Properties Of Cu Nanoparticles Research Articles

Green synthesis, chemical characterization, anti-osteoarthritis properties of Cu nanoparticles

In our latest study, we assessed the effectiveness of a green copper nanoparticle formulation containing curcumin on the chick’s knee joint injury. The NPs were characterized using FE-SEM, TEM, XRD, and EDX techniques. The primary cultured chondrocytes were utilized to check the nanoparticles effectiveness on chondrogenesis in the orthopedic experiments. Subsequently, we assessed the functional restoration post copper nanoparticles transplantation using an osteoarthritis articular model in the knee. Histological, PCR, and western blot analyses were conducted to investigate the underlying mechanisms. The XRD results exhibited the CuO formula for CuNPs and a spherical shape with a size <60 nm was obtained for the NPs from the TEM and FE-SEM images. The presence signals in EDX diagram including signals at 0.22 keV for C Lα, 0.51 keV for O Lα, and 0.93 keV for Cu Lα approve the formation of Cu NPs. The use of nanoparticles effectively inhibited abnormal fibrosis and angiogenesis at the injury site. The nanoparticles presence in the histological test resulted in rised synthesis of cartilage matrix and proliferation of chondrocytes, while also reducing the formation of abnormal vasculature. The study unveiled that the use of nanoparticles accelerated the healing process following an injury after three weeks. Furthermore, we highlighted the beneficial effects of copper nanoparticles in promoting cartilage formation in a laboratory setting. In the immunological domain, the copper nanoparticles demonstrated a decrease in the quantities of IL-1β, TNF-α, p-p65, and MMPs expression. This phenomenon could potentially be attributed to the cellular redox homeostasis modulation associated with the Nrf2 pathway. In conclusion, the results of this research confirmed the positive efficacy of copper nanoparticles containing curcumin in accelerating the osteoarthritis articular cartilage repair.

The Optical and Structural Properties of Cu Nanoparticles: Graphene Prepared by Pulsed Laser Ablation in Deionized Water

Background: In this paper, graphene and copper oxide nanoparticles and graphene-based copper oxide nanoparticles have been produced by means of a pulsed laser ablation process (PLA) in a deionized water solution. Methods: The composition ratio of materials has been investigated in the structure of the prepared materials and their optical properties. The absorbance of the samples was obtained by the UV-VIS single beam spectrophotometer in the wavelength range of 290 to 800 nm. Spectroscopic ellipsometry method was used to investigate the linear optical properties of the samples including the real and imaginary parts of refractive index and dielectric function of the samples. The preferred model in the dielectric function modeling was Tauc-Lorentz. Also, the energy band gap of the samples has been calculated using Tauc relation. In addition, the nonlinear optical properties of graphene based copper oxide have been studied by Z-scan technique. Structure of the samples was studied using TEM image. Results: The most and the least absorbance at 532 nm wavelength, and also band gap energy belong to 1.4 ml Gr-0.6 ml Cu and copper oxide, respectively. Conclusion: The band gap energies of the samples were calculated between 3.30 eV and 3.43 eV. The real and imaginary parts of the complex refractive index were obtained in the order of 10-8cm2/W and 10-5cm/W. The results for nonlinear properties show that these samples are suitable for all-optical switching devices.

Effect of Zr contents and covering Ag layer on microstructure and SERS properties of Cu nanoparticles / Cu-Mo-Zr alloy films on flexible substrates

Cu-Mo-Zr alloy films with different Zr contents were prepared by magnetron sputtering. The microstructure and SERS properties of alloy films were characterized by SEM, TEM, XRD and Raman spectroscopy. A large number of Cu nanoparticles are formed spontaneously on the surface of alloy film after annealing. Moreover, the number, size and particle spacing of Cu nanoparticles are found to be highly sensitive to annealing temperature, annealing time, Zr content and film thickness. Results of the local electric field between Cu particles on the alloy films surface simulated by FDTD reveal that larger particles and smaller spacing can produce stronger local electric fields. Furthermore, a 10 nm Ag layer coating on the alloy film has a significant effect on the size, spacing of Cu particles, and the synergistic enhancement between Ag layer and Cu nanoparticle can significantly increase the local electric field thereby improving the SERS performance of Cu-Mo-Zr alloy films. The Raman signal of 10-13 mol/L Rhodamine 6G solution can be detected by using Ag layer/Cu-30 at% Mo-22.9 at% Zr alloy films as SERS substrates. The present study provides a method for preparing SERS substrates with low cost, high sensitivity and excellent repeatability.

Research on size dependent integral melting thermodynamic properties of Cu nanoparticles

Nanometer copper possesses a broad range of applications in catalytic electrochemistry and functional materials, and these applications are intimately associated with the thermodynamic properties of melting. In this paper, we deduced the exact relationships between the integral melting enthalpy, the entropy of the nanoparticles, respectively, particle size, and discussed the influencing factors, influencing regularities and influencing a degree on the thermodynamic properties of melting. Experimentally, different sizes of Cu nanoparticles were prepared by the microwave method, the melting temperatures, melting enthalpies, and melting entropies were determined by differential scanning calorimetry (DSC). The results demonstrate that the integral thermodynamic properties of Cu nanoparticles decrease with the reduction of particle size, and vary linearly with the reverse particle size within the experimental size range. The experimental results are coherent with the theoretical predictions.

Parameter optimization of copper nanoparticle synthesis by electrodeposition process using RSM and CS

Now-a-days, more concentration attention has been given for synthesizing of copper (Cu) nanoparticles due to its excellent physical and chemical properties. Different approaches are available to synthesize the Cu nanoparticles. Electrodeposition is an easier and simple approach to synthesize the Cu nanoparticles with high purity. The properties of Cu nanoparticles depend on their synthesis approach and electrolysis process parameters. In this work, response surface methodology (RSM), cuckoo search (CS) algorithm was used to optimize the electrodeposition process parameters like concentration of CuSO4 (4–6 g l−1), electrode potential difference (12–27 V) and electrode distance (3–5 cm) on mean size of Cu nanoparticles. The mean particle size of 21.55 nm was obtained with the electrodeposition parameters of (4 g l−1) CuSO4, (3 cm) electrode distance and (27 V) electrode potential difference. The particle size obtained from the experimental result was 20 nm which was very closer to the predicted result (21.5 nm). The size and morphology of Cu nanoparticle were analyzed by using scanning electron microscope and X-ray diffraction technique.

Cu-anchored CNTs for effectively catalytic reduction of 4-nitrophenol

Cu-anchored carbon nanotubes (Cu@CNTs) were cleverly fabricated through the simultaneously thermal treatment of sulfonated polymer nanotubes and copper salt precursor. The effect of calcination temperature (600 °C, 800 °C, 1000 °C) on the catalytic activity of Cu@CNTs for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with the addition of NaBH4 has been studied in detail. The catalytic activity of the Cu@CNTs nanocomposite calcined at 800 °C was found to be better than those of the samples at 600 °C and 1000 °C, which can convert 4-NP to 4-AP in 6 min. The excellent catalytic performance of the nanocomposites was derived from the favorable catalytic properties of Cu nanoparticles, the uniform dispersion of Cu nanoparticles on CNTs and the advisable one-dimensional structure. Hence, this article provides a simple method to prepare an attractive catalyst for the reduction of 4-NP.

Optical trapping reveals differences in dielectric and optical properties of copper nanoparticles compared to their oxides and ferrites

In a nanoplasmonic context, copper (Cu) is a potential and interesting surrogate to less accessible metals such as gold, silver or platinum. We demonstrate optical trapping of individual Cu nanoparticles with diameters between 25 and 70 nm and of two ionic Cu nanoparticle species, CuFe2O4 and CuZnFe2O4, with diameters of 90 nm using a near infrared laser and quantify their interaction with the electromagnetic field experimentally and theoretically. We find that, despite the similarity in size, the trapping stiffness and polarizability of the ferrites are significantly lower than those of Cu nanoparticles, thus inferring a different light-particle interaction. One challenge with using Cu nanoparticles in practice is that upon exposure to the normal atmosphere, Cu is spontaneously passivated by an oxide layer, thus altering its physicochemical properties. We theoretically investigate how the presence of an oxide layer influences the optical properties of Cu nanoparticles. Comparisons to experimental observations infer that oxidation of CuNPs is minimal during optical trapping. By finite element modelling we map out the expected temperature increase of the plasmonic Cu nanoparticles during optical trapping and retrieve temperature increases high enough to change the catalytic properties of the particles.

Synthesis and Characterization of Surfactant Capped Copper Nanoparticles Using Natural Vitamin

Copper nanoparticles (CuNPs) have captivated amazing and renewable interest in recent years due to their fascinating features. In present investigation, CuNPs were produced by reducing copper sulphate with ascorbic acid (vitamin C) in aqueous medium without inert gas insulation at low temperature (80 ºC). In present synthetic procedure, a native vitamin C was applied as insulating agent to prevent oxidation of nascent CuNPs during the process and in storage. Triton X-100 was added that worked both as a size controller and as a capping agent. The CuNPs were characterized by UV-visible and FT-IR spectroscopies, powder X-ray diffraction (PXRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). Optical properties of Cu nanoparticles were explored using UV-vis spectroscopy. FT IR was employed to uncover the bonding between copper nanoparticles and Triton X-100. The CuNPs were discerned by PXRD and SEM-EDX Techniques. From the major diffraction peaks, the average particle size is determined using Debye-Scherer equation and it is found to be about 15 nm. It is hoped that the present results would pave a way for developing plans for the production of nascent CuNPs in the absence of inert gas insulation.

The Influence of Stabilizer on the Formation and Tribotechnical Properties of Cu Nanoparticles

The good wear-resistance of state-of-the-art liquid lubricants is due to the formation of complex metal and organometallic films onto the friction surface, reducing the friction and wear. For this purpose, various additives of metal nanopowders are used, especially ones based on copper. The formation and growth of Cu nanoparticles, as well as the tribotechnical characteristics of lubricants, are mainly affected by the choice of stabilizer, because nanoparticles cannot resist the external conditions without protecting their surface. According to quantum chemical studies, the best stabilizer in the series of gelatin, ammonia, sodium borohydride, and sodium citrate is gelatin due to the very large amount of functional groups in its structure. The characterization of physicochemical properties via dynamic light scattering, atomic force microscopy, and electron microscopy, as well as the tribotechnical characteristics of liquid lubricants with stabilized Cu nanoparticles, are consistent with quantum chemical calculations, confirming that Cu nanoparticles stabilized in gelatin possess the better tribotechnical properties than other stabilizers.

Study on the tribological behaviors of copper nanoparticles in three kinds of commercially available lubricants

PurposeThe purpose of this paper is to study the tribological properties of Cu nanoparticles (NPs) as lubricant additives in three kinds of commercially available lubricants.Design/methodology/approachA four-ball machine is used to estimate the tribological properties of Cu NPs as lubricant additives in three kinds of commercially available lubricants. Three-dimensional optical profiler and electrical contact resistance are evaluated to investigate the morphology of the worn surfaces and the influence of Cu NPs on tribofilms.FindingsWear tests show that the addition of Cu NPs as lubricant additives could reduce wear and increase load-carrying capacity of commercially available lubricants remarkably, indicating that Cu NPs have a good compatibility with the existing lubricant additives in commercially available lubricants.Originality/valueThe tribological properties of Cu NPs as lubricant additives in three kinds of commercially available lubricants were investigated in this paper. These results are reliable and can be very helpful for application of Cu NPs as lubricant additives in industry.

Theoretical Calculation of Optical Properties of Copper NANO PARTICLES

Objectives: In this work the PLASMONIC effects of Cu NANO particles with varying particle sizes and surrounding mediums, such as PEDOT: PSS layers of organic Bulk-HETEROJUNCTION (BHJ) solar cells and silica were investigated. Methods/Statistical Analysis: For this work the optical properties of Cu NANOPARTICLES with different sizes (by varying the particle diameter from 20 to 100 nm) and when surrounded by different mediums (dielectric constant in interval 1.49 to 7) were investigated in the wavelength range 300-900 nm. The Mie theory was used to analyze the light scattering and extinction efficiencies. Findings: The results show that the particle size and dielectric constant of the medium are the key factors that directly influence the PLASMONIC enhancements in the samples. At a wavelength more than 550 nm, there is a second peak of the resonance peaks, as the Cu NANO particle size increases and the efficiency peak slightly shifts to a longer wavelength. The wavelength of the resonance peak was found to haven on-linear dependence on the dielectric constant of the surrounding medium. In addition, the linear dependence of the maximum of the extinction efficiencies on the dielectric constant of the surrounding medium at a fixed particle radius was observed. Application/ Improvements: The Localized Surface PLASMON Resonance (LSPRs) exhibited by noble metal NANOPARTICLES, such as Au, Ag and Cu, leads to strong enhancements on the local electromagnetic fields surrounding the NANOPARTICLES. Keywords: Cu NANOPARTICLE, Localized Surface PLASMON Resonance, Mie Theory, PLASMONIC Enhancements

Study of synthesis and optical properties of Cu nanoparticles

Nanoparticles of Copper (Cu) have attracted great interest in recent years because of their unique physical and optical properties that are of industrial importance. To understand their basic properties, Cu nanoparticles were synthesized by Polyol method. The synthesized powder was characterized by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The average particle size and lattice parameter estimated by XRD were found to be ~42.5 nm and 3.617 Å respectively. The results suggest suitability of these nanoparticles as dopants in other materials such as polymer materials and oxides.

Non-equilibrium MD modeling and simulation to extract mechanical properties of copper nanoparticles under ultra-high strain rate loading

Molecular dynamics (MD) simulations have been carried out to evaluate the mechanical properties of Cu nanoparticles under tensile and compressive loading at ultra-high strain rate regime. Simulations have been carried out in a way analogous to real experiments; but at strain rates of magnitude several orders greater than those used in the experiments for bulk Cu. The engineering stress-strain curves obtained from tensile loading have shown an initial linear elastic region, followed by a plastic region that involves deformation by local necking. However, under the ultra-high strain rates considered in the present simulation, no uniform plastic deformation region is observed. A significant rise in temperature of the nanoparticles has been observed during the tensile and compressive deformation, as a natural consequence of any deformation process. The yield strength and Young’s modulus of Cu nanoparticles have been calculated from the engineering stress-strain curves generated by a set of MD simulations and correlated with strain rate, equilibration temperature, particle size, etc. The tensile deformation at various ultra-high strain rates shows the ductile-to-brittle transition behavior of the Cu nanoparticles after exceeding a certain critical strain velocity which decreases with the increase in particle size. The extrapolated results have indicated that the Cu nanoparticles are several times stronger than bulk Cu and their mechanical properties are highly dependent on the particle size. The present study would provide a useful guideline for the design of nanoparticles under the condition of mechanical loading in advanced applications.

Chemical synthesis, characterization and evaluation of antimicrobial properties of Cu and its oxide nanoparticles

Cu nanoparticles were synthesized using low-temperature aqueous reduction method at pH 3, 5, 7, 9 and 11 in presence of ascorbic acid and polyvinylpyrrolidone. The nanoparticles were characterized using transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction techniques. Results demonstrated a strong dependence of synthesis pH on the size, shape, chemical composition and structure of Cu nanoparticles. While lower pH conditions of 3 and 5 produced Cu0, higher pH levels (more than 7) led to the formation of Cu2O/CuO nanoparticles. The reducing capacity of ascorbic acid, capping efficiency of PVP and the resulting particle sizes were strongly affected by solution pH. The results of in vitro disk diffusion tests showed excellent antimicrobial activity of Cu2O/CuO nanoparticles against a mixture of bacterial strains (Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa), indicating that the size as well as oxidation state of Cu contributes to the antibacterial efficacy. The results indicate that varying synthesis pH is a strategy to tailor the composition, structure and properties of Cu nanoparticles.

Development of highly efficient Cu versus Pd catalysts supported on graphitic carbon materials for the reduction of 4-nitrophenol to 4-aminophenol at room temperature

In this work we report a simple procedure for synthesis of Cu and Pd catalysts supported on high surface area graphite (HSAG) by wetness impregnation technique, and further generation of metal nanoparticles using NaBH4 as reducing agent. The catalysts have been tested in the reduction of 4-nitrophenol to 4-aminophenol, at room temperature, in presence of NaBH4 as hydrogen source. Both Cu and Pd catalysts exhibited exceptionally high catalytic activity with the total degradation of 4-nitrophenol in less than 45 s. Taking into account that Cu is cheaper than Pd, we focused our investigation on studying the catalytic properties of Cu nanoparticles supported over two lab prepared graphene-materials (one N-doped and other undoped) and the commercial HSAG. The maximum catalytic activity was obtained with Cu supported on undoped graphene due to the combination of two parameters: small metal particle size and the unique properties of graphene generated by its electron transference ability. However, recyclability of both Cu/graphene-materials fell after 5 consecutive runs, while Cu/HSAG displayed high stability even after 10 cycles. In order to rationalize these findings, it is postulated that copper nanoparticles in Cu/HSAG are located at the edges of the graphite layers, where a stronger metal-support interaction takes place.

Facile synthesis and enhanced field emission properties of Cu nanoparticles decorated graphene-based emitters

Cu nanoparticles (Cu NPs) were decorated on the surface of graphene films to form composite emitters. The graphene films were deposited by electrophoretic deposition and subsequently coated with Cu NPs via electrochemical reduction. The Cu NPs decorated graphene films exhibited lower turn-on field, lower threshold field and larger field enhancement factor compared with those of the pristine films. The Cu NPs decorated graphene films also showed good emission stability. The field emission properties of Cu NPs decorated graphene films were tunable through adjusting decoration time. This graphene-based composite could be used as a possible candidate for vacuum electron source.

Analysis of Structure, Surface Morphology, Optical and Electrical Properties of Copper Nanoparticles

Copper (Cu) nanoparticles were prepared by chemical reduction method. The synthesized Cu nanoparticles were characterized with different techniques such as powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) spectrum, Transmission electron microscopy (TEM), UV-Visible spectrum and the dielectric properties of the prepared nanoparticles. The X-ray diffraction (XRD) analysis was used to study the structure and crystallite size of Cu nanoparticles. The morphology and the size of the Cu nanoparticles were characterized using Scanning Electron Microscopy and Transmission Electron Microscopy (SEM and TEM). The elemental composition of Cu nanoparticles was analyzed by Energy Dispersive X-ray (EDX) spectrum. The particle size of the Cu nanoparticles was also analyzed, using the Dynamic Light Scattering (DLS) experiment. The optical properties were studied using the UV-Visible spectrum in the wavelength range of 550 - 900 nm. The dielectric properties of Cu nanoparticles were studied at room temperature.

Physical properties of Cu nanoparticles: A molecular dynamics study

Thermodynamical, structural and dynamical properties of Cu nanoparticles are investigated by using Molecular Dynamics (MD) simulations at various temperatures. In this work, MD simulations of the Cu-nanoparticles are performed by means of the MPiSiM codes by utilizing from Quantum Sutton-Chen (Q-SC) many-body force potential to define the interactions between the Cu atoms. The diameters of the copper nanoparticles are varied from 2 nm to 10 nm. MD simulations of Cu nanoparticles are carried out at low and high temperatures to study solid and liquid properties of Cu nanoparticles. Simulation results such as melting point, radial distribution function are compared with the available experimental bulk results. Radial distribution function, mean square displacement, diffusion coefficient, Lindemann index and Honeycutt–Andersen index are also calculated for estimating the melting point of the Copper nanoparticles.

Stability and nonlinear optical properties of Cu nanoparticles prepared by femtosecond laser ablation of Cu target in alcohol and water

By using PVP of different concentrations as the protective agent, Cu nanoparticles (NPs) of different mean sizes are fabricated through laser ablation of Cu target in alcohol, water, and their mixtures. As-grown Cu NPs show good stability in alcohol. The nonlinear absorptions of Cu NPs with different mean sizes are investigated. With the increase of laser intensity, the nonlinear absorption of small NPs changes from saturable absorption (SA) to reverse saturable absorption (RSA) and two-photon absorption (TPA), whereas SA dominates the nonlinear absorption of the large NPs. The modulations of occupied and unoccupied density of states (DOS) in conduction band are proposed to be the key factors for the size-dependence of the nonlinear absorption. For the large Cu NPs, there are sufficiently occupied DOS in the ground state and unoccupied DOS in the first excited state to sustain the increase of SA, whereas for the small Cu NPs, the corresponding DOS is insufficient, so the SA is surpassed by the RSA and TPA at high laser excitation intensity.

Synthesis of nanoparticles in SiO2 by implantation of Cu and Zn ions and their thermal stability in oxygen atmoshphere

Cu nanoparticles (NPs) embedded in silica were synthesized by implantation of 45 keV Cu ions at a fluence of 1.01017 cm-2, and then subjected to post irradiation with 50 keV Zn ions at fluences of 0.51017 cm-2 and 1.01017 cm-2, respectively. Zn post ion implantation induced modifications in structures, optical absorption properties of Cu NPs as well as their thermal stability in oxygen ambient have been investigated in detail. Results clearly show that Cu-Zn alloy NPs could be formed in the Cu pre-implanted silica followed by Zn ion irradiation at a fluence of 0.51017 cm-2, which causes an unique surface plasmon resonance (SPR) absorption peak at about 516 nm. Subsequent annealing in oxygen atmosphere results in the decomposition of Cu-Zn alloy NPs, at 450 ℃, and thus, ZnO and Cu NPs appear in the substrate. Further increase of annealing temperature to 550 ℃ could transform all the Zn and Cu into ZnO and CuO. Moreover, results also demonstrate that introduction of Zn into SiO2 substrate could effectively suppress the oxidation of Cu NPs, meanwhile, the existence of Cu could promote thermal diffusion of Zn towards substrate surface, which enhances the oxidation of Zn. The underlying mechanism has been discussed.