Size Of Copper Nanoparticles Research Articles

Size-dependent biological effects of copper nanopowders on mustard seedlings

Correlation between the size of copper nanoparticles and effects they produce on white mustard seedlings were studied in the paper. Copper nanopowders with average particle sizes of 45 and 200 nm with concentrations of 0.01–1000 wt ppm of seeds were used to treat white mustard seeds. Nonlinear dose effects were displayed by copper nanopowders obtained by chemical synthesis with the particle size of 35-60 nm. For 45 nm nanoparticles the highest biological activity with regard to germinating energy, 3-day stem and root weight was registered at 5.0 wt ppm concentration, while for root length and weight of the 7-day stems the 1.0 wt ppm concentration had the most pronounced effect. Copper submicron powder with average particle size of 200 nm displayed some effect only after 7th day of the experiment at high concentrations (from 100 to 1000 wt ppm) according to the measurements of length and weight of the seedlings. The obtained results can be used in the development of copper nanoparticles-based preparations for pre-sowing treatment of seeds.

Физико-химические и биологические свойства ассоциатов наночастиц меди

Проведено исследование физико-химических параметров ассоциатов не стабилизированных наночастиц (НЧ) меди, полученных плазмохимическим способом. Для определения размеров ассоциатов НЧ использовали оптические методы, включая атомно-силовую микроскопию, спектрофотометрию и флюорометрию. Размеры НЧ меди варьировали от 30 до 75 нм, а размеры ассоциатов НЧ — от 481.1 до 1037 нм. Проведен анализ фазового состава НЧ меди методом рентгеновской дифрактометрии с использованием многофункционального рентгеновского дифрактометра Rigaku Ultima IV. На поверхности ассоциатов НЧ обнаружена оксидная пленка без примеси органических молекул. Изучали действие НЧ меди на культуру клеток А549. Обнаружено изменение биохимических показателей сыворотки крови белых беспородных мышей под влиянием НЧ меди. Выявлен противоопухолевый эффект НЧ меди и сопоставлена его выраженность при разных способах введения НЧ животным с фибросаркомой (С-45) и лимфосаркомой Плисса.

Ferromagnetism and giant paramagnetism of copper nanoparticles in Cum/C nanocomposites

Abstract Carbon coated copper nanoparticles, Cum/C nanocomposites, were synthesized using solid-phase pyrolysis in solid solutions of copper phthalocyanine and metal free copper phthalocyanine, (CuPc)x(H2Pc)1−x where 0 ⩽ x ⩽ 1 . The weight concentration of copper in percentages consistently varies from 0 to 12 wt% and the sizes of copper nanoparticles in samples changes from 2 nm to 500 nm. Samples containing 8 and 12 wt% Cu have a bimodal size distribution. The X-ray diffraction data and HRTEM images show a face-centered cubic structure of Cu nanocrystallites that uniformly distributed in the carbon matrix. The temperature and field dependences of the magnetization in all copper-containing samples exhibit both ferromagnetic and giant-paramagnetic properties in the measured temperature range of 10–300 K. The saturation magnetization of ferromagnetic nanoparticles falls in the range 0.2–1.5 emu/g and weakly depends on the temperature from helium up to the room temperatures. The paramagnetic magnetizations in Cu/C nanocomposites at H = 50 kOe and T = 10 K are practically an order of magnitude higher in all the samples than the ferromagnetic saturation magnetizations. The paramagnetic susceptibilities of the Cum/C nanocomposites at 10 K are of the order of (0.3–1)10−4 emu/gCuOe, which are one and a half to two orders of magnitude higher than the specific paramagnetic susceptibility of the carbon matrix.

A New Portable In Vitro Exposure Cassette for Aerosol Sampling.

This protocol introduces a new in vitro exposure system, capable of being worn, including its characterization and performance. Air-liquid interface (ALI) in vitro exposure systems are often large and bulky, making transport to the field and operation at the source of emission or within the breathing zone difficult. Through miniaturization of these systems, the lab can be brought to the field, expediting processing time and providing a more appropriate exposure method that does not alter the aerosol prior to contacting the cells. The Portable In vitro Exposure Cassette (PIVEC) adapts a 37 mm filter cassette to allow for in vitro toxicity testing outside of a traditional laboratory setting. The PIVEC was characterized using three sizes of copper nanoparticles to determine deposition efficiency based on gravimetric and particle number concentration analysis. Initial cytotoxicity experiments were performed with exposed lung cells to determine the ability of the system to deposit particles while maintaining cell viability. The PIVEC provides a similar or increased deposition efficiency when comparing to available perpendicular flow in vitro exposure devices. Despite the lower sample throughput, the small size gives some advantages to the current in vitro ALI exposure systems. These include the ability to be worn for personal monitoring, mobility from the laboratory to the source of emission, and the option to set-up multiple systems for spatial resolution while maintaining a lower user cost. The PIVEC is a system capable of collecting aerosols in the field and within the breathing zone onto an air-interfaced, in vitro model.

Mechanism and structure sensitivity of methanol synthesis from CO2 over SiO2-supported Cu nanoparticles

The size of copper nanoparticles affects the intrinsic rate of methanol and CO formation in the hydrogenation of CO2 at 230–270 °C and total pressure 8 bar. Cu/SiO2 catalysts with different mean Cu particle sizes were prepared by water-in-oil microemulsions and suitably pretreated to obtain samples with mean particle size between 4 and 36 nm. The intrinsic rates of methanol and CO formation are 3-fold higher for large particles (>10 nm) than for smaller ones (ca. 4 nm). The reaction path was studied by means of kinetic experiments, H/D isotopic substitution, and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS). Results demonstrate that the hydrogenation of formic acid is the rate-determining step (rds) for methanol synthesis, whereas for CO formation the reaction proceeds with the assistance of H atoms and the dissociation of the carboxyl intermediate is the rds. This reaction scheme implies that the ratio of CO to methanol formation rates is inversely proportional to H2 partial pressure, which is also consistent with results for similar catalysts reported in earlier studies. The similar kinetic parameters and H/D kinetic isotope effect observed for catalysts with significantly different Cu mean particle sizes suggests that active surface sites have similar topology regardless of Cu particle size. Step-edge sites whose relative abundance increases with particle size in a way similar to activity are suggested as the active sites for methanol and CO formation reactions.

Optical emission spectroscopy for studying the exploding copper wire plasma parameters in distilled water

This work aims to study the exploding copper wire plasma parameters by optical emission spectroscopy. The emission spectra of the copper plasma have been recorded and analyzed The plasma electron temperature (Te), was calculated by Boltzmann plot, and the electron density (ne) calculated by using Stark broadening method for different copper wire diameter (0.18, 0.24 and 0.3 mm) and currentof 75A in distilled water. The hydrogen (Hα line) 656.279 nm was used to calculate the electron density for different wire diameters by Stark broadening. It was found that the electron density ne decrease from 22.4×1016 cm-3 to 17×1016 cm-3 with increasing wire diameter from 0.18 mm to 0.3 mm while the electron temperatures increase from 0.741 to 0.897 eV for the same wire diameters. The optical emission spectrum (OES) emitted from the plasma have Hα line, small peak at 590 nm corresponding to sodium and others peaks belong to Cu I. The relationship between the plasma electron temperature, emission line intensity and number density with the formed copper nanoparticles size and concentration were studied. It was found that the nanoparticles concentration increase with emission line intensity while its size decrease. It can be conclude the existence of a controlled relationship between the plasma parameters and the formed nanoparticles concentration and size.

Effect of Production Conditions on the Size of Copper Nanoparticles and the Modes of Ignition and Combustion of a Copper Nanopowder in Air

Copper nanoparticles were produced by a chemical metallurgical method and by the thermal decomposition of copper citrate and formate. It was shown that the copper nanopowder obtained from copper citrate is not pyrophoric. Combustion of this copper nanopowder can be initiated by an external source, and the combustion wave velocity is 1.3 ± 0.3 mm/s. The specific surface area (45 ± 5 m2/g) of the copper nanopowder obtained from copper citrate is almost four times as large as that of the nanopowder produced by a chemical metallurgical method. The former nanopowder contains almost no oxides and is stable in atmospheric air, whereas the latter nanopowder is pyrophoric and, therefore, requires passivation, but its passivation gives rise to noticeable amounts of copper oxides. The combustion velocities of the passivated and unpassivated copper nanopowders are almost equal and are 0.3 ± 0.04 mm/s. The dynamics of the temperature fields in ignition and combustion of the copper nanopowders obtained by different methods was studied.

Influence of conditions of synthesis on the size of copper nanoparticles and on the modes of ignition and combustion of copper nanopowder in the air

Influence of conditions of synthesis on the size of copper nanoparticles and on the modes of ignition and combustion of copper nanopowder in the air

SYNTHESIS OF COPPER-BASED NANOPARTICLE CATALYSTS BY DIFFERENT METHODS FOR TOTAL OXIDATION OF VOC

In this paper, the process of preparing 10 wt.% Cu/g-Al2O3 catalysts was studied by different methods. The changes in structure and texture of the catalysts were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier-transform infrared spectroscopy (FT-IR). The activities of catalyst were investigated completely oxidized VOC (toluene and n-butanol) on gas-phase reactions over the Cu/g-Al2O3 catalyst. The results were found that influence of the size of copper nanoparticles enhancing copper dispersion and selectivity of the catalyst prepared by non-thermal plasma (NTP) was superior to those obtained from the impregnation (WI) and deposition-precipitation (DP). The total oxidation of VOC to CO2 and H2O was achieved above 275oC. Compared to the WI and DP, the NTP method increased the oxidation efficiency by 15-30%.

Effect of Electrolyte Concentration during Solution Plasma on Copper Nanoparticle Size

This research was conducted to investigate the effect of electrolyte concentration of solution plasma on copper nanoparticles size. Copper nanoparticles with the size between 1-100 nm have received a huge interest because of their optical, catalytic and electrical conducting properties. Electrolysis via solution plasma method has many advantages such as its cost effectiveness, simplicity, eco-friendliness, and less energy requirements compared to other methods. To synthesize copper nanoparticles via solution plasma, two wires of copper and platinum as cathode and anode respectively were immersed in a glass beaker of 300 ml of two electrolyte solution (K2CO3 and NaOH) with three different concentrations (0.1 M, 0.5M and 1M), and electrical current was applied similar to an electrolysis process. The images of the nanoparticles were obtained using scanning electron microscopy and their sizes were analyzed using ImageJ software. It was found that when the concentration of K2CO3 increased, the size of copper nanoparticle also increased. However, the size of copper nanoparticles decreased when the concentration of NaOH was increased. This research shows the potential of easily controlling size of copper nanoparticles by changing the electrolyte concentration used during solution plasma process.

Probing Adhesion of Metallic Nanoparticles on Polymeric Fibrous and Flat Architectures

The exotic characteristics of nanoscopic metallic materials bestows diverse functionalities that are increasingly being utilized for a broad range of applications. Polymer substrates present robust architectures for nanoparticle anchoring as well as modulating attendant size-induced aggregation. However, in principle, interfacial adhesion of a polymer-metal material system is weak, making the susceptibility to delamination a challenge. We have deposited copper particles on model polymer thin film and fibrous architectures to study adhesion behavior on these distinct geometries. The average sizes of copper nanoparticles deposited on electrospun fibers for metallization times of 3 and 5 minutes were 13 and 10 nm, whereas the metal island sizes under same metallization times on thin films was 79nm and 81nm. Scratch tests using a nanoindentation system were unable to generate macroscopic film delamination, but did exhibit apparent removal of individual particles, with adhesion forces of 14.9μN, 36μN, and 28.8μN obtained for films metallized for 1, 3, and 5 minutes respectively. Macroscopic tensile testing of fiber mats showed the metallization maintains conformity with the polymer ligament, albeit, with intermittent fracture of the conformal metal coating, signifying substantial adhesion exists between the metallic layer and the PAN fiber.

Optimization of copper nanoparticles synthesis using E. coli and the study of its antifungal activity

Objective (s): The green synthesis of copper nanoparticles using metabolites of microorganisms has gained much interest in recent years. In this work, it was studied optimization of copper nanoparticles synthesis using E. coli and its antifungal activity.Materials and Methods: The copper nanoparticles were synthesized by Escherichia coli. Effect of copper nitrate concentration and temperature was studied on size and production efficiency. In addition, copper nanoparticles were analyzed by UV – VIS spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Finally, the antifungal properties of synthesized nanoparticles were tested against Penicillium by disc diffusion method in different concentrations of nanoparticles.Results: It was found that initial concentration of copper nitrate plays a key role in formation of nanoparticles. Also, it was indicated that in lower temperatures, the size of copper nanoparticles is smaller and their distribution is narrower. It was determined the concentration of 15% w/v of copper nanoparticles in distilled water is optimum concentration for the maximum of antifungal activity. Conclusion: The biosynthesized copper nanoparticles displayed antifungal activity against Penicillium. The experiments showed the usability of these nanoparticles in water purification, air purification and antifungal packaging.

Recycling copper nanoparticles from printed circuit board waste etchants via a microemulsion process

Abstract Recently, over 60 million liters of 10–15% copper-containing waste etchants (CCWEs) solution generated from printed circuit board (PCB) manufacturing are disposed of in Taiwan annually. The CCWEs are mainly composed of copper chloride, hydrochloric acid, and water. Since the disposal of etchants without proper treatment has posed an environmental problem, expensive separation or storage methods have been previously used; however, these have not been effective or successful. Therefore, the resource recovery of these undesired waste etchants in the form of copper nanoparticles would be economically and environmentally attractive. Experimentally, copper nanoparticles have been recovered from CCWEs by microemulsion at controllable ambient temperature and pressure. The properties of copper nanoparticles were further analyzed using XRPD, FE–SEM, TEM or XANES/EXAFS spectroscopy. From the FE–SEM or TEM microphotos, most spherical-shaped nanoparticles with diameters of 20–50 nm were observed. It showed that these nanoparticles were well dispersed and without any agglomeration. Moreover, the pH values increased with decreasing particle sizes of copper nanoparticles in the synthetic processes. The XRPD patterns showed that the nanophase precipitates have metallic copper and Cu2O crystalline structures. The existence of the Cu(0) or Cu(I) was also confirmed by XANES or XPS spectroscopy. The metallic Cu and Cu2O nanoparticles with a cubic lattice structure were observed by EPR. The synthesized copper nanoparticle with a CueO (Cu–(O)eCu) bond distance of 1.85 ± 0.02 A (2.69 ± 0.02 A) and a coordination number of 1.39 ± 0.25 (3.5 ± 0.25) was also measured by EXAFS spectroscopy. The surface of the synthesized copper nanoparticles was modified using lauric acid sodium and dispersed in water for over 7 h after ultrasonic dispersion treatment. Thermal conductivity of nanofluid containing copper nanoparticles was proportional to the weight percent of copper nanoparticles. A designed production process of copper nanoparticles for industrial PCB waste etchant recycling via a microemulsion method was also proposed. Payback of 10-TPD and 20-TPD recycling processes of PCB waste etchants for copper nanoparticle production were 2.63 and 2.35 years, respectively.

Copper nanoparticles toxicity: Laboratory strains verses environmental bacterial isolates

ABSTRACTNanoparticles have emerged as significant environmental contaminants and their impact has been studied using laboratory strains of bacteria. This study focuses on investigating the response of environmental isolate and laboratory strains of E. coli to 50 and 100 nm size of copper nanoparticles (CuNPs). The laboratory cultures included pathogenic and non-pathogenic strains. The environmental isolate and the non-pathogenic E. coli strain showed different inactivation patterns. After 2 h exposure to 50 nm CuNPs, the environmental isolate and the lab strain of E. coli lost 7.22 and 6.47 log; whereas the reduction of 6.16 and 6.68 log resulted after exposure to 100 nm CuNPs, respectively. The pathogenic E. coli O157:H7 exposed to 50 and 100 nm CuNPs for 2 h resulted in 5.24 and 6.54 log reduction, respectively. Although the environmental isolate and the laboratory strains of E. coli showed similar inactivation trends; they exhibited different toxicity elicitation mechanisms after exposure to the CuNPs. The pathogenic and non-pathogenic strains elicited significantly different levels of glutathione reductase (GR) activities, an enzyme critical for protection against radicals. Similarly, the environmental isolate and the lab strains of E. coli exhibited opposite trend in GR activities. These results clearly indicate divergence in the toxicity elicitation in the environmental isolate versus the laboratory strains from exposure to CuNPs, which highlights the need for an in-depth investigation of the impact of NPs on the biological processes and long-term effect of high load of NPs on the stability of aquatic and terrestrial ecologies.

Synthesis of Cu-CuO nanocomposite in microreactor and its application to photocatalytic degradation

The nanocomposite of Cu-CuO is successfully prepared via controlled oxidation of Cu nanoparticles synthesized by liquid-phase reduction in a microreactor. The particle's morphology, size, and elemental compositions have been investigated. Experimental results demonstrate that copper nanoparticles are spherical in shape, with good dispersion and narrow particle size distribution. The surface of Cu nanoparticles was oxidized to CuO, and the size of Cu-CuO composites crystallites was around 10 nm, consistent with the size of copper nanoparticles. The prepared Cu-CuO nanocomposite along with the presence of H2O2 exhibits excellent photocatalytic activity for degradation of methylene blue (MB) under UV irradiation. An overall degradation of 98.5% could be achieved with 10 mg of Cu-CuO nanocomposite along with 1 mL of H2O2, within duration of 50 min irradiation. The MB degradation kinetics was observed to follow first order.

Copper nanoparticles catalyzed oxidation of threonine by peroxomonosulfate

The undertaken study describes the synthesis of copper nanoparticles (Cunps) in an aqueous medium using ascorbic acid as a reducing agent via the chemical reduction method. The synthesized copper nanoparticles have resistance to oxidation by atmospheric oxygen for two months. The copper nanoparticles were characterized by UV–Visible spectrophotometry, FTIR spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average sizes of copper nanoparticles were found to be 28, 16, 12nm at increasing concentrations of l-ascorbic acid respectively. Interestingly, it was found that, the catalytic activity depends on the size of nanoparticles. The catalysis by colloidal copper nanoparticles was studied kinetically with the oxidation of l-threonine (Thr) by peroxomonosulfate (PMS) in aqueous medium. The oxidation rate was found to follow first order kinetics with respect to threonine and peroxomonosulfate. The copper nanoparticles are expected to be a suitable alternative and play an important role in the field of catalysis and environmental remediation.

Synthesis and size control of copper nanoparticles and their catalytic application

The synthesis and catalytic properties of copper nanoparticles (Cunps) were reported using L-ascorbic acid as reducing and capping agent in aqueous medium. The effect of different concentrations of L-ascorbic acid on the particle size of Cunps was investigated. The synthesized Cunps were characterized by UV-Visible spectrophotometer, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectrophotometer. The result indicates that the size of copper nanoparticles decreases with the increase in concentration of L-ascorbic acid. L-Ascorbic acid plays an important role to protect the copper nanoparticles from oxidation and agglomeration which helps nanoparticles to get better stability for the application. The synthesized Cunps show excellent catalytic activity in the oxidation of serine (Ser) by peroxomonosulphate (PMS). The catalytic activity of Cunps increases with the decrease in size of Cunps. The Cunps are expected to be suitable alternative and play an imperative role in the fields of catalysis and environmental remediation.

Simulation and modeling of synthesis Cu nanoparticles in sodium alginate media by means of expert systems

This research was to apply the combination of the particle swarm optimization method and artificial neural network training with the aim of building a quantitative model to forecast the size of copper nanoparticles (Cu-NPs) prepared in sodium alginate. Sodium alginate, sodium hydroxide, copper sulfate, hydrazinium hydroxide, and ascorbic acid were used as stabilizer, pH moderator, copper precursor, reducing agent, and antioxidant, respectively. The results showed that the different sizes of Cu-NPs were obtained by changing these functions. Meaning that by increasing the amount of sodium alginate and or increase the volume of hydrazine hydrate, particle sizes of Cu-NPs were reduced. Other variables had the opposite effects due to the increase of the size of the Cu-NPs. The prediction results were remarkably in agreement with the experimental data with a correlation coefficient of 0.99 and a mean square error of 0.0058.

Assessing toxicity of copper nanoparticles across five cladoceran species.

As a result of ever increasing applications, nanoparticles will eventually end up in the environment. However, currently no common principle has been established to help understand the toxicity of nanoparticles (NPs) across species. Therefore, it is difficult to estimate the potential risks of nanoparticles to untested species in the environment. The authors exposed 4 different sizes of copper nanoparticles (CuNPs) and 1 submicron-sized copper particle to 5 cladoceran species (Daphnia magna, Daphnia pulex, Daphnia galeata, Ceriodaphnia dubia, and Chydorus sphaericus) to investigate whether morphological attributes of species can help to assess the acute toxicity of CuNPs across species. The results showed that rod-shaped CuNPs caused much lower toxicity to all species than spherical CuNPs. Both the particles and ions contributed to the total toxicity of the CuNP suspensions. Moreover, the toxicity caused by particles in 5 different copper suspensions increases with decreasing body length, surface area, and body volume of neonates of 5 cladoceran species. Especially the correlations between body volume of the 5 cladoceran species tested and the corresponding toxicity caused by 5 different CuNPs were statistically significant, and in all cases radj (2) was higher than 0.51 (p < 0.001). The highest correlation was found between body volume and the toxicity of the 78-nm CuNPs (radj (2) = 0.95, p < 0.001). To conclude, the correlations between attributes of cladoceran species and the toxicity of CuNPs reported in the present study evoke the possibility to assess and extrapolate the toxicity of nanoparticles across species with similar attributes.

Kinetic Mechanism on Synthesis of Copper Nanoparticle from Reduction Reaction - Effect of Temperature

Copper nanoparticles, due to their interesting properties, low cost preparation and many potential applications in catalysis, cooling fluid or conductive inks, have attracted a lot of interest in recent years. In this study, copper nanoparticles were synthesized through the palm leaves extract that act as reducing agent. In this synthesis route, the hydroxyl groups of the polyphenols in palm extract are capable to act as reducing agent for reduction reaction. The effect of temperature given starting with control parameters at room temperature proceeds to 40, 50, 60, 70 and 80°C with the time length of 2 hours and 10 milimol copper nitrate aqueous solution. Characterization had been conducted using the instrument of UV-vis spectrophotometer, FTIR and ESEM. The average size of all powder nanoparticles was found to 109, 86, 196, 133, 241, and 230nm accordingly from room temperature till 80°C. The correspondence analysis of the results yielded that the optimum temperature was at 40°C which is 86nm of average copper nanoparticle size.