Nano Cupric Oxide Research Articles

A green and facile synthesis route of nanosize cupric oxide at room temperature

Abstract Heat, ultrasonic, microwave, and external energy are the essential conditions in the conventional preparation of nano-cupric oxide (CuO) from copper hydroxide (Cu(OH)2) precursor. In this work, CuSO4 aqueous solution (0.02 mol) was gradually added dropwise into the methanol/sodium hydroxide (NaOH/CH3OH) solution (0.04 mol) in 20 min at normal temperature and then constantly stirred the black solution for about 5 min; nano-CuO was synthesized. The as-prepared CuO had a high purity and a regular nanosize of 4–10 nm. What is more, the by-product sodium sulfate (Na2SO4) could be separated using a high-speed centrifuge, indicating that the methanol could be conveniently recycled; thereby, an environmentally friendly sustainable route of the preparation of nano-CuO was developed. In addition, the as-prepared nano-CuO was melt-compounded with polyamide 6 to produce fiber composites. The results showed that the nano-CuO was uniformly dispersed in PA6 fiber composites and presented an excellent antibacterial performance. Most importantly, the function of methanol in the dehydration process was revealed.

Simultaneous Detection of Epicatechin and Theophylline in Black Tea with Nano Cupric Oxide Infused Graphite Electrode

Simultaneous Detection of Epicatechin and Theophylline in Black Tea with Nano Cupric Oxide Infused Graphite Electrode

Mesoporous Ca-alginate/melamine-rich covalent organic polymer/cupric oxide-based microgel beads as heterogeneous catalyst for efficient catalytic reduction of hazardous water pollutants

Present work focused on employing the advantages of novel porous melamine-rich covalent organic polymer (MCOP)-nano cupric oxide (CuO)–based heterogeneous catalysts for catalytic reduction of diverse pollutants including aromatic nitro compounds (p-nitrophenol, o-nitrophenol), toxic dyes (rhodamine B, methylene blue, congo red, methyl orange), and heavy metal ions (chromium(VI)). First, nano-CuO was prepared in a green process, and MCOP was fabricated by a solvothermal method. Subsequently, MCOP@CuO hybrids were developed. To improve the recyclability and stability of the MCOP@CuO hybrids and prevent secondary contamination by the powdery form of hybrids in the water, microgel beads based on alginate substrate were developed. First, the fabricated catalysts were employed for p-nitrophenol reduction, and the effect of catalyst loading and NaBH4 concentration were optimized. In optimum conditions, the catalytic reduction of other pollutants was tested and kinetic studies were examined. Furthermore, the proposed mechanisms for catalytic reductions were presented. Ca-alginate/MCOP@CuO microgel beads efficiently and successfully reduced toxic contaminants in a short time. All pollutants were removed in the time range of 14–55 min. Conversion percentages in removing pollutants were obtained at 90–98% for Ca-alginate/MCOP@CuO Ex-situ microgel beads. These microgel beads were greatly stable and effortlessly recycled without loss of their performance (for 5 consecutive cycles). The kinetics data were fit to the pseudo-first-order model with good correlation coefficients (R2 > 98). Such microgel-based catalysts will expose an innovative frontier in design materials for different potential requests such as treating toxic pollutants.

AMALGAMATION, PORTRAYAL AND EFFICACY OF HELIANTHUS ANNUUS BIO LUBRICANT WITH NANO ADDITIVE

Owing to the hazardous contribution towards environment from mineral oil-based lubricants, bio-degradable lubricants extracted from vegetable oils seems to be a promising candidate considering climate change, energy security and green environmental approach. In this research work, chemically modified helianthus annuus is considered as a viable option due to its excellent tribological properties and considerable polyunsaturated fatty acid. To further enhance the tribological properties, copper oxide nanoparticles were added to the base oil in varying proportions of 0.2, 0.3 and 0.5% by weight fractions. The application of nano enhanced biolubricants on worm and gearbox is studied. The addition of copper oxide nanoparticles enhances dispersion stability of the biolubricant. Tribological characterization was conducted using pin-on disc machine. Tribological properties such as coefficient of friction and wear rate along with kinematic viscosity is analysed for each composition. The obtained results are compared with synthetic oil SAE 75. It is observed that with the inclusion of copper oxide nanoparticles to the biolubricant, there is a notable decrease in wear rate along with lower friction coefficient. KEYWORDS: Nano enchanced BioLubricants, Nano Cupric Oxide, Recycliablity, Kinematic Viscosity, Anti-Friction.

Toughening carbon fibre composites at cryogenic temperatures using low-thermal expansion nanoparticles

Matrix cracking of carbon fibre reinforced polymer composites at super cold temperatures, such as liquid hydrogen temperature, is a major issue for lightweight fuel storage, because the microcracks induced by the high thermal residual stresses in the matrix can cause fuel leaks and degrade the structural integrity of the storage vessel. Herein, we report a new method of toughening carbon fibre composites using nanomaterials of low-thermal expansion, i.e., nano-silica (nSiO2) and nano-cupric oxide (nCuO), at cryogenic liquid nitrogen temperature (~196 °C). In addition to their low coefficients of thermal expansion, these two nanoparticles are sufficiently small to avoid the filtering effect of carbon fibres during resin infusion process. The surfaces of nCuO are functionalized by a polydopamine coating to enhance their bonding with the epoxy resin and the cross-linking density of the epoxy resin. Results from tension and fracture toughness tests of an epoxy modified with these nanoparticles reveal that PDA-coated nCuO are more effective than their un-coated counterpart and nSiO2 in increasing the mechanical and fracture properties of epoxy nanocomposites at both room and cryogenic temperatures, tripling the fracture toughness values. More importantly, PDA-coated nCuO demonstrate significant improvements in the initiation and propagation fracture toughness of angle-ply carbon fibre composite ([±35°]8) by 113% and 46% respectively at the cryogenic temperature. The underlying toughening mechanisms are identified using scanning electron microscope as being fiber peel-off, debonding, and striation in the matrix. These exceptional improvements stem from the higher interfacial residual thermal stress at cryogenic temperature due to their low thermal expansion properties, which in turn promotes crack branching that increases the energy dissipation of the matrix.

Development of thermal control coatings on AA7075 by plasma electrolytic oxidation (PEO) process

The thermal control coating was produced on AA7075 by pulsed DC plasma electrolytic oxidation (PEO) process in an aqueous electrolyte containing 3 g/l sodium silicate (Na2SiO3) and 6 g/l potassium hydroxide (KOH) along with 4 g/l nanoparticles of Cupric oxide (CuO) or Titanium oxide (TiO2) or CuO and TiO2 with equal mass. PEO coatings were fabricated with different electrolyte compositions with a current density of 150 mA/cm2 and a frequency of 1000 Hz for 6 min. The phase composition, surface morphology, and thickness of the coating were assessed using X-ray diffraction (XRD), scanning electron microscope (SEM), and eddy current thickness gauge, respectively. Thermal diffusivity of the coated sample was measured by the laser flash apparatus and the practical adhesive strength between the substrate and coating layer was evaluated by the scratch test. It was perceived that all the coated samples exhibited superior thermal control properties compared to the bare aluminium and the CuO particles incorporated PEO coating showed the highest thermal diffusivity (80.18 mm2/sec at 30 °C) compared to other PEO coated samples. The nano TiO2 and nano CuO incorporated PEO coatings shown the least porosity compared to the PEO coating without nanoparticles and the scratch testing critical loads are 13.58 N and 9.53 N, respectively.

Parametric investigation of CuO-doped charged nanofluid in solar water heater

Global warming is increasing at an alarming rate nowadays, and to control its after effects is the most challenging task at present. Several steps have been undertaken to minimize its after effects, and in this direction, researchers have focused on the utilization of easily available renewable energy resources. In this perspective, solar energy stands out as a viable option. Solar energy utilization is one of the most attractive and efficient ways to utilize renewable resources for power generation and heating purposes. Nanomaterials generated through modern nanotechnology techniques have been employed which provides more efficient heat transfer and improvement in the performance of solar water heating. Nanocupric oxide (CuO) has been used for enhancement of heat transfer, thermal conductivity, thermal diffusivity of paraffin, and increment in the output temperature. But the presence of nanoparticles reduces the specific heat of paraffin. Field emission scanning electron microscopy and energy-dispersive X-ray (EDAX) have been used to examine the morphology of CuO nanoparticles, paraffin wax, and nano-CuO-paraffin composite. The maximum heat transfer rate and Rayleigh number are obtained as 5.7 KW and 8.84 × 107 pertaining to CuO nano-doped PCM composite while maintaining an air gap of 4 cm between the absorber plate and the glazing.

Fabrication of nano-cupric oxide in phenol–formaldehyde resin adhesive: effect of cupric chloride concentration on resin performance

The potential for simultaneously incorporating nano-copper oxide (CuO) while synthesizing phenol–formaldehyde (PF) resin using different concentrations of cupric chloride (CuCl2) was studied. Curing kinetics, resin morphology, as well as physical and mechanical properties of oriented strand boards produced using the modified PF resin were evaluated. Nano-CuO showed a positive effect on the PF resin curing reactions that was characterized by a significant decrease in the activation energy within conversion degree of 65%. X-ray photoelectron spectrometric analysis showed that bivalent CuO was present in the modified PF resin. Laser scattering particle analysis showed that more than 40% of CuO was in the nanoparticle range. Four types of nano-CuO crystal structures were observed. Incorporation of nano-CuO derived from a 40% concentration of CuCl2 into the PF resin gave a 74% increase in perpendicular MOR. 2-h thickness swelling of PCu-0.5 was improved significantly. The findings of this work have potential application to the engineered wood composites manufacturing.

Bok choy (Brassica rapa) grown in copper oxide nanoparticles-amended soils exhibits toxicity in a phenotype-dependent manner: Translocation, biodistribution and nutritional disturbance

The comparative toxicity of nano/bulk cupric oxide (CuO) and ionic copper (Cu) in Rosie and Green bok choy (Brassica rapa) varieties, with higher and lower anthocyanin contents, respectively, was investigated. Both phenotypes were cultivated for 70 days in natural soil amended with nano CuO (nCuO), bulk CuO (bCuO), and Cu chloride (CuCl2) at 75, 150, 300, and 600 mg Cu/kg soil. Essential elements in tissues, agronomical parameters, chlorophyll content, and Cu distribution in leaf were determined. In both varieties, nCuO treatments significantly increased Cu uptake in roots, compared with bCuO and CuCl2 (p ≤ 0.05). At all treatment concentrations, Rosie variety had more Cu than Green. More physiological impairments such as chlorophyll and leaf biomass reduction were observed in treated-Rosie varieties, compared to Green plants. The adverse effects were higher in nCuO-treated plants than their bCuO- or ionic Cu-exposed counterparts. Different distribution patterns of the translocated Cu in leaf midrib and parenchyma depended on particle size and plant phenotype, as demonstrated by two-photon microscopy. The different effects of CuO-based compounds in Rosie and Green varieties may be related to the anthocyanin content. These findings help to understand the factors involved in nanoparticles uptake and translocation to plant edible parts.

Effect of nano cupric oxide coating on the forced convection performance of a mixed-mode flat plate solar dryer

In this study, mixed mode solar dryer of forced convection type, integrated with a CuO nanoparticle coated flat plate solar collector was developed and its effectiveness of drying maize under the meteorological conditions of Coimbatore, India was evaluated. The aforementioned setup entails a solar collector (flat plate type) with 3 drying trays and a centrifugal blower. The conventional solar absorber plate was made up of aluminium, which was coated with black paint. Another modified solar absorber plate was made up of aluminium with a coating of black paint with two different vol% of CuO nanoparticles (0.02% and 0.04%), for improving the heat transfer rate. Performance tests on the modified dryer were carried out at constant air flow rate (1.5 m3/min) and the results were compared with the conventional type. The efficiency of the collector got improved by 4% while using black paint with 0.04 vol% of CuO nanoparticle coated absorber. Also the drying time got reduced by 6%, when compared to conventional type dryer. Also the collector temperature recorded in the black paint with 0.04 vol% CuO nano-particle coated collector was higher compared to black paint coated and black paint with 0.02 vol% CuO nanoparticle coated collector.

The simultaneous preparation of nano cupric oxide (CuO) and phenol formaldehyde (PF) resin in one system: aimed to apply as wood adhesives

To reduce the cost of nano copper oxide (CuO) modified phenol-formaldehyde (PF) resin, the PF resin synthesis and the preparation of the nano CuO were carried out simultaneously in one system. The modified PF resins were evaluated via X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDXS), and thermogravimetry (TG). Physical and mechanical properties of oriented strand board (OSB) prepared using these modified PF resins were also evaluated. XPS results proved that nano CuO was present in the modified PF resin. XRD data showed that the derived nano CuO has a face-centered cubic structure. The minimum particle size of nano CuO was below 10 nm and the distribution of CuO was uniform as seen in TEM and EDXS images. TG analysis illustrated that the main degradation peak of the modified PF resins narrowed and shifted to a lower temperature by introducing nano CuO. Though the physical and mechanical properties of OSB decreased slightly, values were still within the requirements set by the appropriate Chinese Standard; this means that the modified PF resin has potential to be applied in engineered wood composites manufacturing.

An experimental insight into the effects of silver-doped cupric oxide nanoparticles on the performance of hydrocarbon refrigeration system

Refrigerators are inevitable in domestic and many industrial habitats. Indeed, the performance of refrigerants used in refrigerators can be enhanced when mixed with nanoparticles. In this regard, this study uses cupric oxide nanoparticle to enhance the refrigerant performance. Pure nano-cupric oxide and silver-doped nano-cupric oxide are mixed with R290 in the ratio 1:100. The doped nano-cupric oxide is characterized by XRD followed by EDX. TEM is used for photographic verification of nano-size, and the DRS test is used to calculate and compare band gap. The refrigerator gives better results with the prepared nano-refrigerants. The result is much better with silver-doped nano-cupric oxide than with pure nano-cupric oxide. The coefficient of performance of silver-doped nano-cupric oxide increased up to 29%. On the other hand, the power consumption of the refrigerator is also found to reduce up to 28%, thus helping save energy.

Fabrication of nano-cupric oxide in phenol–formaldehyde resin adhesive: synthesis, curing characteristics, and morphology

To explore the possibilities of reducing the costs of nano-copper oxide (CuO)-modified phenol–formaldehyde (PF) resin, PF resin synthesis and nano-CuO preparation utilizing different copper salts were carried out simultaneously in one system. The curing kinetics, morphology, as well as physical and mechanical properties of modified PF resins-bonded oriented strand boards (OSB) were evaluated. Nano-CuO showed a positive effect on the curing reaction of the PF resin, characterized by a significant decrease in the activation energy of the reaction. X-ray diffraction and transmission electron microscopy tests showed that the derived nano-CuO was in nano- and microscale. Four different types of crystal structure of the nano-CuO, varied according to their copper salts, were observed in scanning electron microscopy images. The water resistance and bonding strength of glued OSB prepared with these resin samples indicated that the influence of nano-CuO on the mechanical properties of the boards was positive. This system has the potential to be applied to the engineered wood-based composites manufacturing.

Nano CuO: Electrochemical sensor for the determination of paracetamol and d-glucose

A green combustion method using Aloe vera latex as a fuel was employed to synthesize nanocrystalline cupric oxide (CuO). The nanocrystalline nature and phase of CuO was confirmed by powder X-ray diffraction. Applying the Kubelka–Monk function to diffuse reflectance spectra showed the band gap of CuO to be 1.632 eV. Paracetamol and d-glucose in 1 M KOH solution were sensed using a carbon paste electrode modified using CuO nanoparticles (NPs). The cyclic voltammetry results suggest that CuO NPs possess superior electrochemical properties due to a lower value of the difference between oxidation and reduction potential (EO-ER). The proton diffusion coefficient for CuO electrode material was1.5047 × 10−5cm2s−1. Electrochemical impedance and Bode studies confirmed that the charge-transfer resistance value of CuO NPs was on the lower side due to the phase angle (55°) being near to ф = ᴨ/2. The electrochemical behavior indicates that CuO is a promising electrode material for sensing molecules such as paracetamol and glucose.

The similar in-situ polymerization of nano cupric oxide preparation and phenol formaldehyde resin synthesis: The process and mechanism

The process and mechanism of phenol-formaldehyde (PF) resin synthesis and nano copper oxide (CuO) preparation simultaneously in the same reaction vessel were studied in this paper. Curing kinetics, molecular structure changes as well as the bonding performance of the modified PF resin was investigated. The results indicated that loading levels of the derived nano CuO at 4% and 8% reduced the apparent activation energy of the PF resin and accelerated both the addition and condensation reactions, while changes of reaction enthalpy were consistent of these results. With the introduction of the derived nano CuO, the chemical shifts of all samples were generally offset to the low field for the solvent effect. A complexation reaction between copper ions and oxygen on the phenolic hydroxyl groups had an influence on phenoxy carbons as shown by NMR. Quantitative analysis indicated that nano CuO had a positive effect on para substituted reaction and thus enhanced both the addition and the condensation reactions. Though the shear strength under several test conditions decreased slightly, values were within the requirements set by the appropriate Chinese Standard.

Effects of Nano-Aluminum Nitride on the Performance of an Ultrahigh-Temperature Inorganic Phosphate Adhesive Cured at Room Temperature.

Based on the optimal proportion of resin and curing agent, an ultrahigh-temperature inorganic phosphate adhesive was prepared with aluminum dihydric phosphate, aluminium oxide (-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+.

An Experimental Study on the Thermal Properties and Electrical Properties of Polylactide Doped with Nano Aluminium Oxide and Nano Cupric Oxide

The research on polylactide has been trending over the past 10 years as it is a versatile biopolymer which finds applications in food packaging and medical industries. In this research, nano aluminium oxide and nano cupric oxide have been impregnated into polylactide matrix using sonication and the nano composite thin films were prepared using solution casting technique. The thermal characterization of the neat and doped polymer films were conducted using thermogravimetric analysis and differential scanning calorimetry. the addition of nano aluminium oxide and nano cupric oxide increased the glass transition temperature and melting temperature of the samples in comparison with neat polylactide. Degree of crystallinity of all the doped samples increased with respect to the neat sample except for the sample doped with 1 mg nano aluminium oxide. The I–V characterization of the neat and doped samples revealed that addition of the nano powders reduced the resistivity of PLA by 35–45%. These results recommend the use of polylactide doped with nano aluminium oxide and nano cupric oxide as a potential semiconducting polymeric materials.

A Study on the FTIR Spectroscopy of Polylactide Doped with Nano-Aluminium Oxide and Nano-Cupric Oxide

ABSTRACTElucidation of the structure of naturally existing or synthesized substances is an important criterion in the study of materials to predict the application of the substance. In this study, polylactide was doped with nano-aluminium oxide and nano-cupric oxide with 1 and 3 mg of concentration variants. The interaction between the polymer matrix and the nanoparticles has been studied using Fourier transform infrared. Successful doping of the polymer has been observed. Attention has been drawn to check the intermolecular bonding in films having varying thicknesses, films prepared at higher sonication temperatures, and chemical homogeneity of the doped polymer films.

Shape-Dependent Surface Reactivity and Antimicrobial Activity of Nano-Cupric Oxide.

Shape of engineered nanomaterials (ENMs) can be used as a design handle to achieve controlled manipulation of physicochemical properties. This tailored material property approach necessitates the establishment of relationships between specific ENM properties that result from such manipulations (e.g., surface area, reactivity, or charge) and the observed trend in behavior, from both a functional performance and hazard perspective. In this study, these structure-property-function (SPF) and structure-property-hazard (SPH) relationships are established for nano-cupric oxide (n-CuO) as a function of shape, including nanospheres and nanosheets. In addition to comparing these shapes at the nanoscale, bulk CuO is studied to compare across length scales. The results from comprehensive material characterization revealed correlations between CuO surface reactivity and bacterial toxicity with CuO nanosheets having the highest surface reactivity, electrochemical activity, and antimicrobial activity. While less active than the nanosheets, CuO nanoparticles (sphere-like shape) demonstrated enhanced reactivity compared to the bulk CuO. This is in agreement with previous studies investigating differences across length-scales. To elucidate the underlying mechanisms of action to further explain the shape-dependent behavior, kinetic models applied to the toxicity data. In addition to revealing different CuO material kinetics, trends in observed response cannot be explained by surface area alone. The compiled results contribute to further elucidate pathways toward controlled design of ENMs.

Effect of solution condition on the precipitation of nano-cupric oxide by using a high gravity process

In order to find the optimum conditions to obtain nano-cupric oxide particles, the synthesis of CuO is carried out by feeding CuCl2 (0.1–0.4 M) and NaOH (0.2–1.0 M) solutions simultaneously into a high gravity apparatus. The precursors obtained are calcined for three hours at 100 and 350°C in an oven prior to further characterization using XRD, SEM, UV, PL (photoluminescence) and BET instruments. The major precursors are found to be CuO, Cu(OH)2 and Cu2Cl(OH)3. The specific surface areas after calcination are in the range of 7.45 to 58.21 m2/g, corresponding to an average diameter between 16.4 and 127.2 nm. In addition, the yields obtained, 0–95.5%, are found to be strongly dependent on the operating conditions. The results show that the reactant concentration ratio, R=[NaOH]:[CuCl2], plays an important role in influencing the product distribution. A roadmap of technology for the production of precursors is established. Finally, the effects of rotating speed and feed rate of the solutions are also discussed.