chlorine, and a second layer comprised of a conventional zinc oxide bilayer. A photovoltaic device according the present invention includes a first thin film layer of semiconductor material formed primarily from copper indium diselenide. Doping of the copper indium diselenide with zinc chloride is accomplished using either a zinc chloride solution or a solid zinc chloride material. Thermal diffusion of zinc chloride into the copper indium diselenide upper region creates the thin n-type copper indium diselenide surface. A second thin film layer of semiconductor material comprising zinc oxide is then applied in two layers. The first layer comprises a thin layer of high resistivity zinc oxide. The second relatively thick layer of zinc oxide is doped to exhibit low resistivity.

21 CFR 73.2991 - Zinc oxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... color additive zinc oxide shall conform in identity and specifications to the requirements of § 73.1991...

21 CFR 182.8991 - Zinc oxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product...

21 CFR 182.8991 - Zinc oxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product...

Zinc oxide nanorod clusters deposited seaweed cellulose sheet for antimicrobial activity.

PubMed

Bhutiya, Priyank L; Mahajan, Mayur S; Abdul Rasheed, M; Pandey, Manoj; Zaheer Hasan, S; Misra, Nirendra

2018-06-01

Seaweed cellulose was isolated from green seaweed Ulva fasciata using a common bleaching agent. Sheet containing porous mesh was prepared from the extracted seaweed crystalline cellulose along with zinc oxide (ZnO) nanorod clusters grown over the sheet by single step hydrothermal method. Seaweed cellulose and zinc oxide nanorod clusters deposited seaweed cellulose sheet was characterized by FT-IR, XRD, TGA, and SEM-EDX. Morphology showed that the diameter of zinc oxide nanorods were around 70nm. Zinc oxide nanorod clusters deposited on seaweed cellulose sheet gave remarkable antibacterial activity towards gram-positive (Staphylococcus aureus, Bacillus ceresus, Streptococcus thermophilis) and gram-negative (Escherichia coli, Pseudomonas aeruginous) microbes. Such deposited sheet has potential applications in pharmaceutical, biomedical, food packaging, water treatment and biotechnological industries. Copyright © 2018 Elsevier B.V. All rights reserved.

Electron spectroscopy imaging and surface defect configuration of zinc oxide nanostructures under different annealing ambient

NASA Astrophysics Data System (ADS)

Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd

2013-01-01

In this study, electron spectroscopy imaging was used to visualize the elemental distribution of zinc oxide nanopowder. Surface modification in zinc oxide was done through annealing treatment and type of surface defect was also inferred from the electron spectroscopy imaging investigation. The micrographs revealed the non-stoichiometric distribution of the elements in the unannealed samples. Annealing the samples in nitrogen and oxygen ambient at 700 °C would alter the density of the elements in the samples as a result of removal or absorption of oxygen. The electrical measurement showed that nitrogen annealing treatment improved surface electrical conductivity, whereas oxygen treatment showed an adverse effect. Observed change in the photoluminescence green emission suggested that oxygen vacancies play a significant role as surface defects. Structural investigation carried out through X-ray diffraction revealed the polycrystalline nature of both zinc oxide samples with hexagonal phase whereby annealing process increased the crystallinity of both zinc oxide specimens. Due to the different morphologies of the two types of zinc oxide nanopowders, X-ray diffraction results showed different stress levels in their structures and the annealing treatment give significant effect to the structural stress. Electron spectroscopy imaging was a useful technique to identify the elemental distribution as well as oxygen defect in zinc oxide nanopowder.

Photocatalytic removal of doxycycline from aqueous solution using ZnO nano-particles: a comparison between UV-C and visible light.

PubMed

Pourmoslemi, Shabnam; Mohammadi, Ali; Kobarfard, Farzad; Amini, Mohsen

2016-10-01

Zinc oxide nano-particles were synthesized, characterized and used for photocatalytic degradation of doxycycline using UV-C and visible light. Effects of several operational factors including initial pH of antibiotic solution, initial antibiotic concentration and ZnO nano-particles loading amount were investigated. Comparing photocatalytic degradation and mineralization of doxycycline under UV-C and visible light showed successful application of the method under both light sources. However, reaction rate was higher under UV-C irradiation, which degraded doxycycline almost completely in 5 hours, and 68% mineralization was achieved. Synthesized ZnO nano-particles were successfully applied for photocatalytic degradation of doxycycline in a pharmaceutical wastewater sample. The process was fitted to the pseudo first order kinetic model with rate constants in the range of 6-22(×10 -3 ) mg L -1 min -1 with respect to initial concentration of doxycycline under UV-C irradiation. The Langmuir-Hinshelwood model was also employed for describing the photocatalytic reaction with surface reaction kinetic constant k c and equilibrium adsorption constant K LH values calculated as 0.12 mg L -1 min -1 and 2.2 L mg -1 , respectively. Degradation of doxycycline was followed by UV-visible spectroscopy and a validated stability indicating high-performance liquid chromatography method that was developed using stressed samples of doxycycline and could selectively determine doxycycline in the presence of its degradation products. Mass spectrometry was used for determining final degradation products.

Characterization of nano-sized oxides in Fe-12Cr oxide-dispersion-strengthened ferritic steel using small-angle neutron scattering

NASA Astrophysics Data System (ADS)

Han, Young-Soo; Mao, Xiaodong; Jang, Jinsung; Kim, Tae-Kyu

2015-04-01

The ferritic ODS steel was manufactured by hot isostatic pressing and heat treatment. The nano-sized microstructures such as yttrium oxides and Cr oxides were quantitatively analyzed by small-angle neutron scattering (SANS). The effects of the fabrication conditions on the nano-sized microstructure were investigated in relation to the quantitative analysis results obtained by SANS. The ratio between magnetic and nuclear scattering components was calculated, and the characteristics of the nano-sized yttrium oxides are discussed based on the SANS analysis results.

Plasma in-liquid method for reduction of zinc oxide in zinc nanoparticle synthesis

NASA Astrophysics Data System (ADS)

Amaliyah, Novriany; Mukasa, Shinobu; Nomura, Shinfuku; Toyota, Hiromichi; Kitamae, Tomohide

2015-02-01

Metal air-batteries with high-energy density are expected to be increasingly applied in electric vehicles. This will require a method of recycling air batteries, and reduction of metal oxide by generating plasma in liquid has been proposed as a possible method. Microwave-induced plasma is generated in ethanol as a reducing agent in which zinc oxide is dispersed. Analysis by energy-dispersive x-ray spectrometry (EDS) and x-ray diffraction (XRD) reveals the reduction of zinc oxide. According to images by transmission electron microscopy (TEM), cubic and hexagonal metallic zinc particles are formed in sizes of 30 to 200 nm. Additionally, spherical fiber flocculates approximately 180 nm in diameter are present.

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.

Nuclear microprobe investigation of the penetration of ultrafine zinc oxide into intact and tape-stripped human skin

NASA Astrophysics Data System (ADS)

Szikszai, Z.; Kertész, Zs.; Bodnár, E.; Major, I.; Borbíró, I.; Kiss, Á. Z.; Hunyadi, J.

2010-06-01

Ultrafine metal oxides, such as titanium dioxide and zinc oxide are widely used in cosmetic and health products like sunscreens. These oxides are potent UV filters and the small particle size makes the product more transparent compared to formulations containing coarser particles. In the present work the penetration of ultrafine zinc oxide into intact and tape-stripped human skin was investigated using nuclear microprobe techniques, such as proton induced X-ray spectroscopy and scanning transmission ion microscopy. Our results indicate that the penetration of ultrafine zinc oxide, in a hydrophobic basis gel with 48 h application time, is limited to the stratum corneum layer of the intact skin. Removing the stratum corneum partially or entirely by tape-stripping did not cause the penetration of the particles into the deeper dermal layers; the zinc particles remained on the surface of the skin.

Method for the regeneration of spent molten zinc chloride

DOEpatents

Zielke, Clyde W.; Rosenhoover, William A.

1981-01-01

In a process for regenerating spent molten zinc chloride which has been used in the hydrocracking of coal or ash-containing polynuclear aromatic hydrocarbonaceous materials derived therefrom and which contains zinc chloride, zinc oxide, zinc oxide complexes and ash-containing carbonaceous residue, by incinerating the spent molten zinc chloride to vaporize the zinc chloride for subsequent condensation to produce a purified molten zinc chloride: an improvement comprising the use of clay in the incineration zone to suppress the vaporization of metals other than zinc. Optionally water is used in conjunction with the clay to further suppress the vaporization of metals other than zinc.

Synthesis, Optical and Photoluminescence Properties of Cu-Doped Zno Nano-Fibers Thin Films: Nonlinear Optics

NASA Astrophysics Data System (ADS)

Ganesh, V.; Salem, G. F.; Yahia, I. S.; Yakuphanoglu, F.

2018-03-01

Different concentrations of copper-doped zinc oxide thin films were coated on a glass substrate by sol-gel/spin-coating technique. The structural properties of pure and Cu-doped ZnO films were characterized by different techniques, i.e., atomic force microscopy (AFM), photoluminescence and UV-Vis-NIR spectroscopy. The AFM study revealed that pure and doped ZnO films are formed as nano-fibers with a granular structure. The photoluminescence spectra of these films showed a strong ultraviolet emission peak centered at 392 nm and a strong blue emission peak cantered at 450 nm. The optical band gap of the pure and copper-doped ZnO thin films calculated from optical transmission spectra (3.29-3.23 eV) were found to be increasing with increasing copper doping concentration. The refractive index dispersion curve of pure and Cu-doped ZnO film obeyed the single-oscillator model. The optical dispersion parameters such as E o , E d , and n_{∞}2 were calculated. Further, the nonlinear refractive index and nonlinear optical susceptibility were also calculated and interpreted.

Zinc-The key to preventing corrosion

USGS Publications Warehouse

Kropschot, S.J.; Doebrich, Jeff L.

2011-01-01

Centuries before it was identified as an element, zinc was used to make brass (an alloy of zinc and copper) and for medicinal purposes. Metallic zinc and zinc oxide were produced in India sometime between the 11th and 14th centuries and in China in the 17th century, although the discovery of pure metallic zinc is credited to the German chemist Andreas Marggraf, who isolated the element in 1746. Refined zinc metal is bluish-white when freshly cast; it is hard and brittle at most temperatures and has relatively low melting and boiling points. Zinc alloys readily with other metals and is chemically active. On exposure to air, it develops a thin gray oxide film (patina), which inhibits deeper oxidation (corrosion) of the metal. The metal's resistance to corrosion is an important characteristic in its use.

Rapid green synthesis of ZnO nanoparticles using a hydroelectric cell without an electrolyte

NASA Astrophysics Data System (ADS)

Shah, Jyoti; Kumar Kotnala, Ravinder

2017-09-01

In this study, zinc oxide (ZnO) nanoparticles were synthesized using a novel environmentally friendly hydroelectric cell without an electrolyte or external current source. The hydroelectric cell comprised a nanoporous Li substituted magnesium ferrite pellet in contact with two electrodes, with zinc as the anode and silver as an inert cathode. The surface unsaturated cations and oxygen vacancies in the nanoporous ferrite dissociated water molecules into hydronium and hydroxide ions when the hydroelectric cell was dipped into deionized water. Hydroxide ions migrated toward the zinc electrode to form zinc hydroxide and the hydronium ions were evolved as H2 gas at the silver electrode. The zinc hydroxide collected as anode mud was converted into ZnO nanoparticles by heating at 250 °C. Structural analysis using Raman spectroscopy indicated the good crystallinity of the ZnO nanoparticles according to the presence of a high intensity E2-(high) mode. The nanoparticle size distribution was 5-20 nm according to high resolution transmission electron microscopy. An indirect band gap of 2.75 eV was determined based on the Tauc plot, which indicated the existence of an interstitial cation level in ZnO. Near band edge and blue emissions were detected in photoluminescence spectral studies. The blue emissions obtained from the ZnO nanoparticles could potentially have applications in blue lasers and LEDs. The ZnO nanoparticles synthesized using this method had a high dielectric constant value of 5 at a frequency of 1 MHz, which could be useful for fabricating nano-oscillators. This facile, clean, and cost-effective method obtained a significant yield of 0.017 g for ZnO nanoparticles without applying an external current source.

OP-AMPS on Flexible Substrates with Printable Materials

DTIC Science & Technology

2011-08-10

Zinc Tin Oxide Thin - Film - Transistor Enhancement...II196, 2010. [3] D. Geng, D. H. Kang, and J. Jang, "High-Performance Amorphous Indium-Gallium- Zinc - Oxide Thin - Film Transistor With a Self-Aligned...B., Dodabalapur, A., “Band transport and mobility edge in amorphous solution-processed zinc tin oxide thin - film transistors ”, Applied

Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

EPA Science Inventory

Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

Ultrasound irradiation based in-situ synthesis of star-like Tragacanth gum/zinc oxide nanoparticles on cotton fabric.

PubMed

Ghayempour, Soraya; Montazer, Majid

2017-01-01

Application of natural biopolymers for green and safe synthesis of zinc oxide nanoparticles on the textiles is a novel and interesting approach. The present study offers the use of natural biopolymer, Tragacanth gum, as the reducing, stabilizing and binding agent for in-situ synthesis of zinc oxide nanoparticles on the cotton fabric. Ultrasonic irradiation leads to clean and easy synthesis of zinc oxide nanoparticles in short-time at low-temperature. FESEM/EDX, XRD, FT-IR spectroscopy, DSC, photocatalytic activities and antimicrobial assay are used to characterize Tragacanth gum/zinc oxide nanoparticles coated cotton fabric. The analysis confirmed synthesis of star-like zinc oxide nanoparticles with hexagonal wurtzite structure on the cotton fabric with the average particle size of 62nm. The finished cotton fabric showed a good photocatalytic activity on degradation of methylene blue and 100% antimicrobial properties with inhibition zone of 3.3±0.1, 3.1±0.1 and 3.0±0.1mm against Staphylococcus aureus, Escherichia coli and Candida albicans. Copyright © 2016 Elsevier B.V. All rights reserved.

Effects of sub-acute exposure to TiO2, ZnO and Al2O3 nanoparticles on oxidative stress and histological changes in mouse liver and brain.

PubMed

Shrivastava, Rupal; Raza, Saimah; Yadav, Abhishek; Kushwaha, Pramod; Flora, Swaran J S

2014-07-01

Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. However the information regarding toxicity of these nanoparticles on humans and environment is still deficient. The present study investigated the toxic effects of three metal oxide nanoparticles, TiO2, ZnO and Al2O3 on mouse erythrocytes, brain and liver. Male mice were administered a single oral dose of 500 mg/kg of each nanoparticles for 21 consecutive days. The results suggest that exposure to these nano metallic particles produced a significant oxidative stress in erythrocyte, liver and brain as evident from enhanced levels of Reactive Oxygen Species (ROS) and altered antioxidant enzymes activities. A significant increase in dopamine and norepinephrine levels in brain cerebral cortex and increased brain oxidative stress suggest neurotoxic potential of these nanoparticles. Transmission electron microscopic (TEM) analysis indicated the presence of these nanoparticles inside the cytoplasm and nucleus. These changes were also supported by the inhibition of CuZnSOD and MnSOD, considered as important biomarkers of oxidative stress. The toxic effects produced by these nanoparticles were more pronounced in the case of zinc oxide, followed by aluminum oxide and titanium dioxide, respectively. The present results further suggest the involvement of oxidative stress as one of the main mechanisms involved in nanoparticles induced toxic manifestations.

Characteristics of phase-change materials containing oxide nano-additives for thermal storage

PubMed Central

2012-01-01

In this study, the authors report the production of nanocomposite-enhanced phase-change materials (NEPCMs) using the direct-synthesis method by mixing paraffin with alumina (Al2O3), titania (TiO2), silica (SiO2), and zinc oxide (ZnO) as the experimental samples. Al2O3, TiO2, SiO2, and ZnO were dispersed into three concentrations of 1.0, 2.0, and 3.0 wt.%. Through heat conduction and differential scanning calorimeter experiments to evaluate the effects of varying concentrations of the nano-additives on the heat conduction performance and thermal storage characteristics of NEPCMs, their feasibility for use in thermal storage was determined. The experimental results demonstrate that TiO2 is more effective than the other additives in enhancing both the heat conduction and thermal storage performance of paraffin for most of the experimental parameters. Furthermore, TiO2 reduces the melting onset temperature and increases the solidification onset temperature of paraffin. This allows the phase-change heat to be applicable to a wider temperature range, and the highest decreased ratio of phase-change heat is only 0.46%, compared to that of paraffin. Therefore, this study demonstrates that TiO2, added to paraffin to form NEPCMs, has significant potential for enhancing the thermal storage characteristics of paraffin. PMID:23127224

Oxidation and Condensation of Zinc Fume From Zn-CO 2-CO-H 2O Streams Relevant to Steelmaking Off-Gas Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bronson, Tyler Mark; Ma, Naiyang; Zhu, Liang Zhu

Here the objective of this research was to study the condensation of zinc vapor to metallic zinc and zinc oxide solid under varying environments to investigate the feasibility of in-process separation of zinc from steelmaking off-gas dusts. Water vapor content, temperature, degree of cooling, gas composition, and initial zinc partial pressure were varied to simulate the possible conditions that can occur within steelmaking off-gas systems, limited to Zn-CO 2-CO-H 2O gas compositions. The temperature of deposition and the effect of rapidly quenching the gas were specifically studied. A homogeneous nucleation model for applicable experiments was applied to the analysis of the experimental data. It was determined that under the experimental conditions, oxidation of zinc vapor by H 2O or CO 2 does not occur above 1108 K (835 °C) even for highly oxidizing streams (CO 2/CO = 40/7). Rate expressions that correlate CO 2 and H 2O oxidation rates to gas composition, partial pressure of water vapor, temperature, and zinc partial pressure were determined to be as follows: Ratemore » $$ \\left(\\frac{mol}{m^2s}\\right) $$ = 406 exp $$ \\left(\\frac{-50.2 kJ/mol}{RT}\\right) $$ (pZnpCO 2 $-$ PCO/K eqCO 2) $$\\frac{mol}{m^2 x s}$$ Rate $$ \\left(\\frac{mol}{m^2s}\\right) $$ = 32.9 exp $$ \\left(\\frac{-13.7 kJ/mol}{RT}\\right) $$ (pZnPH 2O $-$ PH 2/K eqH 2O) $$\\frac{mol}{m^2 x s}$$. It was proven that a rapid cooling rate (500 K/s) significantly increases the ratio of metallic zinc to zinc oxide as opposed to a slow cooling rate (250 K/s). SEM analysis found evidence of heterogeneous growth of ZnO as well as of homogeneous formation of metallic zinc. The homogeneous nucleation model fit well with experiments where only metallic zinc deposited. An expanded model with rates of oxidation by CO 2 and H 2O as shown was combined with the homogenous nucleation model and then compared with experimental data. The calculated results based on the model gave a reasonable fit to the measured data. For the conditions used in this study, the rate equations for the oxidation of zinc by carbon dioxide and water vapor as well as the homogeneous nucleation model of metallic zinc were applicable for various temperatures, zinc partial pressures, CO 2:CO ratios, and H 2O partial pressures.« less

Oxidation and Condensation of Zinc Fume From Zn-CO 2-CO-H 2O Streams Relevant to Steelmaking Off-Gas Systems

DOE PAGES

Bronson, Tyler Mark; Ma, Naiyang; Zhu, Liang Zhu; ...

2017-01-23

Here the objective of this research was to study the condensation of zinc vapor to metallic zinc and zinc oxide solid under varying environments to investigate the feasibility of in-process separation of zinc from steelmaking off-gas dusts. Water vapor content, temperature, degree of cooling, gas composition, and initial zinc partial pressure were varied to simulate the possible conditions that can occur within steelmaking off-gas systems, limited to Zn-CO 2-CO-H 2O gas compositions. The temperature of deposition and the effect of rapidly quenching the gas were specifically studied. A homogeneous nucleation model for applicable experiments was applied to the analysis of the experimental data. It was determined that under the experimental conditions, oxidation of zinc vapor by H 2O or CO 2 does not occur above 1108 K (835 °C) even for highly oxidizing streams (CO 2/CO = 40/7). Rate expressions that correlate CO 2 and H 2O oxidation rates to gas composition, partial pressure of water vapor, temperature, and zinc partial pressure were determined to be as follows: Ratemore » $$ \\left(\\frac{mol}{m^2s}\\right) $$ = 406 exp $$ \\left(\\frac{-50.2 kJ/mol}{RT}\\right) $$ (pZnpCO 2 $-$ PCO/K eqCO 2) $$\\frac{mol}{m^2 x s}$$ Rate $$ \\left(\\frac{mol}{m^2s}\\right) $$ = 32.9 exp $$ \\left(\\frac{-13.7 kJ/mol}{RT}\\right) $$ (pZnPH 2O $-$ PH 2/K eqH 2O) $$\\frac{mol}{m^2 x s}$$. It was proven that a rapid cooling rate (500 K/s) significantly increases the ratio of metallic zinc to zinc oxide as opposed to a slow cooling rate (250 K/s). SEM analysis found evidence of heterogeneous growth of ZnO as well as of homogeneous formation of metallic zinc. The homogeneous nucleation model fit well with experiments where only metallic zinc deposited. An expanded model with rates of oxidation by CO 2 and H 2O as shown was combined with the homogenous nucleation model and then compared with experimental data. The calculated results based on the model gave a reasonable fit to the measured data. For the conditions used in this study, the rate equations for the oxidation of zinc by carbon dioxide and water vapor as well as the homogeneous nucleation model of metallic zinc were applicable for various temperatures, zinc partial pressures, CO 2:CO ratios, and H 2O partial pressures.« less

Green synthesis and characterization of zinc oxide nanoparticle using insulin plant (Costus pictus D. Don) and investigation of its antimicrobial as well as anticancer activities

NASA Astrophysics Data System (ADS)

Suresh, Joghee; Pradheesh, Ganeshan; Alexramani, Vincent; Sundrarajan, Mahalingam; Hong, Sun Ig

2018-03-01

In this work we aim to synthesize biocompatible ZnO nanoparticles from the zinc nitrate via green process using leaf extracts of the Costus pictus D. Don medicinal plant. FTIR studies confirm the presence of biomolecules and metal oxides. X-ray diffraction (XRD) structural analysis reveals the formation of pure hexagonal phase structures of ZnO nanoparticles. The surface morphologies of ZnO nanoparticles observed under a scanning electron microscope (SEM) suggest that most ZnO crystallites are hexagonal. EDX analysis confirms the presence of primarily zinc and oxygen. TEM images show that biosynthesized zinc oxide nanoparticles are hexagonal and spherical. The plausible formation mechanisms of zinc oxide nanoparticles are also predicted. The biosynthesized zinc oxide nanoparticles exhibit strong antimicrobial behavior against bacterial and fungal species when employing the agar diffusion method. Synthesized ZnO nanoparticles exhibit anticancer activity against Daltons lymphoma ascites (DLA) cells as well as antimicrobial activity against some bacterial and fungal strains.

Enhancement of a-IGZO TFT Device Performance Using a Clean Interface Process via Etch-Stopper Nano-layers.

PubMed

Chung, Jae-Moon; Zhang, Xiaokun; Shang, Fei; Kim, Ji-Hoon; Wang, Xiao-Lin; Liu, Shuai; Yang, Baoguo; Xiang, Yong

2018-05-29

To overcome the technological and economic obstacles of amorphous indium-gallium-zinc-oxide (a-IGZO)-based display backplane for industrial production, a clean etch-stopper (CL-ES) process is developed to fabricate a-IGZO-based thin film transistor (TFT) with improved uniformity and reproducibility on 8.5th generation glass substrates (2200 mm × 2500 mm). Compared with a-IGZO-based TFT with back-channel-etched (BCE) structure, a newly formed ES nano-layer (~ 100 nm) and a simultaneous etching of a-IGZO nano-layer (30 nm) and source-drain electrode layer are firstly introduced to a-IGZO-based TFT device with CL-ES structure to improve the uniformity and stability of device for large-area display. The saturation electron mobility of 8.05 cm 2 /V s and the V th uniformity of 0.72 V are realized on the a-IGZO-based TFT device with CL-ES structure. In the negative bias temperature illumination stress and positive bias thermal stress reliability testing under a ± 30 V bias for 3600 s, the measured V th shift of CL-ES-structured device significantly decreased to - 0.51 and + 1.94 V, which are much lower than that of BCE-structured device (- 3.88 V, + 5.58 V). The electrical performance of the a-IGZO-based TFT device with CL-ES structure implies that the economic transfer from a silicon-based TFT process to the metal oxide semiconductor-based process for LCD fabrication is highly feasible.

Dermal absorption and short-term biological impact in hairless mice from sunscreens containing zinc oxide nano- or larger particles

PubMed Central

Oytam, Yalchin; Kirby, Jason K.; Gomez-Fernandez, Laura; Baxter, Brent; McCall, Maxine J.

2014-01-01

Previous studies have shown no, or very limited, skin penetration of metal oxide nanoparticles following topical application of sunscreens, yet concerns remain about their safety compared to larger particles. Here, we assessed the comparative dermal absorption of a traceable form of Zn (68Zn) from 68ZnO nano-sized and larger particles in sunscreens. Sunscreens were applied to the backs of virgin or pregnant hairless mice over four days. Control groups received topical applications of the sunscreen formulation containing no ZnO particles, or no treatment. Major organs were assessed for changes in 68Zn/64Zn ratios, 68Zn tracer and total Zn concentrations. Short-term biological impact was assessed by measuring levels of serum amyloid A in blood, and by performing whole-genome transcriptional profiling on livers from each group. Increased concentrations of 68Zn tracer were detected in internal organs of mice receiving topical applications of 68ZnO (nano-sized and larger particles), as well as in fetal livers from treated dams, compared with controls. Furthermore, concentrations of 68Zn in organs of virgin mice treated with sunscreen containing 68ZnO nanoparticles were found to be significantly higher than in mice treated with sunscreen containing larger 68ZnO particles. However, no ZnO-mediated change in total Zn concentration in any of the major organs was observed. Thus, despite 68Zn absorption, which may have been in the form of soluble 68Zn species or 68ZnO particles (not known), Zn homeostasis was largely maintained, and the presence of ZnO particles in sunscreen did not elicit an adverse biological response in the mice following short-term topical applications. PMID:24266363

Directed spatial organization of zinc oxide nanostructures

DOEpatents

Hsu, Julia [Albuquerque, NM; Liu, Jun [Richland, WA

2009-02-17

A method for controllably forming zinc oxide nanostructures on a surface via an organic template, which is formed using a stamp prepared from pre-defined relief structures, inking the stamp with a solution comprising self-assembled monolayer (SAM) molecules, contacting the stamp to the surface, such as Ag sputtered on Si, and immersing the surface with the patterned SAM molecules with a zinc-containing solution with pH control to form zinc oxide nanostructures on the bare Ag surface.

Zinc is an Antioxidant and Anti-Inflammatory Agent: Its Role in Human Health

PubMed Central

Prasad, Ananda S.

2014-01-01

Zinc supplementation trials in the elderly showed that the incidence of infections was decreased by approximately 66% in the zinc group. Zinc supplementation also decreased oxidative stress biomarkers and decreased inflammatory cytokines in the elderly. In our studies in the experimental model of zinc deficiency in humans, we showed that zinc deficiency per se increased the generation of IL-1β and its mRNA in human mononuclear cells following LPS stimulation. Zinc supplementation upregulated A20, a zinc transcription factor, which inhibited the activation of NF-κB, resulting in decreased generation of inflammatory cytokines. Oxidative stress and chronic inflammation are important contributing factors for several chronic diseases attributed to aging, such as atherosclerosis and related cardiac disorders, cancer, neurodegeneration, immunologic disorders and the aging process itself. Zinc is very effective in decreasing reactive oxygen species (ROS). In this review, the mechanism of zinc actions on oxidative stress and generation of inflammatory cytokines and its impact on health in humans will be presented. PMID:25988117

Effect of graphene oxide nano filler on dynamic behaviour of GFRP composites

NASA Astrophysics Data System (ADS)

Pujar, Nagabhushan V.; Nanjundaradhya, N. V.; Sharma, Ramesh S.

2018-04-01

Nano fillers like Alumina oxide, Titanium oxide, Carbon nano tube, Nano clay have been used to improve the mechanical and damping properties of fiber reinforced polymer composites. In the recent years Graphene oxide nano filler is receiving considerable attention for its outstanding properties. Literature available shows that Graphene oxide nano filler can be used to improve the mechanical properties. The use of Graphene oxide in vibration attenuation by enhancing the passive damping in fiber reinforced polymer composite has not been fully explored. The objective of this work is to investigate the dynamic behaviour of Glass fiber-reinforced composite embedded with Graphene oxide nano filler. Graphene oxide is dispersed in epoxy resin with various concentration (0.1%, 0.5% and 1%wt) using ultra-sonification process. Composite laminates were made using the traditional hand-lay-up followed by vacuum bag process. Experimental modal analysis using traditional `strike method' is used to evaluate modal parameters using FFT analyzer and Data Acquisition System. Experiments were carried out for two different fiber orientations viz 0 ➙ & 45 ➙ and two boundary conditions (Free-Free and Cantilever). The modal parameters such as natural frequency, mode shape, damping ratio were studied. This research work demonstrates the vibration damping behaviour with incorporation of Graphene oxide and provides a basic understanding of the damping characteristics in design and manufacture of high performance composites.

Study of physical properties of metal oxide nanoparticles obtained in acoustoplasma discharge

NASA Astrophysics Data System (ADS)

Bulychev, N. A.; Kazaryan, M. A.; Zakharyan, A. R.; Bodryshev, V. V.; Kirichenko, M. N.; Shevchenko, S. N.; Yakunin, V. G.; Timoshenko, V. Y.; Bychenko, A. B.

2018-04-01

Nanoparticles of tungsten, copper, iron, and zinc oxides were synthesized in acoustoplasma discharge. Their size distribution was studied by electron microscopy and laser correlation spectroscopy. Ultrasound was found to narrow significantly the size distribution width of zinc oxide nanoparticles. Water suspensions of zinc oxide nanoparticles showed photoluminescence in red and near infrared spectral ranges, which makes them a promising material for luminescent diagnostics of biological systems.

Self-aligned periodic Ni nano dots embedded in nano-oxide layer

NASA Astrophysics Data System (ADS)

Doi, M.; Izumi, M.; Kawasaki, S.; Miyake, K.; Sahashi, M.

The Ni nano constriction dots embedded in the Ta-nano-oxide layer (NOL) was prepared by the ion beam sputtering (IBS) method. After the various conditions of the oxidations, the structural analyses of the NOL were performed by RHEED, AES and in situ STM/AFM observations. From the current image of the conductive AFM for NOL, the periodically aligned metallic dots with the size around 5-10 nm were successfully observed. The mechanism of the formation of the self-organized aligned Ni nano constriction dots is discussed from the standpoint of the grain size, the crystal orientation, the preferred oxidation of Ta at the diffused interface.

The route of liquid precursor to ZnO nanoparticles in premixed combustion spray pyrolysis

NASA Astrophysics Data System (ADS)

Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2018-04-01

Zinc oxide nanoparticles had been successfully synthesized by premixed combustion spray pyrolysis. Zinc acetate was dissolved in distilled water was selected as a liquid precursor. Zinc nitrate was also used for comparison the effect of precursor type on the generated particles morphology and the crystallinity. The premixed combustion reaction used liquefied petroleum gas (LPG) mainly consisting of butane and propane as a fuel and compressed air used as an oxidizer. The liquid precursor was atomized using a custom two fluid nozzle to generate droplets. Then, the droplets were sprayed by the flow of air as a carrier gas into the premixed combustion reactor. The zinc precursor was decomposed to zinc oxide due to the high temperature as a result of combustion reaction inside the reactor resulting in nanoparticles formation. The particle size decreased with the increase of the fuel flow rate. In addition, it can be found that at the same flow rate of fuel, the particle size of zinc oxide synthesized using zinc nitrate is larger than that of the use of zinc acetate as a precursor.

Zinc supplementation alleviates the progression of diabetic nephropathy by inhibiting the overexpression of oxidative-stress-mediated molecular markers in streptozotocin-induced experimental rats.

PubMed

Barman, Susmita; Pradeep, Seetur R; Srinivasan, Krishnapura

2018-04-01

Zinc deficiency during diabetes projects a role for zinc nutrition in the management of diabetic nephropathy. The current study explored whether zinc supplementation protects against diabetic nephropathy through modulation of kidney oxidative stress and stress-induced expression related to the inflammatory process in streptozotocin-induced diabetic rats. Groups of hyperglycemic rats were exposed to dietary interventions for 6 weeks with zinc supplementation (5 times and 10 times the normal level). Supplemental-zinc-fed diabetic groups showed a significant reversal of increased kidney weight and creatinine clearance. There was a significant reduction in hyperlipidemic condition along with improved PUFA:SFA ratio in the renal tissue. Expression of the lipid oxidative marker and expression of inflammatory markers, cytokines, fibrosis factors and apoptotic regulatory proteins observed in diabetic kidney were beneficially modulated by zinc supplementation, the ameliorative effect being concomitant with elevated antiapoptosis. There was a significant reduction in advanced glycation, expression of the receptor of the glycated products and oxidative stress markers. Zinc supplementation countered the higher activity and expression of polyol pathway enzymes in the kidney. Overexpression of the glucose transporters, as an adaptation to the increased need for glucose transport in diabetic condition, was minimized by zinc treatment. The pathological abnormalities in the renal architecture of diabetic animals were corrected by zinc intervention. Thus, dietary zinc supplementation has a significant beneficial effect in the control of diabetic nephropathy. This was exerted through a protective influence on oxidative-stress-induced cytokines, inflammatory proliferation and consequent renal injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Low-temperature solution-processed zinc oxide field effect transistor by blending zinc hydroxide and zinc oxide nanoparticle in aqueous solutions

NASA Astrophysics Data System (ADS)

Shin, Hyeonwoo; Kang, Chan-mo; Baek, Kyu-Ha; Kim, Jun Young; Do, Lee-Mi; Lee, Changhee

2018-05-01

We present a novel methods of fabricating low-temperature (180 °C), solution-processed zinc oxide (ZnO) transistors using a ZnO precursor that is blended with zinc hydroxide [Zn(OH)2] and zinc oxide hydrate (ZnO • H2O) in an ammonium solution. By using the proposed method, we successfully improved the electrical performance of the transistor in terms of the mobility (μ), on/off current ratio (I on/I off), sub-threshold swing (SS), and operational stability. Our new approach to forming a ZnO film was systematically compared with previously proposed methods. An atomic forced microscopic (AFM) image and an X-ray photoelectron spectroscopy (XPS) analysis showed that our method increases the ZnO crystallite size with less OH‑ impurities. Thus, we attribute the improved electrical performance to the better ZnO film formation using the blending methods.

Maternal exposure to nanosized titanium dioxide suppresses embryonic development in mice.

PubMed

Hong, Fashui; Zhou, Yingjun; Zhao, Xiaoyang; Sheng, Lei; Wang, Ling

2017-01-01

Although nanoscale titanium dioxide (nano-TiO 2 ) has been extensively used in industrial food applications and daily products for pregnant women, infants, and children, its potential toxicity on fetal development has been rarely studied. The main objective of this investigation was to establish the effects of maternal exposure of nano-TiO 2 on developing embryos. Female imprinting control region mice were orally administered nano-TiO 2 from gestational day 0 to 17. Our findings showed that Ti concentrations in maternal serum, placenta, and fetus were increased in nano-TiO 2 -exposed mice when compared to controls, which resulted in reductions in the contents of calcium and zinc in maternal serum, placenta, and fetus, maternal weight gain, placental weight, fetal weight, number of live fetuses, and fetal crown-rump length as well as cauda length, and caused an increase in the number of both dead fetuses and resorptions. Furthermore, maternal nano-TiO 2 exposure inhibited development of the fetal skeleton, suggesting a significant absence of cartilage, reduced or absent ossification, and an increase in the number of fetuses with dysplasia, including exencephaly, spina bifida, coiled tail, scoliosis, rib absence, and sternum absence. These findings indicated that nano-TiO 2 can cross the blood-fetal barrier and placental barrier, thereby delaying the development of fetal mice and inducing skeletal malformation. These factors may be associated with reductions in both calcium and zinc in maternal serum and the fetus, and both the placenta and embryos may be major targets of developmental toxicity following maternal exposure to nano-TiO 2 during the prenatal period. Therefore, the application of nano-TiO 2 should be carried out with caution.

Maternal exposure to nanosized titanium dioxide suppresses embryonic development in mice

PubMed Central

Hong, Fashui; Zhou, Yingjun; Zhao, Xiaoyang; Sheng, Lei; Wang, Ling

2017-01-01

Although nanoscale titanium dioxide (nano-TiO2) has been extensively used in industrial food applications and daily products for pregnant women, infants, and children, its potential toxicity on fetal development has been rarely studied. The main objective of this investigation was to establish the effects of maternal exposure of nano-TiO2 on developing embryos. Female imprinting control region mice were orally administered nano-TiO2 from gestational day 0 to 17. Our findings showed that Ti concentrations in maternal serum, placenta, and fetus were increased in nano-TiO2-exposed mice when compared to controls, which resulted in reductions in the contents of calcium and zinc in maternal serum, placenta, and fetus, maternal weight gain, placental weight, fetal weight, number of live fetuses, and fetal crown–rump length as well as cauda length, and caused an increase in the number of both dead fetuses and resorptions. Furthermore, maternal nano-TiO2 exposure inhibited development of the fetal skeleton, suggesting a significant absence of cartilage, reduced or absent ossification, and an increase in the number of fetuses with dysplasia, including exencephaly, spina bifida, coiled tail, scoliosis, rib absence, and sternum absence. These findings indicated that nano-TiO2 can cross the blood–fetal barrier and placental barrier, thereby delaying the development of fetal mice and inducing skeletal malformation. These factors may be associated with reductions in both calcium and zinc in maternal serum and the fetus, and both the placenta and embryos may be major targets of developmental toxicity following maternal exposure to nano-TiO2 during the prenatal period. Therefore, the application of nano-TiO2 should be carried out with caution. PMID:28883729

Properties of Zinc Oxide Nanoparticles and Their Activity Against Microbes

NASA Astrophysics Data System (ADS)

Siddiqi, Khwaja Salahuddin; ur Rahman, Aziz; Tajuddin; Husen, Azamal

2018-05-01

Zinc oxide is an essential ingredient of many enzymes, sun screens, and ointments for pain and itch relief. Its microcrystals are very efficient light absorbers in the UVA and UVB region of spectra due to wide bandgap. Impact of zinc oxide on biological functions depends on its morphology, particle size, exposure time, concentration, pH, and biocompatibility. They are more effective against microorganisms such as Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Sarcina lutea, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Pseudomonas vulgaris, Candida albicans, and Aspergillus niger. Mechanism of action has been ascribed to the activation of zinc oxide nanoparticles by light, which penetrate the bacterial cell wall via diffusion. It has been confirmed from SEM and TEM images of the bacterial cells that zinc oxide nanoparticles disintegrate the cell membrane and accumulate in the cytoplasm where they interact with biomolecules causing cell apoptosis leading to cell death.

Properties of Zinc Oxide Nanoparticles and Their Activity Against Microbes.

PubMed

Siddiqi, Khwaja Salahuddin; Ur Rahman, Aziz; Tajuddin; Husen, Azamal

2018-05-08

Zinc oxide is an essential ingredient of many enzymes, sun screens, and ointments for pain and itch relief. Its microcrystals are very efficient light absorbers in the UVA and UVB region of spectra due to wide bandgap. Impact of zinc oxide on biological functions depends on its morphology, particle size, exposure time, concentration, pH, and biocompatibility. They are more effective against microorganisms such as Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Sarcina lutea, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Pseudomonas vulgaris, Candida albicans, and Aspergillus niger. Mechanism of action has been ascribed to the activation of zinc oxide nanoparticles by light, which penetrate the bacterial cell wall via diffusion. It has been confirmed from SEM and TEM images of the bacterial cells that zinc oxide nanoparticles disintegrate the cell membrane and accumulate in the cytoplasm where they interact with biomolecules causing cell apoptosis leading to cell death.

Developing Sensitive and Selective Nanosensors: A Single Molecule - Multiple Excitation Source Approach. Altairnano Lithium Ion Nano-scaled Titanate Oxide Cell and Module Abuse Testing

DTIC Science & Technology

2012-03-13

Source Approach Part II. Altairnano Lithium Ion Nano-scaled Titanate Oxide Cell and Module Abuse Testing 14. ABSTRACT 16. SECURITY CLASSIFICATION OF...Lithium Ion Nano-scaled Titanate Oxide Cell and Module Abuse Testing Report Title ABSTRACT This final report for Contract W911NF-09-C-0135 transmits the...prototype development. The second (Part II.) is "Altairnano Lithium Ion Nano-scaled Titanate Oxide Cell and Module Abuse Test Report". The

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…

Two-stage epitaxial growth of vertically-aligned SnO 2 nano-rods on(001) ceria

DOE PAGES

Solovyov, Vyacheslav F.; Wu, Li-jun; Rupich, Martin W.; ...

2014-09-20

Growth of high-aspect ratio oriented tin oxide, SnO 2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO 2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO 2 deposit. Second, vertical SnO 2nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 μm long nano-rods with an average diameter of ≈20 nm.

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

NASA Astrophysics Data System (ADS)

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

2015-02-01

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.

Investigation of ZnO Nanowire Interfaces for Multi-Scale Composites

DTIC Science & Technology

2012-03-06

growth of zinc oxide ( ZnO ) nanowires on the surface of the...through the growth of zinc oxide ( ZnO ) nanowires on the surface of the reinforcing fibers. The nanowires functionally grade the interface, improve bonding...bulk composite. This has been accomplished through the growth of zinc oxide ( ZnO ) nanowires on the surface of the reinforcing fibers. ZnO

Study on Locally Confined Deposition of Si Nanocrystals in High-Aspect-Ratio Si Nano-Pillar Arrays for Nano-Electronic and Nano-Photonic Applications II

DTIC Science & Technology

2010-12-03

photoluminescence characteristics of equivalent-size controlled silicon quantum dots by employing a nano-porous aluminum oxide membrane as the template for growing...synthesis of Si quantum dots (Si-QDs) embedded in low-temperature (500oC) annealed Si-rich SiOx nano-rod deposited in nano-porous anodic aluminum oxide ...characteristics of the equivalent-size controlled Si-QDs by employing the nano-porous AAO membrane as the template for growing Si-rich SiOx nano-rods

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.

Crystal Structure Characterization of Thin Layer Zinc Oxide

NASA Astrophysics Data System (ADS)

Doyan, Aris; Susilawati; Azizatul Fitri, Siti; Ahzan, Sukainil

2017-05-01

In this research the characterization of the crystal structure of a thin layer of ZnO (zinc oxide) were synthesized by sol - gel method and spin coating deposited on a glass substrate. The samples were divided into three sol concentrations of 0.1, 0.3, 0.5 Molar and two deposition temperature is 350 °C, and 550 °C. UV-Vis. spectrophotometer results showed that in the spectrum of visible light (wavelength range 300-800 nm) has a transmittance value of which increases with increasing concentration and temperature deposition of zinc oxide, otherwise the value of the absorption and the band gap energy decreases with the addition of concentration and deposition temperature. The transmittances value of the highest and lowest absorption was 93.5% and 0.03 is at a concentration of 0.1 M and zinc oxide deposition temperature of 550 °C, with a value of band gap energy of 2.98 eV. The XRD results showed that the zinc oxide crystal orientation in the field of 013 with a crystal grain size 14.4472 nm. SEM results showed the surface morphology of zinc oxide such as rod-like.

Targeted Zinc Delivery: A Novel Treatment for Prostate Cancer

DTIC Science & Technology

2010-06-01

aconitase, which normally functions to oxidize citrate during the Krebs cycle . Because citrate is a principle component of seminal fluid, prostate...tissue, likely due to the metabolic effects of zinc in the Krebs cycle . That is, because zinc inhibits m- aconitase, loss of zinc allows for greater...secretory cells do not complete the oxidation of citrate in the mitochondria and the zinc-mediated inhibition of m-aconitase is crucial for the

Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces.

PubMed

Seifert, Susan; Simon, Frank; Baumann, Giesela; Hietschold, Michael; Seifert, Andreas; Spange, Stefan

2011-12-06

The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions. © 2011 American Chemical Society

Effect of different spiking procedures on the distribution and toxicity of ZnO nanoparticles in soil.

PubMed

Waalewijn-Kool, Pauline L; Diez Ortiz, Maria; van Gestel, Cornelis A M

2012-10-01

Due to the difficulty in dispersing some engineered nanomaterials in exposure media, realizing homogeneous distributions of nanoparticles (NP) in soil may pose major challenges. The present study investigated the distribution of zinc oxide (ZnO) NP (30 nm) and non-nano ZnO (200 nm) in natural soil using two different spiking procedures, i.e. as dry powder and as suspension in soil extract. Both spiking procedures showed a good recovery (>85 %) of zinc and based on total zinc concentrations no difference was found between the two spiking methods. Both spiking procedures resulted in a fairly homogeneous distribution of the ZnO particles in soil, as evidenced by the low variation in total zinc concentration between replicate samples (<12 % in most cases). Survival of Folsomia candida in soil spiked at concentrations up to 6,400 mg Zn kg(-1) d.w. was not affected for both compounds. Reproduction was reduced in a concentration-dependent manner with EC50 values of 3,159 and 2,914 mg Zn kg(-1) d.w. for 30 and 200 nm ZnO spiked as dry powder and 3,593 and 5,633 mg Zn kg(-1) d.w. introduced as suspension. Toxicity of ZnO at 30 and 200 nm did not differ. We conclude that the ZnO particle toxicity is not size related and that the spiking of the soil with ZnO as dry powder or as a suspension in soil extract does not affect its toxicity to F. candida.

Mild zinc deficiency in male and female rats: early postnatal alterations in renal nitric oxide system and morphology.

PubMed

Tomat, Analia Lorena; Veiras, Luciana Cecilia; Aguirre, Sofía; Fasoli, Héctor; Elesgaray, Rosana; Caniffi, Carolina; Costa, María Ángeles; Arranz, Cristina Teresa

2013-03-01

Fetal and postnatal zinc deficiencies induce an increase in arterial blood pressure and impair renal function in male adult rats. We therefore hypothesized that these renal alterations are present in early stages of life and that there are sexual differences in the adaptations to this nutritional injury. The aim was to study the effects of moderate zinc deficiency during fetal life and lactation on renal morphology, oxidative stress, apoptosis, and the nitric oxide system in male and female rats at 21 d of life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy to weaning. Glomerulus number, morphology, oxidative stress, apoptotic cells, nitric oxide synthase activity, and protein expression were evaluated in the kidneys of offspring at 21 d. Zinc deficiency decreased the nephron number, induced glomerular hypertrophy, increased oxidative damage, and decreased nitric oxide synthase activity in the male and female rat kidneys. Nitric oxide synthase activity was not affected by inhibitors of the neuronal or inducible isoforms, so nitric oxide was mainly generated by the endothelial isoenzyme. Gender differences were observed in glomerular areas and antioxidant enzyme activities. Zinc deficiency during fetal life and lactation induces an early decrease in renal functional units, associated with a decrease in nitric oxide activity and an increase in oxidative stress, which would contribute to increased arterial blood pressure and renal dysfunction in adulthood. The sexual differences observed in this model may explain the dissimilar development of hypertension and renal diseases in adult life. Copyright © 2013 Elsevier Inc. All rights reserved.

Spectroscopic characterization of zinc oxide nanorods synthesized by solid-state reaction

NASA Astrophysics Data System (ADS)

Prasad, Virendra; D'Souza, Charlene; Yadav, Deepti; Shaikh, A. J.; Vigneshwaran, Nadanathangam

2006-09-01

Well-crystallized zinc oxide nanorods have been fabricated by single step solid-state reaction using zinc acetate and sodium hydroxide, at room temperature. The sodium lauryl sulfate (SLS) stabilized zinc oxide nanorods were characterized by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and photoluminescence spectroscopy. The X-ray diffraction revealed the wurtzite structure of zinc oxide. The size estimation by XRD and TEM confirmed that the ZnO nanorods are made of single crystals. The growth of zinc oxide crystals into rod shape was found to be closely related to its hexagonal nature. The mass ratio of SLS:ZnO in the nanorods was found to be 1:10 based on the thermogravimetric analysis. Blue shift of photoluminescence emission was noticed in the ZnO nanorods when compared to that of ZnO bulk. FT-IR analysis confirmed the binding of SLS with ZnO nanorods. Apart from ease of preparation, this method has the advantage of eco-friendliness since the solvent and other harmful chemicals were eliminated in the synthesis protocol.

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Juanjuan; Zhang, Yu; Xu, Wentao, E-mail: xuwentaoboy@sina.com

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 notmore » affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{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.« less

Synthesis of graphene oxide and reduced graphene oxide using volumetric method by a novel approach without NaNO2 or NaNO3

NASA Astrophysics Data System (ADS)

Gunda, Rajitha; Madireddy, Buchi Suresh; Dash, Raj Kishora

2018-02-01

In the present work, graphite was processed to graphene oxide (GO) using modified Hummer's method by volumetric titration approach, without attaining zero temperature and the addition of toxic chemicals (NaNO2/NaNO3). The complete oxidation of graphite to graphene oxide was obtained by controlled addition (volumetric titration) of KMnO4. The addition of higher KMnO4 resulted in partial oxidation and 2-3 mono-layers with less defects/disordered structure of reduced graphene oxide (RGO) sheets were achieved. Samples were analyzed by XRD, FT-IR, Raman analysis, and TEM analysis. X-ray diffraction displayed the oxidized peak of graphene oxide at 11.9° and reduced graphene oxide at 23.8°. The prolonged stability of the synthesized GO with lower mole ratios of oxidizing agent was confirmed from UV-visible spectroscopy. Based on the results, processed graphene oxide is found to be a candidate material for thermally stable capacitor application.

Method of fabricating a catalytic structure

DOEpatents

Rollins, Harry W [Idaho Falls, ID; Petkovic, Lucia M [Idaho Falls, ID; Ginosar, Daniel M [Idaho Falls, ID

2009-09-22

A precursor to a catalytic structure comprising zinc oxide and copper oxide. The zinc oxide has a sheet-like morphology or a spherical morphology and the copper oxide comprises particles of copper oxide. The copper oxide is reduced to copper, producing the catalytic structure. The catalytic structure is fabricated by a hydrothermal process. A reaction mixture comprising a zinc salt, a copper salt, a hydroxyl ion source, and a structure-directing agent is formed. The reaction mixture is heated under confined volume conditions to produce the precursor. The copper oxide in the precursor is reduced to copper. A method of hydrogenating a carbon oxide using the catalytic structure is also disclosed, as is a system that includes the catalytic structure.

Novel nano coordination polymer based synthesis of porous ZnO hexagonal nanodisk for higher gas sorption and photocatalytic activities

NASA Astrophysics Data System (ADS)

Rakibuddin, M.; Ananthakrishnan, Rajakumar

2016-01-01

Zinc(II)-based nano co-ordination polymers (NCPs) are first prepared at room temperature from three different isomers of dihydroxysalophen (DHS) ligand with Zn(OAc)2·2H2O and 1,4-benzenedicarboxylic acid (BDC) in DMF solvent. Facile calcinations of [Zn (DHS) (BDC)]·nH2O (shortly denoted as Zn(II)-based NCP) at ambient conditions produces porous ZnO hexagonal nanodisks. Moreover, a novel approach has been introduced to observe the effect of ligand of the NCP on the physico-chemical properties of the as-synthesized ZnO. The porous ZnO nanodisks are characterized by FT-IR, PXRD, TEM, FESEM, EDX and BET analysis, and the results exhibit that they possess different sizes, surface areas and porosities. Nitrogen gas sorption capacity and photocatalytic activities of the as-prepared ZnO nanodisks are also checked, and it is noticed that they differ in these physico-chemical properties due to having different porosities and surface areas. A comparative study is also done with commercially available ZnO; interestingly, the commercial ZnO exhibited lower surface area, gas sorption and photocatalytic activity compared to the ZnO nanodisks. Hence, preparation of the ZnO through the NCP route and tuning their physico-chemical properties would offer new directions in synthesis of various nano metal oxides of unique properties.

Sorption behavior of microamounts of zinc on titanium oxide from aqueous solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hasany, S.M.; Ghaffar, A.; Chughtai, F.A.

1991-08-01

To correlate soil response toward zinc, it is necessary to study its adsorption in detail on soils or on their constituents. The adsorption of microamounts of zinc on titanium oxide, prepared and characterized in this laboratory, has been studied in detail. Zinc adsorption has been found to be dependent on the pH of the aqueous solution, amount of oxide, and zinc concentration. Maximum adsorption is from pH 10 buffer. EDTA and cyanide ions inhibit adsorption significantly. The adsorption of other elements under optimal conditions has also been measured on this oxide. Sc(III) and Cs(I) show almost negligible adsorption. Zinc adsorptionmore » follows the linear form of the Freundlich adsorption isotherm: log C{sub Ads} = log A + (1/n) log C{sub Bulk} with A = 0.48 mol/g and n = 1. Except at a very low bulk concentration (3 {times} 10{sup {minus}5} mol/dm{sup 3}), Langmuir adsorption isotherm is also linear for the entire zinc concentration investigated. The limiting adsorbed concentration is estimated to be 0.18 mol/g.« less

Sulfur dioxide leaching of spent zinc-carbon-battery scrap

NASA Astrophysics Data System (ADS)

Avraamides, J.; Senanayake, G.; Clegg, R.

Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2 M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25 °C. Alkaline leaching with 6 M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30 min at 30 °C using 0.1-1.0 M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1 M to 2 M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide.

Subtractive Plasma-Assisted-Etch Process for Developing High Performance Nanocrystalline Zinc-Oxide Thin-Film-Transistors

DTIC Science & Technology

2015-03-26

THIN - FILM - TRANSISTORS THESIS Thomas M. Donigan, First Lieutenant, USAF AFIT-ENG-MS-15-M-027 DEPARTMENT OF THE AIR FORCE AIR UNIVERSITY AIR...DEVELOPING HIGH PERFORMANCE NANOCRYSTALLINE ZINC-OXIDE THIN - FILM - TRANSISTORS THESIS Presented to the Faculty Department of Electrical and...15-M-027 SUBTRACTIVE PLASMA-ASSISTED-ETCH PROCESS FOR DEVELOPING HIGH PERFORMANCE NANOCRYSTALLINE ZINC-OXIDE THIN - FILM - TRANSISTORS

Studies of Peptide-Mineral Interactions and Biosilicification

DTIC Science & Technology

2010-07-16

His). The effect of zinc oxide -binding peptides ( ZnO -BPs) on the morphology and formation of ZnO were studied using G-12 (GLHVMHKVAPPR) and EM-12...interactions with silica and zinc oxide . Detailed quantitative experimental studies together with molecular modeling studies have shown that G12 (GLHVMHKVAPPR...studies of a primitive 15. SUBJECT TERMS Peptides, zinc oxide , silica, silver, peptide-mineral interactions, computational chemistry, molecular

In vitro assessment of the antimicrobial activity of silver and zinc oxide nanoparticles against fish pathogens.

PubMed

Shaalan, Mohamed Ibrahim; El-Mahdy, Magdy Mohamed; Theiner, Sarah; El-Matbouli, Mansour; Saleh, Mona

2017-07-21

Antibiotic resistance is a global issue that threatens public health. The excessive use of antibiotics contributes to this problem as the genes of antibiotic resistance can be transferred between the bacteria in humans, animals and aquatic organisms. Metallic nanoparticles could serve as future substitutes for some conventional antibiotics because of their antimicrobial activity. The aim of this study was to evaluate the antimicrobial effects of silver and zinc oxide nanoparticles against major fish pathogens and assess their safety in vitro. Silver nanoparticles were synthesized by chemical reduction and characterized with UV-Vis spectroscopy, transmission electron microscopy and zeta sizer. The concentrations of silver and zinc oxide nanoparticles were measured using inductively coupled plasma-mass spectrometry. Subsequently, silver and zinc oxide nanoparticles were tested for their antimicrobial activity against Aeromonas hydrophila, Aeromonas salmonicida subsp. salmonicida, Edwardsiella ictaluri, Edwardsiella tarda, Francisella noatunensis subsp. orientalis, Yersinia ruckeri and Aphanomyces invadans and the minimum inhibitory concentrations were determined. MTT assay was performed on eel kidney cell line (EK-1) to determine the cell viability after incubation with nanoparticles. The interaction between silver nanoparticles and A. salmonicida was investigated by transmission electron microscopy. The tested nanoparticles exhibited marked antimicrobial activity. Silver nanoparticles inhibited the growth of both A. salmonicida and A. invadans at a concentration of 17 µg/mL. Zinc oxide nanoparticles inhibited the growth of A. salmonicida, Y. ruckeri and A. invadans at concentrations of 15.75, 31.5 and 3.15 µg/mL respectively. Silver nanoparticles showed higher cell viability when compared to zinc oxide nanoparticles in the MTT assay. Transmission electron microscopy showed the attachment of silver nanoparticles to the bacterial membrane and disruption of its integrity. This is the first study on inhibitory effects of silver and zinc oxide nanoparticles towards A. salmonicida and A. invadans. Moreover, zinc oxide nanoparticles inhibited the growth of Y. ruckeri. In low concentrations, silver nanoparticles were less cytotoxic than zinc oxide nanoparticles and represent an alternative antimicrobial compound against A. hydrophila, A. salmonicida and A. invadans.

Two-stage epitaxial growth of vertically-aligned SnO2 nano-rods on (001) ceria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solovyov, VF; Wu, LJ; Rupich, MW

2014-12-15

Growth of high-aspect ratio oriented tin oxide, SnO2, nano-rods is complicated by a limited choice of matching substrates. We show that a (001) cerium oxide, CeO2, surface uniquely enables epitaxial growth of tin-oxide nano-rods via a two-stage process. First, (100) oriented nano-wires coat the ceria surface by lateral growth, forming a uniaxially-textured SnO2 deposit. Second, vertical SnO2 nano-rods nucleate on the deposit by homoepitaxy. We demonstrate growth of vertically oriented 1-2 mu m long nano-rods with an average diameter of approximate to 20 nm. 2014 Elsevier B.V. All rights reserved.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Properties of ZnO nanocrystals prepared by radiation method

NASA Astrophysics Data System (ADS)

Čuba, Václav; Gbur, Tomáš; Múčka, Viliam; Nikl, Martin; Kučerková, Romana; Pospíšil, Milan; Jakubec, Ivo

2010-01-01

Zinc oxide nanoparticles were prepared by irradiation of aqueous solutions containing zinc(II) ions, propan-2-ol, polyvinyl alcohol, and hydrogen peroxide. Zinc oxide was found in solid phase either directly after irradiation, or after additional heat treatment. Various physicochemical parameters, including scintillation properties of prepared materials, were studied. After decomposition of impurities and annealing of oxygen vacancies, the samples showed intensive emission in visible spectral range and well-shaped exciton luminescence at 390-400 nm. The best scintillating properties had zinc oxide prepared from aqueous solutions containing zinc formate as initial precursor and hydrogen peroxide. Size of the crystalline particles ranged from tens to hundreds nm, depending on type of irradiated solution and post-irradiation thermal treatment.

Chemical stability and electrical performance of dual-active-layered zinc-tin-oxide/indium-gallium-zinc-oxide thin-film transistors using a solution process.

PubMed

Kim, Chul Ho; Rim, You Seung; Kim, Hyun Jae

2013-07-10

We investigated the chemical stability and electrical properties of dual-active-layered zinc-tin-oxide (ZTO)/indium-gallium-zinc-oxide (IGZO) structures (DALZI) with the durability of the chemical damage. The IGZO film was easily corroded or removed by an etchant, but the DALZI film was effectively protected by the high chemical stability of ZTO. Furthermore, the electrical performance of the DALZI thin-film transistor (TFT) was improved by densification compared to the IGZO TFT owing to the passivation of the pin holes or pore sites and the increase in the carrier concentration due to the effect of Sn(4+) doping.

In situ observation of the formation of hollow zinc oxide shells

DOE PAGES

Tringe, J. W.; Levie, H. W.; El-Dasher, B. S.; ...

2011-06-14

Single crystal zinc particles, 1–2 μm1–2 μm in diameter, were observed in situ with transmission electron microscopy during sublimation. The rate of sublimation is strongly dependent on the presence of a surface oxide layer. Near 375°, minimally oxidized Zn surfaces sublime in tens of seconds, consistent with a model in which the particle behaves similarly to an isolated microscale effusion cell. By contrast, zinc particles fully enclosed by oxide sublime less than one-tenth as quickly. Here these results provide new insight into the synthesis mechanisms of hollow ZnO microspheres and related structures formed from metallic zinc at elevated temperatures.

Ketamine-induced behavioural and brain oxidative changes in mice: an assessment of possible beneficial effects of zinc as mono- or adjunct therapy.

PubMed

Onaolapo, Olakunle James; Ademakinwa, Olayemi Quyyom; Olalekan, Temitayo Opeyemi; Onaolapo, Adejoke Yetunde

2017-09-01

We studied the influence of zinc, haloperidol or olanzapine on neurobehaviour (open-field, radial arm maze and elevated plus maze) and brain antioxidant status in vehicle- or ketamine-treated mice, with the aim of ascertaining the potentials of zinc in counteracting ketamine's effects. Experiment 1 assessed the effects of zinc in healthy animals and the relative degrees of modulation of ketamine's effects by zinc, haloperidol or olanzapine, respectively. Experiment 2 assessed the modulation of ketamine's effects following co-administration of zinc with haloperidol or olanzapine. Male mice weighing 18-20 g each were used. Animals were pretreated with ketamine (except vehicle, zinc, haloperidol and olanzapine controls) for 10 days before commencement of 14-day treatment (day 11-24) with vehicle, zinc, haloperidol or olanzapine (alone or in combination). Ketamine injection also continued alongside zinc and/or standard drugs in the ketamine-treated groups. Zinc, haloperidol and olanzapine were administered by gavage. Treatments were given daily and behaviours assessed on days 11 and 24. On day 24, animals were sacrificed and whole brain homogenates used for estimation of glutathione, nitric oxide and malondialdehyde (MDA) levels. Ketamine increased open-field behaviours, nitric oxide and MDA levels, while it decreased working memory, social interaction and glutathione. Administration of zinc alone or in combination with haloperidol or olanzapine was associated with variable degrees of reversal of these effects. Zinc may have the potential of a possible therapeutic agent and/or adjunct in the reversal of schizophrenia-like changes in behaviour and brain oxidative status.

Reactive oxygen species-related activities of nano-iron metal and nano-iron oxides.

PubMed

Wu, Haohao; Yin, Jun-Jie; Wamer, Wayne G; Zeng, Mingyong; Lo, Y Martin

2014-03-01

Nano-iron metal and nano-iron oxides are among the most widely used engineered and naturally occurring nanostructures, and the increasing incidence of biological exposure to these nanostructures has raised concerns about their biotoxicity. Reactive oxygen species (ROS)-induced oxidative stress is one of the most accepted toxic mechanisms and, in the past decades, considerable efforts have been made to investigate the ROS-related activities of iron nanostructures. In this review, we summarize activities of nano-iron metal and nano-iron oxides in ROS-related redox processes, addressing in detail the known homogeneous and heterogeneous redox mechanisms involved in these processes, intrinsic ROS-related properties of iron nanostructures (chemical composition, particle size, and crystalline phase), and ROS-related bio-microenvironmental factors, including physiological pH and buffers, biogenic reducing agents, and other organic substances. Copyright © 2014. Published by Elsevier B.V.

Ternary and coupled binary zinc tin oxide nanopowders: Synthesis, characterization, and potential application in photocatalytic processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ivetić, T.B., E-mail: tamara.ivetic@df.uns.ac.rs; Finčur, N.L.; Đačanin, Lj. R.

2015-02-15

Highlights: • Mechanochemically synthesized nanocrystalline zinc tin oxide (ZTO) powders. • Photocatalytic degradation of alprazolam in the presence of ZTO water suspensions. • Coupled binary ZTO exhibits enhanced photocatalytic activity compared to ternary ZTO. - Abstract: In this paper, ternary and coupled binary zinc tin oxide nanocrystalline powders were prepared via simple solid-state mechanochemical method. X-ray diffraction, scanning electron microscopy, Raman and reflectance spectroscopy were used to study the structure and optical properties of the obtained powder samples. The thermal behavior of zinc tin oxide system was examined through simultaneous thermogravimetric-differential scanning calorimetric analysis. The efficiencies of ternary (Zn{sub 2}SnO{submore » 4} and ZnSnO{sub 3}) and coupled binary (ZnO/SnO{sub 2}) zinc tin oxide water suspensions in the photocatalytic degradation of alprazolam, short-acting anxiolytic of the benzodiazepine class of psychoactive drugs, under UV irradiation were determined and compared with the efficiency of pure ZnO and SnO{sub 2}.« less

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

PubMed

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

2015-11-01

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

Comparative Study of Antidiabetic Activity and Oxidative Stress Induced by Zinc Oxide Nanoparticles and Zinc Sulfate in Diabetic Rats.

PubMed

Nazarizadeh, Ali; Asri-Rezaie, Siamak

2016-08-01

In the current study, antidiabetic activity and toxic effects of zinc oxide nanoparticles (ZnO) were investigated in diabetic rats compared to zinc sulfate (ZnSO4) with particular emphasis on oxidative stress parameters. One hundred and twenty male Wistar rats were divided into two healthy and diabetic groups, randomly. Each major group was further subdivided into five subgroups and then orally supplemented with various doses of ZnO (1, 3, and 10 mg/kg) and ZnSO4 (30 mg/kg) for 56 consecutive days. ZnO showed greater antidiabetic activity compared to ZnSO4 evidenced by improved glucose disposal, insulin levels, and zinc status. The altered activities of erythrocyte antioxidant enzymes as well as raised levels of lipid peroxidation and a marked reduction of total antioxidant capacity were observed in rats receiving ZnO. ZnO nanoparticles acted as a potent antidiabetic agent, however, severely elicited oxidative stress particularly at higher doses.

Green Synthesis of Formulated Zinc Oxide Nanoparticles for Chemical Protection of Skin Care and Related Applications

NASA Astrophysics Data System (ADS)

Koppolu, Ramya

Nanomaterials have diversified applications based on the unique properties. These nanoparticles and functionalized nanocomposites have been studied in the health care filed. Nanoparticles are mostly used in sunscreens which are a part of human life. These sunscreens consist of titanium dioxide and zinc oxide nanoparticles. Due to the higher band crevices, they help the skin to protect from ultraviolet rays, for instance, ultraviolet B and ultraviolet A. A series of nanostructured zinc oxide nanoparticles were prepared by cost-effective chemical and bioinspired methods and variables were optimized. Highly stable and spherical zinc oxide nanoparticles were formulated by aloe vera ( Aloe barbadensis) plant extract and avocado (Persea americana Mill) fruit extract. The state-of-the-art instrumentation was used to characterize the morphology, elemental composition, and particle size distribution. X-ray diffraction data indicated highly crystalline and ultrafine nanoparticles were obtained from the colloidal methods. The X-ray photoelectron spectroscopy results showed the chemical state of zinc, carbon, and oxygen atoms were well-indexed and are used as fingerprint identification of the elements. Transmission electron microscopy images show the shape of particles were cubic and fiber shape contingent upon the protecting operators and heat treatment conditions. The toxicity studies of zinc oxide nanoparticles were found to cause an increase in nitric oxide, which is protecting against further oxidative stress and appears to be nontoxic.

Copper Doping of Zinc Oxide by Nuclear Transmutation

DTIC Science & Technology

2014-03-27

Copper Doping of Zinc Oxide by Nuclear Transmutation THESIS Matthew C. Recker, Captain, USAF AFIT-ENP-14-M-30 DEPARTMENT OF THE AIR FORCE AIR...NUCLEAR TRANSMUTATION THESIS Presented to the Faculty Department of Engineering Physics Graduate School of Engineering and Management Air Force...COPPER DOPING OF ZINC OXIDE BY NUCLEAR TRANSMUTATION Matthew C. Recker, BS Captain, USAF Approved: //signed// 27 February 2014 John W. McClory, PhD

Enhancement in sensitivity of graphene-based zinc oxide assisted bimetallic surface plasmon resonance (SPR) biosensor

NASA Astrophysics Data System (ADS)

Kumar, Rajeev; Kushwaha, Angad S.; Srivastava, Monika; Mishra, H.; Srivastava, S. K.

2018-03-01

In the present communication, a highly sensitive surface plasmon resonance (SPR) biosensor with Kretschmann configuration having alternate layers, prism/zinc oxide/silver/gold/graphene/biomolecules (ss-DNA) is presented. The optimization of the proposed configuration has been accomplished by keeping the constant thickness of zinc oxide (32 nm), silver (32 nm), graphene (0.34 nm) layer and biomolecules (100 nm) for different values of gold layer thickness (1, 3 and 5 nm). The sensitivity of the proposed SPR biosensor has been demonstrated for a number of design parameters such as gold layer thickness, number of graphene layer, refractive index of biomolecules and the thickness of biomolecules layer. SPR biosensor with optimized geometry has greater sensitivity (66 deg/RIU) than the conventional (52 deg/RIU) as well as other graphene-based (53.2 deg/RIU) SPR biosensor. The effect of zinc oxide layer thickness on the sensitivity of SPR biosensor has also been analysed. From the analysis, it is found that the sensitivity increases significantly by increasing the thickness of zinc oxide layer. It means zinc oxide intermediate layer plays an important role to improve the sensitivity of the biosensor. The sensitivity of SPR biosensor also increases by increasing the number of graphene layer (upto nine layer).

Novel Magnetic Zinc Oxide Nanotubes for Phenol Adsorption: Mechanism Modeling

PubMed Central

Elkady, Marwa F.; Hassan, Hassan Shokry; Amer, Wael A.; Salama, Eslam; Algarni, Hamed; Shaaban, Essam Ramadan

2017-01-01

Considering the great impact of a material’s surface area on adsorption processes, hollow nanotube magnetic zinc oxide with a favorable surface area of 78.39 m2/g was fabricated with the assistance of microwave technology in the presence of poly vinyl alcohol (PVA) as a stabilizing agent followed by sonic precipitation of magnetite nano-particles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs identified the nanotubes’ morphology in the synthesized material with an average aspect ratio of 3. X-ray diffraction (XRD) analysis verified the combination of magnetite material with the hexagonal wurtzite structure of ZnO in the prepared material. The immobilization of magnetite nanoparticles on to ZnO was confirmed using vibrating sample magnetometry (VSM). The sorption affinity of the synthesized magnetic ZnO nanotube for phenolic compounds from aqueous solutions was examined as a function of various processing factors. The degree of acidity of the phenolic solution has great influence on the phenol sorption process on to magnetic ZnO. The calculated value of ΔH0 designated the endothermic nature of the phenol uptake process on to the magnetic ZnO nanotubes. Mathematical modeling indicated a combination of physical and chemical adsorption mechanisms of phenolic compounds on to the fabricated magnetic ZnO nanotubes. The kinetic process correlated better with the second-order rate model compared to the first-order rate model. This result indicates the predominance of the chemical adsorption process of phenol on to magnetic ZnO nanotubes. PMID:29186853

Thermal Conductivity of Wurtzite Zinc-Oxide from First-Principles Lattice Dynamics - a Comparative Study with Gallium Nitride

NASA Astrophysics Data System (ADS)

Wu, Xufei; Lee, Jonghoon; Varshney, Vikas; Wohlwend, Jennifer L.; Roy, Ajit K.; Luo, Tengfei

2016-03-01

Wurtzite Zinc-Oxide (w-ZnO) is a wide bandgap semiconductor that holds promise in power electronics applications, where heat dissipation is of critical importance. However, large discrepancies exist in the literature on the thermal conductivity of w-ZnO. In this paper, we determine the thermal conductivity of w-ZnO using first-principles lattice dynamics and compare it to that of wurtzite Gallium-Nitride (w-GaN) - another important wide bandgap semiconductor with the same crystal structure and similar atomic masses as w-ZnO. However, the thermal conductivity values show large differences (400 W/mK of w-GaN vs. 50 W/mK of w-ZnO at room temperature). It is found that the much lower thermal conductivity of ZnO originates from the smaller phonon group velocities, larger three-phonon scattering phase space and larger anharmonicity. Compared to w-GaN, w-ZnO has a smaller frequency gap in phonon dispersion, which is responsible for the stronger anharmonic phonon scattering, and the weaker interatomic bonds in w-ZnO leads to smaller phonon group velocities. The thermal conductivity of w-ZnO also shows strong size effect with nano-sized grains or structures. The results from this work help identify the cause of large discrepancies in w-ZnO thermal conductivity and will provide in-depth understanding of phonon dynamics for the design of w-ZnO-based electronics.

Thermal Conductivity of Wurtzite Zinc-Oxide from First-Principles Lattice Dynamics – a Comparative Study with Gallium Nitride

PubMed Central

Wu, Xufei; Lee, Jonghoon; Varshney, Vikas; Wohlwend, Jennifer L.; Roy, Ajit K.; Luo, Tengfei

2016-01-01

Wurtzite Zinc-Oxide (w-ZnO) is a wide bandgap semiconductor that holds promise in power electronics applications, where heat dissipation is of critical importance. However, large discrepancies exist in the literature on the thermal conductivity of w-ZnO. In this paper, we determine the thermal conductivity of w-ZnO using first-principles lattice dynamics and compare it to that of wurtzite Gallium-Nitride (w-GaN) – another important wide bandgap semiconductor with the same crystal structure and similar atomic masses as w-ZnO. However, the thermal conductivity values show large differences (400 W/mK of w-GaN vs. 50 W/mK of w-ZnO at room temperature). It is found that the much lower thermal conductivity of ZnO originates from the smaller phonon group velocities, larger three-phonon scattering phase space and larger anharmonicity. Compared to w-GaN, w-ZnO has a smaller frequency gap in phonon dispersion, which is responsible for the stronger anharmonic phonon scattering, and the weaker interatomic bonds in w-ZnO leads to smaller phonon group velocities. The thermal conductivity of w-ZnO also shows strong size effect with nano-sized grains or structures. The results from this work help identify the cause of large discrepancies in w-ZnO thermal conductivity and will provide in-depth understanding of phonon dynamics for the design of w-ZnO-based electronics. PMID:26928396

Effect of Variable Doses of Zinc Oxide Nanoparticles on Male Albino Mice Behavior.

PubMed

Zahra, Javeria; Iqbal, Shahid; Zahra, Kiran; Javed, Zulha; Shad, Muhammad Aslam; Akbar, Atif; Ashiq, Muhammad Naeem; Iqbal, Furhan

2017-02-01

Zinc oxide nanoparticles (ZnO NPs) have diverse utility these days ranging from being part of nanosensors to be ingredient of cosmetics. Present study was designed to report the effect of variable doses of ZnO NPs on selected aspects of male albino mice behavior. Nano particles were synthesized by sol-gel auto-combustion method (Data not shown here). 10 week old male albino mice were divided into four experimental groups; group A, B and C were orally supplemented with 50 (low dose), 300 (medium dose) and 600 mg/ml solvent/kg body weight (high dose) of ZnO NPs for 4 days. Group D (control) orally received 0.2 M sodium phosphate buffer (solvent for ZnO NPs) for the same duration. A series of neurological tests (Rota rod, open field, novel object and light-dark box test) were conducted in all groups and performance was compared between ZnO NPs treated and control group. Muscular functioning during rota rod test was significantly improved in all ZnO NPs treated mice as compared to control group. While no significant differences in open field, novel object and light-dark box test performance were observed when data from studied parameters of specific ZnO NPs treatment were compared with the control group indicating that applied doses of ZnO NPs did not affect the exploratory, anxiolytic behavior and object recognition capability of adult male albino mice.

Evaluation of wound healing potential of β-chitin hydrogel/nano zinc oxide composite bandage.

PubMed

P T, Sudheesh Kumar; Lakshmanan, Vinoth-Kumar; Raj, Mincy; Biswas, Raja; Hiroshi, Tamura; Nair, Shantikumar V; Jayakumar, Rangasamy

2013-02-01

β-chitin hydrogel/nZnO composite bandage was fabricated and evaluated in detail as an alternative to existing bandages. β-chitin hydrogel was synthesized by dissolving β-chitin powder in Methanol/CaCl(2) solvent, followed by the addition of distilled water. ZnO nanoparticles were added to the β-chitin hydrogel and stirred for homogenized distribution. The resultant slurry was frozen at 0°C for 12 h. The frozen samples were lyophilized for 24 h to obtain porous composite bandages. The bandages showed controlled swelling and degradation. The composite bandages showed blood clotting ability as well as platelet activation, which was higher when compared to the control. The antibacterial activity of the bandages were proven against Staphylococcus aureus (S. aureus) and Escherichia coli (E.coli). Cytocompatibility of the composite bandages were assessed using human dermal fibroblast cells (HDF) and these cells on the composite bandages were viable similar to the Kaltostat control bandages and bare β-chitin hydrogel based bandages. The viability was reduced to 50-60% in bandages with higher concentration of zinc oxide nanoparticles (nZnO) and showed 80-90% viability with lower concentration of nZnO. In vivo evaluation in Sprague Dawley rats (S.D. rats) showed faster healing and higher collagen deposition ability of composite bandages when compared to the control. The prepared bandages can be used on various types of infected wounds with large volume of exudates.

Eco-friendly preparation of zinc oxide nanoparticles using Tabernaemontana divaricata and its photocatalytic and antimicrobial activity.

PubMed

Raja, A; Ashokkumar, S; Pavithra Marthandam, R; Jayachandiran, J; Khatiwada, Chandra Prasad; Kaviyarasu, K; Ganapathi Raman, R; Swaminathan, M

2018-04-01

The present work reports the green synthesis of Zinc Oxide Nanoparticles (ZnO NPs) using aqueous Tabernaemontana divaricata green leaf extract. ZnO NPs have been characterized by X-ray diffraction (XRD), Ultra Violet-Visible (UV-Vis) studies, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infra Red (FT-IR) analysis. XRD pattern analysis confirms the presence of pure hexagonal wurtzite crystalline structure of ZnO. The TEM images reveal the formation of spherical shape ZnO NPs with the sizes ranging from 20 to 50 nm. The FT-IR analysis suggests that the obtained ZnO NPs have been stabilized through the interactions of steroids, terpenoids, flavonoids, phenyl propanoids, phenolic acids and enzymes present in the leaf extract. Mechanism for the formation of ZnO NPs using Tabernaemontana divaricata as bioactive compound is proposed. As prepared ZnO NPs reveals antibacterial activity against three bacterial strains, Salmonella paratyphi, Escherichia coli and Staphylococcus aureus. The ZnO NPs shows higher antibacterial activity against S. aureus and E. coli and lesser antibacterial activity against S. paratyphi compared to the standard pharmaceutical formulation. Photocatalytic activity of synthesized ZnO NPs was analyzed for methylene blue (MB) dye degradation with sunlight. Almost complete degradation of dye occurred in 90 min. This nano-ZnO, prepared by eco-friendly method will be much useful for dye removal and bacterial decontamination. Copyright © 2018. Published by Elsevier B.V.

Comparison of the in vitro and in vivo toxic effects of three sizes of zinc oxide (ZnO) particles using flounder gill (FG) cells and zebrafish embryos

NASA Astrophysics Data System (ADS)

Han, Li; Zhai, Yanan; Liu, Yang; Hao, Linhua; Guo, Huarong

2017-02-01

Nano-sized zinc oxide (nZnO) particles are one kind of the most commonly used metal oxide nanoparticles (NPs). This study compared the cytotoxic and embryotoxic effects of three increasing sized ZnO particles (ϕ 30 nm, 80-150 nm and 2 μm) in the flounder gill (FG) cells and zebrafish embryos, and analyzed the contribution of size, agglomeration and released Zn2+ to the toxic effects. All the tested ZnO particles were found to be highly toxic to both FG cells and zebrafish embryos. They induced growth inhibition, LDH release, morphological changes and apoptosis in FG cells in a concentration-, size- and time-dependent manner. Moreover, the release of LDH from the exposed FG cells into the medium occurred before the observable morphological changes happened. The ultrasonication treatment and addition of serum favored the dispersion of ZnO particles and alleviated the agglomeration, thus significantly increased the corresponding cytotoxicity. The released Zn2+ ions from ZnO particles into the extracellular medium only partially contributed to the cytotoxicity. All the three sizes of ZnO particles tested induced developmental malformations, decrease of hatching rates and lethality in zebrafish embryos, but size- and concentration- dependent toxic effects were not so obvious as in FG cells possibly due to the easy aggregation of ZnO particles in freshwater. In conclusion, both FG cells and zebrafish embryos are sensitive bioassay systems for safety assessment of ZnO particles and the environmental release of ZnO particles should be closely monitored as far as the safety of aquatic organisms is concerned.

Immobilization Effect of Morphological, Thermal and Optical Properties in Biotemplate on Zinc Oxide Nanocomposite from Chitosan

NASA Astrophysics Data System (ADS)

Karpuraranjith, M.; Thambidurai, S.

Biotemplate-based zinc oxide nanocomposite was effectively prepared via simple chemical precipitation route. The functional groups of amino (-NH2), hydroxyl (-OH) and O-Zn-O were confirmed and characterized by FTIR spectroscopy. The structural and morphological properties were confirmed by XRD, UV-Vis DRS, HR-SEM and TEM analyses. The elemental composition of carbon, nitrogen, zinc and oxygen was confirmed by energy-dispersive X-ray analysis (EDAX) and Brunauer-Emmett-Teller high surface area of materials was estimated to be 52.49m2/g, respectively. Thermogravimetric analysis (TGA) shows that biotemplate on zinc oxide nanocomposite has higher thermal stability than chitosan matrix. The results demonstrate that biotemplate on zinc oxide matrix causes immobilization effect among the two components. Therefore, chitosan-ZnO nanocomposite has a microcrystalline morphological structure and also good thermal stability, so it can be a promising material for sensors, medical, tissue engineering and wastewater treatment applications.

Novel green synthetic strategy to prepare ZnO nanocrystals using rambutan (Nephelium lappaceum L.) peel extract and its antibacterial applications.

PubMed

Yuvakkumar, R; Suresh, J; Nathanael, A Joseph; Sundrarajan, M; Hong, S I

2014-08-01

In the present investigation, we report a sustainable novel green synthetic strategy to synthesis zinc oxide nanocrystals. This is the first report on sustainable biosynthesis of zinc oxide nanocrystals employing Nephelium lappaceum L., peel extract as a natural ligation agent. Green synthesis of zinc oxide nanocrystals was carried out via zinc-ellagate complex formation using rambutan peel wastes. The successful formation of zinc oxide nanocrystals was confirmed employing standard characterisation studies. A possible mechanism for the formation of ZnO nanocrystals with rambutan peel extract was also proposed. The prepared ZnO nanocrystals were coated on the cotton fabric and their antibacterial activity were analyzed. ZnO nanocrystals coated cotton showed good antibacterial activity towards Escherichia coli (E. coli), gram negative bacteria and Staphylococcus aureus (S. aureus), gram positive bacteria. Copyright © 2014 Elsevier B.V. All rights reserved.

Sodium nitrite potentiates renal oxidative stress and injury in hemoglobin exposed guinea pigs.

PubMed

Baek, Jin Hyen; Zhang, Xiaoyuan; Williams, Matthew C; Hicks, Wayne; Buehler, Paul W; D'Agnillo, Felice

2015-07-03

Methemoglobin-forming drugs, such as sodium nitrite (NaNO2), may exacerbate oxidative toxicity under certain chronic or acute hemolytic settings. In this study, we evaluated markers of renal oxidative stress and injury in guinea pigs exposed to extracellular hemoglobin (Hb) followed by NaNO2 at doses sufficient to simulate clinically relevant acute methemoglobinemia. NaNO2 induced rapid and extensive oxidation of plasma Hb in this model. This was accompanied by increased renal expression of the oxidative response effectors nuclear factor erythroid 2-derived-factor 2 (Nrf-2) and heme oxygenase-1 (HO-1), elevated non-heme iron deposition, lipid peroxidation, interstitial inflammatory cell activation, increased expression of tubular injury markers kidney injury-1 marker (KIM-1) and liver-fatty acid binding protein (L-FABP), podocyte injury, and cell death. Importantly, these indicators of renal oxidative stress and injury were minimal or absent following infusion of Hb or NaNO2 alone. Together, these results suggest that the exposure to NaNO2 in settings associated with increased extracellular Hb may potentiate acute renal toxicity via processes that are independent of NaNO2 induced erythrocyte methemoglobinemia. Published by Elsevier Ireland Ltd.

Bioavailability of Zinc in Wistar Rats Fed with Rice Fortified with Zinc Oxide

PubMed Central

Della Lucia, Ceres Mattos; Santos, Laura Luiza Menezes; Rodrigues, Kellen Cristina da Cruz; Rodrigues, Vivian Cristina da Cruz; Martino, Hércia Stampini Duarte; Pinheiro Sant’Ana, Helena Maria

2014-01-01

The study of zinc bioavailability in foods is important because this mineral intake does not meet the recommended doses for some population groups. Also, the presence of dietary factors that reduce zinc absorption contributes to its deficiency. Rice fortified with micronutrients (Ultra Rice®) is a viable alternative for fortification since this cereal is already inserted into the population habit. The aim of this study was to evaluate the bioavailability of zinc (Zn) in rice fortified with zinc oxide. During 42 days, rats were divided into four groups and fed with diets containing two different sources of Zn (test diet: UR® fortified with zinc oxide, or control diet: zinc carbonate (ZnCO3)), supplying 50% or 100%, respectively, of the recommendations of this mineral for animals. Weight gain, food intake, feed efficiency ratio, weight, thickness and length of femur; retention of zinc, calcium (Ca) and magnesium (Mg) in the femur and the concentrations of Zn in femur, plasma and erythrocytes were evaluated. Control diet showed higher weight gain, feed efficiency ratio, retention of Zn and Zn concentration in the femur (p < 0.05). However, no differences were observed (p > 0.05) for dietary intake, length and thickness of the femur, erythrocyte and plasmatic Zn between groups. Although rice fortified with zinc oxide showed a lower bioavailability compared to ZnCO3, this food can be a viable alternative to be used as a vehicle for fortification. PMID:24932657

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

NASA Astrophysics Data System (ADS)

Kılınç, Mert; Çakal, Gaye Ö.; Yeşil, Sertan; Bayram, Göknur; Eroğlu, İnci; 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.

Investigations into Recycling Zinc from Used Metal Oxide Varistors via pH Selective Leaching: Characterization, Leaching, and Residue Analysis

PubMed Central

Gutknecht, Toni; Gustafsson, Anna; Forsgren, Christer; Steenari, Britt-Marie

2015-01-01

Metal oxide varistors (MOVs) are a type of resistor with significantly nonlinear current-voltage characteristics commonly used in power lines to protect against overvoltages. If a proper recycling plan is developed MOVs can be an excellent source of secondary zinc because they contain over 90 weight percent zinc oxide. The oxides of antimony, bismuth, and to a lesser degree cobalt, manganese, and nickel are also present in varistors. Characterization of the MOV showed that cobalt, nickel, and manganese were not present in the varistor material at concentrations greater than one weight percent. This investigation determined whether a pH selective dissolution (leaching) process can be utilized as a starting point for hydrometallurgical recycling of the zinc in MOVs. This investigation showed it was possible to selectively leach zinc from the MOV without coleaching of bismuth and antimony by selecting a suitable pH, mainly higher than 3 for acids investigated. It was not possible to leach zinc without coleaching of manganese, cobalt, and nickel. It can be concluded from results obtained with the acids used, acetic, hydrochloric, nitric, and sulfuric, that sulfate leaching produced the most desirable results with respect to zinc leaching and it is also used extensively in industrial zinc production. PMID:26421313

In vitro study of improved wound-healing effect of bioactive borate-based glass nano-/micro-fibers.

PubMed

Yang, Qingbo; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

2015-10-01

Because of the promising wound-healing capability, bioactive glasses have been considered as one of the next generation hard- and soft-tissue regeneration materials. The lack of understanding of the substantial mechanisms, however, indicates the need for further study on cell-glass interactions to better interpret the rehabilitation capability. In the present work, three bioactive glass nano-/micro-fibers, silicate-based 45S5, borate-based 13-93B3 and 1605 (additionally doped with copper oxide and zinc oxide), were firstly compared for their in vitro soaking/conversion rate. The results of elemental monitoring and electron microscopic characterization demonstrated that quicker ion releasing and glass conversion occurred in borate-based fibers than that of silicate-based one. This result was also reflected by the formation speed of hydroxyapatite (HA). This process was further correlated with original boron content and surrounding rheological condition. We showed that an optimal fiber pre-soaking time (or an ideal dynamic flow rate) should exist to stimulate the best cell proliferation and migration ability. Moreover, 13-93B3 and 1605 fibers showed different glass conversion and biocompatibility properties as well, indicating that trace amount variation in composition can also influence fiber's bioactivity. In sum, our in vitro rheological module closely simulated in vivo niche environment and proved a potentially improved wound-healing effect by borate-based glass fibers, and the results shall cast light on future improvement in bioactive glass fabrication. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative studies on Indian traditional nanomedicine Yashadha Bhasma and zinc oxide nanoparticles for anti-diabetic activity

NASA Astrophysics Data System (ADS)

Durgalakshmi, D.; Ajay Rakkesh, R.; Bhargavi Ram, T.; Balakumar, S.

2017-07-01

Diabetes mellitus is the most common endocrine disorder due to carbohydrate metabolism. Also, zinc and its supplements have been used in Indian traditional medicines for treating urinary tract infections. In this work, an attempt has been made to compare the properties of ‘Yashadha Bhasma’ a traditional ayurvedic ZnO supplement for diabetic treatment with the laboratory-synthesized ZnO nanoparticles. The nano-sized ZnO particles are synthesized using co-precipitation method and calcined at 400 °C for further purification. Confirmation of ZnO and presence of Ca and K elements additional to Zn in Yashadha Bhasma is confirmed from XPS. The morphology of ZnO is found to be spherical with average diameter of 15 nm. TEM results show that ZnO rods of Yashadha Bhasma are porous and non-uniform. Glucose degradation studies revealed good performance with ZnO nanoparticles with 80% degradation occurring within 15 min itself. Antibacterial studies also performed well establishing efficacy of ZnO nanoparticles against both gram-positive and gram-negative bacterial strains, thereby establishing suitable material for treating diabetes mellitus and also curing bacterial wound infections arising due to diabetes mellitus.

Zinc-oxide-based nanostructured materials for heterostructure solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A., E-mail: vamoshnikov@mail.ru

Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics.

Acetone sensor based on zinc oxide hexagonal tubes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hastir, Anita, E-mail: anitahastir@gmail.com; Singh, Onkar, E-mail: anitahastir@gmail.com; Anand, Kanika, E-mail: anitahastir@gmail.com

2014-04-24

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.

Bandgap-Engineered Zinc-Tin-Oxide Thin Films for Ultraviolet Sensors.

PubMed

Cheng, Tien-Hung; Chang, Sheng-Po; Chang, Shoou-Jinn

2018-07-01

Zinc-tin-oxide thin-film transistors were prepared by radio frequency magnetron co-sputtering, while an identical zinc-tin-oxide thin film was deposited simultaneously on a clear glass substrate to facilitate measurements of the optical properties. When we adjusted the deposition power of ZnO and SnO2, the bandgap of the amorphous thin film was dominated by the deposition power of SnO2. Since the thin-film transistor has obvious absorption in the ultraviolet region owing to the wide bandgap, the drain current increases with the generation of electron-hole pairs. As part of these investigations, a zinc-tin-oxide thin-film transistor has been fabricated that appears to be very promising for ultraviolet applications.

Spectroscopy investigation of nanostructured nickel–zinc ferrite obtained by mechanochemical synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarević, Zorica Ž., E-mail: lzorica@yahoo.com; Milutinović, Aleksandra N.; Jovalekić, Čedomir D.

2015-03-15

Highlights: • Nano powder of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} prepared by a soft mechanochemicaly after 10 h milling. • Phase formation controlled by XRD, Raman and IR spectroscopy. • Spectroscopy measurements indicate that the prepared samples have spinel structure. • The average particles size are found to be around 20 nm. • The degree of inversion is δ = 0.36 for NZF obtained from hydroxides for 10 h. - Abstract: Nano crystalline samples of nickel–zinc ferrite, Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} were prepared by mechanochemical route in a planetary ball mill starting from two mixtures of the appropriate quantitiesmore » of the powders: case (1) oxide powders: NiO, ZnO and α-Fe{sub 2}O{sub 3} in one case, and in the second case (2) hydroxide powders: Ni(OH){sub 2}, Zn(OH){sub 2} and Fe(OH){sub 3}. In order to monitor the progress of chemical reaction and confirm phase formation, powder samples obtained after 5 h and 10 h of milling were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, IR and Mössbauer spectroscopy. It is shown that the soft mechanochemical method, i.e. mechanochemical activation of hydroxides, produces high quality single phase Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} samples in much more efficient way. From the IR spectroscopy of single phase samples it is obvious that energy of modes depends on the ratio of cations. The deconvolution of Raman spectra allows to separate contributions of different cations to a particular type of vibration and to estimate the degree of inversion.« less

Wire-in-tube structure fabricated by single capillary electrospinning via nanoscale Kirkendall effect: the case of nickel-zinc ferrite.

PubMed

Fu, Jiecai; Zhang, Junli; Peng, Yong; Zhao, Changhui; He, Yongmin; Zhang, Zhenxing; Pan, Xiaojun; Mellors, Nigel J; Xie, Erqing

2013-12-21

Wire-in-tube structures have previously been prepared using an electrospinning method by means of tuning hydrolysis/alcoholysis of a precursor solution. Nickel-zinc ferrite (Ni0.5Zn0.5Fe2O4) nanowire-in-nanotubes have been prepared as a demonstration. The detailed nanoscale characterization, formation process and magnetic properties of Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes has been studied comprehensively. The average diameters of the outer tubes and inner wires of Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes are around 120 nm and 42 nm, respectively. Each fully calcined individual nanowire-in-nanotube, either the outer-tube or the inner-wire, is composed of Ni0.5Zn0.5Fe2O4 monocrystallites stacked along the longitudinal direction with random orientation. The process of calcining electrospun polymer composite nanofibres can be viewed as a morphologically template nucleation and precursor diffusion process. This allows the nitrates precursor to diffuse toward the surface of the nanofibres while the oxides (decomposed from hydroxides and nitrates) products diffuse to the core region of the nanofibres; the amorphous nanofibres transforming thereby into crystalline nanowire-in-nanotubes. In addition, the magnetic properties of the Ni0.5Zn0.5Fe2O4 nanowire-in-nanotubes were also examined. It is believed that this nanowire-in-nanotube (sometimes called core-shell) structure, with its uniform size and well-controlled orientation of the long nanowire-in-nanotubes, is particularly attractive for use in the field of nano-fluidic devices and nano-energy harvesting devices.

High-voltage nano-oxidation in deionized water and atmospheric environments by atomic force microscopy.

PubMed

Huang, Jen-Ching; Chen, Chung-Ming

2012-01-01

This study used atomic force microscopy (AFM), metallic probes with a nanoscale tip, and high-voltage generators to investigate the feasibility of high-voltage nano-oxidation processing in deionized water (DI water) and atmospheric environments. Researchers used a combination of wire-cutting and electrochemical etching to transform a 20-μm-thick stainless steel sheet into a conductive metallic AFM probe with a tip radius of 60 nm, capable of withstanding high voltages. The combination of AFM, high-voltage generators, and nanoscale metallic probes enabled nano-oxidation processing at 200 V in DI water environments, producing oxides up to 66.6 nm in height and 467.03 nm in width. Oxides produced through high-voltage nano-oxidation in atmospheric environments were 117.29 nm in height and 551.28 nm in width, considerably exceeding the dimensions of those produced in DI water. An increase in the applied bias voltage led to an apparent logarithmic increase in the height of the oxide dots in the range of 200-400 V. The performance of the proposed high-voltage nano-oxidation technique was relatively high with seamless integration between the AFM machine and the metallic probe fabricated in this study. © Wiley Periodicals, Inc.

Zirconium-based conversion film formation on zinc, aluminium and magnesium oxides and their interactions with functionalized molecules

NASA Astrophysics Data System (ADS)

Fockaert, L. I.; Taheri, P.; Abrahami, S. T.; Boelen, B.; Terryn, H.; Mol, J. M. C.

2017-11-01

Zirconium-based conversion treatment of zinc, aluminium and magnesium oxides have been studied in-situ using ATR-FTIR in a Kretschmann geometry. This set-up was coupled to an electrochemical cell, which allowed to obtain chemical and electrochemical information simultaneously as a function of conversion time. This elucidated the strong relation between physico-chemical surface properties and zirconium-based conversion kinetics. Whereas the surface hydroxyl density of zinc and aluminium increased during conversion, magnesium (hydr)oxide was shown to dissolve in the acid solution. Due to this dissolution, strong surface alkalization can be expected, explaining the rapid conversion kinetics. AES depth profiling was used to determine the final oxide thickness and elemental composition. This confirmed that magnesium is most active and forms a zirconium oxide layer approximately 10 times thicker than zinc. On the other hand, the presence of zirconium oxide on aluminium is very low and can be considered as not fully covering the metal oxide. Additionally, the converted oxide chemistry was related to the bonding mechanisms of amide functionalized molecules using ATR-FTIR and XPS. It was shown that inclusion of zirconium altered the acid-base properties, increasing the substrate proton donating capabilities in case of magnesium oxide and increasing hydrogen bonding and Bronsted interactions due to increased surface hydroxide fractions on zinc and aluminium substrates.

Low Plasma Zinc Is Associated with Higher Mitochondrial Oxidative Stress and Faster Liver Fibrosis Development in the Miami Adult Studies in HIV Cohort.

PubMed

Martinez, Sabrina S; Campa, Adriana; Li, Yinghui; Fleetwood, Christina; Stewart, Tiffanie; Ramamoorthy, Venkataraghavan; Baum, Marianna K

2017-04-01

Background: Oxidative stress and reduced antioxidants may be a trigger for liver fibrogenesis. Reducing oxidative stress through higher antioxidant concentration may be a potential antifibrotic target. Objective: We aimed to investigate longitudinally whether plasma zinc, an antioxidant, is related to mitochondrial oxidative stress and the progression of liver fibrosis in the Miami Adult Studies in HIV (MASH) cohort. Methods: A prospective observational cohort study was conducted in 487 predominantly African American HIV-monoinfected and HIV/hepatitis C virus (HCV)-coinfected adults with a mean ± SD age of 47.08 ± 7.67 y from the MASH cohort and followed for a median of 34 mo. Blood was collected for plasma zinc and measures were used to calculate the fibrosis-4 (FIB-4) score (aspartate amino transferase, alanine aminotransferase, and platelets). Plasma zinc deficiency was defined as <0.75 mg/L. Total DNA was extracted from peripheral blood mononuclear cells and mitochondrial DNA (mtDNA) 8-hydroxyguanosine (8-oxo-dG) was determined. Adjusted mixed models were used to assess the relations between zinc, stage of liver disease, and oxidative stress over time and compared between HIV and HIV/HCV groups. Results: Zinc concentrations (β: -0.368, SE = 0.172; P = 0.033) and deficiency were associated with lower FIB-4 scores over time (β: 0.381, SE = 0.118; P = 0.001). Compared with those who were not zinc deficient, zinc-deficient participants had an increased risk of having more-progressed liver disease (OR: 1.91; 95% CI: 1.15, 3.16; P = 0.012). Higher mtDNA 8-oxo-dG was associated with zinc deficiency (β: 0.049, SE = 0.024; P = 0.044) and higher FIB-4 scores over time (β: 0.597, SE = 0.168, P < 0.001). Conclusions: Lower plasma zinc concentrations were associated with liver fibrosis progression and mitochondrial oxidative stress in the HIV and HIV/HCV groups. Zinc may play a role in the impact of liver disease outcomes. © 2017 American Society for Nutrition.

Low Plasma Zinc Is Associated with Higher Mitochondrial Oxidative Stress and Faster Liver Fibrosis Development in the Miami Adult Studies in HIV Cohort1234

PubMed Central

Martinez, Sabrina S; Campa, Adriana; Li, Yinghui; Fleetwood, Christina; Stewart, Tiffanie; Ramamoorthy, Venkataraghavan; Baum, Marianna K

2017-01-01

Background: Oxidative stress and reduced antioxidants may be a trigger for liver fibrogenesis. Reducing oxidative stress through higher antioxidant concentration may be a potential antifibrotic target. Objective: We aimed to investigate longitudinally whether plasma zinc, an antioxidant, is related to mitochondrial oxidative stress and the progression of liver fibrosis in the Miami Adult Studies in HIV (MASH) cohort. Methods: A prospective observational cohort study was conducted in 487 predominantly African American HIV-monoinfected and HIV/hepatitis C virus (HCV)–coinfected adults with a mean ± SD age of 47.08 ± 7.67 y from the MASH cohort and followed for a median of 34 mo. Blood was collected for plasma zinc and measures were used to calculate the fibrosis-4 (FIB-4) score (aspartate amino transferase, alanine aminotransferase, and platelets). Plasma zinc deficiency was defined as <0.75 mg/L. Total DNA was extracted from peripheral blood mononuclear cells and mitochondrial DNA (mtDNA) 8-hydroxyguanosine (8-oxo-dG) was determined. Adjusted mixed models were used to assess the relations between zinc, stage of liver disease, and oxidative stress over time and compared between HIV and HIV/HCV groups. Results: Zinc concentrations (β: −0.368, SE = 0.172; P = 0.033) and deficiency were associated with lower FIB-4 scores over time (β: 0.381, SE = 0.118; P = 0.001). Compared with those who were not zinc deficient, zinc-deficient participants had an increased risk of having more-progressed liver disease (OR: 1.91; 95% CI: 1.15, 3.16; P = 0.012). Higher mtDNA 8-oxo-dG was associated with zinc deficiency (β: 0.049, SE = 0.024; P = 0.044) and higher FIB-4 scores over time (β: 0.597, SE = 0.168, P < 0.001). Conclusions: Lower plasma zinc concentrations were associated with liver fibrosis progression and mitochondrial oxidative stress in the HIV and HIV/HCV groups. Zinc may play a role in the impact of liver disease outcomes. PMID:28228506

Synthesis, X-ray crystal structures and thermal analyses of some new antimicrobial zinc complexes: New configurations and nano-size structures.

PubMed

Masoudiasl, A; Montazerozohori, M; Naghiha, R; Assoud, A; McArdle, P; Safi Shalamzari, M

2016-04-01

Some new five coordinated ZnLX2 complexes, where L is N3-Schiff base ligand obtained by condensation reaction between diethylenetriamine and (E)-3-(2-nitrophenyl)acrylaldehyde and X (Cl(-), Br(-), I(-), N3(-) and NCS(-)), were synthesized and characterized by FT-IR, (1)H and (13)CNMR, UV-visible, ESI-mass spectra and molar conductivity measurements. The structures of zinc iodide and thiocyanate complexes were determined by X-ray crystallographic analysis. The X-ray results showed that the Zn (II) center in these complexes is five-coordinated in a distorted trigonal-bipyramidal configuration. Zinc iodide and thiocyanate complexes crystallize in the monoclinic and triclinic systems with space groups of C2/c and P1- with eight and two molecules per unit cell respectively. The crystal packing of the complexes consists of intermolecular interactions such as C-H(…)O and C-H(…)I, C-H(···)S, N(…)O, together with π-π stacking and some other unexpected interactions. The mentioned interactions cause three-dimensional supramolecular structure in the solid state. Zinc complexes were also prepared in nano-structure by sonochemical method confirmed by XRD, SEM and TEM analyses. Moreover, ZnO nanoparticles were synthesized by direct thermolysis of zinc iodide complex. Furthermore, antimicrobial and thermal properties of the compounds were completely investigated. Copyright © 2016 Elsevier B.V. All rights reserved.

Review of the Evidence from Epidemiology, Toxicology, and Lung Bioavailability on the Carcinogenicity of Inhaled Iron Oxide Particulates.

PubMed

Pease, Camilla; Rücker, Thomas; Birk, Thomas

2016-03-21

Since the iron-age and throughout the industrial age, humans have been exposed to iron oxides. Here, we review the evidence from epidemiology, toxicology, and lung bioavailability as to whether iron oxides are likely to act as human lung carcinogens. Current evidence suggests that observed lung tumors in rats result from a generic particle overload effect and local inflammation that is rat-specific under the dosing conditions of intratracheal instillation. This mode of action therefore, is not relevant to human exposure. However, there are emerging differences seen in vitro, in cell uptake and cell bioavailability between "bulk" iron oxides and "nano" iron oxides. "Bulk" particulates, as defined here, are those where greater than 70% are >100 nm in diameter. Similarly, "nano" iron oxides are defined in this context as particulates where the majority, usually >95% for pure engineered forms of primary particulates (not agglomerates), fall in the range 1-100 nm in diameter. From the weight of scientific evidence, "bulk" iron oxides are not genotoxic/mutagenic. Recent evidence for "nano" iron oxide is conflicting regarding genotoxic potential, albeit genotoxicity was not observed in an in vivo acute oral dose study, and "nano" iron oxides are considered safe and are being investigated for biomedical uses; there is no specific in vivo genotoxicity study on "nano" iron oxides via inhalation. Some evidence is available that suggests, hypothetically due to the larger surface area of "nano" iron oxide particulates, that toxicity could be exerted via the generation of reactive oxygen species (ROS) in the cell. However, the potential for ROS generation as a basis for explaining rodent tumorigenicity is only apparent if free iron from intracellular "nano" scale iron oxide becomes bioavailable at significant levels inside the cell. This would not be expected from "bulk" iron oxide particulates. Furthermore, human epidemiological evidence from a number of studies suggests that iron oxide is not a human carcinogen, and therefore, based upon the complete weight of evidence, we conclude that "bulk" iron oxides are not human carcinogens.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Jie; Lucero, Antonio T.; Cheng, Lanxia

In this study, we have deposited organic-inorganic hybrid semiconducting hydroquinone (HQ)/zinc oxide (ZnO) superlattices using molecular-atomic layer deposition, which enables accurate control of film thickness, excellent uniformity, and sharp interfaces at a low deposition temperature (150 °C). Self-limiting growth of organic layers is observed for the HQ precursor on ZnO surface. Nano-laminates were prepared by varying the number of HQ to ZnO cycles in order to investigate the physical and electrical effects of different HQ to ZnO ratios. It is indicated that the addition of HQ layer results in enhanced mobility and reduced carrier concentration. The highest Hall mobility of approximatelymore » 2.3 cm{sup 2}/V·s and the lowest n-type carrier concentration of approximately 1.0 × 10{sup 18}/cm{sup 3} were achieved with the organic-inorganic superlattice deposited with a ratio of 10 ZnO cycles to 1 HQ cycle. This study offers an approach to tune the electrical transport characteristics of ALD ZnO matrix thin films using an organic dopant. Moreover, with organic embedment, this nano-laminate material may be useful for flexible electronics.« less

Improved compaction of ZnO nano-powder triggered by the presence of acetate and its effect on sintering.

PubMed

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

2015-04-01

The retention of nanocrystallinity in dense ceramic materials is still a challenge, even with the application of external pressure during sintering. The compaction behavior of high purity and acetate enriched zinc oxide (ZnO) nano-powders was investigated. It was found that acetate in combination with water plays a key role during the compaction into green bodies at moderate temperatures. Application of constant pressure resulted in a homogeneous green body with superior packing density (86% of theoretical value) at moderate temperature (85 °C) in the presence of water. In contrast, no improvement in density could be achieved if pure ZnO powder was used. This compaction behavior offers superior packing of the particles, resulting in a high relative density of the consolidated compact with negligible coarsening. Dissolution accompanying creep diffusion based matter transport is suggested to strongly support reorientation of ZnO particles towards densities beyond the theoretical limit for packing of ideal monosized spheres. Finally, the sintering trajectory reveals that grain growth is retarded compared to conventional processing up to 90% of theoretical density. Moreover, nearly no radial shrinkage was observed after sinter-forging for bodies performed with this advanced processing method.

Photonics and nanophotonics and information and communication technologies in modern food packaging.

PubMed

Sarapulova, Olha; Sherstiuk, Valentyn; Shvalagin, Vitaliy; Kukhta, Aleksander

2015-01-01

The analysis of the problem of conjunction of information and communication technologies (ICT) with packaging industry and food production was made. The perspective of combining the latest advances of nanotechnology, including nanophotonics, and ICT for creating modern smart packaging was shown. There were investigated luminescent films with zinc oxide nanoparticles, which change luminescence intensity as nano-ZnO interacts with decay compounds of food products, for active and intelligent packaging. High luminescent transparent films were obtained from colloidal suspension of ZnO and polyvinylpyrrolidone (PVP). The influence of molecular mass, concentration of nano-ZnO, and film thickness on luminescent properties of films was studied in order to optimize the content of the compositions. The possibility of covering the obtained films with polyvinyl alcohol was considered for eliminating water soluble properties of PVP. The luminescent properties of films with different covers were studied. The insoluble in water composition based on ZnO stabilized with colloidal silicon dioxide and PVP in polymethylmethacrylate was developed, and the luminescent properties of films were investigated. The compositions are non-toxic, safe, and suitable for applying to the inner surface of active and intelligent packaging by printing techniques, such as screen printing, flexography, inkjet, and pad printing.

Applications of Nanomaterials in Food Packaging.

PubMed

Bumbudsanpharoke, Nattinee; Choi, Jungwook; Ko, Seonghyuk

2015-09-01

Nanomaterials have drawn great interest in recent years due to their extraordinary properties that make them advantageous in food packaging applications. Specifically, nanoparticles can impart significant barrier properties, as well as mechanical, optical, catalytic, and antimicrobial properties into packaging. Silver nanoparticles (AgNPs) and nanoclay account for the majority of the nano-enabled food packaging on the market, while others, such as nano-zinc oxide (ZnO) and titanium, share less of the current market. In current food packaging, these nanomaterials are primarily used to impart antimicrobial function and to improve barrier properties, thereby extending the shelf life and freshness of packaged food. On the other hand, there is growing concern about the migration of nanomaterials from food contact materials to foodstuffs and its associated potential risks. Indeed, insufficient data about environmental and human safety assessments of migration and exposure of nanomaterials are hindering their market growth. To overcome this barrier, the public believes that legislation from government agencies is critical. This review provides an overview of the characteristics and functions of major nanomaterials that are commonly applied to food packaging, including available and near- future products. Migration research, safety issues, and public concerns are also discussed.

Improved compaction of ZnO nano-powder triggered by the presence of acetate and its effect on sintering

PubMed Central

Gonzalez-Julian, Jesus; Guillon, Olivier

2015-01-01

The retention of nanocrystallinity in dense ceramic materials is still a challenge, even with the application of external pressure during sintering. The compaction behavior of high purity and acetate enriched zinc oxide (ZnO) nano-powders was investigated. It was found that acetate in combination with water plays a key role during the compaction into green bodies at moderate temperatures. Application of constant pressure resulted in a homogeneous green body with superior packing density (86% of theoretical value) at moderate temperature (85 °C) in the presence of water. In contrast, no improvement in density could be achieved if pure ZnO powder was used. This compaction behavior offers superior packing of the particles, resulting in a high relative density of the consolidated compact with negligible coarsening. Dissolution accompanying creep diffusion based matter transport is suggested to strongly support reorientation of ZnO particles towards densities beyond the theoretical limit for packing of ideal monosized spheres. Finally, the sintering trajectory reveals that grain growth is retarded compared to conventional processing up to 90% of theoretical density. Moreover, nearly no radial shrinkage was observed after sinter-forging for bodies performed with this advanced processing method. PMID:27877777

Photonics and Nanophotonics and Information and Communication Technologies in Modern Food Packaging

NASA Astrophysics Data System (ADS)

Sarapulova, Olha; Sherstiuk, Valentyn; Shvalagin, Vitaliy; Kukhta, Aleksander

2015-05-01

The analysis of the problem of conjunction of information and communication technologies (ICT) with packaging industry and food production was made. The perspective of combining the latest advances of nanotechnology, including nanophotonics, and ICT for creating modern smart packaging was shown. There were investigated luminescent films with zinc oxide nanoparticles, which change luminescence intensity as nano-ZnO interacts with decay compounds of food products, for active and intelligent packaging. High luminescent transparent films were obtained from colloidal suspension of ZnO and polyvinylpyrrolidone (PVP). The influence of molecular mass, concentration of nano-ZnO, and film thickness on luminescent properties of films was studied in order to optimize the content of the compositions. The possibility of covering the obtained films with polyvinyl alcohol was considered for eliminating water soluble properties of PVP. The luminescent properties of films with different covers were studied. The insoluble in water composition based on ZnO stabilized with colloidal silicon dioxide and PVP in polymethylmethacrylate was developed, and the luminescent properties of films were investigated. The compositions are non-toxic, safe, and suitable for applying to the inner surface of active and intelligent packaging by printing techniques, such as screen printing, flexography, inkjet, and pad printing.

Reduction in the Band Gap of Manganese-Doped Zinc Oxide: Role of the Oxidation State

NASA Astrophysics Data System (ADS)

Sharma, Sonia; Ramesh, Pranith; Swaminathan, P.

2015-12-01

Manganese-doped zinc oxide powders were synthesized by solid state reaction of the respective oxides. The high-temperature conditions were chosen such that multiple valence states of manganese were doped in the host zinc oxide lattice. Structural characterization was carried out to confirm the doping and to find the maximum amount of manganese that can be incorporated. Diffuse reflectance spectroscopy was used to measure the optical band gap of the doped sample and the lowering with respect to pure ZnO was attributed to the presence of higher oxidation states of manganese. The presence of these oxidation states was confirmed using x-ray photoelectron spectroscopy. The study shows that a solid state reaction is a viable route for synthesizing doped metal oxides with desired optical properties.

Cs promoted oxidation of Zn and CuZn surfaces: a combined experimental and theoretical study

NASA Astrophysics Data System (ADS)

Chaturvedi, Sanjay; Rodriguez, JoséA.; Hrbek, Jan

1997-07-01

The interaction of O 2 with Zn, {Cs}/{Zn} and {Cs}/{CuZn} surfaces was investigated using photoemission and ab initio self-consistent-field (SCF) calculations. On zinc films, the sticking probability of O 2 is extremely low (10 -3-10 -2), and O 2 exposures in the range of 10 3 to 10 4 langmuirs are necessary to produce a significant adsorption of oxygen and the transformation of metallic zinc into zinc oxide. The presence of sub monolayer coverages of cesium enhances the oxidation rate of zinc by 2-3 orders of magnitude. In the {Cs}/{Zn} system, the alkali atom donates electrons to zinc. This charge transfer facilitates the formation of Zn→O 2 dative bonds and breaking of the OO bond. For the coadsorption of Cs and O 2 on Zn(001), the larger the electron transfer from Zn into the O 2 (1 πg) orbitals, the bigger the adsorption energy of the molecule and the elongation of the OO bond. In general, cesium does not promote the oxidation of copper. In the {Cs}/{CuZn} system, copper withdraws electrons from zinc. The presence of copper in the {Cs}/{CuZn} system inhibits the oxidation of the Zn component compared with the {Cs}/{Zn} system by lowering the electron density on the Zn atoms. After exposing the {Cs}/{CuZn} system to O 2, zinc is oxidized at a rate that is larger than that found for clean CuZn surfaces and smaller than seen in {Cs}/{Zn} surfaces. Molecular hydrogen is found to have no effect on oxidized Cu, Zn and CuZn films. However, atomic hydrogen reduces ZnO to metallic zinc and CuO to Cu 2O. In the oxidized CuZn alloy, CuO is reduced first followed by the reduction of ZnO. A comparison of the behavior of O 2/Cs/Zn and H 2O/Cs/Zn systems shows that while O 2 causes severe oxidation of Cs promoted Zn surfaces, H 2O has little or no effect.

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...

Fruit peel extract mediated green synthesis of zinc oxide nanoparticles

NASA Astrophysics Data System (ADS)

Nava, O. J.; Soto-Robles, C. A.; Gómez-Gutiérrez, C. M.; Vilchis-Nestor, A. R.; Castro-Beltrán, A.; Olivas, A.; Luque, P. A.

2017-11-01

This work presents a study of the effects on the photocatalytic capabilities of zinc oxide nanoparticles when prepared via green synthesis using different fruit peel extracts as reducing agents. Zinc nitrate was used as a source of the zinc ions, while Lycopersicon esculentum (tomato), Citrus sinensis (orange), Citrus paradisi (grapefruit) and Citrus aurantifolia (lemon) contributed their peels for extracts. The Synthesized Samples were studied and characterized through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and High Resolution Transmission Electron Microscopy (HRTEM). All samples presented a band at 618 cm-1, indicating the presence of the Znsbnd O bond. The different samples all presented the same hexagonal crystal growth in their structure, the Wurtzite phase. The surface morphology of the nanoparticles showed that, depending on the extract used, the samples vary in size and shape distribution due to the chemical composition of the extracts. The photocatalytic properties of the zinc oxide samples were tested through UV light aided degradation of methylene blue. Most samples exhibited degradation rates at 180 min of around 97%, a major improvement when compared to chemically synthesized commercially available zinc oxide nanoparticles.

Oxidative stress upregulates zinc uptake activity via Zrt/Irt-like protein 1 (ZIP1) in cultured mouse astrocytes.

PubMed

Furuta, Takahiro; Ohshima, Chiaki; Matsumura, Mayu; Takebayashi, Naoto; Hirota, Emi; Mawaribuchi, Toshiki; Nishida, Kentaro; Nagasawa, Kazuki

2016-04-15

Zinc released from glutamatergic boutons and astrocytes acts as neuro- and glio-transmitters, and thus its extracellular level has to be strictly regulated. We previously revealed that uptake of zinc by astrocytes plays a critical role in its clearance, and zinc transporter Zrt/Irt-like protein 1 (ZIP1) is the molecule responsible for the uptake. However, it is unknown whether or not the functionality of the zinc clearance system is altered under oxidative stress-loaded conditions. Here, we characterized zinc uptake by oxidative stress-loaded astrocytes. Cultured mouse astrocytes were treated with hydrogen peroxide (H2O2) to load oxidative stress. Functional expression of ZIP1 in astrocytes was evaluated by means of (65)Zn uptake, Western blotting and immunocytochemical analysis. Treatment of astrocytes with 0.4mM H2O2 for 24h increased the expression levels of glial fibrillary acidic protein and 4-hydroxynonenal without significant decreases in their viability, indicating that induction of oxidative stress in astrocytes. Under oxidative stress-loaded conditions, astrocytes exhibited increased (65)Zn uptake activity, and the maximum uptake velocity for the uptake was significantly increased compared to that in the control group, while there was no change in the Michaelis constants, which were almost identical to that of mouse ZIP1. In the H2O2-treated astrocytes, the expression levels of ZIP1 were significantly increased in the cellular and plasma membrane fractions. It appears that under oxidative stress-loaded conditions, astrocytes exhibit increased zinc clearance activity and this is due, at least in part, to increased ZIP1 expression. Copyright © 2016 Elsevier Inc. All rights reserved.

Oxidative stress-induced increase of intracellular zinc in astrocytes decreases their functional expression of P2X7 receptors and engulfing activity.

PubMed

Furuta, Takahiro; Mukai, Ayumi; Ohishi, Akihiro; Nishida, Kentaro; Nagasawa, Kazuki

2017-12-01

Neuron-glia communication mediated by neuro- and glio-transmitters such as ATP and zinc is crucial for the maintenance of brain homeostasis, and its dysregulation is found under pathological conditions. It is reported that under oxidative stress-loaded conditions, astrocytes exhibit increased intra- and extra-cellular labile zinc, the latter triggering microglial M1 activation, while the pathophysiological role of the former remains unrevealed. In this study, we examined whether the oxidative stress-induced increase of intracellular labile zinc is involved in the P2X7 receptor (P2X7R)-mediated regulation of astrocytic engulfing activity. The exposure of cultured astrocytes to sub-lethal oxidative stress through their treatment with 400 μM H 2 O 2 increased intracellular labile zinc, of which the concentration reached a peak level of approximately 2 μM at 2 h after the treatment. In astrocytes under sub-lethal oxidative stress, the uptake of YO-PRO-1 and latex beads as markers for P2X7R channel/pore activity and astrocytic engulfing activity, respectively, was decreased, and these decreased activities were accompanied by decreased expression of P2X7R at the plasma membrane via intracellular labile zinc-mediated translocation of it. With the oxidative stress, the expression level of full length P2X7R relative to that of its splice variants in astrocytes was decreased, leading to a decrease of the relative expression of the trimer consisting of full length P2X7R. Collectively, sub-lethal oxidative stress induces an astrocytic modal shift from the normal resting engulfing mode to the activated astrogliosis mode via an intracellular labile zinc-mediated decrease of the functional expression of P2X7R.

The NanoCare project: A German initiative on health aspects of synthetic nanoparticles

NASA Astrophysics Data System (ADS)

Nau, Katja; Krug, Harald F.

2009-05-01

Nanotechnology is increasingly considered to be the future technology. It will enable science and industry to provide new and better product solutions for the society. NanoCare is a German project, funded by the German Federal Ministry of Education and Research (BMBF), which aims to broaden knowledge about synthetic nanomaterials with regard to the potential impacts of nanomaterials on human health. 13 partners from industry, universities and research institutes are contributing their expertise to this partnership. The work plan of the NanoCare project is composed of three different parts: (1) the generation, (2) the management, and (3) the transfer of knowledge. The production of synthetic nanoparticles, the subsequent analysis of primary particles, aggregates and agglomerates, as well as the behaviour in biological media and effects on biological systems are focused in the generation of knowledge. In addition to the production and characterization of new synthetic nanoparticles (metal oxides like zirconium dioxide or zinc oxide), titanium dioxide and Carbon Black will be established as reference materials. This enables the comparison of the results of all partners of our project. Various analytical methods for characterization will be applied, for example: transmission and scanning electron microscopy, inductive coupled plasma mass spectroscopy (ICP-MS), atomic absorption spectroscopy (AAS) and the Brunner-Edward-Teller method (BET). In vitro studies will systematically investigate biological mechanisms of action of nanoparticles and the dependency on their size, shape, zeta potential and other important properties. In vitro data will be complemented by in vivo studies. Another work package deals with the measurement of working place exposure and agglomerate stabilities. Established measurement devices and methods will be developed further in order to determine aerosols and nanoparticles directly at the workplace during ongoing work processes. The stabilities of the agglomerated nanoparticle powders are additionally investigated with three different methods to assess deagglomeration probabilities which also influence the possible exposure. Data created within the NanoCare project consortium will be interpreted together with information from literature and then published for the public in a data base on the World Wide Web (www.nanopartikel.info). Furthermore, the results will be presented and discussed with the interested public, politicians and non-governmental organizations (NGOs) at dialogue events. Together with two other BMBF-funded projects (INOS, TRACER) NanoCare will help to standardize analytical procedures and will substantially increase knowledge about the biological activities of nanomaterials.

Zinc stimulates glucose oxidation and glycemic control by modulating the insulin signaling pathway in human and mouse skeletal muscle cell lines.

PubMed

Norouzi, Shaghayegh; Adulcikas, John; Sohal, Sukhwinder Singh; Myers, Stephen

2018-01-01

Zinc is a metal ion that is an essential cell signaling molecule. Highlighting this, zinc is an insulin mimetic, activating cellular pathways that regulate cellular homeostasis and physiological responses. Previous studies have linked dysfunctional zinc signaling with several disease states including cancer, obesity, cardiovascular disease and type 2 diabetes. The present study evaluated the insulin-like effects of zinc on cell signaling molecules including tyrosine, PRSA40, Akt, ERK1/2, SHP-2, GSK-3β and p38, and glucose oxidation in human and mouse skeletal muscle cells. Insulin and zinc independently led to the phosphorylation of these proteins over a 60-minute time course in both mouse and human skeletal muscle cells. Similarly, utilizing a protein array we identified that zinc could active the phosphorylation of p38, ERK1/2 and GSK-3B in human and ERK1/2 and GSK-3B in mouse skeletal muscle cells. Glucose oxidation assays were performed on skeletal muscle cells treated with insulin, zinc, or a combination of both and resulted in a significant induction of glucose consumption in mouse (p<0.01) and human (p<0.05) skeletal muscle cells when treated with zinc alone. Insulin, as expected, increased glucose oxidation in mouse (p<0.001) and human (0.001) skeletal muscle cells, however the combination of zinc and insulin did not augment glucose consumption in these cells. Zinc acts as an insulin mimetic, activating key molecules implicated in cell signaling to maintain glucose homeostasis in mouse and human skeletal muscle cells. Zinc is an important metal ion implicated in several biological processes. The role of zinc as an insulin memetic in activating key signaling molecules involved in glucose homeostasis could provide opportunities to utilize this ion therapeutically in treating disorders associated with dysfunctional zinc signaling.

Room temperature ferromagnetism in liquid-phase pulsed laser ablation synthesized nanoparticles of nonmagnetic oxides

NASA Astrophysics Data System (ADS)

Singh, S. C.; Kotnala, R. K.; Gopal, R.

2015-08-01

Intrinsic Room Temperature Ferromagnetism (RTF) has been observed in undoped/uncapped zinc oxide and titanium dioxide spherical nanoparticles (NPs) obtained by a purely green approach of liquid phase pulsed laser ablation of corresponding metal targets in pure water. Saturation magnetization values observed for zinc oxide (average size, 9 ± 1.2 nm) and titanium dioxide (average size, 4.4 ± 0.3 nm) NPs are 62.37 and 42.17 memu/g, respectively, which are several orders of magnitude larger than those of previous reports. In contrast to the previous works, no postprocessing treatments or surface modification is required to induce ferromagnetism in the case of present communication. The most important result, related to the field of intrinsic ferromagnetism in nonmagnetic materials, is the observation of size dependent ferromagnetism. Degree of ferromagnetism in titanium dioxide increases with the increase in particle size, while it is reverse for zinc oxide. Surface and volume defects play significant roles for the origin of RTF in zinc oxide and titanium dioxide NPs, respectively. Single ionized oxygen and neutral zinc vacancies in zinc oxide and oxygen and neutral/ionized titanium vacancies in titanium dioxide are considered as predominant defect centres responsible for observed ferromagnetism. It is expected that origin of ferromagnetism is a consequence of exchange interactions between localized electron spin moments resulting from point defects.

Room temperature ferromagnetism in liquid-phase pulsed laser ablation synthesized nanoparticles of nonmagnetic oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, S. C., E-mail: subhash.laserlab@gmail.com; Gopal, R.; Kotnala, R. K.

2015-08-14

Intrinsic Room Temperature Ferromagnetism (RTF) has been observed in undoped/uncapped zinc oxide and titanium dioxide spherical nanoparticles (NPs) obtained by a purely green approach of liquid phase pulsed laser ablation of corresponding metal targets in pure water. Saturation magnetization values observed for zinc oxide (average size, 9 ± 1.2 nm) and titanium dioxide (average size, 4.4 ± 0.3 nm) NPs are 62.37 and 42.17 memu/g, respectively, which are several orders of magnitude larger than those of previous reports. In contrast to the previous works, no postprocessing treatments or surface modification is required to induce ferromagnetism in the case of present communication. The most important result, relatedmore » to the field of intrinsic ferromagnetism in nonmagnetic materials, is the observation of size dependent ferromagnetism. Degree of ferromagnetism in titanium dioxide increases with the increase in particle size, while it is reverse for zinc oxide. Surface and volume defects play significant roles for the origin of RTF in zinc oxide and titanium dioxide NPs, respectively. Single ionized oxygen and neutral zinc vacancies in zinc oxide and oxygen and neutral/ionized titanium vacancies in titanium dioxide are considered as predominant defect centres responsible for observed ferromagnetism. It is expected that origin of ferromagnetism is a consequence of exchange interactions between localized electron spin moments resulting from point defects.« less

Zinc (hydr)oxide/graphite oxide/AuNPs composites: role of surface features in H₂S reactive adsorption.

PubMed

Giannakoudakis, Dimitrios A; Bandosz, Teresa J

2014-12-15

Zinc hydroxide/graphite oxide/AuNPs composites with various levels of complexity were synthesized using an in situ precipitation method. Then they were used as H2S adsorbents in visible light. The materials' surfaces were characterized before and after H2S adsorption by various physical and chemical methods (XRD, FTIR, thermal analysis, potentiometric titration, adsorption of nitrogen and SEM/EDX). Significant differences in surface features and synergistic effects were found depending on the materials' composition. Addition of graphite oxide and the deposition of gold nanoparticles resulted in a marked increase in the adsorption capacity in comparison with that on the zinc hydroxide and zinc hydroxide/AuNP. Addition of AuNPs to zinc hydroxide led to a crystalline ZnO/AuNP composite while the zinc hydroxide/graphite oxide/AuNP composite was amorphous. The ZnOH/GO/AuNPs composite exhibited the greatest H2S adsorption capacity due to the increased number of OH terminal groups and the conductive properties of GO that facilitated the electron transfer and consequently the formation of superoxide ions promoting oxidation of hydrogen sulfide. AuNPs present in the composite increased the conductivity, helped with electron transfer to oxygen, and prevented the fast recombination of the electrons and holes. Copyright © 2014 Elsevier Inc. All rights reserved.

Fabrication of polymeric nano-batteries array using anodic aluminum oxide templates.

PubMed

Zhao, Qiang; Cui, Xiaoli; Chen, Ling; Liu, Ling; Sun, Zhenkun; Jiang, Zhiyu

2009-02-01

Rechargeable nano-batteries were fabricated in the array pores of anodic aluminum oxide (AAO) template, combining template method and electrochemical method. The battery consisted of electropolymerized PPy electrode, porous TiO2 separator, and chemically polymerized PAn electrode was fabricated in the array pores of two-step anodizing aluminum oxide (AAO) membrane, based on three-step assembling method. It performs typical electrochemical battery behavior with good charge-discharge ability, and presents a capacity of 25 nAs. AFM results show the hexagonal array of nano-batteries' top side. The nano-battery may be a promising device for the development of Micro-Electro-Mechanical Systems (MEMS), and Nano-Electro-Mechanical Systems (NEMS).

Novel hybrid materials based on the vanadium oxide nanobelts

NASA Astrophysics Data System (ADS)

Zabrodina, G. S.; Makarov, S. G.; Kremlev, K. V.; Yunin, P. A.; Gusev, S. A.; Kaverin, B. S.; Kaverina, L. B.; Ketkov, S. Yu.

2016-04-01

Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V2O5·nH2O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB - cetyltrimethylammonium bromide, TBAB - tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA)0.33V2O5 flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA)0.33V2O5, (TBA)0.16V2O5 nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

Thermodynamics Calculation and Experimental Study on Separation of Bismuth from a Bismuth Glance Concentrate Through a Low-Temperature Molten Salt Smelting Process

NASA Astrophysics Data System (ADS)

Yang, Jian-Guang; He, De-Wen; Tang, Chao-Bo; Chen, Yong-Ming; Sun, Ya-Hui; Tang, Mo-Tang

2011-08-01

The main purpose of this study is to characterize and separate bismuth from a bismuth glance concentrate through a low-temperature, sulfur-fixing smelting process. This article reports on a study conducted on the optimization of process parameters, such as Na2CO3 and zinc oxide wt pct in charging, smelting temperature, smelting duration on the bismuth yield, resultant crude bismuth grade, and sulfur-fixing rate. A maximum bismuth recovery of 97.31 pct, crude bismuth grade of 96.93 pct, and 98.23 pct sulfur-fixing rate are obtained when a charge (containing 63.50 wt pct of Na2CO3 and 22.50 wt pct of bismuth glance, as well as 5 pct in excess of the stoichiometric requirement of zinc oxide dosage) is smelted at 1000 K (727 °C) for 150 minutes. This smelting operation is free from atmospheric pollution because zinc oxide is used as the sulfur-fixing agent, which can capture sulfur from bismuth sulfide and form the more thermodynamic-stable compound, zinc sulfide. The solid residue is subjected to a mineral dressing operation to obtain suspension, which is filtered to produce a cake, representing the solid particles of zinc sulfide. Based on the results of the chemical content analysis of the as-resultant zinc sulfide, more than 93 pct zinc sulfide can be recovered, and the recovered zinc sulfide grade can reach 60.20 pct. This material can be sold as zinc sulfide concentrate or roasted to be regenerated as zinc oxide.

Zinc Oxide—From Synthesis to Application: A Review

PubMed Central

Kołodziejczak-Radzimska, Agnieszka; Jesionowski, Teofil

2014-01-01

Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide. PMID:28788596

Photoluminescence of Porous Silicon-Zinc Oxide Hybrid structures

NASA Astrophysics Data System (ADS)

Olenych, I. B.; Monastyrskii, L. S.; Luchechko, A. P.

2017-03-01

Arrays of ZnO nanostructures, which are optically transparent in the visible range, were grown on the surface of porous silicon by electrochemical deposition. Photoluminescence excitation and emission spectra of the obtained hybrid structures were investigated in 220-450 and 400-800 nm regions, respectively. It is established that multicolor emission is formed by combining the luminescence bands of porous silicon and zinc oxide. The possibility of controlling the photoluminescence spectra by changing the excitation energy is demonstrated. It is revealed that thermal annealing has an effect on the luminescent properties of porous silicon/zinc oxide hybrid structures. Thermal processing at 500°C leads to a sharp decrease of long-wavelength luminescence associated with porous silicon and to an increase of short-wavelength luminescence intensity related to zinc oxide.

EXAMINATION OF THE OXIDATION PROTECTION OF ZINC COATINGS FORMED ON COPPER ALLOYS AND STEEL SUBSTRATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papazoglou, M.; Chaliampalias, D.; Vourlias, G.

2010-01-21

The exposure of metallic components at aggressive high temperature environments, usually limit their usage at similar application because they suffer from severe oxidation attack. Copper alloys are used in a wide range of high-quality indoor and outdoor applications, statue parts, art hardware, high strength and high thermal conductivity applications. On the other hand, steel is commonly used as mechanical part of industrial set outs or in the construction sector due to its high mechanical properties. The aim of the present work is the examination of the oxidation resistance of pack cementation zinc coatings deposited on copper, leaded brass and steelmore » substrates at elevated temperature conditions. Furthermore, an effort made to make a long-term evaluation of the coated samples durability. The oxidation results showed that bare substrates appear to have undergone severe damage comparing with the coated ones. Furthermore, the mass gain of the uncoated samples was higher than this of the zinc covered ones. Particularly zinc coated brass was found to be more resistant to oxidation conditions in which it was exposed as it has the lower mass gain as compared to the bare substrates and zinc coated copper. Zinc coated steel was also proved to be more resistive than the uncoated steel.« less

Tunable infrared absorption and visible transparency of colloidal aluminum-doped zinc oxide nanocrystals.

PubMed

Buonsanti, Raffaella; Llordes, Anna; Aloni, Shaul; Helms, Brett A; Milliron, Delia J

2011-11-09

Plasmonic nanocrystals have been attracting a lot of attention both for fundamental studies and different applications, from sensing to imaging and optoelectronic devices. Transparent conductive oxides represent an interesting class of plasmonic materials in addition to metals and vacancy-doped semiconductor quantum dots. Herein, we report a rational synthetic strategy of high-quality colloidal aluminum-doped zinc oxide nanocrystals. The presence of substitutional aluminum in the zinc oxide lattice accompanied by the generation of free electrons is proved for the first time by tunable surface plasmon absorption in the infrared region both in solution and in thin films.

Effects of surface hydroxylation on adhesion at zinc/silica interfaces.

PubMed

Le, Ha-Linh Thi; Goniakowski, Jacek; Noguera, Claudine; Koltsov, Alexey; Mataigne, Jean-Michel

2018-06-06

The weak interaction between zinc and silica is responsible for the poor performance of anti-corrosive galvanic zinc coatings on modern advanced high-strength steels, which are fundamental in the automotive industry, and important for rail transport, shipbuilding, and aerospace. With the goal of identifying possible methods for its improvement, we report an ab initio study of the effect of surface hydroxylation on the adhesion characteristics of model zinc/β-cristobalite interfaces, representative of various surface hydroxylation/hydrogenation conditions. We show that surface silanols resulting from dissociative water adsorption at the most stable stoichiometric (001) and (111) surfaces prevent strong zinc-silica interactions. However, dehydrogenation of such interfaces produces oxygen-rich zinc/silica contacts with excellent adhesion characteristics. These are due to partial zinc oxidation and the formation of strong iono-covalent Zn-O bonds between zinc atoms and the under-coordinated excess anions, remnant of the hydroxylation layer. Interestingly, these interfaces appear as the most thermodynamically stable in a wide range of realistic oxygen-rich and hydrogen-lean environments. We also point out that the partial oxidation of zinc atoms in direct contact with the oxide substrate may somewhat weaken the cohesion in the zinc deposit itself. This fundamental analysis of the microscopic mechanisms responsible for the improved zinc wetting on pre-hydroxylated silica substrates provides useful guidelines towards practical attempts to improve adhesion.

Hierarchical Carbon Fibers with ZnO Nanowires for Volatile Sensing in Composite Curing (Postprint)

DTIC Science & Technology

2014-07-01

needed to demonstrate the use of Zinc Oxide (ZnO) nanowire coated carbon fibers as a volatile sensor. ZnO nanowires are demonstrated to function as...processing. For this work, we report on the foundational study needed to demonstrate the use of Zinc Oxide (ZnO) nanowire coated carbon fibers as a...array of ZnO nanowires. Zinc oxide nanowires become more conductive in the presence of ethanol – as analyte sorbs to the surface, electron density

Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes.

PubMed

Lee, Sook-Jeong; Koh, Jae-Young

2010-10-26

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.

Characterization, Degradation, and Reaction Pathways of Indoor Toluene over Visible-light-driven S, Zn Co-doped TiO2

NASA Astrophysics Data System (ADS)

Chu, H.; Lin, Y. H.; Lin, C. Y.

2017-01-01

Sulfur and Zinc co-doped TiO2 prepared by a sol-gel method to degrade toluene under a fluorescent lamp was investigated. The results indicate that S,Zn co-doped TiO2 photocatalysts are mainly nano-size with an anatase phase structure. The degradation reactions of toluene were performed under various operation conditions. The results show that the toluene conversion increases with increasing toluene concentration and decreasing relative humidity. Based on the results of activity test, S0.05Zn0.001/TiO2 was chosen for further studies. The main oxidation products of toluene photodegradation are CO2, H2O, benzyl alcohol, acetone, butadiene and acetic acid. Two possible mechanisms have been developed for photodegradation of toluene in a dry and a humid environment.

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

NASA Astrophysics Data System (ADS)

Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

2016-10-01

With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

Improved Sp1 and Betaine Homocysteine-S-Methyltransferase Expression and Homocysteine Clearance Are Involved in the Effects of Zinc on Oxidative Stress in High-Fat-Diet-Pretreated Mice.

PubMed

Wu, Li; Zhou, Xihong; Li, Tiejun; He, Juyun; Huang, Linli; Ouyang, Zicheng; He, Liuqin; Wei, Tao; He, Qinghua

2017-12-04

Zinc plays a role in alleviating oxidative stress. However, the related mechanisms remain to be further elucidated. The present study was conducted to investigate whether the recovery of oxidative stress in high-fat-diet (HFD)-pretreated mice was affected by zinc. Male mice received either an HFD or a low-fat-diet (LFD) for 8 weeks. Then, the mice fed with HFD and LFD were both assigned to either a control diet (30 mg zinc, ZD) or a no-added zinc diet (NZD) for an additional 4 weeks. The results showed that after feeding with NZD for 4 weeks, the HFD-pretreated mice had the highest plasma glucose and insulin concentrations, while had the lowest CuZn-SOD and glutathione concentrations. Moreover, after feeding with NZD for 4 weeks, the HFD-pretreated mice had the highest hepatic ROS and homocysteine concentrations, while had the lowest glutathione and methionine concentrations. Furthermore, the HFD-pretreated mice fed with NZD for 4 weeks had the lowest gene and protein expression of betaine homocysteine-S-methyltransferase (BHMT), cystathionine β-synthase, and Sp1. The results suggested that zinc was critical for oxidative stress alleviation and homocysteine clearance in HFD-pretreated mice. It was further elucidated that improved Sp1 and BHMT expression are involved in the effects of zinc on oxidative stress.

The effect of operational parameters on the photocatalytic degradation of Congo red organic dye using ZnO-CdS core-shell nano-structure coated on glass by Doctor Blade method.

PubMed

Habibi, Mohammad Hossein; Rahmati, Mohammad Hossein

2015-02-25

Photocatalytic degradation of Congo red was investigated using ZnO-CdS core-shell nano-structure coated on glass by Doctor Blade method in aqueous solution under irradiation. Field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) techniques were used for the morphological and structural characterization of ZnO-CdS core-shell nanostructures. XRD results showed diffractions of wurtzite zinc oxide core and wurtzite cadmium sulfide shell. FESEM results showed that nanoparticles are nearly hexagonal with an average diameter of about 50 nm. The effect of catalyst loading, UV-light irradiation time and solution pH on photocatalytic degradation of Congo red was studied and optimized values were obtained. Results showed that the employment of efficient photocatalyst and selection of optimal operational parameters may lead to complete decolorization of dye solutions. It was found that ZnO-CdS core-shell nano-structure is more favorable for the degradation of Congo red compare to pure ZnO or pure CdS due to lower electron hole recombination. The results showed that the photocatalytic degradation rate of Congo red is enhanced with increasing the content of ZnO up to ZnO(0.2 M)/CdS(0.075 M) which is reached 88.0% within 100 min irradiation. Copyright © 2014 Elsevier B.V. All rights reserved.

Leaching with Penicillium simplicissimum: Influence of metals and buffers on proton extrusion and citric acid production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Franz, A.; Burgstaller, W.; Schinner, F.

1991-03-01

In the presence of insoluble metal oxides (industrial filter dust, zinc oxide, synthetic mixture of metal oxides), Penicillium simplicissimum developed the ability to excrete considerable amounts of citric acid (>100 mM). Parallel with the increase of citric acid concentration in the culture broth, zinc was solubilized from zinc oxide. The adsorption of filter dust onto the mycelium (the pellets formed were less than 1 mm in diameter) was required for not only the citric acid excretion but also the leaching of zinc. When the filter dust was replaced with a synthetic mixture of metal oxides or with zinc oxide inmore » combination with trace elements, levels of adsorption and citric acid production were observed to be similar to those in experiments where industrial filter dust was used. The two most important properties of the filter dust were its heavy-metal content and its buffering capacity. These properties were simulated by adding heavy metals in soluble form (as chlorides, sulfates, or nitrates) or soluble buffers to the medium. Both heavy metals and buffers were not able to induce a citric acid efflux. As with citric acid production by Aspergillus niger, the addition of manganese lowered citric acid excretion (by 40% with metal oxide-induced citric acid efflux and by 100% with urea-induced citric acid efflux). Copper antagonized the effect of manganese. The mechanism for the bulk of citric acid excretion by P. simplicissimum, however, seemed to be different from that described for citric acid accumulation by A. niger. Because of the inefficiency of metals in solubilized form and of soluble buffers to induce a strong citric acid efflux, adsorption of an insoluble metal compound (zinc oxide) turned out to be essential.« less

Thermal annealing behavior of nano-size metal-oxide particles synthesized by ion implantation in Fe-Cr alloy

NASA Astrophysics Data System (ADS)

Zheng, C.; Gentils, A.; Ribis, J.; Borodin, V. A.; Descoins, M.; Mangelinck, D.; Dalle, F.; Arnal, B.; Delauche, L.

2017-05-01

Oxide dispersion strengthened (ODS) steels are promising structural materials for the next generation nuclear reactors, as well as fusion facilities. The detailed understanding of the mechanisms involved in the precipitation of nano-oxides during ODS steel production would strongly contribute to the improvement of the mechanical properties and the optimization of manufacturing of ODS steels, with a potentially strong economic impact for their industrialization. A useful tool for the experimental study of nano-oxide precipitation is ion implantation, a technique that is widely used to synthesize precipitate nanostructures in well-controlled conditions. Earlier, we have demonstrated the feasibility of synthesizing aluminum-oxide particles in the high purity Fe-10Cr alloy by consecutive implantation with Al and O ions at room temperature. This paper describes the effects of high-temperature annealing after the ion implantation stage on the development of the aluminum based oxide nanoparticle system. Using transmission electron microscopy and atom probe tomography experiments, we demonstrate that post-implantation heat treatment induces the growth of the nano-sized oxides in the implanted region and nucleation of new oxide precipitates behind the implantation zone as a result of the diffusion driven broadening of implant profiles. A tentative scenario for the development of metal-oxide nano-particles at both ion implantation and heat treatment stages is suggested based on the experimental observations.

Stable White Coatings

NASA Technical Reports Server (NTRS)

Zerlaut, Gene A.; Gilligan, J. E.; Harada, Y.

1965-01-01

In a previous research program for the Jet Propulsion- Laboratory, extensive studies led to the development and specifications of three zinc oxide-pigmented thermal-control coatings. The principal objectives of this program are: improvement of the three paints (as engineering materials), determination of the validity of our accelerated space-simulation testing, and continuation of the zinc oxide photolysis studies begun in the preceding program. Specific tasks that are discussed include: improvement of potassium silicate coatings as engineering materials and elucidation of their storage and handling problems; improvement of methyl silicone coatings as engineering materials; studies of zinc oxide photolysis to establish reasons for the observed stability of zinc oxide; and determination of space-simulation parameters such as long-term stability (to 8000 ESH), effect of coating surface temperature on the rate of degradation, and validity of accelerated testing (by reciprocity and wavelength dependency studies).

Study on the pre-treatment of oxidized zinc ore prior to flotation

NASA Astrophysics Data System (ADS)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

Nanoscale surface analysis on second generation advanced high strength steel after hot dip galvanizing.

PubMed

Arndt, M; Duchoslav, J; Preis, K; Samek, L; Stifter, D

2013-09-01

Second generation advanced high strength steel is one promising material of choice for modern automotive structural parts because of its outstanding maximal elongation and tensile strength. Nonetheless there is still a lack of corrosion protection for this material due to the fact that cost efficient hot dip galvanizing cannot be applied. The reason for the insufficient coatability with zinc is found in the segregation of manganese to the surface during annealing and the formation of manganese oxides prior coating. This work analyses the structure and chemical composition of the surface oxides on so called nano-TWIP (twinning induced plasticity) steel on the nanoscopic scale after hot dip galvanizing in a simulator with employed analytical methods comprising scanning Auger electron spectroscopy (SAES), energy dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) for cross section preparation. By the combination of these methods, it was possible to obtain detailed chemical images serving a better understanding which processes exactly occur on the surface of this novel kind of steel and how to promote in the future for this material system galvanic protection.

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

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

PubMed

Nagarajan, Sangeetha; Arumugam Kuppusamy, Kumaraguru

2013-12-03

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. 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. 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.

Ameliorative role of nano-ceria against amine coated Ag-NP induced toxicity in Labeo rohita

NASA Astrophysics Data System (ADS)

Khan, Muhammad Saleem; Qureshi, Naureen Aziz; Jabeen, Farhat

2018-03-01

Silver nanoparticles (Ag-NPs) and its byproducts can spread pollution in aquatic habitat. Liver and gills are key target for toxicity. Oxidative stress, tissue alterations, and hemotoxicity are assumed to be associated with Ag-NPs in target animals. Cerium oxide nanoparticles (nano-ceria) show antioxidant potential in scavenging the free radicals generated in Ag-NP-induced oxidative stress. We determined ameliorated role of nano-ceria against Ag-NP-induced toxicity in fresh water Labeo rohita (L. rohita). Four groups were used in study including control, nano-ceria, Ag-NPs, and Ag-NPs + nano-ceria. Ag-NPs (30 mg l-1) and nano-ceria (50 µg kg-1) were given through water and prepared feed, respectively. The samples were taken after 28 days. Results demonstrated that pre-treatment of nano-ceria recovered L. rohita from Ag-NP-induced toxicity and oxidative stress. Nano-ceria pre-treatment actively mimics the activity of GST, GSH, CAT, and SOD. Furthermore, Ag-NPs' treatment caused severe inflammation and necrosis in hepatic parenchyma which leaded to congestion of blood in hepatic tissues. Accumulation of a yellow pigment in hepatic tissue was also seen due to necrosis of affected cells. In nano-ceria pre-treatment, there was no congestion in hepatic tissue. Vacuolization of cells and necrosis in some area was recorded in nano-ceria pre-treated group, but the gill and hepatic tissue showed improvement against Ag-NP-induced damage. Nano-ceria pre-treatment also improved hematological parameters in Ag-NP-treated fish. This study concluded that Ag-NP-induced toxicity in treated fish and pre-treatment of nano-ceria show ameliorative role.

Feeding Low or Pharmacological Concentrations of Zinc Oxide Changes the Hepatic Proteome Profiles in Weaned Piglets

PubMed Central

Bondzio, Angelika; Pieper, Robert; Gabler, Christoph; Weise, Christoph; Schulze, Petra; Zentek, Juergen; Einspanier, Ralf

2013-01-01

Pharmacological levels of zinc oxide can promote growth and health of weaning piglets, but the underlying molecular mechanisms are yet not fully understood. The aim of this study was to determine changes in the global hepatic protein expression in response to dietary zinc oxide in weaned piglets. Nine half-sib piglets were allocated to three dietary zinc treatment groups (50, 150, 2500 mg/kg dry matter). After 14 d, pigs were euthanized and liver samples taken. The increase in hepatic zinc concentration following dietary supplementation of zinc was accompanied by up-regulation of metallothionein mRNA and protein expression. Global hepatic protein profiles were obtained by two-dimensional difference gel electrophoresis following matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. A total of 15 proteins were differentially (P<0.05) expressed between groups receiving control (150 mg/kg) or pharmacological levels of zinc (2500 mg/kg) with 7 down- (e.g. arginase1, thiosulfate sulfurtransferase, HSP70) and 8 up-regulated (e.g. apolipoprotein AI, transferrin, C1-tetrahydrofolate synthase) proteins. Additionally, three proteins were differentially expressed with low zinc supply (50 mg/kg Zn) in comparison to the control diet. The identified proteins were mainly associated with functions related to cellular stress, transport, metabolism, and signal transduction. The differential regulation was evaluated at the mRNA level and a subset of three proteins of different functional groups was selected for confirmation by western blotting. The results of this proteomic study suggest that zinc affects important liver functions such as blood protein secretion, protein metabolism, detoxification and redox homeostasis, thus supporting the hypothesis of intermediary effects of pharmacological levels of zinc oxide fed to pigs. PMID:24282572

Mechanisms of inhibition of zinc-finger transcription factors by selenium compounds ebselen and selenite.

PubMed

Larabee, Jason L; Hocker, James R; Hanas, Jay S

2009-03-01

The anti-inflammatory selenium compounds, ebselen (2-phenyl-1,2-benzisoselenazol-3[2H]-one) and selenite, were found to alter the DNA binding mechanisms and structures of cysteine-rich zinc-finger transcription factors. As assayed by DNase I protection, DNA binding by TFIIIA (transcription factor IIIA, prototypical Cys(2)His(2) zinc finger protein), was inhibited by micromolar amounts of ebselen. In a gel shift assay, ebselen inhibited the Cys(2)His(2) zinc finger-containing DNA binding domain (DBD) of the NF-kappaB mediated transcription factor Sp1. Ebselen also inhibited DNA binding by the p50 subunit of the pro-inflammatory Cys-containing NF-kappaB transcription factor. Electrospray ionization mass spectrometry (ESI-MS) was utilized to elucidate mechanisms of chemical interaction between ebselen and a zinc-bound Cys(2)His(2) zinc finger polypeptide modeled after the third finger of Sp1 (Sp1-3). Exposing Sp1-3 to micromolar amounts of ebselen resulted in Zn(2+) release from this peptide and the formation of a disulfide bond by oxidation of zinc finger SH groups, the likely mechanism for DNA binding inhibition. Selenite was shown by ESI-MS to also eject zinc from Sp1-3 as well as induce disulfide bond formation through SH oxidation. The selenite-dependent inhibition/oxidation mechanism differed from that of ebselen by inducing the formation of a stable selenotrisulfide bond. Selenite-induced selenotrisulfide formation was dependent upon the structure of the Cys(2)His(2) zinc finger as alteration in the finger structure enhanced this reaction as well as selenite-dependent zinc release. Ebselen and selenite-dependent inhibition/oxidation of Cys-rich zinc finger proteins, with concomitant release of zinc and finger structural changes, points to mechanisms at the atomic and protein level for selenium-induced alterations in Cys-rich proteins, and possible amelioration of certain inflammatory, neurodegenerative, and oncogenic responses.

Zinc Supplementation Ameliorates Diabetic Cataract Through Modulation of Crystallin Proteins and Polyol Pathway in Experimental Rats.

PubMed

Barman, Susmita; Srinivasan, Krishnapura

2018-05-13

Non-enzymatic glycation of lens proteins and elevated polyol pathway in the eye lens have been the characteristic features of a diabetic condition. We have previously reported the benefits of zinc supplementation in reducing hyperglycemia and associated metabolic abnormalities and oxidative stress in diabetic rats. The current study explored whether zinc supplementation protects against cataractogenesis through modulation of glycation of lens proteins, elevated polyol pathway, oxidative stress, and proportion of different heat shock proteins in the eye lens of diabetic rats. Streptozotocin-induced diabetic rats were fed with a zinc-enriched diet (5 and 10 times of normal) for 6 weeks. Supplemental zinc alleviated the progression and maturation of diabetes-induced cataract. Zinc was also effective in preventing the reduced content of total and imbalanced proportion of soluble proteins in the lens. Supplemental zinc also alleviated cross-linked glycation and concomitant expression of the receptor of glycated products and oxidative stress indicators in the eye lens. Zinc supplementation further induced the concentration of heat shock protein in the eye lens of diabetic rats, specifically α-crystallin. Zinc supplementation counteracted the elevated activity and expression of polyol pathway enzymes and molecules in the lens. The results of this animal study endorsed the advantage of zinc supplementation in exerting the antiglycating influence and downregulating polyol pathway enzymes to defer cataractogenesis in diabetic rats.

(HEL MRI) 3D Meta Optics for High Energy Lasers

DTIC Science & Technology

2016-09-13

based metal-oxide nano- hair structures for optical vortex generation," Opt. Express 23, 19056-19065 (2015) 15. Li, Yuan, Zeyu Zhang, Wenzhe Li, Jerome...Indumathi Raghu Srimathi, Aaron J. Pung, Yuan Li, Raymond C. Rumpf, and Eric G. Johnson, "Fabrication of metal-oxide nano- hairs for effective index...Grating Based Optical Nano- Hairs Using ALD Nano- Patterning Subwavelength gratings (SWGs) based artificial dielectric elements are used to obtain the

The effects of cetyltrimethylammonium bromide surfactant on alumina modified zinc oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gac, Wojciech, E-mail: wojciech.gac@umcs.lublin.pl; Zawadzki, Witold; Słowik, Grzegorz

Highlights: • Synthesis of novel ZnO−Al{sub 2}O{sub 3} oxides in the presence of CTAB surfactant. • Determination of the structural, surface and optical properties. • Nanocrystalline, high-surface area ZnO−Al{sub 2}O{sub 3} oxides. • ZnO-Al{sub 2}O{sub 3} materials of different gap energy. - Abstract: Novel alumina modified zinc oxide materials were prepared by co-precipitation method in the presence of different amounts of cetyltrimethylammonium bromide (CTAB) surfactant. X-ray diffraction, {sup 27}Al magic-angle spinning Nuclear Magnetic Resonance Spectroscopy, and transmission electron microscopy studies evidenced formation of 10–15 nm zinc oxide nanoparticles in the presence of the small amounts of surfactant. Amorphous alumina andmore » zinc aluminate phases of different coordination environment of Al sites were identified. An increase of surfactant concentration led to the elongation of nanoparticles and changes of the nature of hydroxyl groups. Precipitation in the high CTAB concentration conditions facilitated formation of mesoporous materials of high specific surface area. The materials were composed of very small (2–3 nm) zinc aluminate spinel nanoparticles. High concentration of CTAB induced widening of band gap energy.« less

Clinical and radiographic evaluation of zinc oxide with aloe vera as an obturating material in pulpectomy: an in vivo study.

PubMed

Khairwa, Abhishek; Bhat, Manohar; Sharma, Rajesh; Satish, V; Maganur, Prabhadevi; Goyal, Anil Kumar

2014-01-01

Pulp therapy for pulpally involved primary teeth continues to be a challenge to clinicians. One of the major areas of continued research is in the area of finding obturating materials to suit the specific properties of these teeth. Zinc oxide eugenol is used frequently in pulpectomy for the obturation of the primary teeth. To evaluate clinically and radiographically a mixture of zinc oxide eugenol and aloe vera as an obturating material. A total of 50 children, aged between 4 and 9 years, who were screened for unilateral or bilateral carious deciduous molars were studied. Out of these, 15 children were randomly selected for endodontic treatment. Obturation was done with a mixture of zinc oxide powder and aloe vera gel. Clinical and radiographic evaluation was done after 7 days, 1 month, 3 months, 6 months, and 9 months. The data were statistically analyzed. Endodontic treatment using a mixture of zinc oxide powder and aloe vera gel in primary teeth has shown good clinical and radiographic success. A detailed observational study with longer follow-up will highlight the benefits of aloe vera in primary teeth as an obturating medium.

Quantifying charge carrier concentration in ZnO thin films by Scanning Kelvin Probe Microscopy

PubMed Central

Maragliano, C.; Lilliu, S.; Dahlem, M. S.; Chiesa, M.; Souier, T.; Stefancich, M.

2014-01-01

In the last years there has been a renewed interest for zinc oxide semiconductor, mainly triggered by its prospects in optoelectronic applications. In particular, zinc oxide thin films are being widely used for photovoltaic applications, in which the determination of the electrical conductivity is of great importance. Being an intrinsically doped material, the quantification of its doping concentration has always been challenging. Here we show how to probe the charge carrier density of zinc oxide thin films by Scanning Kelvin Probe Microscopy, a technique that allows measuring the contact potential difference between the tip and the sample surface with high spatial resolution. A simple electronic energy model is used for correlating the contact potential difference with the doping concentration in the material. Limitations of this technique are discussed in details and some experimental solutions are proposed. Two-dimensional doping concentration images acquired on radio frequency-sputtered intrinsic zinc oxide thin films with different thickness and deposited under different conditions are reported. We show that results inferred with this technique are in accordance with carrier concentration expected for zinc oxide thin films deposited under different conditions and obtained from resistivity and mobility measurements. PMID:24569599

Respiratory Symptoms and Pulmonary Function Tests among Galvanized Workers Exposed To Zinc Oxide.

PubMed

Aminian, Omid; Zeinodin, Hamidreza; Sadeghniiat-Haghighi, Khosro; Izadi, Nazanin

2015-01-01

Galvanization is the process of coating steel or cast iron pieces with a thin layer of zinc allowing protection against corrosion. One of the important hazards in this industry is exposure to zinc compounds specially zinc oxide fumes and dusts. In this study, we evaluated chronic effects of zinc oxide on the respiratory tract of galvanizers. Overall, 188 workers were selected from Arak galvanization plant in 2012, 71 galvanizers as exposed group and 117 workers from other departments of plants as control group. Information was collected using American Thoracic Society (ATS) standard questionnaire, physical examination and demographic data sheet. Pulmonary function tests were measured for all subjects. Exposure assessment was done with NIOSH 7030 method. The Personal Breathing Zone (PBZ) air sampling results for zinc ranged from 6.61 to 8.25 mg/m³ above the permissible levels (Time weighted average; TWA:2 mg/m³). The prevalence of the respiratory symptoms such as dyspnea, throat and nose irritation in the exposed group was significantly (P<0.01) more than the control group. Decreasing in average percent in all spirometric parameters were seen in the galvanizers who exposed to zinc oxide fumes and dusts. The prevalence of obstructive respiratory disease was significantly (P=0.034) higher in the exposed group. High workplace zinc levels are associated with an increase in respiratory morbidity in galvanizers. Therefore administrators should evaluate these workers with periodic medical examinations and implement respiratory protection program in the working areas.

Visible-light-enhanced interactions of hydrogen sulfide with composites of zinc (oxy)hydroxide with graphite oxide and graphene.

PubMed

Seredych, Mykola; Mabayoje, Oluwaniyi; Bandosz, Teresa J

2012-01-17

Composites of zinc(oxy)hydroxide-graphite oxide and of zinc(oxy)hydroxide-graphene were used as adsorbents of hydrogen sulfide under ambient conditions. The initial and exhausted samples were characterized by XRD, FTIR, potentiometric titration, EDX, thermal analysis, and nitrogen adsorption. An increase in the amount of H(2)S adsorbed/oxidized on their surfaces in comparison with that of pure Zn(OH)(2) is linked to the structure of the composite, the relative number of terminal hydroxyls, and the kind of graphene-based phase used. Although terminal groups are activated by a photochemical process, the graphite oxide component owing to the chemical bonds with the zinc(oxy)hydroxide phase and conductive properties helps in electron transfer, leading to more efficient oxygen activation via the formation of superoxide ions. Elemental sulfur, zinc sulfide, sulfite, and sulfate are formed on the surface. The formation of sulfur compounds on the surface of zinc(oxy)hydroxide during the course of the breakthrough experiments and thus Zn(OH)(2)-ZnS heterojunctions can also contribute to the increased surface activity of our materials. The results show the superiority of graphite oxide in the formation of composites owing to its active surface chemistry and the possibility of interface bond formation, leading to an increase in the number of electron-transfer reactions. © 2011 American Chemical Society

Effect of the temperature on structural and optical properties of zinc oxide nanoparticles.

PubMed

Hadia, N M A; García-Granda, Santiago; García, José R

2014-07-01

Zinc nitrate hexahydrate, Zn(NO3)2 x 6H2O was used as a precursor with urea NH2CONH2 to prepare hydrozincite Zn5(CO3)2(OH)6 powder using hydrothermal method for 8 h at 90 degrees C. Zinc oxide (ZnO) nanoparticles (NPs) were prepared by thermal annealing of hydrozincite powder at different annealing temperatures, i.e., 350, 550 750 and 950 degrees C in air for 2 h. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The optical properties of the products were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and photoluminescence (PL) spectra. It was found that the particle size increased from - 33 to 250 nm with increasing in the annealing temperatures. FTIR results showed that the standard peaks of zinc oxide were presented at 428.17 and 532.32 cm(-1). Thermal analysis study showed that the primary weight loss starts at - 93 degrees C is due to solvent evaporation. The secondary weight loss, observed at - 378 degrees C, is due to phase transition from hydrated zinc oxide to zinc oxide. The band gaps of the products were in the range - 3.26-3.30 eV. The PL spectrum showed that the as-synthesized ZnO nanoparticles had UV (381 nm) and green (537 nm) emissions.

Surface enrichment of Pt in stable Pt-Ir nano-alloy particles on MgAl 2O 4 spinel in oxidizing atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wei -Zhen; Nie, Lei; Cheng, Yingwen

With the capability of MgAl 2O 4 spinel {111} nano-facets in stabilizing small Rh, Ir and Pt particles, bimetallic Ir-Pt catalysts on the same support were investigated in this paper, aiming at further lowering the catalyst cost by substituting expensive Pt with cheaper Ir in the bulk. Small Pt-Ir nano-alloy particles (< 2 nm) were successfully stabilized on the spinel {111} nano-facets as expected. Interestingly, methanol oxidative dehydrogenation (ODH) rate on the surface Pt atoms increases with oxidizing aging but decreases upon reducing treatment, where Ir is almost inactive under the same reaction conditions. Up to three times enhancement inmore » Pt exposure was achieved when the sample was oxidized at 800 °C in air for 1 week and subsequently reduced by H 2 for 2 h, demonstrating successful surface enrichment of Pt on Pt-Ir nano-alloy particles. Finally, a dynamic stabilization mechanism involving wetting/nucleation seems to be responsible for the evolution of surface compositions upon cyclic oxidizing and reducing thermal treatments.« less

Surface enrichment of Pt in stable Pt-Ir nano-alloy particles on MgAl 2O 4 spinel in oxidizing atmosphere

DOE PAGES

Li, Wei -Zhen; Nie, Lei; Cheng, Yingwen; ...

2017-01-13

With the capability of MgAl 2O 4 spinel {111} nano-facets in stabilizing small Rh, Ir and Pt particles, bimetallic Ir-Pt catalysts on the same support were investigated in this paper, aiming at further lowering the catalyst cost by substituting expensive Pt with cheaper Ir in the bulk. Small Pt-Ir nano-alloy particles (< 2 nm) were successfully stabilized on the spinel {111} nano-facets as expected. Interestingly, methanol oxidative dehydrogenation (ODH) rate on the surface Pt atoms increases with oxidizing aging but decreases upon reducing treatment, where Ir is almost inactive under the same reaction conditions. Up to three times enhancement inmore » Pt exposure was achieved when the sample was oxidized at 800 °C in air for 1 week and subsequently reduced by H 2 for 2 h, demonstrating successful surface enrichment of Pt on Pt-Ir nano-alloy particles. Finally, a dynamic stabilization mechanism involving wetting/nucleation seems to be responsible for the evolution of surface compositions upon cyclic oxidizing and reducing thermal treatments.« less

Involvement of l-arginine-nitric oxide pathway in anxiolytic-like effects of zinc chloride in rats.

PubMed

Navabi, Seyedeh Parisa; Eshagh Harooni, Hooman; Moazedi, Ahmad Ali; Khajepour, Lotfolah; Fathinia, Kosar

2016-10-01

Zinc is crucial for normal development of the brain, and Zinc deficiency has been shown to associate with neurological disorders (e.g. anxiety) through interactions with several neurotransmitter systems such as nitric oxide (NO). In this regard, our study aimed to evaluate the possible involvement of l-arginine NO pathway on anxiolytic effects of zinc in adult male rats. Zinc chloride at doses of 2.5 and 10mg/kg (intraperitoneal or ip) or saline (1ml/kg, ip) were injected 30min before the anxiety test. Zinc administrated rats (10mg/kg) were pre-treated with intra-CA1 microinjection of l-arginine in sub-effective dose of 1μg/rat (dorsal hippocampus, vehicle: saline1μl/rat). In addition, zinc chloride and NG-nitro-l-arginine methyl ester (l-NAME) were intraperitoneally co-administrated in sub-effective doses of 2.5mg/kg and 80mg/kg, respectively. The percentage of open arm time (OAT%), percentage of open arm entry (OAE%), as measures of anxiety, and total number of arm entries, as measures of locomotor activity, were recorded. Treatment with zinc (10mg/kg) markedly produced an increase in OAT% and OAE% in the Elevated plus maze test (EPM). A decrease of OAT% and OAE% was shown in groups which received zinc (10mg/kg) and l-arginine (1μg/rat) concomitantly as compared to the control group. Moreover, an increase of OAE% was revealed in the group exposed to Zinc (2.5mg/kg) and l-NAME (80mg/kg) co-administration. Although, Two-way ANOVA showed no significant differences of anxiety indices in rats received drug+zinc chloride in compare to the zinc pretreated with saline group. Anxiolytic- like effect of zinc reversed by nitric oxide precursor l-arginine. Additionally, the synergistic effects of l-NAME and ZnCl 2 were shown in the EPM. Thus our findings suggest that at least in part the anxiolytic effects of zinc can be mediated through the nitric oxide system. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Ultrasonic measurements of thin zinc layers on concrete

NASA Astrophysics Data System (ADS)

Jansen, Henri; Brooks, Bill; Nguyen, Vinh; Koretsky, Milo

2008-05-01

In order to protect bridges at the coast from corrosion, a thin layer (approximately 0.5 mm) of zinc is sprayed on the concrete of the bridge. When this zinc layer is electrically connected to the reinforcing steel (rebar) and placed at a positive potential with respect to the rebar, oxidation is favored at the zinc layer and reduced at the rebar. The resulting protection of the rebar fails when the zinc layer delaminates from the concrete or when the zinc oxidation product layer becomes too thick. We have used ultrasonic detection to investigate the properties of the zinc layer. This method has been applied very successfully in the semiconductor industry. We present the details of the method and the expected response. Unfortunately, we are not able to measure changes in the zinc layer, because either the frequency we use (10-20 MHz) is too low, or scattering in the concrete is a dominant effect.

40 CFR 60.171 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.171 Definitions... and in subpart A of this part. (a) Primary zinc smelter means any installation engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc sulfide ore...

40 CFR 60.171 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and in subpart A of this part. (a) Primary zinc smelter means any installation engaged in the production, or any intermediate process in the production, of zinc or zinc oxide from zinc sulfide ore... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Primary Zinc Smelters § 60.171 Definitions...

On Controlling the Hydrophobicity of Nanostructured Zinc-Oxide Layers Grown by Pulsed Electrodeposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klochko, N. P., E-mail: klochko-np@mail.ru; Klepikova, K. S.; Kopach, V. R.

The possibility of fabricating highly hydrophobic nanostructured zinc-oxide layers by the inexpensive method of pulsed electrodeposition from aqueous solutions without water-repellent coatings, adapted for large-scale production, is shown. The conditions of the deposition of highly hydrophobic nanostructured zinc-oxide layers exhibiting the “rose-petal” effect with specific morphology, optical properties, crystal structure and texture are determined. The grown ZnO nanostructures are promising for micro- and nanoelectronics as an adaptive material able to reversibly transform to the hydrophilic state upon exposure to ultraviolet radiation.

The anti-sigma factor RsrA responds to oxidative stress by reburying its hydrophobic core

PubMed Central

Rajasekar, Karthik V.; Zdanowski, Konrad; Yan, Jun; Hopper, Jonathan T. S.; Francis, Marie-Louise R.; Seepersad, Colin; Sharp, Connor; Pecqueur, Ludovic; Werner, Jörn M.; Robinson, Carol V.; Mohammed, Shabaz; Potts, Jennifer R.; Kleanthous, Colin

2016-01-01

Redox-regulated effector systems that counteract oxidative stress are essential for all forms of life. Here we uncover a new paradigm for sensing oxidative stress centred on the hydrophobic core of a sensor protein. RsrA is an archetypal zinc-binding anti-sigma factor that responds to disulfide stress in the cytoplasm of Actinobacteria. We show that RsrA utilizes its hydrophobic core to bind the sigma factor σR preventing its association with RNA polymerase, and that zinc plays a central role in maintaining this high-affinity complex. Oxidation of RsrA is limited by the rate of zinc release, which weakens the RsrA–σR complex by accelerating its dissociation. The subsequent trigger disulfide, formed between specific combinations of RsrA's three zinc-binding cysteines, precipitates structural collapse to a compact state where all σR-binding residues are sequestered back into its hydrophobic core, releasing σR to activate transcription of anti-oxidant genes. PMID:27432510

Membrane lipid profiles of coral responded to zinc oxide nanoparticle-induced perturbations on the cellular membrane.

PubMed

Tang, Chuan-Ho; Lin, Ching-Yu; Lee, Shu-Hui; Wang, Wei-Hsien

2017-06-01

Zinc oxide nanoparticles (nZnOs) released from popular sunscreens used during marine recreation apparently endanger corals; however, the known biological effects are very limited. Membrane lipids constitute the basic structural element to create cell a dynamic structure according to the circumstance. Nano-specific effects have been shown to mechanically perturb the physical state of the lipid membrane, and the cells accommodating the actions of nZnOs can be involved in the alteration of the membrane lipid composition. To gain insight into the effects of nanoparticles on coral, glycerophosphocholine (GPC) profiling of the coral Seriatopora caliendrum exposed to nZnOs was performed in this study. Increasing lyso-GPCs, docosapentaenoic acid-possessing GPCs and docosahexaenoic acid-possessing GPCs and decreasing arachidonic acid-possessing GPCs were the predominant changes responded to nZnO exposure in the coral. A backfilling of polyunsaturated plasmanylcholines was observed in the coral exposed to nZnO levels over a threshold. These changes can be logically interpreted as an accommodation to nZnOs-induced mechanical disturbances in the cellular membrane based on the biophysical properties of the lipids. Moreover, the coral demonstrated a difference in the changes in lipid profiles between intra-colonial functionally differentiated polyps, indicating an initial membrane composition-dependent response. Based on the physicochemical properties and physiological functions of these changed lipids, some chronic biological effects can be incubated once the coral receives long-term exposure to nZnOs. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of zinc oxide nanoparticles on lettuce (Lactuca sativa L.) growth and soil bacterial community.

PubMed

Xu, Jiangbing; Luo, Xiaosan; Wang, Yanling; Feng, Youzhi

2018-02-01

The wide spread of nanoparticles (NPs) has caused tremendous concerns on agricultural ecosystem. Some metallic NPs, such as zinc oxide (ZnO), can be utilized as a nano-fertilizer when used at optimal doses. However, little is known about the responses of plant development and concomitant soil bacteria community to ZnO NPs. The present pot experiment studied the impacts of different doses of ZnO NPs and bulk ZnO (0, 1, 10, 100 mg ZnO/kg), on the growth of lettuce (Lactuca sativa L.) and the associated rhizospheric soil bacterial community. Results showed that at a dose of 10 mg/kg, ZnO NPs and bulk ZnO, enhanced the lettuce biomass and the net photosynthetic rate; whereas, the Zn content in plant tissue was higher in NPs treatment than in their bulk counterpart at 10 mg/kg dose or higher. For the underground observations, 10 mg/kg treatment doses (NPs or bulk) significantly changed the soil bacterial community structure, despite the non-significant variations in alpha diversity. Taxonomic distribution revealed that some lineages within Cyanobacteria and other phyla individually demonstrated similar or different responses to ZnO NPs and bulk ZnO. Moreover, some lineages associated with plant growth promotion were also influenced to different extents by ZnO NPs and bulk ZnO, suggesting the distinct microbial processes occurring in soil. Collectively, this study expanded our understanding of the influence of ZnO NPs on plant performance and the associated soil microorganisms.

1.55 Micrometer Sub-Micron Finger, Interdigitated MSM Photodetector Arrays with Low Dark Current

DTIC Science & Technology

2010-02-02

pf a- IGZO TFTs. IV. RF Characteristics of Room Temperature Deposited Indium Zinc Oxide Thin - Film Transistors Depletion-mode indium zinc...III. High Performance Indium Gallium Zinc Oxide Thin Film Transistors Fabricated On Polyethylene Terephthalate Substrates High-performance...amorphous (a-) InGaZnO-based thin film transistors (TFTs) were fabricated on flexible polyethylene terephthalate (PET) substrates coated with indium

Effect of Nano-Al₂O₃ on the Toxicity and Oxidative Stress of Copper towards Scenedesmus obliquus.

PubMed

Li, Xiaomin; Zhou, Suyang; Fan, Wenhong

2016-06-09

Nano-Al₂O₃ has been widely used in various industries; unfortunately, it can be released into the aquatic environment. Although nano-Al₂O₃ is believed to be of low toxicity, it can interact with other pollutants in water, such as heavy metals. However, the interactions between nano-Al₂O₃ and heavy metals as well as the effect of nano-Al₂O₃ on the toxicity of the metals have been rarely investigated. The current study investigated copper toxicity in the presence of nano-Al₂O₃ towards Scenedesmus obliquus. Superoxide dismutase activity and concentration of glutathione and malondialdehyde in cells were determined in order to quantify oxidative stress in this study. Results showed that the presence of nano-Al₂O₃ reduced the toxicity of Cu towards S. obliquus. The existence of nano-Al₂O₃ decreased the growth inhibition of S. obliquus. The accumulation of copper and the level of oxidative stress in algae were reduced in the presence of nano-Al₂O₃. Furthermore, lower copper accumulation was the main factor that mitigated copper toxicity with the addition of nano-Al₂O₃. The decreased copper uptake could be attributed to the adsorption of copper onto nanoparticles and the subsequent decrease of available copper in water.

Doped zinc oxide microspheres

DOEpatents

Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

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.

Zinc Oxide Nanoparticles for Revolutionizing Agriculture: Synthesis and Applications

PubMed Central

Sabir, Sidra; Arshad, Muhammad

2014-01-01

Nanotechnology is the most innovative field of 21st century. Extensive research is going on for commercializing nanoproducts throughout the world. Due to their unique properties, nanoparticles have gained considerable importance compared to bulk counterparts. Among other metal nanoparticles, zinc oxide nanoparticles are very much important due to their utilization in gas sensors, biosensors, cosmetics, drug-delivery systems, and so forth. Zinc oxide nanoparticles (ZnO NPs) also have remarkable optical, physical, and antimicrobial properties and therefore have great potential to enhance agriculture. As far as method of formation is concerned, ZnO NPs can be synthesized by several chemical methods such as precipitation method, vapor transport method, and hydrothermal process. The biogenic synthesis of ZnO NPs by using different plant extracts is also common nowadays. This green synthesis is quite safe and ecofriendly compared to chemical synthesis. This paper elaborates the synthesis, properties, and applications of zinc oxide nanoparticles. PMID:25436235

BIOCHEMISTRY OF MOBILE ZINC AND NITRIC OXIDE REVEALED BY FLUORESCENT SENSORS

PubMed Central

Pluth, Michael D.; Tomat, Elisa; Lippard, Stephen J.

2010-01-01

Biologically 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 of these two species has emerged in several areas of human physiology, providing additional incentive for developing adequate detection systems for Zn(II) ions and NO in biological specimens. Fluorescent probes for both of these bioinorganic analytes provide excellent tools for their detection, with high spatial and temporal resolution. We review the most widely used fluorescent sensors for biological zinc and nitric oxide, together with promising new developments and unmet needs of contemporary Zn(II) and NO biological imaging. The interplay between zinc and nitric oxide in the nervous, cardiovascular, and immune systems is highlighted to illustrate the contributions of selective fluorescent probes to the study of these two important bioinorganic analytes. PMID:21675918

Evaluation of the optical characteristics of c-axis oriented zinc oxide thin films grown by sol gel spin coating technique

NASA Astrophysics Data System (ADS)

Baisakh, K.; Behera, S.; Pati, S.

2018-03-01

In this work we have systematically studied the optical characteristics of synthesized wurzite zinc oxide thin films exhibiting (002) orientation. Using sol gel spin coating technique zinc oxide thin films are grown on pre cleaned fused quartz substrates. Structural properties of the films are studied using X-ray diffraction analysis. Micro structural analysis and thickness of the grown samples are analyzed using field emission scanning electron microscopy. With an aim to investigate the optical characteristics of the grown zinc oxide thin films the transmission and reflection spectra are evaluated in the ultraviolet-visible (UV-VIS) range. Using envelope method, the refractive index, extinction coefficient, absorption coefficient, band gap energy and the thickness of the synthesized films are estimated from the recorded UV-VIS spectra. An attempt has also been made to study the influence of crystallographic orientation on the optical characteristics of the grown films.

Nanoparticles of nickel oxide: growth and organization on zinc-substituted anionic clay matrix by one-pot route at room temperature

NASA Astrophysics Data System (ADS)

Carja, Gabriela; Nakajima, Akira; Dranca, Cristian; Okada, Kiyoshi

2010-10-01

A room temperature nanocarving strategy is developed for the fabrication of nanoparticles of nickel oxide on zinc-substituted anionic clay matrix (Ni/ZnLDH). It is based on the growth and organization of nanoparticles of nickel oxide which occur during the structural reconstruction of the layered structure of the anionic clay in NiSO4 aqueous solution. No organic compounds are used during the fabrication. The described material was characterized by X-ray diffraction (XRD), IR spectroscopy (FTIR), transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Results show that the nickel-clay nanoarchitecture consists of small nanoparticles of nickel oxide (average size 7 nm) deposited on the larger nanoparticles (average size 90 nm) of zinc-substituted clay. The optical properties of the new nickel-zinc formulation are studied by UV-Vis.

Zinc oxide nanoparticles for revolutionizing agriculture: synthesis and applications.

PubMed

Sabir, Sidra; Arshad, Muhammad; Chaudhari, Sunbal Khalil

2014-01-01

Nanotechnology is the most innovative field of 21st century. Extensive research is going on for commercializing nanoproducts throughout the world. Due to their unique properties, nanoparticles have gained considerable importance compared to bulk counterparts. Among other metal nanoparticles, zinc oxide nanoparticles are very much important due to their utilization in gas sensors, biosensors, cosmetics, drug-delivery systems, and so forth. Zinc oxide nanoparticles (ZnO NPs) also have remarkable optical, physical, and antimicrobial properties and therefore have great potential to enhance agriculture. As far as method of formation is concerned, ZnO NPs can be synthesized by several chemical methods such as precipitation method, vapor transport method, and hydrothermal process. The biogenic synthesis of ZnO NPs by using different plant extracts is also common nowadays. This green synthesis is quite safe and ecofriendly compared to chemical synthesis. This paper elaborates the synthesis, properties, and applications of zinc oxide nanoparticles.

Effect of NaNO3 concentration on anodic electrochemical behavior on the Sb surface in NaOH solution

NASA Astrophysics Data System (ADS)

He, Yun-long; Xu, Rui-dong; He, Shi-wei; Chen, Han-sen; Li, Kuo; Zhu, Yun; Shen, Qing-feng

2018-03-01

The effect of NaNO3 concentration on the anodic electrochemical behavior of antimony in 4 M NaOH solution was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses. The mechanism of NO 3 - concentration effect on the anodic electrochemical behavior of antimony was proposed, and its availability was confirmed by experimental results. The effect of NaNO3 on the anodic behavior of antimony in NaOH solution can be interpreted as a stepwise formation of different antimony compounds with different NaNO3 concentrations. Metallic antimony is apt to be oxidized into Sb2O3 within the NaNO3 concentration range of 0-0.48 M. NaSbO3 can be found on the antimony surface when the NaNO3 concentration increases gradually. Insoluable NaSbO3 inhibits the anodic oxidation of antimony due to its shielding effect on the mass transport of the reactants and products. Surface morphology and composition were analyzed by X-ray photoelectron spectroscopy (XPS), scanning electronic microscopy (SEM), and electron dispersion spectroscopy (EDS) analyses. Results indicate that the anodic oxidation layer is composed of Sb2O3, NaSbO3, and Sb. The atomic proportion of antimony in the form of NaSbO3 increases with increasing NaNO3 concentration due to the powerful oxidizing property of NaNO3.

Nano-Ceramic Coated Plastics

NASA Technical Reports Server (NTRS)

Cho, Junghyun

2013-01-01

Plastic products, due to their durability, safety, and low manufacturing cost, are now rapidly replacing cookware items traditionally made of glass and ceramics. Despite this trend, some still prefer relatively expensive and more fragile ceramic/glassware because plastics can deteriorate over time after exposure to foods, which can generate odors, bad appearance, and/or color change. Nano-ceramic coatings can eliminate these drawbacks while still retaining the advantages of the plastic, since the coating only alters the surface of the plastic. The surface coating adds functionality to the plastics such as self-cleaning and disinfectant capabilities that result from a photocatalytic effect of certain ceramic systems. These ceramic coatings can also provide non-stick surfaces and higher temperature capabilities for the base plastics without resorting to ceramic or glass materials. Titanium dioxide (TiO2) and zinc oxide (ZnO) are the candidates for a nano-ceramic coating to deposit on the plastics or plastic films used in cookware and kitchenware. Both are wide-bandgap semiconductors (3.0 to 3.2 eV for TiO2 and 3.2 to 3.3 eV for ZnO), so they exhibit a photocatalytic property under ultraviolet (UV) light. This will lead to decomposition of organic compounds. Decomposed products can be easily washed off by water, so the use of detergents will be minimal. High-crystalline film with large surface area for the reaction is essential to guarantee good photocatalytic performance of these oxides. Low-temperature processing (<100 C) is also a key to generating these ceramic coatings on the plastics. One possible way of processing nanoceramic coatings at low temperatures (< 90 C) is to take advantage of in-situ precipitated nanoparticles and nanostructures grown from aqueous solution. These nanostructures can be tailored to ceramic film formation and the subsequent microstructure development. In addition, the process provides environment- friendly processing because of the aqueous solution. Low-temperature processing has also shown versatility to generate various nanostructures. The growth of low-dimensional nanostructures (0-D, 1-D) provides a means of enhancing the crystallinity of the solution-prepared films that is of importance for photocatalytic performance. This technology can generate durable, fully functional nano-ceramic coatings (TiO2, ZnO) on plastic materials (silicone, Teflon, PET, etc.) that can possess both photocatalytic oxide properties and flexible plastic properties. Processing cost is low and it does not require any expensive equipment investment. Processing can be scalable to current manufacturing infrastructure.

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents by X-ray photoelectron spectroscopy and scanning electron microscopy

NASA Astrophysics Data System (ADS)

Siriwardane, Ranjani V.; Poston, James A.

1993-05-01

Characterization of copper oxides, iron oxides, and zinc copper ferrite desulfurization sorbents was performed by X-ray photoelectron spectroscopy and scanning electron microscopy/energy-dispersive spectroscopy at temperatures of 298 to 823 K. Analysis of copper oxides indicated that the satellite structure of the Cu22p region was absent in the Cu(I) state but was present in the Cu(II) state. Reduction of CuO at room temperature was observed when the ion gauge was placed close to the sample. The satellite structure was absent in all the copper oxides at 823 K in vacuum. Differentiation of the oxidation state of copper utilizing both Cu(L 3M 4,5M 4,5) X-ray-induced Auger lines and Cu2p satellite structure, indicated that the copper in zinc copper ferrite was in the + 1 oxidation state at 823 K. This + 1 state of copper was not significantly changed after exposure to H 2, CO, and H 2O. There was an increase in Cu/Zn ratio and a decrease in Fe/Zn ratio on the surface of zinc copper ferrite at 823 K compared to that at room temperature. These conditions of copper offered the best sulfidation equilibrium for the zinc copper ferrite desulfurization sorbent. Analysis of iron oxides indicated that there was some reduction of both Fe 2O 3 and FeO at 823K. The iron in zinc copper ferrite was similar to that of Fe 2O 3 at room temperature but there was some reduction of this Fe(III) state to Fe(II) at 823 K. This reduction was more enhanced in the presence of H 2 and CO. Reduction to Fe(II) may not be desirable for the lifetime of the sorbent.

Method of producing exfoliated graphite, flexible graphite, and nano-scaled graphene platelets

DOEpatents

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z.

2010-11-02

The present invention provides a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of graphite, graphite oxide, or a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.

Comparison of Antibacterial Effects of ZnO and CuO Nanoparticles Coated Brackets against Streptococcus Mutans.

PubMed

Ramazanzadeh, Baratali; Jahanbin, Arezoo; Yaghoubi, Masoud; Shahtahmassbi, Nasser; Ghazvini, Kiarash; Shakeri, Mohammadtaghi; Shafaee, Hooman

2015-09-01

During the orthodontic treatment, microbial plaques may accumulate around the brackets and cause caries, especially in high-risk patients. Finding ways to eliminate this microbial plaque seems to be essential. The aim of this study was to compare the antibacterial effects of nano copper oxide (CuO) and nano zinc oxide (ZnO) coated brackets against Streptococcus mutans (S.mutans) in order to decrease the risk of caries around the orthodontic brackets during the treatment. Sixty brackets were coated with nanoparticles of ZnO (n=20), CuO (n=20) and CuO-ZnO (n=20). Twelve uncoated brackets constituted the control group. The brackets were bonded to the crowns of extracted premolars, sterilized and prepared for antimicrobial tests (S.mutans ATCC35668). The samples taken after 0, 2, 4, 6 and 24 hours were cultured on agar plates. Colonies were counted 24 hours after incubation. One-way ANOVA and Tukey tests were used for statistical analysis. In CuO and CuO-ZnO coated brackets, no colony growth was seen after two hours. Between 0-6 hours, the mean colony counts were not significantly different between the ZnO and the control group (p>0.05). During 6-24 hours, the growth of S.mutans was significantly reduced by ZnO nanoparticles in comparison with the control group (p< 0.001). However, these bacteria were not totally eliminated. CuO and ZnO-CuO nanoparticles coated brackets have better antimicrobial effect on S.mutans than ZnO coated brackets.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

PubMed

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

Formation and anisotropic magnetoresistance of Co/Pt nano-contacts through aluminum oxide barrier

NASA Astrophysics Data System (ADS)

Al-Mahdawi, Muftah; Sahashi, Masashi

2014-01-01

We report on the observation of anisotropic magnetoresistance (AMR) in vertical asymmetric nano-contacts (NCs) made through AlOx nano-oxide layer (NOL) formed by ion-assisted oxidation method in the film stack of Co/AlOx-NOL/Pt. Analysis of NC formation was based on in situ conductive atomic force microscopy and transmission electron microscopy. Depending on the purity of NCs from Al contamination, we observed up to 29% AMR ratio at room temperature.

Preparation of Zinc Oxide (ZnO) Thin Film as Transparent Conductive Oxide (TCO) from Zinc Complex Compound on Thin Film Solar Cells: A Study of O2 Effect on Annealing Process

NASA Astrophysics Data System (ADS)

Muslih, E. Y.; Kim, K. H.

2017-07-01

Zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) for thin film solar cell application was successfully prepared through two step preparations which consisted of deposition by spin coating at 2000 rpm for 10 second and followed by annealing at 500 °C for 2 hours under O2 and ambient atmosphere. Zinc acetate dehydrate was used as a precursor which dissolved in ethanol and acetone (1:1 mol) mixture in order to make a zinc complex compound. In this work, we reported the O2 effect, reaction mechanism, structure, morphology, optical and electrical properties. ZnO thin film in this work shows a single phase of wurtzite, with n-type semiconductor and has band gap, carrier concentration, mobility, and resistivity as 3.18 eV, 1.21 × 10-19cm3, 11 cm2/Vs, 2.35 × 10-3 Ωcm respectively which is suitable for TCO at thin film solar cell.

Study of the presence of fluorine in the recycled fractions during carbothermal treatment of EAF dust.

PubMed

Menad, N; Ayala, J N; Garcia-Carcedo, Fernando; Ruiz-Ayúcar, E; Hernández, A

2003-01-01

Carbothermal treatment tests of electric arc furnace dusts (EAFD) using the Waelz kiln process were carried out in pilot-scale for the production of zinc oxide. The association of halides in the EAFD, and the recycled products, such as zinc oxide fumes and high-grade iron contents fractions were examined by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. XRD reveals the presence of chlorine and fluorine in the dusts in the form of KCl, NaCl and CaF2. An ultra-pure fraction of zinc was obtained after the Double Leaching Waelz Oxide (DLWO) process was performed on the zinc oxide fumes. The halide contents were reduced to approximately 100 ppm Cl and 700 ppm F. The rest of these elements are in the form of CaF2. About 65% F is volatilised as lead and zinc fluorides, 15% is expected in the magnetic fractions and 20% in non-magnetic fractions as CaF2 and MnF2, respectively.

Process for the manufacture of an attrition resistant sorbent used for gas desulfurization

DOEpatents

Venkataramani, Venkat S.; Ayala, Raul E.

2003-09-16

This process produces a sorbent for use in desulfurization of coal gas. A zinc titanate compound and a metal oxide are mixed by milling the compounds in an aqueous medium, the resulting mixture is dried and then calcined, crushed, sleved and formed into pellets for use in a moving-bed reactor. Metal oxides suitable for use as an additive in this process include: magnesium oxide, magnesium oxide plus molybdenum oxide, calcium oxide, yttrium oxide, hafnium oxide, zirconium oxide, cupric oxide, and tin oxide. The resulting sorbent has a percentage of the original zinc or titanium ions substituted for the oxide metal of the chosen additive.

The influence of oxidation time on the properties of oxidized zinc films

NASA Astrophysics Data System (ADS)

Rambu, A. P.

2012-09-01

The effect of oxidation time on the structural characteristics and electronic transport mechanism of zinc oxide thin films prepared by thermal oxidation, have been investigated. Zinc metallic films were deposited by thermal evaporation under vacuum, the subsequent oxidation of Zn films being carried out in open atmosphere. XRD and AFM analysis indicate that obtained films posses a polycrystalline structure, the crystallites having a preferential orientation. Structural analysis reveals that microstructure of the films (crystallite size, surface roughness, internal stress) is depending on the oxidation time of metallic films. The electrical behavior of ZnO films was investigated, during a heat treatment (two heating/cooling cycles). It was observed that after the first heating, the temperature dependences of electrical conductivity become reversible. Mott variable range hopping model was proposed to analyze the temperature dependence of the electrical conductivity, in low temperature ranges. Values of some characteristic parameters were calculated.

Surface enrichment of Pt in stable Pt-Ir nano-alloy particles on MgAl 2 O 4 spinel in oxidizing atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Wei-Zhen; Nie, Lei; Cheng, Yingwen

With the capability of MgAl2O4 spinel {111} nano-facets in stabilizing small Rh, Ir and Pt particles, bimetallic Ir-Pt catalysts on the same support were investigated, aiming at further lowering the catalyst cost by substituting expensive Pt with cheaper Ir in the bulk. Small Pt-Ir nano-alloy particles (< 2nm) were successfully stabilized on the spinel {111} nano-facets as expected. Interestingly, methanol oxidative dehydrogenation (ODH) rate on the surface Pt atoms increases with oxidizing aging but decreases upon reducing treatment, where Ir is almost inactive under the same reaction conditions. Up to three times enhancement in Pt exposure was achieved when themore » sample was oxidized at 800 °C in air for 1 week and subsequently reduced by H2 for 2 h, demonstrating successful surface enrichment of Pt on Pt-Ir nano-alloy particles. A dynamic stabilization mechanism involving wetting\

Angiotensin II potentiates zinc-induced cortical neuronal death by acting on angiotensin II type 2 receptor.

PubMed

Park, Mi-Ha; Kim, Ha Na; Lim, Joon Seo; Ahn, Jae-Sung; Koh, Jae-Young

2013-12-01

The angiotensin system has several non-vascular functions in the central nervous system. For instance, inhibition of the brain angiotensin system results in a reduction in neuronal death following acute brain injury such as ischemia and intracerebral hemorrhage, even under conditions of constant blood pressure. Since endogenous zinc has been implicated as a key mediator of ischemic neuronal death, we investigated the possibility that the angiotensin system affects the outcome of zinc-triggered neuronal death in cortical cell cultures. Exposure of cortical cultures containing neurons and astrocytes to 300 μM zinc for 15 min induced submaximal death in both types of cells. Interestingly, addition of angiotensin II significantly enhanced the zinc-triggered neuronal death, while leaving astrocytic cell death relatively unchanged. Both type 1 and 2 angiotensin II receptors (AT1R and AT2R, respectively) were expressed in neurons as well as astrocytes. Zinc neurotoxicity was substantially attenuated by PD123319, a specific inhibitor of AT2R, and augmented by CGP42112, a selective activator of AT2R, indicating a critical role for this receptor subtype in the augmentation of neuronal cell death.Because zinc toxicity occurs largely through oxidative stress, the levels of superoxides in zinc-treated neurons were assessed by DCF fluorescence microscopy. Combined treatment with zinc and angiotensin II substantially increased the levels of superoxides in neurons compared to those induced by zinc alone. This increase in oxidative stress by angiotensin II was completely blocked by the addition of PD123319. Finally, since zinc-induced oxidative stress may be caused by induction and/or activation of NADPH oxidase, the activation status of Rac and the level of the NADPH oxidase subunit p67phox were measured. Angiotensin II markedly increased Rac activity and the levels of p67phox in zinc-treated neurons and astrocytes in a PD123319-dependent manner. The present study shows that the angiotensin system, especially that involving AT2R, may have an oxidative injury-potentiating effect via augmentation of the activity of NADPH oxidase. Hence, blockade of angiotensin signaling cascades in the brain may prove useful in protecting against the oxidative neuronal death that is likely to occur in acute brain injury.

Effects of Nano-Aluminum Nitride on the Performance of an Ultrahigh-Temperature Inorganic Phosphate Adhesive Cured at Room Temperature

PubMed Central

Ma, Chengkun; Chen, Hailong; Wang, Chao; Zhang, Jifeng; Qi, Hui; Zhou, Limin

2017-01-01

Based on the optimal proportion of resin and curing agent, an ultrahigh-temperature inorganic phosphate adhesive was prepared with aluminum dihydric phosphate, aluminium oxide (α-Al2O3), etc. and cured at room temperature (RT). Then, nano-aluminum nitride (nano-AlN), nano-Cupric oxide (nano-CuO), and nano-titanium oxide (nano-TiO2) were added into the adhesive. Differential scanning calorimetry was conducted using the inorganic phosphate adhesive to analyze the phosphate reactions during heat treatment, and it was found that 15 wt % nano-AlN could clearly decrease the curing temperature. Scanning electron microscopy was used to observe the microphenomenon of the modified adhesive at ultrahigh-temperature. The differential thermal analysis of the inorganic phosphate adhesive showed that the weight loss was approximately 6.5 wt % when the mass ratio of resin to curing agent was 1:1.5. An X-ray diffraction analysis of the adhesive with 10% nano-AlN showed that the phase structure changed from AlPO4(11-0500) to the more stable AlPO4(10-0423) structure after heat treatment. The shear strength of the adhesive containing 10% nano-AlN reached 7.3 MPa at RT due to the addition of nano-AlN, which promoted the formation of phosphate and increased the Al3+. PMID:29099812

Skin changes induced by a zinc oxide dressing compared with a hydrocolloid dressing in healthy individuals.

PubMed

Nielsen, Lene Feldskov; Blume, Niels; Romme, Tina; Samuelsen, Peter; Everland, Hanne; Ifversen, Peter; Karlsmark, Tonny

2005-05-01

Incidence of skin complications in ostomy patients constitutes a well-known and well-described problem. The reasons are, however, very difficult to describe because of the many factors contributing to the problem. This article describes the skin changes derived exclusively from the adhesives used in a carefully controlled, long-term study using two fundamentally different types of adhesives: a hydrocolloid adhesive and a zinc oxide adhesive. The adhesives were changed daily on the volar forearm of 11 volunteers for a 4-week period. Once a week, transepidermal water-loss (TEWL), water content of the skin, erythema and the peel force applied for removal of the adhesives were measured. On the last day of the study, a replica of the skin surface was obtained to determine changes in the skin topography, and a biopsy was taken to study changes at the cellular level. We found increased TEWL and decreased water content in skin treated with the zinc oxide adhesive, but increased water-loss and water content when the hydrocolloid adhesive was used. In addition, the area treated with zinc oxide adhesive showed significant increase of epidermal thickness, scaly appearance and parakeratosis with similarities to pathological dry skin diseases such as psoriasis and atopic dermatitis, changes that were not found when using the hydrocolloid adhesive. The skin response seems to be the result of the content of zinc oxide and the mechanical interaction of the zinc oxide adhesive. We conclude that the nature of the adhesive plays an important role in the skin response to repeated application of adhesives, as seen in peristomal skin.

Flame Retardant Effect of Nano Fillers on Polydimethylsiloxane Composites.

PubMed

Jagdale, Pravin; Salimpour, Samera; Islam, Md Hujjatul; Cuttica, Fabio; Hernandez, Francisco C Robles; Tagliaferro, Alberto; Frache, Alberto

2018-02-01

Polydimethylsiloxane has exceptional fire retardancy characteristics, which make it a popular polymer in flame retardancy applications. Flame retardancy of polydimethylsiloxane with different nano fillers was studied. Polydimethylsiloxane composite fire property varies because of the shape, size, density, and chemical nature of nano fillers. In house made carbon and bismuth oxide nano fillers were used in polydimethylsiloxane composite. Carbon from biochar (carbonised bamboo) and a carbon by-product (carbon soot) were selected. For comparative study of nano fillers, standard commercial multiwall carbon nano tubes (functionalised, graphitised and pristine) as nano fillers were selected. Nano fillers in polydimethylsiloxane positively affects their fire retardant properties such as total smoke release, peak heat release rate, and time to ignition. Charring and surface ceramization are the main reasons for such improvement. Nano fillers in polydimethylsiloxane may affect the thermal mobility of polymer chains, which can directly affect the time to ignition. The study concludes that the addition of pristine multiwall carbon nano tubes and bismuth oxide nano particles as filler in polydimethylsiloxane composite improves the fire retardant property.

Effects of rare earth oxide nanoparticles on root elongation of plants.

PubMed

Ma, Yuhui; Kuang, Linglin; He, Xiao; Bai, Wei; Ding, Yayun; Zhang, Zhiyong; Zhao, Yuliang; Chai, Zhifang

2010-01-01

The phytotoxicity of four rare earth oxide nanoparticles, nano-CeO(2), nano-La(2)O(3), nano-Gd(2)O(3) and nano-Yb(2)O(3) on seven higher plant species (radish, rape, tomato, lettuce, wheat, cabbage, and cucumber) were investigated in the present study by means of root elongation experiments. Their effects on root growth varied greatly between different nanoparticles and plant species. A suspension of 2000 mg L(-1) nano-CeO(2) had no effect on the root elongation of six plants, except lettuce. On the contrary, 2000 mg L(-1) suspensions of nano-La(2)O(3), nano-Gd(2)O(3) and nano-Yb(2)O(3) severely inhibited the root elongation of all the seven species. Inhibitory effects of nano-La(2)O(3), nano-Gd(2)O(3), and nano-Yb(2)O(3) also differed in the different growth process of plants. For wheat, the inhibition mainly took place during the seed incubation process, while lettuce and rape were inhibited on both seed soaking and incubation process. The fifty percent inhibitory concentrations (IC(50)) for rape were about 40 mg L(-1) of nano-La(2)O(3), 20mg L(-1) of nano-Gd(2)O(3), and 70 mg L(-1) of nano-Yb(2)O(3), respectively. In the concentration ranges used in this study, the RE(3+) ion released from the nanoparticles had negligible effects on the root elongation. These results are helpful in understanding phytotoxicity of rare earth oxide nanoparticles. Copyright 2009 Elsevier Ltd. All rights reserved.

Protective effects of Nano-elemental selenium against chromium-vi-induced oxidative stress in broiler liver.

PubMed

Xueting, L; Rehman, M U; Zhang, H; Tian, X; Wu, X; Shixue; Mehmood, K; Zhou, D

2018-01-01

The valuable role of selenium in mitigation of oxidative stress and heavy metal toxicity is well-known. Thus, the aim of the current study on broiler chickens was to examine whether nano elemental selenium (Nano-Se) supplementation can reduce the effects of chromium VI (K2Cr2O7) toxicity. For this purpose, a total of 150, one-day-old broiler chickens were allotted to five groups with three replicates: control group (standard diet), poisoned group (K2Cr2O7 via drinking water), protection group (K2Cr2O7 + Nano- Se), cure group (K2Cr2O7 for initial 2 weeks and then Nano-Se), and prevention group (opposite to the cure group). The broilers were detected by the activities of marker enzymes and oxidative stress markers including, aspartate aminotransferase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT) and superoxide dismutase (SOD), glutathione peroxidase (GSH-px), malondialdehyde (MDA), respectively. The (K2Cr2O7 administration caused histopathological damage in the liver of the chickens. Moreover, changes in serum biochemical indicators and oxidative stress parameters were also observed. Nano-Se supplementation increased the levels of GSH-px but reduced the activities of SOD, MDA, GGT, ALT and AST in the experimental groups (P less than 0.05). Our results showed that Nano-Se plays a protective role by preventing the oxidative stress induced by the chromium VI in broiler chickens.

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.

Surface acoustic waves/silicon monolithic sensor processor

NASA Technical Reports Server (NTRS)

Kowel, S. T.; Kornreich, P. G.; Fathimulla, M. A.; Mehter, E. A.

1981-01-01

Progress is reported in the creation of a two dimensional Fourier transformer for optical images based on the zinc oxide on silicon technology. The sputtering of zinc oxide films using a micro etch system and the possibility of a spray-on technique based on zinc chloride dissolved in alcohol solution are discussed. Refinements to techniques for making platinum silicide Schottky barrier junctions essential for constructing the ultimate convolver structure are described.

[Efficacy of using zinc oxide nanoparticles in nutrition. Experiments on the laboratory animal].

PubMed

Raspopov, R V; Trushina, E N; Mustafina, O K; Tananova, O N; Gmoshinskiĭ, I V; Khotimchenko, S A

2011-01-01

In experiments on rats there was researched bioavailability of zinc oxide (ZnO) nanoparticles. There were determined the content of Zn in blood serum and tibia, intestinal uptake of macromolecules of egg albumin, some hematological, biochemical and immune indices, liver cells apoptosis. The results obtained show that the uptake of nanoparticles of ZnO enables restoration of this microelement status damaged by zinc deficit diet.

Mechanically Milled Irregular Zinc Nanoparticles for Printable Bioresorbable Electronics.

PubMed

Mahajan, Bikram K; Yu, Xiaowei; Shou, Wan; Pan, Heng; Huang, Xian

2017-05-01

Bioresorbable electronics is predominantly realized by complex and time-consuming anhydrous fabrication processes. New technology explores printable methods using inks containing micro- or nano-bioresorbable particles (e.g., Zn and Mg). However, these particles have seldom been obtained in the context of bioresorbable electronics using cheap, reliable, and effective approaches with limited study on properties essential to printable electronics. Here, irregular nanocrystalline Zn with controllable sizes and optimized electrical performance is obtained through ball milling approach using polyvinylpyrrolidone (PVP) as a process control agent to stabilize Zn particles and prevent cold welding. Time and PVP dependence of the ball milled particles are studied with systematic characterizations of morphology and composition of the nanoparticles. The results reveal crystallized Zn nanoparticles with a size of ≈34.834 ± 1.76 nm and low surface oxidation. The resulting Zn nanoparticles can be readily printed onto bioresorbable substrates and sintered at room temperature using a photonic sintering approach, leading to a high conductivity of 44 643 S m -1 for printable zinc nanoparticles. The techniques to obtain Zn nanoparticles through ball milling and processing them through photonic sintering may potentially lead to a mass fabrication method for bioresorbable electronics and promote its applications in healthcare, environmental protection, and consumer electronics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Color stability of pigmented maxillofacial silicone elastomer: effects of nano-oxides as opacifiers.

PubMed

Han, Ying; Zhao, Yimin; Xie, Chao; Powers, John M; Kiat-amnuay, Sudarat

2010-01-01

This study evaluated the effects of nano-oxides on the color stability of pigmented silicone A-2186 maxillofacial prosthetic elastomers before and after artificial aging. Each of three widely used UV-shielding nano-sized particle oxides (TiO(2), ZnO, CeO(2)), based on recent survey of the industry at 1%, 2%, 2.5% concentrations were combined with each of five intrinsic silicone pigment types (no pigments, red, yellow, blue, and a mixture of the three pigments). Silicone A-2186 without nano-oxides or pigments served as control, for a total of 46 experimental groups of elastomers. In each group of the study, all specimens were aged in an artificial aging chamber for an energy exposure of 450kJ/m(2). CIE L*a*b* values were measured by a spectrophotometer. The 50:50% perceptibility (ΔE*=1.1) and acceptability threshold (ΔE*=3.0) were used in interpretation of recorded color differences. Color differences after aging were subjected to three-way analysis of variance. Means were compared by Fisher's PLSD intervals at the 0.05 level of significance. Yellow pigments mixed with all three nano-oxides at all intervals increased ΔE* values significantly from 3.7 up to 8.4. When mixed pigment groups were considered, TiO(2) at 2%, and 2.5% exhibited the smallest color changes, followed by ZnO and CeO(2), respectively (p<0.001). At 1%, CeO(2) exhibited the smallest color changes, followed by TiO(2) and ZnO, respectively (p<0.001). The smallest color differences, observed for nano-oxides groups, were recorded for CeO(2) at 1%, and TiO(2) at 2% and 2.5%. When the nano-oxides were tested at all concentrations, CeO(2) groups overall had the most color changes, and TiO(2) groups had the least. All ΔE* values of the mixed pigment groups were below the 50:50% acceptability threshold (ΔE*=1.2-2.3, below 3.0) except 2% CeO(2) (ΔE*=4.2). 1% nano-CeO(2) and 2% and 2.5% nano-TiO(2) used as opacifiers for silicone A-2186 maxillofacial prostheses with mixed pigments exhibited the least color changes when subjected to artificial aging at 450kJ/m(2). Yellow silicone pigment mixed with all three nano-oxides significantly affected color stability of A-2186 silicone elastomer. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

PubMed Central

Najafpour, Mohammad Mahdi; Rahimi, Fahimeh; Aro, Eva-Mari; Lee, Choon-Hwan; Allakhverdiev, Suleyman I.

2012-01-01

There has been a tremendous surge in research on the synthesis of various metal compounds aimed at simulating the water-oxidizing complex (WOC) of photosystem II (PSII). This is crucial because the water oxidation half reaction is overwhelmingly rate-limiting and needs high over-voltage (approx. 1 V), which results in low conversion efficiencies when working at current densities required for hydrogen production via water splitting. Particular attention has been given to the manganese compounds not only because manganese has been used by nature to oxidize water but also because manganese is cheap and environmentally friendly. The manganese–calcium cluster in PSII has a dimension of about approximately 0.5 nm. Thus, nano-sized manganese compounds might be good structural and functional models for the cluster. As in the nanometre-size of the synthetic models, most of the active sites are at the surface, these compounds could be more efficient catalysts than micrometre (or bigger) particles. In this paper, we focus on nano-sized manganese oxides as functional and structural models of the WOC of PSII for hydrogen production via water splitting and review nano-sized manganese oxides used in water oxidation by some research groups. PMID:22809849

The effect of zinc injection on the increasing of Inconel 600 TT corrosion resistances

NASA Astrophysics Data System (ADS)

Febrianto; Sriyono; Widodo, Surip; Sunaryo, Geni Rina

2018-02-01

Many failures were found in reactor pressure vessel head penetration (RPV) head material. Those failures caused by boric acid corrosion, and from visual examination were found a big hole and white deposit crystal of boric acid during shutdown maintenance at David Besse reactor. Zinc Oxide addition in BWR reactor known as Zinc Injection that has purposed to reduce radiation exposure cause of Hydrogen addition. Beside reducing the radiation exposure, Zinc injection also has an effect in reducing material corrosion. The purpose of study is to determine the effect of zinc addition, boric acid, temperature also the effects of Cobalt Nitrate and Zinc Oxide addition to Inconel 600 TT as RPV head penetration material. The result in the BWR reactor experience will be implementated at PWR reactor, weather zinc oxide addition also has an effect in reducing the corrosion of Inconel 600. The method that used in this research is to observe the corrosion rates for Inconel 600 material using Potentiostat. Examination were conducted in 30, 40, 60, 70, 80 and 80 °C using 1000, 1500, 2000, 2500 and 3000 ppm boric acid concentration. The results showed that the corrosion rate for the material were very small, but the highest corrosion rate occurred in 3000 ppm boric acid concentration at 90 °C with Cobalt Nitrate addition, around 5.210 x 10-1 mpy. In the same condition at 3000 ppm boric acid concentration for temperature at 90 °C, Inconel 600 TT corrosion rate is smaller with Zinc oxide addition, around 4.631 x 10-1 mpy.

Effects of Zinc Supplementation on Endocrine Outcomes in Women with Polycystic Ovary Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Jamilian, Mehri; Foroozanfard, Fatemeh; Bahmani, Fereshteh; Talaee, Rezvan; Monavari, Mahshid; Asemi, Zatollah

2016-04-01

The current study was conducted to evaluate the effects of zinc supplementation on endocrine outcomes, biomarkers of inflammation, and oxidative stress in patients with polycystic ovary syndrome (PCOS). This study was a randomized double-blind, placebo-controlled trial. Forty-eight women (18-40 years) with PCOS diagnosed according to Rotterdam criteria were randomly assigned to receive either 220 mg zinc sulfate (containing 50 mg zinc) (group 1; n = 24) and/or placebo (group 2; n = 24) for 8 weeks. Hormonal profiles, biomarkers of inflammation, and oxidative stress were measured at study baseline and after 8-week intervention. After 8 weeks of intervention, alopecia (41.7 vs. 12.5%, P = 0.02) decreased compared with the placebo. Additionally, patients who received zinc supplements had significantly decreased hirsutism (modified Ferriman-Gallwey scores) (-1.71 ± 0.99 vs. -0.29 ± 0.95, P < 0.001) and plasma malondialdehyde (MDA) levels (-0.09 ± 1.31 vs. +2.34 ± 5.53 μmol/L, P = 0.04) compared with the placebo. A trend toward a significant effect of zinc intake on reducing high-sensitivity C-reactive protein (hs-CRP) levels (P = 0.06) was also observed. We did observe no significant changes of zinc supplementation on hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress. In conclusion, using 50 mg/day elemental zinc for 8 weeks among PCOS women had beneficial effects on alopecia, hirsutism, and plasma MDA levels; however, it did not affect hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress.

Room-temperature solution-processed and metal oxide-free nano-composite for the flexible transparent bottom electrode of perovskite solar cells

NASA Astrophysics Data System (ADS)

Lu, Haifei; Sun, Jingsong; Zhang, Hong; Lu, Shunmian; Choy, Wallace C. H.

2016-03-01

The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies.The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00011h

Regeneration of zinc chloride hydrocracking catalyst

DOEpatents

Zielke, Clyde W.

1979-01-01

Improved rate of recovery of zinc values from the solids which are carried over by the effluent vapors from the oxidative vapor phase regeneration of spent zinc chloride catalyst is achieved by treatment of the solids with both hydrogen chloride and calcium chloride to selectively and rapidly recover the zinc values as zinc chloride.

Zinc deficiency during growth: influence on renal function and morphology.

PubMed

Tomat, Analía Lorena; Costa, María Angeles; Girgulsky, Luciana Carolina; Veiras, Luciana; Weisstaub, Adriana Ruth; Inserra, Felipe; Balaszczuk, Ana María; Arranz, Cristina Teresa

2007-03-13

This study was designed to investigate the effects of moderate zinc deficiency during growth on renal morphology and function in adult life. Weaned male Wistar rats were divided into two groups and fed either a moderately zinc-deficient diet (zinc: 8 mg/kg, n=12) or a control diet (zinc: 30 mg/kg, n=12) for 60 days. We evaluated: renal parameters, NADPH-diaphorase and nitric oxide synthase activity in kidney, renal morphology and apoptotic cells in renal cortex. Zinc-deficient rats showed a decrease in glomerular filtration rate and no changes in sodium and potassium urinary excretion. Zinc deficiency decreased NADPH diaphorase activity in glomeruli and tubular segment of nephrons, and reduced activity of nitric oxide synthase in the renal medulla and cortex, showing that zinc plays an important role in preservation of the renal nitric oxide system. A reduction in nephron number, glomerular capillary area and number of glomerular nuclei in cortical and juxtamedullary areas was observed in zinc deficient kidneys. Sirius red staining and immunostaining for alpha-smooth muscle-actin and collagen III showed no signs of fibrosis in the renal cortex and medulla. An increase in the number of apoptotic cells in distal tubules and cortical collecting ducts neighboring glomeruli and, to a lesser extent, in the glomeruli was observed in zinc deficient rats. The major finding of our study is the emergence of moderate zinc deficiency during growth as a potential nutritional factor related to abnormalities in renal morphology and function that facilitates the development of cardiovascular and renal diseases in adult life.

Piezoelectric two-dimensional nanosheets/anionic layer heterojunction for efficient direct current power generation.

PubMed

Kim, Kwon-Ho; Kumar, Brijesh; Lee, Keun Young; Park, Hyun-Kyu; Lee, Ju-Hyuck; Lee, Hyun Hwi; Jun, Hoin; Lee, Dongyun; Kim, Sang-Woo

2013-01-01

Direct current (DC) piezoelectric power generator is promising for the miniaturization of a power package and self-powering of nanorobots and body-implanted devices. Hence, we report the first use of two-dimensional (2D) zinc oxide (ZnO) nanostructure and an anionic nanoclay layer to generate piezoelectric DC output power. The device, made from 2D nanosheets and an anionic nanoclay layer heterojunction, has potential to be the smallest size power package, and could be used to charge wireless nano/micro scale systems without the use of rectifier circuits to convert alternating current into DC to store the generated power. The combined effect of buckling behaviour of the ZnO nanosheets, a self-formed anionic nanoclay layer, and coupled semiconducting and piezoelectric properties of ZnO nanosheets contributes to efficient DC power generation. The networked ZnO nanosheets proved to be structurally stable under huge external mechanical loads.

Spectroscopic ellipsometry data inversion using constrained splines and application to characterization of ZnO with various morphologies

NASA Astrophysics Data System (ADS)

Gilliot, Mickaël; Hadjadj, Aomar; Stchakovsky, Michel

2017-11-01

An original method of ellipsometric data inversion is proposed based on the use of constrained splines. The imaginary part of the dielectric function is represented by a series of splines, constructed with particular constraints on slopes at the node boundaries to avoid well-know oscillations of natural splines. The nodes are used as fit parameters. The real part is calculated using Kramers-Kronig relations. The inversion can be performed in successive inversion steps with increasing resolution. This method is used to characterize thin zinc oxide layers obtained by a sol-gel and spin-coating process, with a particular recipe yielding very thin layers presenting nano-porosity. Such layers have particular optical properties correlated with thickness, morphological and structural properties. The use of the constrained spline method is particularly efficient for such materials which may not be easily represented by standard dielectric function models.

The Kirkendall effect towards oxynitride nanotubes with improved visible light driven conversion of CO2 into CH4.

PubMed

Zhou, P; Gao, H L; Yan, S C; Zou, Z G

2016-02-28

Functional hollow nanomaterials are of great interest due to their unique physical-chemical properties. Oxynitride photocatalysts are a kind of promising material for solar energy conversion. However, nanoscale design of hollow oxynitrides was difficult to achieve due to the thermal instability of oxide precursors at high temperature. Here, single crystal zinc gallium oxynitride nanotubes were successfully synthesized via the Kirkendall effect with ZnO nanorods and Ga2O3 nanosheets as precursors, which can be attributed to the high diffusion rate of ZnO and the high melting point of oxynitride. Enhanced photocatalytic performance in CO2 reduction was achieved over the as-prepared ZnGaNO nanotubes, due to their higher specific surface area and less recombination of the photogenerated carriers. These results are expected to provide new guidance in the design and preparation of highly efficient nano-scaled oxynitride photocatalysts.

Process for fabricating doped zinc oxide microsphere gel

DOEpatents

Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

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.

Zinc oxide nanorods functionalized paper for protein preconcentration in biodiagnostics

NASA Astrophysics Data System (ADS)

Tiwari, Sadhana; Vinchurkar, Madhuri; Rao, V. Ramgopal; Garnier, Gil

2017-03-01

Distinguishing a specific biomarker from a biofluid sample containing a large variety of proteins often requires the selective preconcentration of that particular biomarker to a detectable level for analysis. Low-cost, paper-based device is an emerging opportunity in diagnostics. In the present study, we report a novel Zinc oxide nanorods functionalized paper platform for the preconcentration of Myoglobin, a cardiac biomarker. Zinc oxide nanorods were grown on a Whatman filter paper no. 1 via the standard hydrothermal route. The growth of Zinc oxide nanorods on paper was confirmed by a combination of techniques consisting of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS,) scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX) analysis. The Zinc oxide nanorods modified Whatman filter paper (ZnO-NRs/WFP) was further tested for use as a protein preconcentrator. Paper-based ELISA was performed for determination of pre-concentration of cardiac marker protein Myoglobin using the new ZnO-NRs/WFP platform. The ZnO-NRs/WFP could efficiently capture the biomarker even from a very dilute solution (Myoglobin < 50 nM). Our ELISA results show a threefold enhancement in protein capture with ZnO-NRs/WFP compared to unmodified Whatman filter paper, allowing accurate protein analysis and showing the diagnostic concept.

Zinc oxide nanoparticles as selective killers of proliferating cells

PubMed Central

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant. PMID:21698081

Zinc oxide nanoparticles as selective killers of proliferating cells.

PubMed

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant.

Nanogenerators and Piezotronics

NASA Astrophysics Data System (ADS)

Wang, Zhong Lin

2011-03-01

Developing wireless nanodevices and nanosystems is of critical importance for sensing, medical science, environmental/infrastructure monitoring, defense technology and even personal electronics. It is highly desirable for wireless devices to be self-powered without using battery. This is a new initiative in today's energy research for mico/nano-systems in searching for sustainable self-sufficient power sources. We have invented an innovative approach for converting nano-scale mechanical energy into electric energy by piezoelectric zinc oxide nanowire arrays. As today, a gentle straining can output 1-3 V from an integrated nanogenerator, using which a self-powered nanosensor has been demonstrated. A commercial LED has been lid up [3-5]. Due to the polarization of ions in a crystal that has non-central symmetry, a piezoelectric potential (piezopotential) is created in the crystal by applying a stress. The effect of piezopotential to the transport behavior of charge carriers is significant due to their multiple functionalities of piezoelectricity, semiconductor and photon excitation. Electronics fabricated by using inner-crystal piezopotential as a ``gate'' voltage to tune/control the charge transport behavior is named piezotronics [6,7].Piezo-phototronic effect is a result of three-way coupling among piezoelectricity, photonic excitation and semiconductor transport, which allows tuning and controlling of electro-optical processes by strain induced piezopotential.

Gate- and Light-Tunable pn Heterojunction Microwire Arrays Fabricated via Evaporative Assembly.

PubMed

Park, Jae Hoon; Kim, Jong Su; Choi, Young Jin; Lee, Wi Hyoung; Lee, Dong Yun; Cho, Jeong Ho

2017-02-01

One-dimensional (1D) nano/microwires have attracted considerable attention as versatile building blocks for use in diverse electronic, optoelectronic, and magnetic device applications. The large-area assembly of nano/microwires at desired positions presents a significant challenge for developing high-density electronic devices. Here, we demonstrated the fabrication of cross-stacked pn heterojunction diode arrays by integrating well-aligned inorganic and organic microwires fabricated via evaporative assembly. We utilized solution-processed n-type inorganic indium-gallium-zinc-oxide (IGZO) microwires and p-type organic 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-PEN) microwires. The formation of organic TIPS-PEN semiconductor microwire and their electrical properties were optimized by controlling both the amounts of added insulating polymer and the widths of the microwires. The resulting cross-stacked IGZO/TIPS-PEN microwire pn heterojunction devices exhibited rectifying behavior with a forward-to-reverse bias current ratio exceeding 10 2 . The ultrathin nature of the underlying n-type IGZO microwires yielded gate tunability in the charge transport behaviors, ranging from insulating to rectifying. The rectifying behaviors of the heterojunction devices could be modulated by controlling the optical power of the irradiated light. The fabrication of semiconducting microwires through evaporative assembly provides a facile and reliable approach to patterning or positioning 1D microwires for the fabrication of future flexible large-area electronics.

Rational design of hierarchical ZnO@Carbon nanoflower for high performance lithium ion battery anodes

NASA Astrophysics Data System (ADS)

liu, Huichao; Shi, Ludi; Li, Dongzhi; Yu, Jiali; Zhang, Han-Ming; Ullah, Shahid; Yang, Bo; Li, Cuihua; Zhu, Caizhen; Xu, Jian

2018-05-01

The rational structure design and strong interfacial bonding are crucially desired for high performance zinc oxide (ZnO)/carbon composite electrodes. In this context, micro-nano secondary structure design and strong dopamine coating strategies are adopted for the fabrication of flower-like ZnO/carbon (ZnO@C nanoflowers) composite electrodes. The results show the ZnO@C nanoflowers (2-6 μm) are assembled by hierarchical ZnO nanosheets (∼27 nm) and continuous carbon framework. The micro-nano secondary architecture can facilitate the penetration of electrolyte, shorten lithium ions diffusion length, and hinder the aggregation of the nanosheets. Moreover, the strong chemical interaction between ZnO and coating carbon layer via C-Zn bond improves structure stability as well as the electronic conductivity. As a synergistic result, when evaluated as lithium ion batteries (LIBs) anode, the ZnO@C nanoflower electrodes show high reversible capacity of ca. 1200 mA h g-1 at 0.1 A g-1 after 80 cycles. As well as good long-cycling stability (638 and 420 mA h g-1 at 1 and 5 A g-1 after 500 cycles, respectively) and excellent rate capability. Therefore, this rational design of ZnO@C nanoflowers electrode is a promising anode for high-performance LIBs.

Do Nanoparticle Physico-Chemical Properties and Developmental Exposure Window Influence Nano ZnO Embryotoxicity in Xenopus laevis?

PubMed

Bonfanti, Patrizia; Moschini, Elisa; Saibene, Melissa; Bacchetta, Renato; Rettighieri, Leonardo; Calabri, Lorenzo; Colombo, Anita; Mantecca, Paride

2015-07-28

The growing global production of zinc oxide nanoparticles (ZnONPs) suggests a realistic increase in the environmental exposure to such a nanomaterial, making the knowledge of its biological reactivity and its safe-by-design synthesis mandatory. In this study, the embryotoxicity of ZnONPs (1-100 mg/L) specifically synthesized for industrial purposes with different sizes, shapes (round, rod) and surface coatings (PEG, PVP) was tested using the frog embryo teratogenesis assay-Xenopus (FETAX) to identify potential target tissues and the most sensitive developmental stages. The ZnONPs did not cause embryolethality, but induced a high incidence of malformations, in particular misfolded gut and abdominal edema. Smaller, round NPs were more effective than the bigger, rod ones, and PEGylation determined a reduction in embryotoxicity. Ingestion appeared to be the most relevant exposure route. Only the embryos exposed from the stomodeum opening showed anatomical and histological lesions to the intestine, mainly referable to a swelling of paracellular spaces among enterocytes. In conclusion, ZnONPs differing in shape and surface coating displayed similar toxicity in X. laevis embryos and shared the same target organ. Nevertheless, we cannot exclude that the physico-chemical characteristics may influence the severity of such effects. Further research efforts are mandatory to ensure the synthesis of safer nano-ZnO-containing products.

Nano lead oxide and epdm composite for development of polymer based radiation shielding material: Gamma irradiation and attenuation tests

NASA Astrophysics Data System (ADS)

Özdemir, T.; Güngör, A.; Akbay, I. K.; Uzun, H.; Babucçuoglu, Y.

2018-03-01

It is important to have a shielding material that is not easily breaking in order to have a robust product that guarantee the radiation protection of the patients and radiation workers especially during the medical exposure. In this study, nano sized lead oxide (PbO) particles were used, for the first time, to obtain an elastomeric composite material in which lead oxide nanoparticles, after the surface modification with silane binding agent, was used as functional material for radiation shielding. In addition, the composite material including 1%, 5%, 10%, 15% and 20% weight percent nano sized lead oxide was irradiated with doses of 81, 100 and 120 kGy up to an irradiation period of 248 days in a gamma ray source with an initial dose rate of 21.1 Gy/h. Mechanical, thermal properties of the irradiated materials were investigated using DSC, DMA, TGA and tensile testing and modifications in thermal and mechanical properties of the nano lead oxide containing composite material via gamma irradiation were reported. Moreover, effect of bismuth-III oxide addition on radiation attenuation of the composite material was investigated. Nano lead oxide and bismuth-III oxide particles were mixed with different weight ratios. Attenuation tests have been conducted to determine lead equivalent values for the developed composite material. Lead equivalent thickness values from 0.07 to 0.65 (2-6 mm sample thickness) were obtained.

Effect of Nano-Al2O3 on the Toxicity and Oxidative Stress of Copper towards Scenedesmus obliquus

PubMed Central

Li, Xiaomin; Zhou, Suyang; Fan, Wenhong

2016-01-01

Nano-Al2O3 has been widely used in various industries; unfortunately, it can be released into the aquatic environment. Although nano-Al2O3 is believed to be of low toxicity, it can interact with other pollutants in water, such as heavy metals. However, the interactions between nano-Al2O3 and heavy metals as well as the effect of nano-Al2O3 on the toxicity of the metals have been rarely investigated. The current study investigated copper toxicity in the presence of nano-Al2O3 towards Scenedesmus obliquus. Superoxide dismutase activity and concentration of glutathione and malondialdehyde in cells were determined in order to quantify oxidative stress in this study. Results showed that the presence of nano-Al2O3 reduced the toxicity of Cu towards S. obliquus. The existence of nano-Al2O3 decreased the growth inhibition of S. obliquus. The accumulation of copper and the level of oxidative stress in algae were reduced in the presence of nano-Al2O3. Furthermore, lower copper accumulation was the main factor that mitigated copper toxicity with the addition of nano-Al2O3. The decreased copper uptake could be attributed to the adsorption of copper onto nanoparticles and the subsequent decrease of available copper in water. PMID:27294942

Reactivity of metal oxide sorbents for removal of sulfur compounds from coal gases at high temperature and pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwon, K.C.; Crowe, E.R.; Gangwal, S.K.

1997-01-01

Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated to effectively remove hydrogen sulfide with various metal oxide sorbents at high temperatures and pressures. Metal oxide sorbents such as zinc titanate oxide, zinc ferrite oxide, copper oxide, manganese oxide and calcium oxide were found to be promising sorbents in comparison with other removal methods such as membrane separation and reactive membrane separation. The removal reaction of H{sub 2}S from coal gas mixtures with zinc titanate oxide sorbents was conducted in a batch reactor. The main objectives of this research are to formulate promising metal oxide sorbentsmore » for removal of hydrogen sulfide from coal gas mixtures, to compare reactivity of a formulated sorbent with a sorbent supplied by the Research Triangle Institute at high temperatures and pressures, and to determine effects of concentrations of moisture contained in coal gas mixtures on equilibrium absorption of H{sub 2}S into metal oxide sorbents. Promising durable metal oxide sorbents with high-sulfur-absorbing capacity were formulated by mixing active metal oxide powders with inert metal oxide powders and calcining these powder mixtures.« less

Accelerated effects of nano-ZnO on phosphorus removal by Chlorella vulgaris: Formation of zinc phosphate crystallites.

PubMed

Xiao, Huaixian; Liu, Na; Tian, Ke; Liu, Shixiang; Ge, Fei

2018-09-01

Nanoparticles have been reported to induce toxicity to aquatic organisms, however, their potential impacts on phosphorus removal from wastewater by algae are unclear. In this study, the effects of nanoparticle ZnO (nano-ZnO) on phosphate (PO 4 3- ) removal by a green alga Chlorella vulgaris were investigated. We found that PO 4 3- removal efficiency was accelerated with high concentrations of nano-ZnO (0.04-0.15mM) but reduced with low concentrations of nano-ZnO (0.005-0.04mM) compared to the control (without nano-ZnO), suggesting that PO 4 3- removal efficiency by C. vulgaris was related to nano-ZnO concentrations. Moreover, we observed changes of nano-ZnO morphology and detected element P on the surface of nano-ZnO by using transmission electronic microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDX), indicating that PO 4 3- was interacted with nano-ZnO or the dissolved Zn 2+ from nano-ZnO. Furthermore, we confirmed this interaction induced the formation of Zn 3 (PO 4 ) 2 crystallites sedimentation by employing X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS), which finally accelerates the removal of PO 4 3- . Copyright © 2018 Elsevier B.V. All rights reserved.

Reactor Experiments at the University of Minnesota.

DTIC Science & Technology

1987-07-15

metallurgy; zinc, zinc oxide; solar thermal,’ solar Pi% thermoelectrochemical’ water splitting, separation devices; reactors e, ? 20. AeSiRACT (Continue oe...reported. Water splitting, recovery of hydrogen 4. and sulfur from hydrogen sulfide, electrolysis of zinc oxide in vapor and liquid phases, oil...CH4-CO2 reforming process. 2. Hydrogen production from water and the production of hydrogen and sulfur (or ammonia and sulfuric acid) from H2S. 3

Zinc oxide doped graphene oxide films for gas sensing applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chetna,, E-mail: chetna2288@gmail.com; Kumar, Shani; Chaudhary, S.

Graphene Oxide (GO) is analogous to graphene, but presence of many functional groups makes its physical and chemical properties essentially different from those of graphene. GO is found to be a promising material for low cost fabrication of highly versatile and environment friendly gas sensors. Selectivity, reversibility and sensitivity of GO based gas sensor have been improved by hybridization with Zinc Oxide nanoparticles. The device is fabricated by spin coating of deionized water dispersed GO flakes (synthesized using traditional hummer’s method) doped with Zinc Oxide on standard glass substrate. Since GO is an insulator and functional groups on GO nanosheetsmore » play vital role in adsorbing gas molecules, it is being used as an adsorber. Additionally, on being exposed to certain gases the electric and optical characteristics of GO material exhibit an alteration in behavior. For the conductivity, we use Zinc Oxide, as it displays a high sensitivity towards conduction. The effects of the compositions, structural defects and morphologies of graphene based sensing layers and the configurations of sensing devices on the performances of gas sensors were investigated by Raman Spectroscopy, X-ray diffraction(XRD) and Keithley Sourcemeter.« less

Electrochemistry of the Zinc-Silver Oxide System. Part 2: Practical Measurements of Energy Conversion Using Commercial Miniature Cells.

ERIC Educational Resources Information Center

Smith, Michael J.; Vincent, Colin A.

1989-01-01

Summarizes the quantitative relationships pertaining to the operation of electrochemical cells. Energy conversion efficiency, cycle efficiency, battery power, and energy/power density of two types of zinc-silver oxide cells are discussed. (YP)

Nanos genes and their role in development and beyond.

PubMed

De Keuckelaere, Evi; Hulpiau, Paco; Saeys, Yvan; Berx, Geert; van Roy, Frans

2018-06-01

The hallmark of Nanos proteins is their typical (CCHC) 2 zinc finger motif (zf-nanos). Animals have one to four nanos genes. For example, the fruit fly and demosponge have only one nanos gene, zebrafish and humans have three, and Fugu rubripes has four. Nanos genes are mainly known for their evolutionarily preserved role in germ cell survival and pluripotency. Nanos proteins have been reported to bind the C-terminal RNA-binding domain of Pumilio to form a post-transcriptional repressor complex. Several observations point to a link between the miRNA-mediated repression complex and the Nanos/Pumilio complex. Repression of the E2F3 oncogene product is, indeed, mediated by cooperation between the Nanos/Pumilio complex and miRNAs. Another important interaction partner of Nanos is the CCR4-NOT deadenylase complex. Besides the tissue-specific contribution of Nanos proteins to normal development, their ectopic expression has been observed in several cancer cell lines and various human cancers. An inverse correlation between the expression levels of human Nanos1 and Nanos3 and E-cadherin was observed in several cancer cell lines. Loss of E-cadherin, an important cell-cell adhesion protein, contributes to tumor invasion and metastasis. Overexpression of Nanos3 induces epithelial-mesenchymal transition in lung cancer cell lines partly by repressing E-cadherin. Other than some most interesting data from Nanos knockout mice, little is known about mammalian Nanos proteins, and further research is needed. In this review, we summarize the main roles of Nanos proteins and discuss the emerging concept of Nanos proteins as oncofetal antigens.

Crossover from disordered to core-shell structures of nano-oxide Y{sub 2}O{sub 3} dispersed particles in Fe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higgins, M. P.; Wang, L. M.; Gao, F., E-mail: gaofeium@umich.edu

Molecular dynamic simulations of Y{sub 2}O{sub 3} in bcc Fe and transmission electron microscopy (TEM) observations were used to understand the structure of Y{sub 2}O{sub 3} nano-clusters in an oxide dispersion strengthened steel matrix. The study showed that Y{sub 2}O{sub 3} nano-clusters below 2 nm were completely disordered. Y{sub 2}O{sub 3} nano-clusters above 2 nm, however, form a core-shell structure, with a shell thickness of 0.5–0.7 nm that is independent of nano-cluster size. Y{sub 2}O{sub 3} nano-clusters were surrounded by off-lattice Fe atoms, further increasing the stability of these nano-clusters. TEM was used to corroborate our simulation results and showed a crossover frommore » a disordered nano-cluster to a core-shell structure.« less

High-volumetric performance aligned nano-porous microwave exfoliated graphite oxide-based electrochemical capacitors.

PubMed

Ghaffari, Mehdi; Zhou, Yue; Xu, Haiping; Lin, Minren; Kim, Tae Young; Ruoff, Rodney S; Zhang, Q M

2013-09-20

Ultra-high volumetric performance electrochemical double layer capacitors based on high density aligned nano-porous microwave exfoliated graphite oxide have been studied. Elimination of macro-, meso-, and larger micro-pores from electrodes and controlling the nano-morphology results in very high volumetric capacitance, energy, and power density values. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vitro toxicity test of nano-sized magnesium oxide synthesized via solid-phase transformation

NASA Astrophysics Data System (ADS)

Zheng, Jun; Zhou, Wei

2018-04-01

Nano-sized magnesium oxide (MgO) has been a promising potential material for biomedical pharmaceuticals. In the present investigation, MgO nanoparticles synthesized through in-situ solid-phase transformation based on the previous work (nano-Mg(OH)2 prepared by precipitation technique) using magnesium nitrate and sodium hydroxide. The phase structure and morphology of the MgO nanoparticles are characterized by X-ray powder diffraction (XRD), selected area electronic diffraction (SAED) and transmission electron microscopy (TEM) respectively. In vitro hemolysis tests are adopted to evaluate the toxicity of the synthesized nano-MgO. The results evident that nano-MgO with lower concentration is slightly hemolytic, and with concentration increasing nano-MgO exhibit dose-responsive hemolysis.

Characterization of zinc oxide thin film for pH detector

NASA Astrophysics Data System (ADS)

Hashim, Uda; Fathil, M. F. M.; Arshad, M. K. Md; Gopinath, Subash C. B.; Uda, M. N. A.

2017-03-01

This paper presents the fabrication process of the zinc oxide thin films for using to act as pH detection by using different PH solution. Sol-gel solution technique is used for preparing zinc oxide seed solution, followed by metal oxide deposition process by using spin coater on the silicon dioxide. Silicon dioxide layer is grown on the silicon wafer, then, ZnO seed solution is deposited on the silicon layer, baked, and annealing process carried on to undergo the characterization of its surface morphology, structural and crystalline phase. Electrical characterization is showed by using PH 4, 7, and 10 is dropped on the surface of the die, in addition, APTES solution is used as linker and also as a references of the electrical characterization.

Structural, morphological, magnetic and dielectric characterization of nano-phased antimony doped manganese zinc ferrites

NASA Astrophysics Data System (ADS)

Sridhar, Ch. S. L. N.; Lakshmi, Ch. S.; Govindraj, G.; Bangarraju, S.; Satyanarayana, L.; Potukuchi, D. M.

2016-05-01

Nano-phased doped Mn-Zn ferrites, viz., Mn0.5-x/2Zn0.5-x/2SbXFe2O4 for x=0 to 0.3 (in steps of 0.05) prepared by hydrothermal method are characterized by X-ray diffraction, Infrared and scanning electron microscopy. XRD and SEM infer the growth of nano-crystalline cubic and hematite (α-Fe2O3) phase structures. IR reveals the ferrite phase abundance and metal ion replacement with dopant. Decreasing trend of lattice constant with dopant reflects the preferential replacement of Fe3+ions by Sb5+ion. Doping is found to cause for the decrease (i.e., 46-14 nm) of grain size. An overall trend of decreasing saturation magnetization is observed with doping. Low magnetization is attributed to the diamagnetic nature of dopant, abundance of hematite (α-Fe2O3) phase, non-stoichiometry and low temperature (800 °C) sintering conditions. Increasing Yafet-Kittel angle reflects surface spin canting to pronounce lower Ms. Lower coercivity is observed for x≤0.1, while a large Hc results for higher concentrations. High ac resistivity (~106 ohm-cm) and low dielectric loss factor (tan δ~10-2-10-3) are witnessed. Resistivity is explained on the base of a transformation in the Metal Cation-to-Oxide anion bond configuration and blockade of conductivity path. Retarded hopping (between adjacent B-sites) of carriers across the grain boundaries is addressed. Relatively higher resistivity and low dielectric loss in Sbdoped Mn-Zn ferrite systems pronounce their utility in high frequency applications.

Enhanced photocatalytic activity of nanocellulose supported zinc oxide composite for RhB dye as well as ciprofloxacin drug under sunlight/visible light

NASA Astrophysics Data System (ADS)

Tavker, Neha; Sharma, Manu

2018-05-01

Zinc oxide nanoparticles were synthesised from zinc acetate di-hydrate via co-precipitation method. Nanocellulose was isolated from agrowaste using chemo-mechanical treatments and characterized. Nanocellulose supported zinc oxide composites were prepared through in-situ method by adding different amounts of nanocellulose. The photocatalytic efficiency of pure Zno and nanocellulose supported ZnO was calculated using RhB dye under visible light and sun light. The composites which had nanocellulose in greater ratio showed higher degradation efficiency in sunlight rather than visible light for both; dye and drug. All the composites showed high rate of photodegradation compared to bare ZnO and bare nanocellulose. The enhancement in photocatalytic activity was observed maximum where the amount of cellulose was maximum. The maximum observed rate was 0.025 min-1 using Ciprofloxacin drug due to the increase in lifetime of Z4 sample delaying the electron and hole pair recombination. The degrading efficiency of nanocellulose supported zinc oxide (NC/ZnO) composite for RhB was found to be 35% in visible, 76% in sunlight and 75% for ciprofloxacin under sunlight.

Effects of the essential metals copper and zinc in two freshwater detritivores species: Biochemical approach.

PubMed

Quintaneiro, C; Ranville, J; Nogueira, A J A

2015-08-01

The input of metals into freshwater ecosystems from natural and anthropogenic sources impairs water quality and can lead to biological alterations in organisms and plants, compromising the structure and the function of these ecosystems. Biochemical biomarkers may provide early detection of exposure to contaminants and indicate potential effects at higher levels of biological organisation. The effects of 48h exposures to copper and zinc on Atyaephyra desmarestii and Echinogammarus meridionalis were evaluated with a battery of biomarkers of oxidative stress and the determination of ingestion rates. The results showed different responses of biomarkers between species and each metal. Copper inhibited the enzymatic defence system of both species without signs of oxidative damage. Zinc induced the defence system in E. meriodionalis with no evidence of oxidative damage. However, in A. desmarestii exposed to zinc was observed oxidative damage. In addition, only zinc had significantly reduced the ingestion rate and just for E. meridionalis. The value of the integrated biomarkers response increased with concentration of both metals, which indicates that might be a valuable tool to interpretation of data as a whole, as different parameters have different weight according to type of exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

Transport of Zinc Oxide Nanoparticles in a Simulated Gastric Environment

NASA Astrophysics Data System (ADS)

Mayfield, Ryan T.

Recent years have seen a growing interest in the use of many types of nano sized materials in the consumer sector. Potential uses include encapsulation of nutrients, providing antimicrobial activity, altering texture, or changing bioavailability of nutrients. Engineered nanoparticles (ENP) possess properties that are different than larger particles made of the same constituents. Properties such as solubility, aggregation state, and toxicity can all be changed as a function of size. The gastric environment is an important area for study of engineered nanoparticles because of the varied physical, chemical, and enzymatic processes that are prevalent there. These all have the potential to alter those properties of ENP that make them different from their bulk counterparts. The Human Gastric Simulator (HGS) is an advanced in vitro model that can be used to study many facets of digestion. The HGS consists of a plastic lining that acts as the stomach cavity with two sets of U-shaped arms on belts that provide the physical forces needed to replicate peristalsis. Altering the position of the arms or changing the speed of the motor which powers them allows one to tightly hone and replicate varied digestive conditions. Gastric juice, consisting of salts, enzymes, and acid levels which replicate physiological conditions, is introduced to the cavity at a controllable rate. The release of digested food from the lumen of simulated stomach is controlled by a peristaltic pump. The goal of the HGS is to accurately and repeatedly simulate human digestion. This study focused on introducing foods spiked with zinc oxide ENP and bulk zinc oxide into the HGS and then monitoring how the concentration of each changed at two locations in the HGS over a two hour period. The two locations chosen were the highest point in the lumen of the stomach, which represented the fundus, and a point just beyond the equivalent of the pylorus, which represented the antrum of the stomach. These points were chosen in order to elucidate if and how two different particle sizes of the same material are transported during digestion. Results showed that particles preferentially collected at Location A; time played a minor role in the separation to the two locations while particle size did not play any role.

Impact of glutathione metabolism on zinc homeostasis in Saccharomyces cerevisiae.

PubMed

Steiger, Matthias G; Patzschke, Anett; Holz, Caterina; Lang, Christine; Causon, Tim; Hann, Stephan; Mattanovich, Diethard; Sauer, Michael

2017-06-01

Zinc is a crucial mineral for all organisms as it is an essential cofactor for the proper function of a plethora of proteins and depletion of zinc causes oxidative stress. Glutathione is the major redox buffering agent in the cell and therefore important for mitigation of the adverse effects of oxidative stress. In mammalian cells, zinc deficiency is accompanied by a glutathione depletion. In the yeast Saccharomyces cerevisiae, the opposite effect is observed: under low zinc conditions, an elevated glutathione concentration is found. The main regulator to overcome zinc deficiency is Zap1p. However, we show that Zap1p is not involved in this glutathione accumulation phenotype. Furthermore, we found that in glutathione-accumulating strains also the metal ion-binding phytochelatin-2, which is an oligomer of glutathione, is accumulated. This increased phytochelatin concentration correlates with a lower free zinc level in the vacuole. These results suggest that phytochelatin is important for zinc buffering in S. cerevisiae and thus explains how zinc homeostasis is connected with glutathione metabolism. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The interaction of zinc oxide-based dental cements with aqueous solutions of potassium fluoride.

PubMed

Pawluk, K; Booth, S E; Coleman, N J; Nicholson, J W

2008-09-01

The ability of zinc oxide-based dental cements (zinc phosphate and zinc polycarboxylate) to take up fluoride from aqueous solution has been studied. Only zinc phosphate cement was found to take up any measurable fluoride after 5 h exposure to the solutions. The zinc oxide filler of the zinc phosphate also failed to take up fluoride from solution. The key interaction for this uptake was thus shown to involve the phosphate groups of the set cement. However, whether this took the form of phosphate/fluoride exchange, or the formation of oxyfluoro-phosphate groups was not clear. Fluoride uptake followed radicaltime kinetics for about 2 h in some cases, but was generally better modelled by the Elovich equation, dq(t)/dt = alpha exp(-betaq(t)). Values for alpha varied from 3.80 to 2.48 x 10(4), and for beta from 7.19 x 10(-3) to 0.1946, though only beta showed any sort of trend, becoming smaller with increasing fluoride concentration. Fluoride was released from the zinc phosphate cements in processes that were diffusion based up to M(t)/M(infinity) of about 0.4. No further release occurred when specimens were placed in fresh volumes of deionised water. Only a fraction of the fluoride taken up was re-released, demonstrating that most of the fluoride taken up becomes irreversibly bound within the cement.

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.

New CVD-based method for the growth of high-quality crystalline zinc oxide layers

NASA Astrophysics Data System (ADS)

Huber, Florian; Madel, Manfred; Reiser, Anton; Bauer, Sebastian; Thonke, Klaus

2016-07-01

High-quality zinc oxide (ZnO) layers were grown using a new chemical vapour deposition (CVD)-based low-cost growth method. The process is characterized by total simplicity, high growth rates, and cheap, less hazardous precursors. To produce elementary zinc vapour, methane (CH4) is used to reduce a ZnO powder. By re-oxidizing the zinc with pure oxygen, highly crystalline ZnO layers were grown on gallium nitride (GaN) layers and on sapphire substrates with an aluminum nitride (AlN) nucleation layer. Using simple CH4 as precursor has the big advantage of good controllability and the avoidance of highly toxic gases like nitrogen oxides. In photoluminescence (PL) measurements the samples show a strong near-band-edge emission and a sharp line width at 5 K. The good crystal quality has been confirmed in high resolution X-ray diffraction (HRXRD) measurements. This new growth method has great potential for industrial large-scale production of high-quality single crystal ZnO layers.

Room-temperature synthesis of zinc oxide nanoparticles in different media and their application in cyanide photodegradation

PubMed Central

2013-01-01

Cyanide is an extreme hazard and extensively found in the wastes of refinery, coke plant, and metal plating industries. A simple, fast, cost-effective, room-temperature wet chemical route, based on cyclohexylamine, for synthesizing zinc oxide nanoparticles in aqueous and enthanolic media was established and tested for the photodegradation of cyanide ions. Particles of polyhedra morphology were obtained for zinc oxide, prepared in ethanol (ZnOE), while spherical and some chunky particles were observed for zinc oxide, prepared in water (ZnOW). The morphology was crucial in enhancing the cyanide ion photocatalytic degradation efficiency of ZnOE by a factor of 1.5 in comparison to the efficiency of ZnOW at an equivalent concentration of 0.02 wt.% ZnO. Increasing the concentration wt.% of ZnOE from 0.01 to 0.09 led to an increase in the photocatalytic degradation efficiency from 85% to almost 100% after 180 min and a doubling of the first-order rate constant (k). PMID:24314056

Zinc oxide nanocolloids prepared by picosecond pulsed laser ablation in water at different temperatures

NASA Astrophysics Data System (ADS)

D'Urso, Luisa; Spadaro, Salvatore; Bonsignore, Martina; Santangelo, Saveria; Compagnini, Giuseppe; Neri, Fortunato; Fazio, Enza

2018-01-01

Zinc oxide with wide direct band gap and high exciton binding energy is one of the most promising materials for ultraviolet (UV) light-emitting devices. It further exhibits good performance in the degradation of non-biodegradable pollutants under UV irradiation. In this work, zinc oxide (ZnO) and zinc oxide/gold (ZnO/Au) nanocolloids are prepared by picosecond pulsed laser ablation (ps-PLA), using a Zn and Au metallic targets in water media at room temperature (RT) and 80°C. ZnO and Au nanoparticles (NPs) with size in the 10-50 nm range are obtained at RT, while ZnO nanorods (NRs) are formed when water is maintained at 80°C during the ps-PLA process. Au NPs, added to ZnO colloids after the ablation process, decorate ZnO NRs. The crystalline phase of all ZnO nanocolloids is wurtzite. Methylene blue dye is used to investigate the photo-catalytic activity of all the synthesised nanocolloids, under UV light irradiation.

Highly Attrition Resistant Zinc Oxide-Based Sorbents for H2S Removal by Spray Drying Technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryu, C.K.; Lee, J.B.; Ahn, D.H.

2002-09-19

Primary issues for the fluidized-bed/transport reactor process are high attrition resistant sorbent, its high sorption capacity and regenerability, durability, and cost. The overall objective of this project is the development of a superior attrition resistant zinc oxide-based sorbent for hot gas cleanup in integrated coal gasification combined cycle (IGCC). Sorbents applicable to a fluidized-bed hot gas desulfurization process must have a high attrition resistance to withstand the fast solid circulation between a desulfurizer and a regenerator, fast kinetic reactions, and high sulfur sorption capacity. The oxidative regeneration of zinc-based sorbent usually initiated at greater than 600 C with highly exothermicmore » nature causing deactivation of sorbent as well as complication of sulfidation process by side reaction. Focusing on solving the sorbent attrition and regenerability of zinc oxide-based sorbent, we have adapted multi-binder matrices and direct incorporation of regeneration promoter. The sorbent forming was done with a spray drying technique that is easily scalable to commercial quantity.« less

Plasmon resonance and perfect light absorption in subwavelength trench arrays etched in gallium-doped zinc oxide film

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendrickson, Joshua R., E-mail: joshua.hendrickson.4@us.af.mil; Leedy, Kevin; Cleary, Justin W.

Near-perfect light absorption in subwavelength trench arrays etched in highly conductive gallium-doped zinc oxide films was experimentally observed in the mid infrared regime. At wavelengths corresponding to the resonant excitation of surface plasmons, up to 99% of impinging light is efficiently trapped and absorbed in the periodic trenches. Scattering cross sectional calculations reveal that each individual trench acts like a vertical split ring resonator with a broad plasmon resonance spectrum. The coupling of these individual plasmon resonators in the grating structure leads to enhanced photon absorption and significant resonant spectral linewidth narrowing. Ellipsometry measurements taken before and after device fabricationmore » result in different permittivity values for the doped zinc oxide material, indicating that localized annealing occurred during the plasma etching process due to surface heating. Simulations, which incorporate a 50 nm annealed region at the zinc oxide surface, are in a good agreement with the experimental results.« less

Gaseous species as reaction tracers in the solvothermal synthesis of the zinc oxide terephthalate MOF-5.

PubMed

Hausdorf, Steffen; Baitalow, Felix; Seidel, Jürgen; Mertens, Florian O R L

2007-05-24

Gaseous species emitted during the zinc oxide/zinc hydroxide 1,4-benzenedicarboxylate metal organic framework synthesis (MOF-5, MOF-69c) have been used to investigate the reaction scheme that leads to the framework creation. Changes of the gas-phase composition over time indicate that the decomposition of the solvent diethylformamide occurs at least via two competing reaction pathways that can be linked to the reaction's overall water and pH management. From isotope exchange experiments, we deduce that one of the decomposition pathways leads to the removal of water from the reaction mixture, which sets the conditions when the synthesis of an oxide-based (MOF-5) instead of an hydroxide-based MOF (MOF-69c) occurs. A quantitative account of most reactants and byproducts before and after the MOF-5/MOF-69c synthesis is presented. From the investigation of the reaction intermediates and byproducts, we derive a proposal of a basic reaction scheme for the standard synthesis zinc oxide carboxylate MOFs.

Hydrothermal Synthesis of Nanostructured Vanadium Oxides

PubMed Central

Livage, Jacques

2010-01-01

A wide range of vanadium oxides have been obtained via the hydrothermal treatment of aqueous V(V) solutions. They exhibit a large variety of nanostructures ranging from molecular clusters to 1D and 2D layered compounds. Nanotubes are obtained via a self-rolling process while amazing morphologies such as nano-spheres, nano-flowers and even nano-urchins are formed via the self-assembling of nano-particles. This paper provides some correlation between the molecular structure of precursors in the solution and the nanostructure of the solid phases obtained by hydrothermal treatment. PMID:28883325

Fabrication of transparent ceramics using nanoparticles

DOEpatents

Cherepy, Nerine J; Tillotson, Thomas M; Kuntz, Joshua D; Payne, Stephen A

2012-09-18

A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.

The effect of Mg dopants on magnetic and structural properties of iron oxide and zinc ferrite thin films

NASA Astrophysics Data System (ADS)

Saritaş, Sevda; Ceviz Sakar, Betul; Kundakci, Mutlu; Yildirim, Muhammet

2018-06-01

Iron oxide thin films have been obtained significant interest as a material that put forwards applications in photovoltaics, gas sensors, biosensors, optoelectronic and especially in spintronics. Iron oxide is one of the considerable interest due to its chemical and thermal stability. Metallic ion dopant influenced superexchange interactions and thus changed the structural, electrical and magnetic properties of the thin film. Mg dopped zinc ferrite (Mg:ZnxFe3-xO4) crystal was used to avoid the damage of Fe3O4 (magnetite) crystal instead of Zn2+ in this study. Because the radius of the Mg2+ ion in the A-site (tetrahedral) is almost equal to that of the replaced Fe3+ ion. Inverse-spinel structure in which oxygen ions (O2-) are arranged to form a face-centered cubic (FCC) lattice where there are two kinds of sublattices, namely, A-site and B-site (octahedral) interstitial sites and in which the super exchange interactions occur. In this study, to increase the saturation of magnetization (Ms) value for iron oxide, inverse-spinal ferrite materials have been prepared, in which the iron oxide was doped by multifarious divalent metallic elements including Zn and Mg. Triple and quaternary; iron oxide and zinc ferrite thin films with Mg metal dopants were grown by using Spray Pyrolysis (SP) technique. The structural, electrical and magnetic properties of Mg dopped iron oxide (Fe2O3) and zinc ferrite (ZnxFe3-xO4) thin films have been investigated. Vibrating Sample Magnetometer (VSM) technique was used to study for the magnetic properties. As a result, we can say that Mg dopped iron oxide thin film has huge diamagnetic and of Mg dopped zinc ferrite thin film has paramagnetic property at bigger magnetic field.

Zinc transport by respiratory epithelial cells and interaction with iron homeostasis.

PubMed

Deng, Zhongping; Dailey, Lisa A; Soukup, Joleen; Stonehuerner, Jacqueline; Richards, Judy D; Callaghan, Kimberly D; Yang, Funmei; Ghio, Andrew J

2009-10-01

Despite recurrent exposure to zinc through inhalation of ambient air pollution particles, relatively little information is known about the homeostasis of this metal in respiratory epithelial cells. We describe zinc uptake and release by respiratory epithelial cells and test the postulate that Zn(2+) transport interacts with iron homeostasis in these same cells. Zn(2+) uptake after 4 and 8 h of exposure to zinc sulfate was concentration- and time-dependent. A majority of Zn(2+) release occurred in the 4 h immediately following cell exposure to ZnSO(4). Regarding metal importers, mRNA for Zip1 and Zip2 showed no change after respiratory epithelial cell exposure to zinc while mRNA for divalent metal transporter (DMT)1 increased. Western blot assay for DMT1 protein supported an elevated expression of this transport protein following zinc exposure. RT-PCR confirmed mRNA for the metal exporters ZnT1 and ZnT4 with the former increasing after ZnSO(4). Cell concentrations of ferritin increased with zinc exposure while oxidative stress, measured as lipid peroxides, was decreased supporting an anti-oxidant function for Zn(2+). Increased DMT1 expression, following pre-incubations of respiratory epithelial cells with TNF-alpha, IFN-gamma, and endotoxin, was associated with significantly decreased intracellular zinc transport. Finally, incubations of respiratory epithelial cells with both zinc sulfate and ferric ammonium citrate resulted in elevated intracellular concentrations of both metals. We conclude that exposure to zinc increases iron uptake by respiratory epithelial cells. Elevations in cell iron can possibly affect an increased expression of DMT1 and ferritin which function to diminish oxidative stress. Comparable to other metal exposures, changes in iron homeostasis may contribute to the biological effects of zinc in specific cells and tissues.

Decolorization of brilliant green dye using immersed lamp sonophotocatalytic reactor

NASA Astrophysics Data System (ADS)

Gole, Vitthal L.; Priya, Astha; Danao, Sanjay P.

2017-12-01

The textile and dye industries require an enormous amount of water for processing and produce a large volume of wastewater. Generated wastewater had potential hazards and a threat to the aquatic biota. The present work investigates the decolorization of brilliant green dye using a combination of two advanced oxidation techniques viz sonocatalysis and photocatalysis (immersed lamp) known as sonophotocatalysis (3 L capacity). The efficiency of decolorization is further improved in the presence of various additives viz. copper oxide, zinc oxide, and sodium chloride. The maximum decolorization of brilliant green (BG) (94.8% in 120 min) obtained in the presence of zinc oxide. The total organic carbon of the treated samples was measured to monitor complete mineralization of BG. The sonophotocatalytic process (in the presence of zinc oxide) shows maximum mineralization. Synergic combination of two oxidation processes increased the production of oxidizing radicals. Continuous cleaning of catalyst surface (due to sonolysis effect) improves the activity of the catalyst for photolysis operation. The present work is highly useful for the development of a sonophotocatalytic process.

Thermodynamic Analysis of Oxygen-Enriched Direct Smelting of Jamesonite Concentrate

NASA Astrophysics Data System (ADS)

Zhang, Zhong-Tang; Dai, Xi; Zhang, Wen-Hai

2017-12-01

Thermodynamic analysis of oxygen-enriched direct smelting of jamesonite concentrate is reported in this article. First, the occurrence state of lead, antimony and other metallic elements in the smelting process was investigated theoretically. Then, the verification test was carried out. The results indicate that lead and antimony mainly exist in the alloy in the form of metallic lead and metallic antimony. Simultaneously, lead and antimony were also oxidized into the slag in the form of lead-antimony oxide. Iron and copper could be oxidized into the slag in the form of oxides in addition to combining with antimony in the alloy, while zinc was mainly oxidized into the slag in the form of zinc oxide. The verification test indicates that the main phases in the alloy contain metallic lead, metallic antimony and a small amount of Cu2Sb, FeSb2 intermetallic compounds, and the slag is mainly composed of kirschsteinite, fayalite and zinc oxide, in agreement with the thermodynamic analysis.

A Photoluminescence Study of the Changes Induced in the Zinc White Pigment by Formation of Zinc Complexes

PubMed Central

Artesani, Alessia; Gherardi, Francesca; Nevin, Austin; Valentini, Gianluca; Comelli, Daniela

2017-01-01

It is known that oil paintings containing zinc white are subject to rapid degradation. This is caused by the interaction between the active groups of binder and the metal ions of the pigment, which gives rise to the formation of new zinc complexes (metal soaps). Ongoing studies on zinc white paints have been limited to the chemical mechanisms that lead to the formation of zinc complexes. On the contrary, little is known of the photo-physical changes induced in the zinc oxide crystal structure following this interaction. Time-resolved photoluminescence spectroscopy has been applied to follow modifications in the luminescent zinc white pigment when mixed with binder. Significant changes in trap state photoluminescence emissions have been detected: the enhancement of a blue emission combined with a change of the decay kinetic of the well-known green emission. Complementary data from molecular analysis of paints using Fourier transform infrared spectroscopy confirms the formation of zinc carboxylates and corroborates the mechanism for zinc complexes formation. We support the hypothesis that zinc ions migrate into binder creating novel vacancies, affecting the photoluminescence intensity and lifetime properties of zinc oxide. Here, we further demonstrate the advantages of a time-resolved photoluminescence approach for studying defects in semiconductor pigments. PMID:28772700

Chrysanthemum flower-like NiCo2O4-nitrogen doped graphene oxide composite: an efficient electrocatalyst for lithium-oxygen and zinc-air batteries.

PubMed

Moni, Prabu; Hyun, Suyeon; Vignesh, Ahilan; Shanmugam, Sangaraju

2017-07-06

Chrysanthemum flower-like NiCo 2 O 4 -nitrogen doped graphene oxide composite material has been explored as a bifunctional cathode electrocatalyst for aqueous zinc-air and non-aqueous lithium-oxygen batteries. This cathode exhibits maximum discharge capacities of 712 and 15 046 mA h g -1 for zinc-air and lithium-oxygen batteries, respectively, with stable cycling over 50 cycles.

Influence of ultrasound power and frequency upon corrosion kinetics of zinc in saline media.

PubMed

Doche, M-L; Hihn, J-Y; Mandroyan, A; Viennet, R; Touyeras, F

2003-10-01

This paper is devoted to zinc corrosion and oxidation mechanism in an ultrasonically stirred aerated sodium sulfate electrolyte. It follows a previous study devoted to the influence of 20 kHz ultrasound upon zinc corrosion in NaOH electrolytes [Ultrason. Sonochemis. 8 (2001) 291]. In the present work, various ultrasound regimes were applied by changing the transmitted power and the wave frequency (20 and 40 kHz). Unlike NaOH electrolyte which turns the zinc electrode into a passive state, Na2SO4 saline media induces soft corrosion conditions. This allows a study of the combined effects of ultrasonically modified hydrodynamic and mechanical damage (cavitation) upon the zinc corrosion process. A series of initial experiments were carried out so as to determine the transmitted power and to characterize mass transfer distribution in the electrochemical cell. Zinc corrosion and oxidation process were subsequently studied with respect to the vibrating parameters. When exposed to a 20 kHz ultrasonic field, and provided that the electrode is situated at a maximum mass transfer point, the corrosion rate reaches values six to eight times greater than in silent conditions. The zinc oxidation reaction, in the absence of competitive reduction reactions, is also activated by ultrasound (20 and 40 kHz) but probably through a different process of surface activation.

Bactericidal Effect of Zero-Valent Iron Nanoparticles on Escherichia coli

PubMed Central

Lee, Changha; Kim, Jee Yeon; Lee, Won Il; Nelson, Kara L.; Yoon, Jeyong; Sedlak, David L.

2008-01-01

Zero-valent iron nanoparticles (nano-Fe0) in aqueous solution rapidly inactivated Escherichia coli (E. coli). A strong bactericidal effect of nano-Fe0 was found under deaerated conditions, with a linear correlation between log inactivation and nano-Fe0 dose (0.82 log inactivation / mg/L nano-Fe0 · hr). The inactivation of E. coli under air saturation required much higher nano-Fe0 doses due to the corrosion and surface oxidation of nano-Fe0 by dissolved oxygen. Significant physical disruption of the cell membranes was observed in E. coli exposed to nano-Fe0, which may have caused the inactivation, or enhanced the biocidal effects of dissolved iron. The reaction of Fe(II) with intracellular oxygen or hydrogen peroxide also may have induced oxidative stress by producing reactive oxygen species. The bactericidal effect of nano-Fe0 was a unique property of nano-Fe0, which was not observed in other types of iron-based compounds. PMID:18678028

A new approach to synthesize ZnO tetrapod-like nanoparticles with DC thermal plasma technique

NASA Astrophysics Data System (ADS)

Lin, Hsiu-Fen; Liao, Shih-Chieh; Hu, Chen-Ti

2009-02-01

The feasibility of fabricating the tetrapod-like zinc oxide (TZ) nanoparticles with a DC thermal plasma reactor was demonstrated in the present study. Advantages of this process include the low cost and high yield rate (0.8-1.0 kg/h) in producing high TZ content mixtures (with small portion of rod-like zinc oxide (RZ) and plate-like zinc oxide (PZ) nanoparticles) from commercial metal zinc powders. ZnO nanopowders with high TZ content could be employed as the starting material for photocatalytic filters. The ratio of TZ to RZ and PZ in the products was observed to be strongly influenced by the plasma power and the plasma gas flow rate. The optical spectrum, photostability and anti-microbial property of the as-grown and annealed TZ mixtures were examined and compared in this study.

Surface acoustic wave/silicon monolithic sensor/processor

NASA Technical Reports Server (NTRS)

Kowel, S. T.; Kornreich, P. G.; Nouhi, A.; Kilmer, R.; Fathimulla, M. A.; Mehter, E.

1983-01-01

A new technique for sputter deposition of piezoelectric zinc oxide (ZnO) is described. An argon-ion milling system was converted to sputter zinc oxide films in an oxygen atmosphere using a pure zinc oxide target. Piezoelectric films were grown on silicon dioxide and silicon dioxide overlayed with gold. The sputtered films were evaluated using surface acoustic wave measurements, X-ray diffraction, scanning electron microscopy, Auger electron spectroscopy, and resistivity measurements. The effect of the sputtering conditions on the film quality and the result of post-deposition annealing are discussed. The application of these films to the generation of surface acoustic waves is also discussed.

Structural and electrical properties of sputter deposited ZnO thin films

NASA Astrophysics Data System (ADS)

Muhammed Shameem P., V.; Mekala, Laxman; Kumar, M. Senthil

2018-05-01

The growth of zinc oxide thin films having different oxygen content was achieved at ambient temperature by reactive dc magnetron sputtering technique and their structural and electrical properties are studied. The structural studies show that the films are polycrystalline with a preferential orientation of the grains along the c-axis [002], which increases with increase in oxygen partial pressure. The grain size and the surface roughness of the zinc oxide films are found to decrease with increasing oxygen partial pressure. It is observed that the resistivity of the zinc oxide films can be tuned from semiconducting to insulating regime by varying the oxygen content.

Eco-friendly approach towards green synthesis of zinc oxide nanocrystals and its potential applications.

PubMed

Velmurugan, Palanivel; Park, Jung-Hee; Lee, Sang-Myeong; Yi, Young-Joo; Cho, Min; Jang, Jum-Suk; Myung, Hyun; Bang, Keuk-Soo; Oh, Byung-Taek

2016-09-01

In the present study, we investigated a novel green route for synthesis of zinc oxide (ZnO) nanocrystals using Prunus × yedoensis Matsumura leaf extract as a reducing agent without using any surfactant or external energy. Standard characterization studies were carried out to confirm the obtained product using UV-Vis spectra, SEM-EDS, FTIR, TEM, and XRD. In addition, the synthesized ZnO nanocrystals were coated onto fabric and leather samples to study their bacteriostatic effect against odor-causing bacteria Brevibacterium linens and Staphylococcus epidermidis. Zinc oxide nanocrystal-coated fabric and leather showed good activity against both bacteria.

21 CFR 582.5991 - Zinc oxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements...

Zinc oxide hierarchical nanostructures for photocatalysis

NASA Astrophysics Data System (ADS)

Yukhnovets, O.; Semenova, A. A.; Levkevich, E. A.; Maximov, A. I.; Moshnikov, V. A.

2018-03-01

In this work, we perform the study of zinc oxide hierarchical structures synthesized by the low-temperature hydrothermal method. The paper considers morphological properties of obtained structures. Photocatalytic activity of samples was analysed by methyl orange degradation under UV irradiation. The sufficient decrease in methyl orange has been demonstrated.

The Influence of Different Metal Ions on the Absorption Properties of Nano-Nickel Zinc Ferrite

PubMed Central

Ma, Zhijun; Mang, Changye; Weng, Xingyuan; Si, Liwei; Zhao, Haitao

2018-01-01

The hydrothermal method was used to dope different amounts of Co2+, Mn2+, and Cu2+ in nano-nickel zinc ferrite powder. X-ray diffraction (XRD), a scanning electron microscopy (TEM), and a vector network analyzer (VNA) were used to explore the influence of doping on particle size, morphology, and electromagnetic wave absorption performance. Pure nanometer cobalt nickel zinc ferrite phase was prepared using the hydrothermal method with an increasing Co2+ content. Results showed that the grain type structure changed from a spherical structure to an irregular quadrilateral structure with the average particle size increasing from 35 nm to 60 nm. The lattice constant increased from 0.8352 to 0.8404 nm with Co2+ doping. The increasing Co2+ can change the position of the absorption peak, increase the bandwidth of the absorber, and improve the performance of the materials in GHz low frequency. The doping ratio of Mn2+ can affect the size of the lattice constant, but nanocrystals are easy to reunite without improving the electromagnetic loss. However, the absorbance performance decreases. For the doping of Cu2+, there is an agglomeration phenomenon. When the doping quantity is 0.15, the absorbing wave performance becomes better. PMID:29641477

The Influence of Different Metal Ions on the Absorption Properties of Nano-Nickel Zinc Ferrite.

PubMed

Ma, Zhijun; Mang, Changye; Weng, Xingyuan; Zhang, Qi; Si, Liwei; Zhao, Haitao

2018-04-11

The hydrothermal method was used to dope different amounts of Co 2+ , Mn 2+ , and Cu 2+ in nano-nickel zinc ferrite powder. X-ray diffraction (XRD), a scanning electron microscopy (TEM), and a vector network analyzer (VNA) were used to explore the influence of doping on particle size, morphology, and electromagnetic wave absorption performance. Pure nanometer cobalt nickel zinc ferrite phase was prepared using the hydrothermal method with an increasing Co 2+ content. Results showed that the grain type structure changed from a spherical structure to an irregular quadrilateral structure with the average particle size increasing from 35 nm to 60 nm. The lattice constant increased from 0.8352 to 0.8404 nm with Co 2+ doping. The increasing Co 2+ can change the position of the absorption peak, increase the bandwidth of the absorber, and improve the performance of the materials in GHz low frequency. The doping ratio of Mn 2+ can affect the size of the lattice constant, but nanocrystals are easy to reunite without improving the electromagnetic loss. However, the absorbance performance decreases. For the doping of Cu 2+ , there is an agglomeration phenomenon. When the doping quantity is 0.15, the absorbing wave performance becomes better.

Thiolated polyethylene oxide as a non-fouling element for nano-patterned bio-devices

NASA Astrophysics Data System (ADS)

Lisboa, Patrícia; Valsesia, Andrea; Colpo, Pascal; Gilliland, Douglas; Ceccone, Giacomo; Papadopoulou-Bouraoui, Andri; Rauscher, Hubert; Reniero, Fabiano; Guillou, Claude; Rossi, François

2007-03-01

This work describes the synthesis of a thiolated polyethylene oxide that self-assembles on gold to create a non-fouling surface. Thiolated polyethylene oxide was synthesised by reacting 16-mercaptohexadecanoic acid with polyethylene glycol mono methyl ether. The coverage of the thiolated polyethylene oxide on gold was studied by cyclic voltammetry, and the modified surfaces were characterised by X-ray photoelectron spectroscopy and ellipsometry. Protein resistance was assessed using quartz crystal microbalance. Results showed a non-fouling character produced by the thiolated polyethylene oxide. The synthesised product was used as the passivation layer on nano-patterned surfaces consisting of arrayed nano-spots, fabricated by plasma based colloidal lithography. The specific adsorption of anti-bovine serum albumin in the mercaptohexadecanoic acid spots was verified by atomic force microscopy.

Synthesis, characterization and application of a nano-manganese-catalyst as an efficient solid catalyst for solvent free selective oxidation of ethylbenzene, cyclohexene, and benzylalcohol

NASA Astrophysics Data System (ADS)

Habibi, Davood; Faraji, Ali Reza

2013-07-01

The object of this study is to synthesize the heterogeneous Mn-nano-catalyst (MNC) which has been covalently anchored on a modified nanoscaleSiO2/Al2O3, and characterized by FT-IR, UV-Vis, CHN elemental analysis, EDS, TEM, and EDX. The method is efficient for the highly selective oxidation of ethylbenzene, cyclohexene, and benzylalcohol without the need to any solvents, using tert-butyl hydroperoxide (TBHP) as an oxidant. Oxidation of ethylbenzene, cyclohexene, and benzylalcohol gave acetophenone, 2-cyclohexene-1-one and benzaldehyde, respectively, as major products. Reaction conditions have been optimized by considering the effect of various factors such as reaction time, amounts of substrates and oxidant, Mn-nano-catalyst and application of various solvents.

Manufactured aluminum oxide nanoparticles decrease expression of tight junction proteins in brain vasculature.

PubMed

Chen, Lei; Yokel, Robert A; Hennig, Bernhard; Toborek, Michal

2008-12-01

Manufactured nanoparticles of aluminum oxide (nano-alumina) have been widely used in the environment; however, their potential toxicity provides a growing concern for human health. The present study focuses on the hypothesis that nano-alumina can affect the blood-brain barrier and induce endothelial toxicity. In the first series of experiments, human brain microvascular endothelial cells (HBMEC) were exposed to alumina and control nanoparticles in dose- and time-responsive manners. Treatment with nano-alumina markedly reduced HBMEC viability, altered mitochondrial potential, increased cellular oxidation, and decreased tight junction protein expression as compared to control nanoparticles. Alterations of tight junction protein levels were prevented by cellular enrichment with glutathione. In the second series of experiments, rats were infused with nano-alumina at the dose of 29 mg/kg and the brains were stained for expression of tight junction proteins. Treatment with nano-alumina resulted in a marked fragmentation and disruption of integrity of claudin-5 and occludin. These results indicate that cerebral vasculature can be affected by nano-alumina. In addition, our data indicate that alterations of mitochondrial functions may be the underlying mechanism of nano-alumina toxicity.

Thermodynamic analysis of the selective chlorination of electric arc furnace dust.

PubMed

Pickles, C A

2009-07-30

The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

Biosynthesis of silver and zinc oxide nanoparticles using Pichia fermentans JA2 and their antimicrobial property

NASA Astrophysics Data System (ADS)

Chauhan, Ritika; Reddy, Arpita; Abraham, Jayanthi

2015-01-01

The development of eco-friendly alternative to chemical synthesis of metal nanoparticles is of great challenge among researchers. The present study aimed to investigate the biological synthesis, characterization, antimicrobial study and synergistic effect of silver and zinc oxide nanoparticles against clinical pathogens using Pichia fermentans JA2. The extracellular biosynthesis of silver and zinc oxide nanoparticles was investigated using Pichia fermentans JA2 isolated from spoiled fruit pulp bought in Vellore local market. The crystalline and stable metallic nanoparticles were characterized evolving several analytical techniques including UV-visible spectrophotometer, X-ray diffraction pattern analysis and FE-scanning electron microscope with EDX-analysis. The biosynthesized metallic nanoparticles were tested for their antimicrobial property against medically important Gram positive, Gram negative and fungal pathogenic microorganisms. Furthermore, the biosynthesized nanoparticles were also evaluated for their increased antimicrobial activities with various commercially available antibiotics against clinical pathogens. The biosynthesized silver nanoparticles inhibited most of the Gram negative clinical pathogens, whereas zinc oxide nanoparticles were able to inhibit only Pseudomonas aeruginosa. The combined effect of standard antibiotic disc and biosynthesized metallic nanoparticles enhanced the inhibitory effect against clinical pathogens. The biological synthesis of silver and zinc oxide nanoparticles is a novel and cost-effective approach over harmful chemical synthesis techniques. The metallic nanoparticles synthesized using Pichia fermentans JA2 possess potent inhibitory effect that offers valuable contribution to pharmaceutical associations.

An Atomistic View of the Incipient Growth of Zinc Oxide Nanolayers

DOE PAGES

Chu, Manh Hung; Tian, Liang; Chaker, Ahmad; ...

2016-08-09

The growth of zinc oxide thin films by atomic layer deposition is believed to proceed through an embryonic step in which three-dimensional nanoislands form and then coalesce to trigger a layer-by-layer growth mode. This transient initial state is characterized by a poorly ordered atomic structure, which may be inaccessible by X-ray diffraction techniques. Here in this work, we apply X-ray absorption spectroscopy in situ to address the local structure of Zn after each atomic layer deposition cycle, using a custom-built reactor mounted at a synchrotron beamline, and we shed light on the atomistic mechanisms taking place during the first stagesmore » of the growth. We find that such mechanisms are surprisingly different for zinc oxide growth on amorphous (silica) and crystalline (sapphire) substrate. Ab initio simulations and quantitative data analysis allow the formulation of a comprehensive growth model, based on the different effects of surface atoms and grain boundaries in the nanoscale islands, and the consequent induced local disorder. From a comparison of these spectroscopy results with those from X-ray diffraction reported recently, we observe that the final structure of the zinc oxide nanolayers depends strongly on the mechanisms taking place during the initial stages of growth. Finally, the approach followed here for the case of zinc oxide will be of general interest for characterizing and optimizing the growth and properties of more complex nanostructures.« less

Developmental phytotoxicity of metal oxide nanoparticles to Arabidopsis thaliana.

PubMed

Lee, Chang Woo; Mahendra, Shaily; Zodrow, Katherine; Li, Dong; Tsai, Yu-Chang; Braam, Janet; Alvarez, Pedro J J

2010-03-01

Phytotoxicity is an important consideration to understand the potential environmental impacts of manufactured nanomaterials. Here, we report on the effects of four metal oxide nanoparticles, aluminum oxide (nAl(2)O(3)), silicon dioxide (nSiO(2)), magnetite (nFe(3)O(4)), and zinc oxide (nZnO), on the development of Arabidopsis thaliana (Mouse-ear cress). Three toxicity indicators (seed germination, root elongation, and number of leaves) were quantified following exposure to each nanoparticle at three concentrations: 400, 2,000, and 4,000 mg/L. Among these particles, nZnO was most phytotoxic, followed by nFe(3)O(4), nSiO(2), and nAl(2)O(3), which was not toxic. Consequently, nZnO was further studied to discern the importance of particle size and zinc dissolution as toxicity determinants. Soluble zinc concentrations in nanoparticle suspensions were 33-fold lower than the minimum inhibitory concentration of dissolved zinc salt (ZnCl(2)), indicating that zinc dissolution could not solely account for the observed toxicity. Inhibition of seed germination by ZnO depended on particle size, with nanoparticles exerting higher toxicity than larger (micron-sized) particles at equivalent concentrations. Overall, this study shows that direct exposure to nanoparticles significantly contributed to phytotoxicity and underscores the need for eco-responsible disposal of wastes and sludge containing metal oxide nanoparticles.

An Atomistic View of the Incipient Growth of Zinc Oxide Nanolayers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chu, Manh Hung; Tian, Liang; Chaker, Ahmad

The growth of zinc oxide thin films by atomic layer deposition is believed to proceed through an embryonic step in which three-dimensional nanoislands form and then coalesce to trigger a layer-by-layer growth mode. This transient initial state is characterized by a poorly ordered atomic structure, which may be inaccessible by X-ray diffraction techniques. Here in this work, we apply X-ray absorption spectroscopy in situ to address the local structure of Zn after each atomic layer deposition cycle, using a custom-built reactor mounted at a synchrotron beamline, and we shed light on the atomistic mechanisms taking place during the first stagesmore » of the growth. We find that such mechanisms are surprisingly different for zinc oxide growth on amorphous (silica) and crystalline (sapphire) substrate. Ab initio simulations and quantitative data analysis allow the formulation of a comprehensive growth model, based on the different effects of surface atoms and grain boundaries in the nanoscale islands, and the consequent induced local disorder. From a comparison of these spectroscopy results with those from X-ray diffraction reported recently, we observe that the final structure of the zinc oxide nanolayers depends strongly on the mechanisms taking place during the initial stages of growth. Finally, the approach followed here for the case of zinc oxide will be of general interest for characterizing and optimizing the growth and properties of more complex nanostructures.« less

Primary battery design and safety guidelines handbook

NASA Technical Reports Server (NTRS)

Bragg, Bobby J.; Casey, John E.; Trout, J. Barry

1994-01-01

This handbook provides engineers and safety personnel with guidelines for the safe design or selection and use of primary batteries in spaceflight programs. Types of primary batteries described are silver oxide zinc alkaline, carbon-zinc, zinc-air alkaline, manganese dioxide-zionc alkaline, mercuric oxide-zinc alkaline, and lithium anode cells. Along with typical applications, the discussions of the individual battery types include electrochemistry, construction, capacities and configurations, and appropriate safety measures. A chapter on general battery safety covers hazard sources and controls applicable to all battery types. Guidelines are given for qualification and acceptance testing that should precede space applications. Permissible failure levels for NASA applications are discussed.

Preventive effects of zinc against psychological stress-induced iron dyshomeostasis, erythropoiesis inhibition, and oxidative stress status in rats.

PubMed

Li, Yingjie; Zheng, Yuanyuan; Qian, Jianxin; Chen, Xinmin; Shen, Zhilei; Tao, Liping; Li, Hongxia; Qin, Haihong; Li, Min; Shen, Hui

2012-06-01

Psychological stress (PS) could cause decreased iron absorption and iron redistribution in body resulting in low iron concentration in the bone marrow and inhibition of erythropoiesis. In the present study, we investigated the effect of zinc supplementation on the iron metabolism, erythropoiesis, and oxidative stress status in PS-induced rats. Thirty-two rats were divided into two groups randomly: control group and zinc supplementation group. Each group was subdivided into two subgroups: control group and PS group. Rats received zinc supplementation before PS exposure established by a communication box. We investigated the serum corticosterone (CORT) level; iron apparent absorption; iron contents in liver, spleen, cortex, hippocampus, striatum, and serum; hematological parameters; malondialdehyde (MDA); reduced glutathione (GSH); and superoxide dismutase (SOD). Compared to PS-treated rats with normal diet, the PS-treated rats with zinc supplementation showed increased iron apparent absorption, serum iron, hemoglobin, red blood cell, GSH, and SOD activities; while the serum CORT; iron contents in liver, spleen, and regional brain; and MDA decreased. These results indicated that dietary zinc supplementation had preventive effects against PS-induced iron dyshomeostasis, erythropoiesis inhibition, and oxidative stress status in rats.

Small angle neutron scattering study of nano sized microstructure in Fe-Cr ODS steels for gen IV in-core applications.

PubMed

Han, Young-Soo; Mao, Xiadong; Jang, Jinsung

2013-11-01

The nano-sized microstructures in Fe-Cr oxide dispersion strengthened steel for Gen IV in-core applications were studied using small angle neutron scattering. The oxide dispersion strengthened steel was manufactured through hot isostatic pressing with various chemical compositions and fabrication conditions. Small angle neutron scattering experiments were performed using a 40 m small angle neutron scattering instrument at HANARO. Nano sized microstructures, namely, yttrium oxides and Cr-oxides were quantitatively analyzed by small angle neutron scattering. The yttrium oxides and Cr-oxides were also observed by transmission electron microscopy. The microstructural analysis results from small angle neutron scattering were compared with those obtained by transmission electron microscopy. The effects of the chemical compositions and fabrication conditions on the microstructure were investigated in relation to the quantitative microstructural analysis results obtained by small angle neutron scattering. The volume fraction of Y-oxide increases after fabrication, and this result is considered to be due to the formation of non-stochiometric Y-Ti-oxides.

Potential Role of L-Arginine and Vitamin E Against Bone Loss Induced by Nano-Zinc Oxide in Rats.

PubMed

Abdelkarem, Hala M; Fadda, Laila H; El-Sayed, Eman M; Radwan, Omyma K

2018-05-04

The purpose of this study was to illustrate the effects of zinc oxide nanoparticles (ZnO-NPs) administration on bone turnover and bone resorbing agents in rats and how L-arginine (L-arg) or vitamin E (vit E) co-administrations might affect them. Fasting rats were randomly divided into four groups (n = 10): G1-normal healthy animals; G2-ZnO-NPs-exposed rats (600 mg/kg - 1/day -1 ); G3-ZnO-NPs-exposed rats co-administrated L-arg (200 mg/kg - 1/day -1 ); G4-ZnO-NPs-exposed rats co-administrated vit E (200 mg/kg - 1/day -1 ). The ingredients were orally administered daily. The body weight and food consumption of rats were recorded during the administration period and the experiment continued for three consecutive weeks. The results demonstrated that ZnO-NPs administration induced bone loss in rats as manifested by reduced activity of bone alkaline phosphatase (B-ALP) and increased level of C-terminal peptide type I collagen (CTx). The increase of inflammatory markers, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) by ZnO-NPs suggests that deleterious effects of ZnO-NPs on bone turnover were, in part, due to inflammation. Confirming to this suggestion, both L-arg and vit E reduced TNF-α and IL-6 levels and consequently decreased bone resorption as indicated by reduced serum CTx level. This study proved that ZnO-NPs can induce bone turnover, which may be reduced by L-arg or vit.E co-administration, partly by anti-inflammatory mechanism.