Effect Of Copper Oxide Research Articles

The Effect of CuO on the Thermal Behavior and Combustion Features of Pyrotechnic Compositions with AN/MgAl

Ammonium nitrate (AN) is of considerable interest to researchers in developing new types of energetic mixtures due to the release of environmentally benign gaseous products during burning and thermal decomposition. However, poor ignition and a low burning rate require special additives to speed up this process. The advantage of this research is the use of high-energy aluminum-based alloys as fuel to compensate for the disadvantages of AN. In addition, the effect of copper oxide (CuO) on the burning kinetics and thermodynamics of the energetic mixture based on ammonium nitrate–magnesium–aluminum alloys (AN/MgAl) is investigated. Alloys based on aluminum were created through a process of high-temperature diffusion welding, conducted in an environment of argon gas. The structure and thermal characteristics of alloys are determined by X-ray diffraction, scanning electron microscopy, and DTA-TG analyses. It has been found that CuO has significant effects on the thermal decomposition of an AN/MgAl-based energetic mixture by shifting the decomposition temperature from 269.33 °C to 261.34 °C and decreasing the activation energy from 91.41 kJ mol−1 to 89.26 kJ mol−1. Adding CuO reduced the pressure deflagration limit from 2 MPa to 1 MPa, and the linear burning rate of the AN/MgAl energetic mixture increased approximately twice (rb = 6.17 mm/s vs. rb = 15.44 mm/s, at a chamber pressure of P0 = 5 MPa).

Effect of copper oxide and zinc oxide nanoparticles on photosynthesis and physiology of Raphanus sativus L. under salinity stress

The study evaluates the impact of two metal oxide nanoparticles: copper oxide (CuO) and zinc oxide (ZnO) on the growth and physiology of Raphanus sativus L. (radish) under salinity stress. Fifteen days old seedlings of R. sativus were subjected to different concentrations of salt stress (0 mM, 150 mM, and 300 mM NaCl) alone and in interaction with 100 mgL−1 metal oxide nanoparticle treatments (CuO and ZnO NPs via foliar spray) for 15 days. The results confirmed the severe effects of salinity stress on the growth and physiology of radish plants by decreasing nutrient uptake, leaf area, and photosystems photochemistry and by increasing proline accumulation, anthocyanin, flavonoids content, and antioxidant enzyme activities which is directly linked to increased oxidative stress. The foliar application of CuO and ZnO NPs alleviated the adverse effects of salt stress on radish plants, as indicated by improving these attributes. Foliar spray of ZnO NPs was found efficient in improving the leaf area, photosynthetic electron transport rate, the PSII quantum yield, proton conductance and mineral content in radish plants under NaCl stress. Besides, ZnO NPs decreased the NaCl-induced oxidative stress by declining proline, anthocyanin, and flavonoids contents and enzymatic activities such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (GOPX). Thus, our study revealed that ZnO NPs are more effective and have beneficial effects over CuO NPs in promoting growth and reducing the adverse effects of NaCl stress in radish plants.

Effect of copper oxide (CuO) and vanadium oxide (V2O5) addition on the structural, optical and electrical properties of corundum (α-Al2O3)

In this work, we prepared a pure α-Al2O3, α-Al2O3/CuO (AC) and α-Al2O3/V2O5 (AV) nanocomposite. The sol–gel method was used to prepare pure α-Al2O3, (AC) and (AV) samples at 1200 °C. Structural, electrical, and optical properties of the prepared samples were investigated using the X-ray diffraction (XRD), UV–Visible spectrophotometer, and conductivity meter, respectively. The XRD results confirmed the crystalline nature and the presence of the hexagonal structure of α-Al2O3, the rhombohedra structure of CuAlO2 and the tetragonal structure of V2O5. Moreover, the crystallite size of pure α-Al2O3 was 43.1 nm, while the crystallite size of α-Al2O3 in samples AC and AV nanocompsite was 24.05 nm and 34.84 nm respectively. The optical measurements showed that the band gap α-Al2O3 decreased significantly from 5.28 eV for pure to 3.7 and 3.4 eV to AC and AV respectively. The DC electrical conductivity (σd.c) values were measured for all prepared samples at room temperature. The electrical conductivity was 2.4 × 10–7 and 1.8 × 10–7 (Ω cm)−1 in AC and AV nanocompsite respectively, while ionic conductivity (σion) decreased from 3 × 10–10 in pure α-Al2O3 to 7 × 10–5 and 1 × 10–5 in AC and AV nanocompsite, respectively. The results showed an improvement in the structural, optical, and electrical properties, which may make these materials a candidate for use in many applications, such as photocatalytic, gas sensors, optoelectronics, microelectronics, semiconductor devices, ……etc.

Effect of copper oxides on defect formation during PTA cladding of Stellite 6 on copper substrates

Stellite 6 coating is ideal for the protection of copper components in high-temperature environments, but the quality of the coating can be affected by the formation of copper oxide at the interface. In this study, plasma transfer arc cladding was employed to prepare Stellite 6 alloy cladding layers on copper substrates, with a preheating temperature of 700 °C and a cladding current of 120–170 A. Cladding experiments were conducted to investigate the impact of copper oxides generated during the cladding process on the quality of the cladding layer. Results showed that, when the current was below 140 A, insufficient current input caused edge cracking of the cladding layer, and the cracks tend to extend along the oxide layer at the interface. Interfacial reactions between the Stellite 6 alloy and copper oxide on the copper substrate produced CO/CO2, which led to pores forming at the interface. When the current was above 140 A, the localized overheating resulted in the upturning of the substrate, destroying the continuous copper oxide layer and eventually forming localized dents. The copper oxide affects the bonding of the cladding layer to the substrate. Increasing the cladding current helps to eliminate cracks and porosity, resulting in a good bond, but excessive current leads to localized dents. In this paper, 140 A was a relatively suitable current to produce satisfactory cladding layers. The wear resistance of the cladding layer was 1.9 and 2.2 times higher than that of the copper substrate at 25 and 300 °C, respectively.

Effect of insulation material on the firing performance of TaN@(Al/Ni)

In order to improve the ignition ability of reactive film, in this paper, the effects of copper oxide and silicon nitride on the flame height of the TaN@(Al/Ni) energy exchanger were investigated by using a high-speed photographic system. The insulating layer material was applied to the preparation TaN@(Al/Ni) by the MEMS process. The experimental results showed that the flame height of (Al/Ni)–TaN energy exchanger was obviously higher than that of silicon nitride when copper oxide was used as the insulation layer, which indicates that the oxygen-containing insulation layer could increase the flame height of the energy exchanger.

Viscosity of CuO Nanofluid Due to Nanoparticles Size and Concentration

Past studies showed that varying nanoparticles size could affect several properties of nanofluids. This could lead to significant change of hydro-thermal performance in various applications. In the present study, the effect of copper oxide (CuO) nanoparticle size on the viscosity of nanofluid was investigated under different working temperature and concentration. Base fluid consists of equal amount of distilled water and ethylene glycol. It was found that the addition of 0.05 vol.% CuO into base fluid caused increment of viscosity by 11.8% and 7.27%. On the other side, particle size effect was found to be insignificant on the viscosity of nanofluids at low concentration of CuO nanoparticles (0.025 vol.%). Lastly, the viscosity measured in the present study was predictable by two correlations proposed in past studies and only slight deviation was observed.

Influence of nanoparticles on emission and performance characteristics of biodiesel-diesel blends in a DI diesel engine

ABSTRACT In this experimental work, the effects of copper oxide (CuO) nanoparticles on emissions and performance of 4.4 kW diesel engine powered by palm biodiesel were studied. Palm biodiesel of 20% by volume was blended with diesel fuel (B20). Each test fuel blend was doped with CuO nanoparticles with concentrations of 25, 50, and 75 ppm. Experimentations were carried out for 0%, 25%, 50%, 75%, and 100% engine loads at a constant speed of 1500 rpm. Different parameters, such as brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity were analysed. From the results, it is observed that by using CuO nanoparticles along with B20, BTE (1.18%-7.69%) were significantly increased and BSFC (4.12%-6.76) were lowered. Besides, by using CuO nanoparticles, there were also substantial reductions in CO (2.21%-8.86%). Furthermore, there is an insignificant increase in HC (0.3%-9.78%), CO2 (2.38%-5.97%), and NOx (1.75%-5.27%) emissions when compared to B20 blend. However, when compared to diesel fuel all the emissions were low for all biodiesel blends except NOx emission. Overall, it is concluded that CuO could be considered as a appropriate petroleum additive for palm biodiesel blends.

The Effect of Particle Size of Copper Oxide (CuO) on the Heat‐Induced Catalysis Decomposition of Molecular Perovskite‐Based Energetic Material DAP‐4

In this study, the effect of copper oxide (CuO) with different sizes on the heat‐induced catalysis decomposition of typical molecular perovskite‐based energetic material DAP‐4 was studied. Pure CuO with different sizes and DAP‐4 are characterized by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). Heat‐induced catalysis decomposition performances of DAP‐4 with adding CuO were investigated by differential scanning calorimeter (DSC). Results demonstrated that with a lower‐addition CuO at the nanoscale added (1 wt%), DAP‐4 had decreased at least by 36°C with the heating rate of 10°C/min, compared with pure DAP‐4. With the CuO particle size of 50 nm, the Ea of DAP‐4 heat‐induced decomposition in DAP‐4/CuO‐50 had reduced from 159.8 kJ/mol to 120.2 kJ/mol, which is lower than DAP‐4/CuO‐150. The heat‐induced catalysis decomposition mechanism of DAP‐4 by using CuO as a nanoadditive was proposed.

The experimental comparison between the effect of copper oxide and graphene nanoparticles on rheological behavior and thermal properties of engine oil

The low thermal conductivity and viscosity index of conventional lubricants limit their performance. Therefore, it is crucial to achieving a nano-lubricant with suitable thermophysical properties as an alternative for the base-oil. Some investigations have been carried out in the past decade on the anti-frictional and thermal properties of nano-lubricants containing different nanoparticles. Meanwhile, studies on copper oxide nanoparticles are mostly concerned with their effect on thermal conductivity, and only a small number of studies have been carried out on graphene, which is focused on its effect on viscosity. However, rarely investigations have been performed on the simultaneous effect of these nanoparticles on the rheological behavior and thermal properties of engine oil. Also, there are only a few published articles on deriving the thermo-physical properties of nano-lubricants containing these nano-additives from experimental and theoretical approaches. Therefore, current work aims to compare the thermophysical features (dynamic viscosity, shear stress, thermal conductivity, flash point, and pour point) of the engine oil using copper oxide and graphene nano-additives under the influence of the effective variables includes shear rate, temperature, and nanoparticles mass fraction. Also, some correlations are proposed based on the experimental data to predict the rheological behavior and thermal conductivity of the nanofluids.

Properties of Inorganic Polymers Based on Ground Waste Concrete Containing CuO and ZnO Nanoparticles.

The effect of copper oxide and zinc oxide nanoparticles (NPs) on the mechanical and thermal properties of ground waste concrete inorganic polymers (GWC IPs) has been investigated. NPs are added to GWC IPs at loadings of 0.1, 0.5, 1, and 2% w/w. The phase composition and microstructure of NPs GWC IPs have also been examined using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM/EDS) techniques. Results show that the mechanical properties of GWC IPs are improved (23 MPa) due to addition of NPs (1% ZnO). In particular, GWC IPs embedded with 0.5% CuO and 1% ZnO NPs exhibited relatively improved compressive strength. The addition of NPs decreases the macroporosity and increases the mesoporosity of IPs matrix and decreases relatively the ability of IPs matrix to water absorption. The antimicrobial activity of GWC IPs doped with 0.5 and 1% CuO NPs against E. coli was also determined.

Toxicity Going Nano: Ionic Versus Engineered Cu Nanoparticles Impacts on the Physiological Fitness of the Model Diatom Phaeodactylum tricornutum

Increasing input of Metal Engineered Nano Particles (MeENPs) in marine ecosystems has raised concerns about their potential toxicity on phytoplankton. Given the lack of knowledge on MeENPs impact on these important primary producers, the effects of Copper Oxide (CuO) ENPs on growth, physiology, pigment profiles, fatty acid (FA) metabolism, and oxidative stress were investigated in the model diatom Pheodactylum tricornutum, to provide suitable biomarkers of CuO ENP exposure versus its ionic counterpart. Diatom growth was inhibited by CuO ENPs but not Ionic Cu, suggesting CuO ENP cytotoxicity. Pulse Modulated Amplitude (PAM) phenotyping evidenced a decrease in the electron transport energy flux, pointing to a reduction in chemical energy generation following CuO ENPs exposure, as well as an increase in the content of the non-functional Cu-substituted chlorophyll a (CuChl a). A significant decrease in eicosapentaenoic acid (C20:5) associated with a significant rise in thylakoid membranes FAs reflected the activation of counteractive measures to photosynthetic impairment. Significant increase in the omega 6/omega 3 ratio, underline expectable negative repercussions to marine food webs. Increased thiobarbituric acid reactive substances reflected heightened oxidative stress by CuO ENP. Enhanced Glutathione Reductase and Ascorbate Peroxidase activity were also more evident for CuO ENPs than ionic Cu. Overall, observed molecular changes highlighted a battery of possible suitable biomarkers to efficiently determine the harmful effects of CuO ENPs. The results suggest that the occurrence and contamination of these new forms of metal contaminants can impose added stress to the marine diatom community, which could have significant impacts on marine ecosystems, namely through a reduction of the primary productivity, oxygen production and omega 6 production, all essential to sustain heterotrophic marine life.

Effect of copper oxide on monochloramine decomposition in bromide-containing waters

Copper oxide (CuO), a common corrosion product found in copper pipes, has been shown to catalyse the decay of different oxidants in drinking water, including chlorine, bromine, iodine, and chlorine dioxide. However, its impact on monochloramine (NH2Cl), a disinfectant commonly used in long distribution system worldwide is still unknown. In this study, the effect of CuO on NH2Cl decay in the absence or presence of bromide was investigated. Results showed that in the presence of CuO and the absence of bromide, NH2Cl slightly decayed under acidic conditions. When bromide was present in NH2Cl solutions, the total oxidant concentration (sum of the different bromo-chloro-amines) was significantly decreased by CuO. This was primarily due to the degradation of bromochloramine (NHBrCl) by CuO which was evidenced by membrane inlet mass spectrometry. The decomposition rate of the total oxidant was similar for different CuO dosages (0.02–0.2 g/L) but increased with increasing bromide concentration (0–80 μM) and decreasing pH (6.5–8). An apparent second-order rate constant of 0.73 M−1 s−1 was determined with respect to NH2Cl and bromide concentrations for a CuO concentration of 0.05 g/L. Our findings suggest that, during water transportation in copper pipes or in distribution systems where copper oxide is present, special attention should be given to the stability of chloramines when bromide-containing waters are chloraminated.

Effects of copper oxide and sulfuric acid on the pyrolysis behavior of ammonium nitrate under thermal radiation experiments

Statistics have indicated that industrial accidents of ammonium nitrate were primarily caused by uncontrolled external fires where heating was dominantly controlled by radiation, and yet existing studies at milligram scale cannot fully simulate the real fire scenarios. To explore the pyrolysis behavior in typical fires, this study conducted thermal radiation experiments using pure ammonium nitrate, and its mixtures with copper oxide and sulfuric acid. Different from the pyrolysis process identified in milligram scale tests, the bench-scale pyrolysis of ammonium nitrate under radiation consisted of four stages. Pyrolysis structure model of each stage was built to reveal the differences in dominated thermal behavior. Results indicated that two additives had different thermo-chemical effects on pyrolysis of ammonium nitrate. Sulfuric acid accelerated the reaction rate of each stage by generating catalytic nitric acid; copper oxide reduced the number of reaction stages into three via surface absorptions. The time and mass loss rate of different stages were determined. Recommendations on effective emergency response were made to prevent the transition of slow decomposition into fast decomposition, and thus to intervene the fire-induced domino effect of ammonium nitrate. This study helps to understand the pyrolysis behavior of ammonium nitrate under fire exposure, and provides insights for pyrolysis modeling and firefighting in industry of interest.

The Effect of Copper Oxide on the Mechanical Properties of Y-TZP Ceramics

Small amount of Copper Oxide powder between 0.05 to 1 wt% were added into commercially available Y-TZP and its effect were investigated. The compacted samples underwent pressureless sintering in air at temperature between 1250°C to 1500°C. The mechanical properties of the samples’ such as bulk density, its Vickers hardness, and the samples’ fracture toughness were then evaluated. It was found that compared to Y-TZP without CuO content, doping ≥ 0.3 wt% of CuO was beneficial in enhancing Y-TZP’s mechanical properties by improving its densification rate, improving the matrix stiffness and also Vickers hardness when sintered at low temperatures such as below 1350°C. In addition, it also found that with the exception of undoped Y-TZP samples, there were enhancement of fracture toughness (KIC) of all samples when sintered below 1350°C.

The Combined Effect of Copper Oxide and Magnesium Oxide Nanoparticles Against Water and Food Borne Bacteria

The Combined Effect of Copper Oxide and Magnesium Oxide Nanoparticles Against Water and Food Borne Bacteria

Effect of CuO on the photoluminescence quenching and photocatalytic activity of ZnO multilayered thin films prepared by sol-gel spin coating technique

Sol-gel spin coating technique has been successfully employed for the preparation of monolayer, bilayer, and multilayer zinc oxide thin films on the glass substrate. The effect of copper oxide (CuO) on the photoluminescence (PL) quenching and photocatalytic activity of multilayered zinc oxide (ZnO) thin films were investigated. The +2 oxidation state of Zn and Cu in multilayered films was confirmed by x-ray photoelectron spectroscopy (XPS). The origin of green emission in the layered film is due to the presence of CuO and it acts as a trap for electrons generated in the ZnO layer thus preventing electron-hole recombination. The photocatalytic activity of multilayer zinc oxide thin films were evaluated on the basis of degradation of malachite green (MG) dye under UV irradiation. The formation of a p-n junction in multilayered zinc oxide thin films dissociate the excitons and this will cause the photoluminescence quenching and enhancement of degradation rate of malachite green in multilayered zinc oxide thin films. The results reveal that the CuO layer improves the crystalline quality, optical and photocatalytic properties of ZnO multilayered thin films.

Effect of Copper Oxide on Structural, Optical and Photocatalytic Activity of Reduced Graphene Oxide for Eosin B

Nowadays incorporation of few oxygen groups between the layers of graphite have shown potential approach for industrialization of graphene oxide for different potential applications. During the strong oxidation process in modified Hummers method, these oxygen based functional groups may increase the distance, weakening the van der Waals forces and facilitation the exfoliation of graphite layers from. The reduced graphene oxide/copper oxide (rGO-CuO) is highly potentially active and selective catalyst for many environmental applications. Different wt. % of Cu(II) and loaded on rGO surface to form a nanocomposite, which were prepared by hydrothermal method. The influence of hydrothermal temperature, rGO sheet and loaded CuO on structure of graphene was systematically investigated. The structure and optical properties of the obtained hybrid composite was evaluated employing scanning electron microscope, X-ray diffraction, UV-visible and infrared spectroscopies. The photocatalytic activities of rGO-CuO nanocomposites for the degradation of Eosin B acid red under sunlight were investigated. The results revealed the decrease in percentage photocatalytic degradation rate occurred on rGO-CuO, because a single sheet of rGO can shield the light from reaching the surface of CuO photocatalyst. It is possible to provide a new way to use the host rGO as prepared by hydrothermal method for water remediation applications.

Effect of Copper Oxide on Fast Pyrolysis of Enzymatic/mild Acidolysis Lignin

Abstract The effect of copper oxide on fast pyrolysis of enzymatic/mild acidolysis lignin (EMAL) isolate from moso bamboo were investigated under nitrogen and atmospheric pressure. The products distributions were closely linked with the addition of CuO. The experiment was set on a tubular reactor furnace at the addition of CuO by 1%, 3%, 5%, 10%, 15% based on the weight of EMAL. With the addition of about 5% CuO based on the weight of EMAL, the bio-oil yield reached to its highest level, and the amount of polycyclic aromatic hydrocarbon decreased obviously. Simultaneously, it increased the relative content of phenols. In gas products, CO and C 2 H 4 decreased obviously while H 2 , CH 4 , C 2 H 6 almost stayed the same.

Effects of Copper Oxide and Carbon Nanotubes on Thermal Stability of Silicone Rubber Nanocomposites

Silicone rubber (SR) filled with carbon nanotubes (CNTs), copper oxide (CuO) and CuO modified CNTs (CuO-CNTs) were prepared to detect the effects of these additives on thermal stability of SR by thermogravimetric analysis and tensile testing before and after aging. Flynn-Wall-Ozawa method was also employed to analyze the thermal degradation kinetics. The results indicated that all the additives could increase the initial thermal degradation temperature and thermal oxidative aging properties of SR and a synergistic effect was found in CuO-CNTs/SR. Meanwhile, activation energies of SR filled with additives increased significantly relative to neat SR and found to be optimal for CuO-CNTs/SR with activation energy increasing to 231.29, 121.68 kJ·mol-1 larger than that of blank sample. It is because that CNTs and CuO could promote each other to capture the free radicals generated by thermal oxidative reaction of the methyl side groups and thereby terminate the process.

Effect of copper oxide on structure and physical properties of lithium lead borate glasses

Copper-doped Lead lithium borate glass samples with the composition of (35-x) Pb3O4–xCuO–65Li2B4O7, where x = 5, 10, 15 or 20 mol%, have been prepared by melt quenching technique. Glass-forming ability, density, electrical conductivity, magnetic susceptibility and structural properties of lead lithium borate glasses have been investigated. IR spectroscopic data show that the copper ions play the role of glass modifier. Addition of CuO influences BO3 ↔ BO4 conversion. Density is expressed in terms of the structural modifications that take place in glass matrix. The increase in Tg reflects an increase in bond strength, and samples obtain more rigid glass structure. Electrical conductivity and magnetic susceptibility χ data show a variable behavior with the increase in the copper content in two valance states Cu+ and Cu+2. In addition, optical properties depend on the change of the role of copper ions in the samples’ structure. Optical energy band gap E opt and Urbach energy E tail are determined. The increase in E opt and UV cutoff with an increase in CuO content is due to the decrease in non-bridging oxygen concentration. The decrease in E tail at higher concentrations is attributed to the copper ion accumulation in the interstitial positions and to the formation of orthoborate groups. These samples are suitable for the green light longpass filters.