Effect Of Zinc Oxide Addition Research Articles

Evaluation on the Effect of Zinc Oxide Addition to Aging Rate of Asphalt and Performance of Resilience Modulus in Asphalt Concrete–Wearing Course

This study discussed the effect of the addition of the antioxidant Zinc Oxide (ZnO) on the aging rate of AC-WC coated asphalt and found out the effect of the addition of ZnO antioxidant on the stiffness of the asphalt layer. The aging of asphalt can be caused by two main factors, namely evaporation of light oil fractions contained in asphalt and oxidation. In this study, it showed that, compared to the addition of 5% and 15% ZnO to asphalt, the addition of 10% ZnO provided the most effective results on the asphalt base affecting the rheological properties of asphalt, namely reducing the penetration value by 1 dmm, increasing the softening point of asphalt by 0.5℃ but reducing the ductility by 10 cm. In the resilience modulus test which was carried out after aging at 135℃ for 0, 24, 48, 72, 96, and 120 hours, the modulus value containing ZnO was always smaller than that of asphalt without ZnO content. The addition of antioxidant Zinc Oxide (ZnO) antioxidant to asphalt had a positive effect on the aging rate of asphalt and the performance of the open-graded AC-WC resilience modulus of asphalt mixture was effective at an additional 10% level.

Effect of zinc oxide addition on antimicrobial and antibiofilm activity of hydroxyapatite: a potential nanocomposite for biomedical applications

Bacterial infections and biofilm formations are the main problems associated with implants. Hence, the aims of this study are to develop nanocomposite biomaterials having different ratios of hydroxyapatite nanoparticles (nHAP) with green and chemically synthesized zinc oxide (ZnO) nanoparticle (NP) and examine its antimicrobial and antibiofilm activity. The synthesized nanoparticles were characterized for phase and microstructural analysis. The nanocomposite at 90:10, 75:25 and 60:40 ratio of nHAP and ZnO NPs respectively, showed a different level of antimicrobial and antibiofilm activity against clinical specimen isolated gram-positive Staphylococcus aureus and gram-negative Escherichia coli. Moreover, the minimum inhibitory concentration (MIC) was the lowest concentration of ZnO NPs in the nanocomposite inhibiting the growth of each bacteria species and it was investigated for the given ratio of nanoparticles and found to be 0.2 mg/mL of 90:10 nanocomposite for both pathogens. The minimum bactericidal concentration (MBC) was the lowest concentration of ZnO NPs in the nanocomposite required to kill each of the bacterial species and it was found to be 0.2 mg/mL of 75:25 and 60:40 nanocomposite for S. aureus and E. coli, respectively. The maximum percentage of biofilm inhibition was found at 60 (nHAP): 40 (ZnO NPs) ratio of the nanocomposites. It was 52% and 54% against S. aureus and E. coli biofilm respectively, for green synthesized ZnO NPs and 51% and 52% against S. aureus and E. coli biofilm respectively, for chemically synthesized ZnO NPs. Hence, based on these results we suggest that the biomaterials containing different ratios of nHAP- ZnO NPs can be used as antimicrobial and antibiofilm materials in bone implant and bone regenerative medicine.

Processing of Polyurethane Nanocomposite Reinforced with nanosized Zinc Oxide: Effect on Mechanical and Acoustic Properties

Nanostructured materials are an important subject in different applications. Zinc oxide (ZnO) nanoparticles have much attention because of their unique properties. The objective of this work is to synthesis zinc oxide nanoparticles by simplest chemical method (direct aqueous precipitation). Also, the effect of zinc oxide addition to polyurethane foam (PUF) on the mechanical and sound properties has been evaluated. Different concentrations of ZnO (0.25, 0.5, 1, 2 and 3 wt.%) were used. ZnO nanoparticles were characterized by some techniques such as X-Ray diffraction, Energy dispersive X-ray spectrometry and Transmission electron microscopy analysis. Scanning electron microscope was used to describe the dispersion state of the nanoparticles in the polyurethane foam. Density of PUF increased while the particle size decreased. Finally, it was confirmed that the mechanical and acoustic properties of polyurethane nanocomposites were improved and depend on the amount of nanozinc oxide.

Effect of ZnO addition on the purity and densification of forsterite ceramic

Forsterite was found to the next potential candidate for bone implant application due to its superior mechanical properties as compared to the commonly used hydroxyapatite (HA). Various methods including two-step sintering and improvise synthesis method were introduced in hope to further improve the mechanical properties of forsterite. In this work, sintering additives, particularly zinc oxide (ZnO), was introduced into forsterite to provide enhancement on the densification of forsterite at lower sintering temperature. Forsterite powder was synthesized via solid-state reaction method with heat treatment at 1000°C for 2 hours with 10°C/min ramping rate. Addition of ZnO was conducted using milling process with composition of 0.5 wt% and 1.0 wt% ZnO. Green bulk samples were prepared prior to sintering process at 1200°C to 1500°C for 2 hours with 10°C/min ramping rate. Characterization was conducted in terms of phase stability and densification of forsterite with morphology examination to observe the grain surface of all samples. It was revealed that the addition of ZnO showed a more superior densification as compared to the undoped samples at all sintering regime studied with a maximum relative density obtained at 97.7% by 0.5 wt% ZnO doped sample sintered at 1500°C.

Effect of zinc oxide addition in slag system and heating manner on boron removal from metallurgical grade silicon

Different amount of ZnO was added to calcium silicate reagent to improve boron removal from metallurgical grade silicon (MG-Si). The thermodynamic analysis showed that the reagent CaO-SiO2-ZnO had a stronger ability to boron removal than the reagent CaO-SiO2. Two kinds of heating manners of electromagnetic induction and resistance were used to refine MG-Si. Compared with the resistance heating, the induction heating showed a much higher efficiency of boron removal. The mechanism of boron removal from MG-Si by ternary CaO-SiO2-ZnO slag reagent was put forward and the role of ZnO in slag to boron removal was described. The by-product Zn in refined silicon can be thoroughly removed by a vacuum distillation treatment, which showed an absolute advantage to the residual zinc removal in silicon by comparison with the acid leaching treatment. The residual zinc in silicon was reduced to lower than 0.05ppmw after a vacuum treatment at 1723K.

The effect of ZnO addition on the phase transformation, microstructure, and ionic conductivity of 8YSZ ceramics

In this paper the effect of zinc oxide (ZnO) addition on the phase transformation and ionic conductivity of 8 mol % Yttria-stabilised Zirconia (8YSZ) is investigated. Pure 8YSZ and ZnO doped YSZ ceramics are prepared using the solid state reaction method sintered at 1550°C for 2 hours. The X-ray Diffraction (XRD) results reveal the presence of tetragonal, cubic and monoclinic phase of Zirconium dioxide (ZrO 2 ) for all undoped and doped YSZ sintered samples. The phase stability of tetragonal YSZ was found to be increased with the increase in ZnO addition. Minor fraction of monoclinic phase was found in pure YSZ sintered sample and the amount of monoclinic phase decreased with the increasing amount of Zn after sintering at 1550°C for 2 hours. The fraction of cubic phase was also found to decrease with the increase in Zn concentration. The highest ionic conductivity of 1.03×10 −3 S cm −1 was obtained at room temperature for samples with 3 mol% ZnO. Pure 8YSZ sintered sample on the other hand, yielded 9.88x10 −4 S cm −1 .

The Effect of Zinc Oxide Addition to Alumina-Supported Gold Catalyst in Low Temperature Carbon Monoxide Oxidation

Gold catalysts supported on alumina (Au/Al2O3) and zinc oxide/Al2O3 (Au/ZnO/Al2O3) were prepared by deposition-precipitation with ammonium bicarbonate, and were characterized by nitrogen gas adsorption, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and temperature programmed reduction. The effect of ZnO addition to the surface of Al2O3 on the catalytic activity of Al2O3-supported gold catalysts in carbon monoxide oxidation is discussed in detail. The additions of 4 wt% ZnO loading to Au/Al2O3 showed a higher degree of gold particle dispersion which resulted in higher catalytic activity with Au/ZnO/Al2O3 catalyst than with Au/Al2O3 catalyst.

Characterization of oxygen defect and zinc segregation in the dense tin dioxide ceramics added with zinc oxide

We investigated the effect of zinc oxide addition for the defects in the dense SnO2 ceramics. Cathode and photoluminescence properties revealed the luminescence originated to oxygen vacancies in SnO2 grains and the presence of non-radiative defect at the grain boundaries. The oxygen diffusion profile showed that the oxygen diffusion was controlled by the limited process at the surface and uniform concentration of 18O at the grain boundaries inner side of sample. This sample exhibited a low Zn concentration in grains and a high Zn concentration at grain boundaries. We conclude that segregation of Zn at grain boundaries prevents SnO2 from decomposing at high temperatures, enabling dense SnO2 ceramics to be obtained.

The effect of zinc oxide addition on the compatibilization efficiency of maleic anhydride grafted high‐density polyethylene compatibilizer for high‐density polyethylene/polyamide 6 blends

AbstractA high‐density polyethylene with grafted maleic anhydride units has been investigated as a compatibilizer for high‐density polyethylene with polyamide 6. The material acts as an effective compatibilizer, causing a marked reduction in dispersed phase size as well as an increase in tensile strength and toughness. Compatibilizer also affects the glass‐transition temperature, crystallization kinetics, and amount of crystalline material for certain blend compositions. The addition of zinc cations, which are effective in increasing ethylene‐acid copolymer compatibilizer performance in low‐density polyethylene/polyamide blends, has little, if any, effect on compatibilizer performance in these high‐density polyethylene/polyamide blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3871–3881, 2007

The protection of mild steel by zinc-rich paint in flowing aerated 0.5 M NaCl solution—IV. The effect of zinc oxide addition

By employing mixtures of zinc and zinc oxide it was shown that when painted surface areas are exposed to flowing aerated NaCl solutions, the total solids content is more important than the actual amount of zinc. If the total solids content in the dried film was 93%, the zinc content could be replaced by up to 43% of zinc oxide without unduly affecting the protection afforded over 144 h.