Nano-sized Zinc Research Articles

Biological resistance of pine wood treated with nano-sized zinc oxide and zinc borate against brown-rot fungi

In this work, the biological resistance of Scots pine (Pinus sylvestris L.) wood impregnated with nano-sized zinc oxide and zinc borate against the fungi Daedalea quercina, Poria placenta and Serpula lacrymans was evaluated. It can be concluded that nano-sized zinc oxide inhibited the biological degradation of pine wood against Serpula lacrymans, while it was ineffective against the brown-rot fungus Poria placenta. Pine wood treated with nano-sized zinc borate exhibited higher biological resistance against the fungi Serpula lacrymans and Poria placenta.

Reactivity of nano-size zinc powder in the aqueous solution of [FeIII(edta)(H2O)

ABSTRACTNitrogen mono-oxide and sulfur dioxide can be removed by simultaneous absorption into aqueous mixed solutions of sulfite and [FeII(edta)]H2O)]2−, ferrous ion coordinated to an anion of ethylene-diaminetetraacetic acid (EDTA or edta). In the industrial system with coexisting oxygen in the gas phase, [FeII(edta)](H2O)]2− complex is oxidized to [FeIII(edta)](H2O)]− by molecular oxygen. Because the ferric complex has no capability for reaction with NO, the suppression of this undesired oxidation process is a very important technological problem to be overcome. In our preceding work, we discussed the reduction kinetics of ferric ion by metal powder on the basis of the kinetic data regarding the ferric ion reduction in aqueous solutions of [FeIII(edta)](H2O)]− containing aluminum, tin or zinc powders. Zinc powder of normal size was recognized as an effective reducing agent. In the present work, augmentation of reducing capability of zinc powder was examined more. The rate of reduction of nano-size zinc powder was found to be about 11 times higher than that of normal-size zinc one.

Properties of silver phosphate glass doped with nanosize zinc oxide

High valence cations when doped in phosphate glasses, modify the properties, basically due to changes in glass structural network, through formation of cross-linked bonds. In the present paper 5, 10, 15 and 20wt% nanosize ZnO were doped in Ag2O–P2O5 glass prepared by melt-quench method. Glass transition temperatures were determined by DSC technique, whereas structural investigations were carried out by FTIR spectroscopic technique. X-ray diffraction studies showed that all the prepared glasses are poorly crystalline. SEM studies were made to have an idea about morphological changes in the presence of nanosize ZnO. Electrical conductivities and dielectric constants were measured as a function of temperature and frequency. Cole–Cole plot indicated that grain boundary and relaxation processes affected the electrical properties. It was found that glass transition temperatures increased in the presence of ZnO and conductivities increased with frequency.

Fast photoresponse of zinc ferrite nanotube arrays fabricated by electrodeposition

Although nano-sized zinc ferrite materials exhibit excellent visible light activity, their photoresponse characteristics as photodetectors have rarely been investigated. In this paper, zinc ferrite nanotube arrays were fabricated using electrodeposition with the aid of zinc oxide nanowire arrays as a template. These nanotube arrays showed tens of milliseconds-response photocurrents under the irradiation of a 532 nm solid-state laser, and the magnitudes of the photocurrents were linearly increased with increasing laser power. These features of ZnFe2O4 nanotube arrays revealed their potential applications in high-frequency or high-speed photodevices.

Nanosize of zinc oxide and the effects on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets

The aim of this study was to investigate the effect of dietary supplementation of nanosize zinc on zinc digestibility, growth performances, immune response and serum parameters of weanling piglets. Ninety-six LYD weanling piglets were assigned to control, zinc oxide (ZnO), organic-Zn (Zn-methionine) and nanosize ZnO (nano-Zn) groups with four replicates. The zinc was at the 120 mg/kg level in the treatment group's diet, while the control group's was 80 mg/kg Zn. The experiment results indicated that the nano-Zn and organic-Zn groups had significantly higher Zn digestibility compared to the ZnO and control groups. For the immune response traits, the IgG level and goat red blood cells (GRBC) antibody titer were nano-Zn and organic-Zn>ZnO>control; in the phytohemagglutinin (PHA) challenge test result, nano-Zn>organic-Zn>ZnO>control; in regard to the γ-globulin level, nano-Zn and organic-Zn>ZnO and control, with significant difference between groups. In the serum parameters aspect, serum Zn concentration in nano-Zn and organic-Zn groups were higher than in the ZnO and control groups, serum growth hormone concentration was increased in the nano-Zn group than in the other groups. In conclusion, nanosize zinc oxide for dietary supplementation can increase zinc digestibility, serum growth hormone levels and carbonic anhydrase activity and enhance the immune response of weanling piglets.

Effects of nanosize zinc oxide on zinc retention, eggshell quality, immune response and serum parameters of aged laying hens

The aim of this study was to investigate how dietary supplementation of nanosize zinc oxide affect zinc retention, egg production and eggshell quality, immune response and serum parameters of aged layers. In trial 1, twenty white Leghorn laying hens (68weeks-old) were assigned to the control, ZnO, organic-Zn (Zn-methionine) and nano-Zn (nanosize ZnO) groups. The Zinc was maintained at a 60mg/kg level in the treatment groups’ diet, while the control group’s diet contained 40mg/kg Zn to evaluate the nutrient retention and zinc bioavailability. In trial 2, eighty old white Leghorn laying hens (68weeks-old) were randomly allotted to four dietary treatments (as trial 1) to evaluate the egg production and eggshell quality, immune response and serum parameters. The results of trial 1 indicated that there were no differences in nutrient retention among the groups, but zinc retention was significantly higher in the nano-Zn and organic-Zn groups than that in the control and ZnO groups (P<0.05). Trial 2 results indicated that eggshell thickness was increased in the nano-Zn and organic-Zn groups compared to the control group (P<0.05); immune responses parameters, including: PHA (phytohemagglutinin) skin challenge test result, GRBC (goat red blood cells) antibody titer and IgG levels exhibited no differences among the groups; serum growth hormone concentration and carbonic anhydrase activity was significantly higher in the nano-Zn and organic-Zn groups compare to control group (P<0.05); serum albumin concentration in organic-Zn group was lower than that of the control group (P<0.05). In conclusion, nanosize zinc for dietary supplementation can increase zinc retention, as well as enhance eggshell thickness, serum carbonic anhydrase activity and growth hormone level of layers. We therefore concluded that nanosized zinc oxide can enhance zinc absorption in the intestine of layers compare to regular zinc oxide.

Covalency, hybridization and valence state effects in nano- and micro-sized ZnFe2O4

In the present work, Fe valence state, covalency effects, and metal–oxygen hybridization are discussed for ZnFe2O4 using X-ray absorption spectroscopy. A few sets of nano-sized and micro-sized zinc ferrite were synthesized using the nitrate method. Nanoparticles of ZnFe2O4 were synthesized by heating precursor at 300, 400, 500, 800, 1000, and 1200 °C for 1 h. To synthesize micro-sized ZnFe2O4, the obtained nanoparticles were annealed at 1200 °C for 12 h (bulk treatment). X-ray diffraction shows the presence of cubic spinel phase in nano-sized as well as micro-sized ZnFe2O4. Scanning electron microscopy measurements show that particle size ranges are 40–80 nm and 1–2 μm for nano-sized and micro-sized ZnFe2O4, respectively. Fe L-edge spectra of these materials envisage the presence of spectral features corresponding to t2g and eg symmetry states created due to Fe(2p3/2)-Fe(3d) and Fe(2p1/2)-Fe(3d) in octahedral crystal field. This reflects the presence of Fe3+ states in nano-sized and micro-sized ZnFe2O4. eg states dominate in micro-sized ZnFe2O4. O K-edge spectra for these materials can be distinguished by pre-edge and post-edge regions. Pre-edge and post-edge regions are associated with O(2p)–Fe(3d) and O(2p)–Fe(4s,4p) hybridized states. The extent of hybridization estimated from the intensity ratio of O(2p)–Fe(3d) and O(2p)–Fe(4s,4p) hybridized states is higher in nano-sized ZnFe2O4.

High-performance photocatalyst based on nanosized ZnO-reduced graphene oxide hybrid for removal of Rhodamine B under visible light irradiation

Nano-sized zinc oxide-reduced graphene oxide (ZnO-RGO) hybrid containing well-dispersed ZnO nanoparticles with an average diameter of 4.5 ± 0.5 nm has been successfully prepared via a one-step sol-gel method. FTIR characterization reveals that GO underwent deoxygenation during the preparation of ZnO nanoparticle. The introduction of RGO in the ZnO-RGO hybrid significantly improved the photocatalytic efficiency of ZnO in the degradation of Rhodamine B under visible light irradiation. The apparent reaction constant of ZnO-RGO is 8 times higher than that of pure ZnO, and the photocatalytic efficiency of ZnO-RGO remains high even after 4 consecutive reactions. Results from the X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller surface area measurements, and electrochemical impedance spectroscopy analysis suggest that the enhancement in the photocatalytic activity of the ZnO-RGO hybrid comes from (1) the enormous surface area provided by the nano-sized ZnO particles, (2) significant dye adsorption from RGO template, and (3) excellent electron reception and conduction of RGO. The attractive properties of ZnO-RGO make it a promising candidate material in addressing the environmental pollution issues we have to face today.

Application of nano-sized nanoporous zinc 2-methylimidazole metal-organic framework for electrocatalytic oxidation of methanol in alkaline solution

In this work, a novel non-platinum group metals (non-PGM) catalyst based on modified zinc 2-methylimidazole metal-organic framework (ZIF-8) is proposed and used for electrooxidation of methanol. Nano-sized particles of nonporous ZIF-8 are synthesized at room temperature using a simple template-free method. The synthesized ZIF-8 nanoparticles are characterized by X-ray diffraction, scanning electronic microscopy and nitrogen adsorption-desorption techniques. In order to decrease the overvoltage of methanol oxidation on carbon paste electrode (CPE), nickel species doped ZIF-8 modified carbon paste electrode (Ni/ZIF-8CPE) is fabricated as a modified electrode. Electrochemical techniques such as cyclic voltammetry and chronoamperometry are used to investigate the electrocatalytic activity of Ni/ZIF-8CPE toward methanol oxidation in alkaline solution. Cyclic voltammetry results show that oxidation current is considerably increased using Ni/ZIF-8CPE in comparison with unmodified CPE. Catalytic rate constant of methanol oxidation on Ni/ZIF-8CPE is obtained using chronoamperometric studies. Besides the good catalytic activity of the modified electrode toward methanol oxidation, it has other advantages such as simple preparation, ease of operation, good stability and low cost, which can be promising in the field of preparation of non-PGM electrocatalysts for application in fuel cells.

Photocatalytic self-cleaning poly(l-lactide) materials based on a hybrid between nanosized zinc oxide and expanded graphite or fullerene

New self-cleaning materials of polymer fibers decorated with a hybrid between nanosized zinc oxide and expanded graphite (EG) or fullerene (C60) were obtained. The new materials were prepared by applying electrospinning in conjunction with electrospraying. Poly(l-lactide) (PLA) was selected as a biocompatible and (bio)degradable polymer carrier. PLA solution was electrospun in combination with electrospraying of a suspension that contained the ZnO/EG or ZnO/C60 hybrid. Mats with different content of EG or C60 were obtained. The new materials were characterized by scanning and transmission electron microscopy (SEM and TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction analysis (XRD). The photocatalytic activity of the materials was evaluated by using model dyes. The formation of a hybrid between ZnO and EG led to enhancement of the photocatalytic activity of the mats at ZnO/EG weight ratios of 90/10 and 85/15. Increase in the photocatalytic activity of the ZnO-containing mats was also achieved by the formation of a hybrid between ZnO and C60 at a fullerene content of 0.5 and 1.0wt.% in respect to ZnO weight. The new materials exhibited antibacterial activity as evidenced by the performed studies against Staphylococcus aureus.

Effects of zinc oxide nanoparticles on bioaccumulation and oxidative stress in different organs of tilapia (Oreochromis niloticus)

Nano-size zinc oxide particles (ZnO NPs) are used in diverse industrial and commercial fields. However, the information from existing studies is not sufficient in evaluating the potential toxic effects of ZnO NPs. In this study, tilapia fish (Oreochromis niloticus) were exposed to different concentrations of small and large ZnO NPs in vivo. Accumulation in various organs/tissues (liver, gill, intestine, kidney, brain and muscle) and possible oxidative stress mechanisms were investigated comparatively. Fish were exposed to 1 and 10mg/L concentrations of small (10-30 nm) and large (100 nm) ZnO NPs semi-statically for 14 days. Both small and large ZnO NPs accumulated substantially in the tissues. Accumulation for the small ZnO NPs was significantly higher compared to larger NPs under same exposure regimes. Significant fluctuations were observed in antioxidant defense system biomarkers, including Superoxide dismutase (SOD), Catalase (CAT) and Glutathione (GSH) levels depending on particle size, exposure time and concentration. Lipid peroxidation measured with TBARS levels were higher in groups exposed to the suspensions of small ZnO NPs than that of large ZnO NPs and controls. These results imply that colloidal suspensions of small ZnO NPs induce elevated oxidative stress and toxic effects on tilapia compared to the larger NPs.

Effect of metal precursor on Cu/ZnO/Al2O3 synthesized by flame spray pyrolysis for direct DME production

Cu/ZnO/Al2O3 catalysts were synthesized by flame spray pyrolysis (FSP). The effect of different metal precursor types, i.e. metal nitrates and organometallics, on the catalytic properties was investigated. Organometallic precursors are commonly used for flame spray pyrolysis because small nanoparticles can be produced. In this study, we have obtained nanosized copper and zinc oxide clusters also from the nitrate precursors. Characterization was applied to reveal the difference between the clusters obtained from the different precursor types. Both precursors allowed the formation of well-ordered Cu/ZnO/Al2O3 particles with similar size according to TEM investigations.However, the catalyst from metal nitrate precursors possessed a lower reduction temperature, a higher active copper surface area, and a lower overall BET surface area than the one from the organometallic precursor. The catalytic performance of the obtained catalysts was investigated in the direct DME synthesis from synthesis gas. Methanol dehydration catalyst, H-ZSM-5, was therefore admixed to the FSP powders in a pre-defined amount; the FSP powders served as methanol synthesis catalyst in the mixture. The catalyst from metal nitrate precursors showed higher conversion of syngas than the catalyst from the organometallic precursors at same reaction conditions. This effect can be explained mainly by the higher copper surface area. Catalysts with different Cu/Zn ratio were also tested and the best catalyst was further studied by variation of the reaction conditions. In conclusion, we have demonstrated an efficient utilization of less expensive precursor materials for flame spray pyrolysis for production of Cu/ZnO/Al2O3 catalysts.

Development of bio-active pigment printed fabric loaded with nano-sized silver/zinc particles

Purpose – This paper aims to evaluate the antibacterial properties of pigment printed fabric loaded with nano-sized silver and zinc. Design/methodology/approach – The pigment printing paste was mixed with nano-sized silver/zinc particles and applied to the cotton fabrics by the hand screen-printing technique. The nano-sized particles, distribution on the fabric surface, were analysed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The ASTM E2149-01 test method was used to determine the bacteriodynamic activity of the treated fabrics. The wash and light fastness properties of the treated fabrics were investigated. Findings – The experimental results of the study showed that antibacterial properties could be obtained by loading with nano-size silver/zinc particles on pigment printed cotton fabrics. There is no negative or positive effect of the addition of nano silver/zinc particles to the printing paste on fastness properties. Research limitations/implications – The nano-sized metal particles and pigment printing paste should be well mixed to achieve uniform distribution on the printed surface. Practical implications – The described process marks the introduction of a nano-technological aspect to pigment printing by its application to cotton fabrics. Originality/value – The novelty/originality of the study lies in the new application process of nano-size silver/zinc particles to the textile pigment printing for antibacterial properties.

Preferential spin canting in nanosize zinc ferrite

Zinc ferrite nanoparticles powder with average size of 10.0±0.5nm was synthesized by the citrate precursor route. We studied the structural and magnetic properties using X-ray diffraction, vibrating sample magnetometry and Mössbauer spectroscopy. X-ray diffraction patterns show that the synthesized zinc ferrite possesses good spinel structure. Both Mössbauer and magnetization data indicate superparamagnetic ferrimagnetic particles at room temperature. The magnetic behavior is determined by a considerable degree of cation inversion with FeIII in tetrahedral A-sites. Mössbauer spectroscopy at low temperature and in high applied magnetic field reveals that A-site spins are aligned antiparallel to the applied field with some possible angular scatter whereas practically all octahedral B-site spins are canted contrasting some earlier reported partial B-site spin canting in nanosize zinc ferrite. Deviations from the antiferromagnetic arrangement of B-site spins are supposed to be caused by magnetic frustration effects.

Microstructure and Electrical Properties of La2O3 and Sm2O3 Co-doped ZnO-Based Varistor Ceramics Prepared From Nanosize ZnO Powder

High-performance ZnO–Bi2O3 varistors co-doped with a fixed amount of La2O3 and different amounts of Sm2O3 have been fabricated from nanosize zinc oxide powders by solid-state reaction. Phase composition, microstructure, and electrical properties were studied by x-ray diffractometry (XRD), scanning electron microscopy, and direct current electrical measurement. XRD analysis of the samples showed that a ZnO phase, a Bi2O3-rich phase, a spinel phase, and a pyrochlore-type phase were present; an Sm-rich phase was found in varistor ceramics containing large amounts of Sm2O3. The varistor ceramics had fine microstructures, and the corresponding grain size varied from 2.30 to 3.10 μm. Varistor ceramics doped with 0.1 mol% La2O3 and 0.5 mol% Sm2O3 then sintered at 1100°C for 2 h had good electrical properties (a breakdown field of 1130 V/mm, a nonlinear coefficient of 74, and a leakage current of 4.2 μA).

Optimizing stem cell functions and antibacterial properties of TiO2 nanotubes incorporated with ZnO nanoparticles: experiments and modeling.

To optimize mesenchymal stem cell differentiation and antibacterial properties of titanium (Ti), nano-sized zinc oxide (ZnO) particles with tunable concentrations were incorporated into TiO2 nanotubes (TNTs) using a facile hydrothermal strategy. It is revealed here for the first time that the TNTs incorporated with ZnO nanoparticles exhibited better biocompatibility compared with pure Ti samples (controls) and that the amount of ZnO (tailored by the concentration of Zn(NO3)2 in the precursor) introduced into TNTs played a crucial role on their osteogenic properties. Not only was the alkaline phosphatase activity improved to about 13.8 U/g protein, but the osterix, collagen-I, and osteocalcin gene expressions was improved from mesenchymal stem cells compared to controls. To further explore the mechanism of TNTs decorated with ZnO on cell functions, a response surface mathematical model was used to optimize the concentration of ZnO incorporation into the Ti nanotubes for stem cell differentiation and antibacterial properties for the first time. Both experimental and modeling results confirmed (R2 values of 0.8873–0.9138 and 0.9596–0.9941, respectively) that Ti incorporated with appropriate concentrations (with an initial concentration of Zn(NO3)2 at 0.015 M) of ZnO can provide exceptional osteogenic properties for stem cell differentiation in bone cells with strong antibacterial effects, properties important for improving dental and orthopedic implant efficacy.

Improvement of the Protective Properties of Alkyd Coatings by Nanosized Phosphate Pigments

Zinc phosphate nanoparticles with a thickness of ~20 nm are synthesized by an ion-exchange reaction. We study the influence of the nature of reaction media and modifiers of the surface on their shapes and sizes. It is shown that acryl monomers are optimal modifiers of the surface. We investigate the anticorrosion activity of synthesized nanosized zinc phosphate in alkyd coatings on aluminum alloys by the method of electrochemical impedance spectroscopy. It is shown that nanosized zinc phosphate has better inhibiting properties than modified phosphate pigments and can be used in paint primer coatings.

Effects of foliar spray of two kinds of zinc oxide on the growth and ion concentration of sunflower cultivars under salt stress

ABSTRACTThis study investigated the effects of foliar application of normal and nano-sized zinc oxide on the response of sunflower cultivars to salinity. Treatments included five cultivars (‘Alstar’, ‘Olsion’, ‘Yourflor’, ‘Hysun36’ and ‘Hysun33’), two salinity levels [0 and 100 mM sodium chloride (NaCl)], and three levels of fertilizer application. Fertilizer treatments were the foliar application of normal and nano-sized zinc oxide (ZnO). Foliar application of ZnO in either forms increased leaf area, shoot dry weight, net carbon dioxide (CO2) assimilation rate (A), sub-stomatal CO2 concentration (Ci), chlorophyll content, Fv/Fm, and Zn content and decreased Na content in leaves. The extent of increase in chlorophyll content, Fv/Fm and shoot weight was greater as nano-sized ZnO was applied to the normal form. The results show that the nano-sized particles of ZnO compared to normal form has greater effect on biomass production of sunflower plants.

Zinc Oxide-urea Formaldehyde Nanocomposite Film As Low-cost Adsorbent For Removal Of Cu(II) From Aqueous Solution

Copper is widely used in different industries and found its significant loss during the manufacturing and processing. The lost Cu is discharged in the effluent, thus adsorption of heavy metals is an important technology for treatment of wastewater containing different types of selected heavy metals. In this study, nanosize (~95 nm) zinc oxide was prepared through KNO3-NaNO3 eutectic melt at 450 °C. The obtained ZnO was encapsulated in urea-formaldehyde (UF) resin during acid catalysed polymerization process. The characterization of ZnO and ZnO-UF were made by X- ray diffraction (XRD), Scanning electron microscope (SEM) and Infra red spectroscopic (FT-IR) techniques. The prepared ZnO encapsulated in urea-formaldehyde resin casted in the form of film (~0.5 mm thickness) was used to remove 80% Cu (II) content from aqueous solution in 15 minutes. Further, the adsorption process was investigated and data was explained with Langmuir adsorption isotherm model. Copyright © 2015 VBRI press.

Synthetic zeolite supported ZnO nanoparticle materials for photocatalytic applications

Nanosize zinc oxide (ZnO) particles were supported on a suitable, inert and porous zeolite by a simple hydrothermal and sol–gel method in order to maximise adsorption and photocatalytic performance as well as retrievability and cost down. The effects of zeolite type, soak cycles, soak temperature and soak time of ZnO/zeolite composite materials on photocatalytic activity were discussed, which showed that the degradation of methylene blue dye in water can reach 91% after 150 min under UV light irradiation using synthetic zeolite as the supporting material with single soak cycles for 15 min under 50°C.