Laser-Induced, Local Oxidation of Copper Nanoparticle Films During Raman Measurements

Science.gov (United States)

Hight Walker, Angela R.; Cheng, Guangjun; Calizo, Irene

2011-03-01

The optical properties of gold and silver nanoparticles and their films have been thoroughly investigated as surface enhanced Raman scattering (SERS) substrates and chemical reaction promoters. Similar to gold and silver nanoparticles, copper nanoparticles exhibit distinct plasmon absorptions in the visible region. The work on copper nanoparticles and their films is limited due to their oxidization in air. However, their high reactivity actually provides an opportunity to exploit the laser-induced thermal effect and chemical reactions of these nanoparticles. Here, we present our investigation of the local oxidation of a copper nanoparticle film induced by a visible laser source during Raman spectroscopic measurements. The copper nanoparticle film is prepared by drop-casting chemically synthesized copper colloid onto silicon oxide/silicon substrate. The local oxidation induced by visible lasers in Raman spectroscopy is monitored with the distinct scattering peaks for copper oxides. Optical microscopy and scanning electron microscopy have been used to characterize the laser-induced morphological changes in the film. The results of this oxidation process with different excitation wavelengths and different laser powers will be presented.

One-pot production of copper ferrite nanoparticles using a chemical method

Energy Technology Data Exchange (ETDEWEB)

Nishida, Naoki, E-mail: nnishida@rs.tus.ac.jp; Amagasa, Shota [Tokyo University of Science, Department of Chemistry (Japan); Kobayashi, Yoshio [The University of Electro-Communications, Department of Engineering Science (Japan); Yamada, Yasuhiro [Tokyo University of Science, Department of Chemistry (Japan)

2016-12-15

Copper ferrite nanoparticles were synthesized via the oxidation of precipitates obtained from the reaction of FeCl{sub 2}, CuSO{sub 4} and N{sub 2}H{sub 4} in the presence of gelatin. These copper ferrite particles were subsequently examined using powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and Mössbauer spectroscopy. The average size of the copper ferrite nanoparticles was less than 5 nm, and they exhibited superparamagnetic behavior as a result of their small size. The low temperature Mössbauer spectrum exhibited three sets of sextets, two corresponding to the tetrahedral and octahedral sites of the copper spinel structure and one with small hyperfine magnetic field corresponding to the surface or defects of the nanoparticles. When the ratio of copper salt was increased, the tetrahedral site became preferable for copper, and metallic copper and copper ferrite were both present in a single nanoparticle.

Incorporation of copper nanoparticles into paper for point-of-use water purification

OpenAIRE

Dankovich, Theresa A.; Smith, James A.

2014-01-01

As a cost-effective alternative to silver nanoparticles, we have investigated the use of copper nanoparticles in paper filters for point-of-use water purification. This work reports an environmentally benign method for the direct in situ preparation of copper nanoparticles (CuNPs) in paper by reducing sorbed copper ions with ascorbic acid. Copper nanoparticles were quickly formed in less than 10 minutes and were well distributed on the paper fiber surfaces. Paper sheets were characterized by ...

Thermal Properties of Polymethyl Methacrylate Composite Containing Copper Nanoparticles.

Science.gov (United States)

Yu, Wei; Xie, Huaqing; Xin, Sha; Yin, Junshan; Jiang, Yitong; Wang, Mingzhu

2015-04-01

Thermal functional Materials have wide applications in thermal management fields, and inserting highly thermal conductive materials is effective in enhancing thermal conductivity of matrix. In this paper, copper nanoparticles were selected as the additive to prepare polymethyl methacrylate (PMMA) based nanocomposite with enhanced thermal properties. Uniform copper nanoparticles with pure face-centered lattice were prepared by liquid phase reduction method. Then, they were added into PMMA/N, N-Dimethylmethanamide (DMF) solution according to the different mass fraction for uniform dispersion. After DMF was evaporated, Cu-PMMA nanocomposites were gained. The thermal analysis measurement results showed that the decomposition temperature of nanocomposites decreased gradually with the increasing particle loadings. The thermal conductivity of the Cu-PMMA nanocomposites rose with the increasing contents of copper nanoparticles. With a 20 vol.% addition, the thermal conductivity was up to 1.2 W/m · K, a 380.5% increase compared to the pure PMMA. The results demonstrate that copper nanoparticles have great potential in enhancing thermal transport properties of polymer.

Preparation and structure of carbon encapsulated copper nanoparticles

International Nuclear Information System (INIS)

Hao Chuncheng; Xiao Feng; Cui Zuolin

2008-01-01

Carbon-encapsulated copper nanoparticles were synthesized by a modified arc plasma method using methane as carbon source. The particles were characterized in detail by transmission electron microscope, high-resolution transmission electron microscopy, selected-area electron diffraction, X-ray diffraction, thermogravimetric and differential scanning calorimetry. The encapsulated copper nanoparticles were about 30 nm in diameter with 3-5 nm graphitic carbon shells. The outside graphitic carbon layers effectively prevented unwanted oxidation of the copper inside. The effect of the ratio of He/CH 4 on the morphologies and the formation of the carbon shell were investigated

Kinetic formation of silver-copper nanoparticles and its characterization

Science.gov (United States)

Zulkafi, Nurul Hikmah; Idrus, Nor Faeqah; Jai, Junaidah; Hadi, Abdul

2017-12-01

A study of the kinetic formation of silver-copper nanoparticles in aqueous medium on the basis of size distribution and its characterization has been carried out and reported in this paper. The Ag-Cu nanoparticles were synthesized through polyol method that using Ethylene Glycol (H2C6O12) as a reduction agent and solvent and Polyoxyethylene-(80)-Sorbitan Monooleate (Tween 80) as a stabilizer. The kinetic formation of Ag-Cu nanoparticles was observed using Dynamic Light Scattering (DLS) and characterized by using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscope (TEM). The XRD analysis results confirmed that size distribution was strongly dependent on molarity of precursors of silver (AgNO3) and copper (Cu(NO3)2.3H2O). The FESEM and TEM analysis indicated the existence of Ag and Cu nanoparticles in the core-shell shape. The silver-copper nanoparticles were spherical and uniform particles size with the average size of about 28 nm and 38 nm for silver and copper, respectively. DLS observation showed the growth of nanoparticles at the temperature of 140°C as the effect of reaction time at 1, 2, 3, 4 and 5 hours.

Copper nanoparticles functionalized PE: Preparation, characterization and magnetic properties

International Nuclear Information System (INIS)

Reznickova, A.; Orendac, M.; Kolska, Z.; Cizmar, E.; Dendisova, M.; Svorcik, V.

2016-01-01

Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Copper nanoparticles were coated on polyethylene via dithiol interlayer. • Prepared samples exhibit excellent structural and magnetic properties. • Studied properties may be utilized in design and fabrication of electronic devices. - Abstract: We report grafting of copper nanoparticles (CuNP) on plasma activated high density polyethylene (HDPE) via dithiol interlayer pointing out to the structural and magnetic properties of those composites. The as-synthesized Cu nanoparticles have been characterized by high-resolution transmission electron microscopy (HRTEM/TEM) and UV–vis spectroscopy. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, energy dispersive X-ray spectroscopy (EDS), zeta potential, electron spin resonance (ESR) and SQUID magnetometry. From TEM and HRTEM analyses, it is found that the size of high purity Cu nanoparticles is (12.2 ± 5.2) nm. It was determined that in the CuNPs, the copper atoms are arranged mostly in the (111) and (200) planes. Absorption in UV–vis region by these nanoparticles is ranging from 570 to 670 nm. EDS revealed that after 1 h of grafting are Cu nanoparticles homogeneously distributed over the whole surface and after 24 h of grafting Cu nanoparticles tend to aggregate slightly. The combined investigation of magnetic properties using ESR spectrometry and SQUID magnetometry confirmed the presence of copper nanoparticles anchored on PE substrate and indicated ferromagnetic interactions.

Copper nanoparticles functionalized PE: Preparation, characterization and magnetic properties

Energy Technology Data Exchange (ETDEWEB)

Reznickova, A., E-mail: alena.reznickova@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic); Orendac, M., E-mail: martin.orendac@upjs.sk [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Kolska, Z., E-mail: zdenka.kolska@seznam.cz [Faculty of Science, J.E. Purkyne University, 400 96 Usti nad Labem (Czech Republic); Cizmar, E., E-mail: erik.cizmar@upjs.sk [Faculty of Science, P.J. Safarik University, Park Angelinum 9, 04013 Kosice (Slovakia); Dendisova, M., E-mail: vyskovsm@vscht.cz [Department of Physical Chemistry, University of Chemistry and Technology Prague, 166 28 Prague 6 (Czech Republic); Svorcik, V., E-mail: vaclav.svorcik@vscht.cz [Department of Solid State Engineering, University of Chemistry and Technology, 166 28 Prague 6 (Czech Republic)

2016-12-30

Highlights: • Polyethylene (PE) surface was activated by argon plasma discharge. • Copper nanoparticles were coated on polyethylene via dithiol interlayer. • Prepared samples exhibit excellent structural and magnetic properties. • Studied properties may be utilized in design and fabrication of electronic devices. - Abstract: We report grafting of copper nanoparticles (CuNP) on plasma activated high density polyethylene (HDPE) via dithiol interlayer pointing out to the structural and magnetic properties of those composites. The as-synthesized Cu nanoparticles have been characterized by high-resolution transmission electron microscopy (HRTEM/TEM) and UV–vis spectroscopy. Properties of pristine PE and their plasma treated counterparts were studied by different experimental techniques: X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, energy dispersive X-ray spectroscopy (EDS), zeta potential, electron spin resonance (ESR) and SQUID magnetometry. From TEM and HRTEM analyses, it is found that the size of high purity Cu nanoparticles is (12.2 ± 5.2) nm. It was determined that in the CuNPs, the copper atoms are arranged mostly in the (111) and (200) planes. Absorption in UV–vis region by these nanoparticles is ranging from 570 to 670 nm. EDS revealed that after 1 h of grafting are Cu nanoparticles homogeneously distributed over the whole surface and after 24 h of grafting Cu nanoparticles tend to aggregate slightly. The combined investigation of magnetic properties using ESR spectrometry and SQUID magnetometry confirmed the presence of copper nanoparticles anchored on PE substrate and indicated ferromagnetic interactions.

Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

International Nuclear Information System (INIS)

Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna; Jana, Madhurya; Pramanik, Panchanan; Karmakar, Parimal

2014-01-01

Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

Energy Technology Data Exchange (ETDEWEB)

Laha, Dipranjan; Pramanik, Arindam [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Laskar, Aparna [CSIR-Indian Institute of Chemical Biology, Kolkata 700032 (India); Jana, Madhurya [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India); Pramanik, Panchanan [Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India); Karmakar, Parimal, E-mail: pkarmakar_28@yahoo.co.in [Department of Life Science and Biotechnology, Jadavpur University, 188, Raja S C Mallick Road, Kolkata 700032 (India)

2014-11-15

Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.

Revealing the Formation of Copper Nanoparticles from a Homogeneous Solid Precursor by Electron Microscopy

DEFF Research Database (Denmark)

van den Berg, Roy; Elkjær, Christian Fink; Gommes, Cedric J.

2016-01-01

The understanding of processes leading to the formation of nanometer-sized particles is important for tailoring of their size, shape and location. The growth mechanisms and kinetics of nanoparticles from solid precursors are, however, often poorly described. Here we employ transmission electron...... microscopy (TEM) to examine the formation of copper nanoparticles on a silica support during the reduction by H2 of homogeneous copper phyllosilicate platelets, as a prototype precursor for a coprecipitated catalyst. Specifically, time-lapsed TEM image series acquired of the material during the reduction...... process provide a direct visualization of the growth dynamics of an ensemble of individual nanoparticles and enable a quantitative evaluation of the nucleation and growth of the nanoparticles. This quantitative information is compared with kinetic models and found to be best described by a nucleation...

Gold and gold-copper nanoparticles in 2-propanol: A radiation chemical study

International Nuclear Information System (INIS)

Dey, G.R.

2011-01-01

The studies on the reduction of Au 3+ to gold nanoparticles in presence and absence of Cu 2+ under deoxygenated conditions in 2-propanol by radiolytic method have been carried out. On γ-radiolysis, preliminary yellow colored solution of Au 3+ changed to purple color owing to gold nanoparticles formation, which exhibits an absorption peak at around 540 nm. In the presence of Cu 2+ , absorption of gold-copper nanoparticles, which was also produced during γ-radiolysis, was red shifted in contrast to the system containing no Cu 2+ . Under DLS studies the sizes of gold nanoparticles in the absence and the presence of Cu 2+ were found to be larger (>400 nm). However, in presence of polyethylene glycol, a stabilizer the nanoparticle sizes became smaller, sizes measured for gold and gold-copper nanoparticles are 40 and 140 nm, respectively. Moreover, the change in UV-vis spectra in the Cu 2+ and Au 3+ mixed system highlights the formation of gold-copper nanoparticles in core-shell type arrangement. - Highlights: → Present radiation chemical study highlights high reactivity of Au ·2+ with Cu 2+ . → Absorption of gold-copper nanoparticles is blue shifted as compared to copper nanoparticles. → Change in UV-vis spectra with dose emphasizes core-shell type arrangement of Au-Cu nanoparticles.

Copper nanoparticle modified carbon electrode for determination of dopamine

International Nuclear Information System (INIS)

Oztekin, Yasemin; Tok, Mutahire; Bilici, Esra; Mikoliunaite, Lina; Yazicigil, Zafer; Ramanaviciene, Almira; Ramanavicius, Arunas

2012-01-01

This paper reports the synthesis and characterization of copper nanoparticles (CuNPs) and application of copper nanoparticle-modified glassy carbon electrode for the electrochemical determination of dopamine. Electrochemical measurements were performed using differently modified glassy carbon (GC) electrodes. Bare, oxidized before modification and copper nanoparticle-modified glassy carbon electrodes (bare-GC, ox-GC and CuNP/GC electrodes, respectively) were characterized by cyclic voltammetry and electrochemical impedance spectroscopy in the presence of redox probes. Atomic force microscopy was used for the visualization of electrode surfaces. The CuNP/GC electrode was found to be suitable for the selective determination of dopamine even in the presence of ascorbic acid, uric acid, and p-acetamidophenol. The observed linear range of CuNP/GC for dopamine was from 0.1 nM to 1.0 μM while the detection limit was estimated to be 50 pM. It was demonstrated that here reported glassy carbon electrode modified by copper nanoparticles is suitable for the determination of dopamine in real samples such as human blood serum.

Iron Oxide-Supported Copper Oxide Nanoparticles (Nanocat-Fe-CuO): Magnetically Recyclable Catalysts for the Synthesis of Pyrazole Derivatives, 4-Methoxyaniline, and Ullmann-type Condensation Reactions

Science.gov (United States)

An efficient and benign protocol is reported for the synthesis of 4-methoxyaniline, medicinally important pyrazole derivatives, and Ullmann-type condensation reaction using magnetically separable and reusable magnetite-supported copper (nanocat-Fe-CuO) nanoparticles under mild co...

Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

International Nuclear Information System (INIS)

Kumar, Nikhil; Upadhyay, Lata Sheo Bachan

2016-01-01

Highlights: • A facile and eco-friendly method for the synthesis of L-cysteine functionalized copper nanoparticles is reported. • Synthesis of Highly stable L-cysteine functionalized copper nanoparticles (∼40 nm) was done in an aqueous medium. • FTIR analysis shows that L-cysteine bound to the nanoparticle surface via thiol group. - Abstract: A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month

Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Kumar, Nikhil, E-mail: nkumar.phd2011.bt@nitrr.ac.in; Upadhyay, Lata Sheo Bachan, E-mail: contactlataupadhyay@gmail.com

2016-11-01

Highlights: • A facile and eco-friendly method for the synthesis of L-cysteine functionalized copper nanoparticles is reported. • Synthesis of Highly stable L-cysteine functionalized copper nanoparticles (∼40 nm) was done in an aqueous medium. • FTIR analysis shows that L-cysteine bound to the nanoparticle surface via thiol group. - Abstract: A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month.

Ultrasonic-assisted chemical reduction synthesis and structural characterization of copper nanoparticles

Science.gov (United States)

Anh-Nga, Nguyen T.; Tuan-Anh, Nguyen; Thanh-Quoc, Nguyen; Ha, Do Tuong

2018-04-01

Copper nanoparticles, due to their special properties, small dimensions and low-cost preparation, have many potential applications such as in optical, electronics, catalysis, sensors, antibacterial agents. In this study, copper nanoparticles were synthesized by chemical reduction method with different conditions in order to investigate the optimum conditions which gave the smallest (particle diameter) dimensions. The synthesis step used copper (II) acetate salt as precursor, ascorbic acid as reducing agent, glycerin and polyvinylpyrrolidone (PVP) as protector and stabilizer. The assistance of ultrasonic was were considered as the significant factor affecting the size of the synthesized particles. The results showed that the copper nanoparticles have been successfully synthesized with the diameter as small as 20-40 nm and the conditions of ultrasonic waves were 48 kHz of frequency, 20 minutes of treated time and 65-70 °C of temperature. The synthesized copper nanoparticles were characterized by optical absorption spectrum, scanning electron microscopy (SEM), and Fourier Transform Infrared Spectrometry.

Two-step flash light sintering of copper nanoparticle ink to remove substrate warping

Energy Technology Data Exchange (ETDEWEB)

Ryu, Chung-Hyeon; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul, 133-791 (Korea, Republic of)

2016-10-30

Highlights: • We performed the two-step flash light sintering for copper nanoparticle ink to remove substrate warping. • 12 J/cm{sup 2} of preheating and 7 J/cm{sup 2} of main sintering energies were determined as optimum conditions to sinter the copper nanoparticle ink. • The resistivity of two-step sintered copper nanoparticle ink was 3.81 μΩ cm with 5B adhesion level, 2.3 times greater than that of bulk copper. • The two-step sintered case showed a high conductivity without any substrate warping. - Abstract: A two-step flash light sintering process was devised to reduce the warping of polymer substrates during the sintering of copper nanoparticle ink. To determine the optimum sintering conditions of the copper nanoparticle ink, the flash light irradiation conditions (pulse power, pulse number, on-time, and off-time) were varied and optimized. In order to monitor the flash light sintering process, in situ resistance and temperature monitoring of copper nanoink were conducted during the flash light sintering process. Also, a transient heat transfer analysis was performed by using the finite-element program ABAQUS to predict the temperature changes of copper nanoink and polymer substrate. The microstructures of the sintered copper nanoink films were analyzed by scanning electron microscopy. Additionally, an X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the crystal phase change of the sintered copper nanoparticles. The resulting two-step flash light sintered copper nanoink films exhibited a low resistivity (3.81 μΩ cm, 2.3 times of that of bulk copper) and 5B level of adhesion strength without warping of the polymer substrate.

Synthesis of Copper Nanoparticles Coated with Nitrogen Ligands

Directory of Open Access Journals (Sweden)

Rubén Sierra-Ávila

2014-01-01

Full Text Available The synthesis of copper nanoparticles was studied by wet chemical methods using copper sulfate pentahydrate (CuSO4·5H2O and nitrogen ligands allylamine (AAm and polyallylamine (PAAm as stabilizers. The results suggest that the use of these ligands leads to the exclusive formation of metallic copper nanoparticles (Cu-NPs. The use of partially crosslinked polyallylamine (PAAmc leads to nanoparticles (NPs with low yields and high coating content, while linear PAAm leads to NPs with high yields and low coating content. The chemical composition of the particles was determined by XRD and average particle diameters were determined by the Debye-Scherrer equation. TGA analysis provided evidence of the content and thermal stability of the coating on the nanoparticles and PAAm. The morphology, particle size distribution, and presence of PAAm coating were observed through TEM. The use of AAm in the synthesis of NPs could be a good alternative to reduce costs. By using TGA, TEM, and DSC techniques, it was determined that synthesized NPs with AAm presented a coating with similar characteristics to NPs with PAAm, suggesting that AAm underwent polymerization during the synthesis.

Copper nanoparticles synthesis by gamma irradiation in chitosan aqueous system

International Nuclear Information System (INIS)

Shahrul Izwan Ahmad; Md Soot Ahmad; Shahidan Radiman

2009-01-01

A study on effect of chitosan concentration on the copper nanoparticles synthesis using gamma irradiation as source of reducing agent has been done at total absorbed dose of 50 kGy. The addition of ethanol is vital as scavenger of oxidation radical that eliminate the function of reducing agent produced by radiolysis process of gamma ray in water system. Transmission electron microscopy observations show the formation of copper nanoparticles embedded in chitosan matrix. As the concentration of chitosan increase the solution become darker and nanoparticles produced are densely, in order form with polydisperse size. While at the low concentration of chitosan, the color of solution become more reddish and the particles produced are monodisperse in size with regular shape and more orderly. The phase of pure copper nanoparticles embedded in the chitosan matrix was confirmed by X-ray diffraction. (Author)

Copper nanoparticle-deposited graphite felt electrodes for all vanadium redox flow batteries

International Nuclear Information System (INIS)

Wei, L.; Zhao, T.S.; Zeng, L.; Zhou, X.L.; Zeng, Y.K.

2016-01-01

Highlights: • Copper nanoparticle is proposed as electrocatalyst for VRFBs for the first time. • Propose a binder-free copper nanoparticle decorated electrode. • The energy efficiency is up to 80.1% at 300 mA cm"−"2, enhancing more than 17%. • High stability and capacity retention are achieved by battery with copper catalyst. - Abstract: A copper nanoparticle deposited graphite felt electrode for all vanadium redox flow batteries (VRFBs) is developed and tested. It is found that the copper catalyst enables a significant improvement in the electrochemical kinetics of the V"3"+/V"2"+ redox reaction. The battery’s utilization of the electrolyte and energy efficiency are found to be as high as 83.7% and 80.1%, at a current density of 300 mA cm"−"2, which are 53.1% and 17.8% higher than those of the battery without the catalyst. Moreover, the present battery shows a good stability during the cycle test. The results suggest that the inexpensive copper nanoparticle catalyst without tedious preparation process offers a great promise for VRFB application.

3D interconnect technology based on low temperature copper nanoparticle sintering

NARCIS (Netherlands)

Zhang, B.; Carisey, Y.C.P.; Damian, A.; Poelma, R.H.; Zhang, G.Q.; van Zeijl, H.W.; Bi, Keyun; Liu, Sheng; Zhou, Shengjun

2016-01-01

We explore a methodology for patterned copper nanoparticle paste for 3D interconnect applications in wafer to wafer (W2W) bonding. A novel fine pitch thermal compression bonding process (sintering) with coated copper nanoparticle paste was developed. Most of the particle size is between 10-30 nm.

Photochemical synthesis of copper nanoparticles incorporated in poly(vinyl pyrrolidone)

International Nuclear Information System (INIS)

Giuffrida, Salvatore; Costanzo, Lucia L.; Ventimiglia, Giorgio; Bongiorno, Corrado

2008-01-01

The effect of the presence of poly(vinyl pyrrolidone) (PVP) on the copper nanoparticle formation, obtained by UV irradiation of ethanol solution of Cu(acac) 2 (acac = 2,4-pentanedionato), was investigated. At 254 nm, in conditions of light completely absorbed by complex, the PVP exhibited protective and stabilizing effects, as shown by the formation of a colloidal copper solution and by a block of the heterogeneous process, which leads to thin film formation on the quartz walls. The colloidal solution was tested for several months by plasmon position and it was found that it remained unaltered in inert atmosphere, but returned to the starting complex on contact with air. The PVP ability to control the particle size was investigated by carrying out photoreduction sensitized by Hacac at 254 and 300 nm, in the presence of PVP concentration varying from 0 to 0.2 M. In this range it was possible to obtain copper nanoparticles of dimensions decreasing from 30 to 4 nm. Besides this, the PVP (0.005-0.05 M) role as sensitizer was investigated by irradiating solutions of Cu(acac) 2 at 300 nm which is an inactive wavelength for copper reduction by direct light absorption. It was found that the PVP was an efficient sensitizer of the copper photoreduction. The nanoparticles were characterized by plasmon band, Trasmission Electron Microscope (TEM) as well as Dynamic Light Scattering (DSL) analysis. The overall results evidence the advantages of the PVP use in the nanoparticle copper formation through the photochemical technique such as the exclusive formation of colloidal copper, their size control, stable colloidal solution and complete return to the starting complex.

Synthesis and characterization of silver-copper core-shell nanoparticles using polyol method for antimicrobial agent

Science.gov (United States)

Hikmah, N.; Idrus, N. F.; Jai, J.; Hadi, A.

2016-06-01

Silver and copper nanoparticles are well-known as the good antimicrobial agent. The nano-size of particles influences in enhancing the antimicrobial activity. This paper discusses the effect of molarity on the microstructure and morphology of silver-copper core-shell nanoparticles prepared by a polyol method. In this study, silver-copper nanoparticles are synthesized through the green approach of polyol method using ethylene glycol (EG) as green solvent and reductant, and polyoxyethylene-(80)-sorbitan monooleate (Tween 80) as a nontoxic stabilizer. The phase and morphology of silver-copper nanoparticles are characterized by X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM) and Transmission electron microscope (TEM). The results XRD confirm the pure crystalline of silver and copper nanoparticles with face-centered cubic (FCC) structure. FESEM and TEM analysis confirm the existence of Ag and Cu nanoparticles in core-shell shape.

Synthesis and characterization of copper nanoparticles by using the exploding wire method

International Nuclear Information System (INIS)

Das, Rashmita; Das, Basanta Kumar; Shyam, Anurag

2012-01-01

During the past few years, the synthesis of copper nanoparticles has attracted much attention because of their huge potential for replacing the expensive nano silver inks utilized in conductive printing. This opens a new possibility in printed electronics. Copper-based inkjet inks can be used to form various devices such as solar cells, RF identification tags and electroluminescence devices. This paper describes controlled synthesis of pure copper nanoparticles, mainly by using the exploding wire method. A wire of 0.26 mm in diameter was exploded in a nitrogen environment. The sample was characterized by using X-ray diffraction (XRD) and atomic force microscopy (AFM). XRD revealed the presence of pure copper and AFM revealed the presence of nanoparticles with an average size of 55 nm.

Determination of the threshold of nanoparticle behavior: Structural and electronic properties study of nano-sized copper

International Nuclear Information System (INIS)

Torres-Vega, Juan J.; Medrano, L.R.; Landauro, C.V.; Rojas-Tapia, J.

2014-01-01

In the present work we determine the threshold of the nanoparticle behavior of copper nanoparticles by studying their structural and electronic properties. The studied nanoparticles contain from 13 to 8217 atoms and were obtained by molecular dynamics simulations using the Johnson potential for copper based on the embedded atom method. The results indicate that for small copper nanoparticles ( 2000atoms, ∼3.5 nm), with spherical-like external shape and large percentage of fcc-like local structure, this effect is negligible and their electronic character are similar to such expected in solid copper. Finally, it has also been shown that copper nanoparticles change their electronic character, from metallic to insulating, after increasing the strength of the chemical disorder

Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen.

Science.gov (United States)

Sivaraj, Rajeshwari; Rahman, Pattanathu K S M; Rajiv, P; Salam, Hasna Abdul; Venckatesh, R

2014-12-10

This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48±4nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli). Copyright © 2014 Elsevier B.V. All rights reserved.

Biogenic copper oxide nanoparticles synthesis using Tabernaemontana divaricate leaf extract and its antibacterial activity against urinary tract pathogen

Science.gov (United States)

Sivaraj, Rajeshwari; Rahman, Pattanathu K. S. M.; Rajiv, P.; Salam, Hasna Abdul; Venckatesh, R.

2014-12-01

This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48 ± 4 nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50 μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli).

Molecular dynamic simulations of the high-speed copper nanoparticles collision with the aluminum surface

Science.gov (United States)

Pogorelko, V. V.; Mayer, A. E.

2016-11-01

With the use of the molecular dynamic simulations, we investigated the effect of the high-speed (500 m/s, 1000 m/s) copper nanoparticle impact on the mechanical properties of an aluminum surface. Dislocation analysis shows that a large number of dislocations are formed in the impact area; the total length of dislocations is determined not only by the speed and size of the incoming copper nanoparticle (kinetic energy of the nanoparticle), but by a temperature of the system as well. The dislocations occupy the whole area of the aluminum single crystal at high kinetic energy of the nanoparticle. With the decrease of the nanoparticle kinetic energy, the dislocation structures are formed in the near-surface layer; formation of the dislocation loops takes place. Temperature rise of the system (aluminum substrate + nanoparticle) reduces the total dislocation length in the single crystal of aluminum; there is deeper penetration of the copper atoms in the aluminum at high temperatures. Average energy of the nanoparticles and room temperature of the system are optimal for production of high-quality layers of copper on the aluminum surface.

Laser sintering of copper nanoparticles

International Nuclear Information System (INIS)

Zenou, Michael; Saar, Amir; Ermak, Oleg; Kotler, Zvi

2014-01-01

Copper nanoparticle (NP) inks serve as an attractive potential replacement to silver NP inks in functional printing applications. However their tendency to rapidly oxidize has so far limited their wider use. In this work we have studied the conditions for laser sintering of Cu-NP inks in ambient conditions while avoiding oxidation. We have determined the regime for stable, low-resistivity copper (< ×3 bulk resistivity value) generation in terms of laser irradiance and exposure duration and have indicated the limits on fast processing. The role of pre-drying conditions on sintering outcome has also been studied. A method, based on spectral reflectivity measurements, was used for non-contact monitoring of the sintering process evolution. It also indicates preferred spectral regions for sintering. Finally, we illustrated how selective laser sintering can generate high-quality, fine line (<5 µm wide) and dense copper circuits. (paper)

Copper-assisted shape control in colloidal synthesis of indium oxide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Selishcheva, Elena; Parisi, Juergen; Kolny-Olesiak, Joanna, E-mail: joanna.kolny@uni-oldenburg.de [University of Oldenburg, Energy and Semiconductor Research Laboratory, Institute of Physics (Germany)

2012-02-15

Indium oxide is an important n-type transparent semiconductor, finding application in solar cells, sensors, and optoelectronic devices. We present here a novel non-injection synthesis route for the preparation of colloidal indium oxide nanocrystals by using oleylamine (OLA) as ligand and as solvent. Indium oxide with cubic crystallographic structure is formed in a reaction between indium acetate and OLA, the latter is converted to oleylamide during the synthesis. The shape of the nanocrystals can be influenced by the addition of copper ions. When only indium (III) acetate is used as precursor flower-shaped indium oxide nanoparticles are obtained. Addition of copper salts such as copper (I) acetate, copper (II) acetate, copper (II) acetylacetonate, or copper (I) chloride, under otherwise identical reaction conditions changes the shape of nanoparticles to quasi-spherical or elongated. The anions, except for chloride, do not influence the shape of the resulting nanocrystals. This finding suggests that adsorption of copper ions on the In{sub 2}O{sub 3} surface during the nanoparticles growth is responsible for shape control, whereas changes in the reactivity of the In cations caused by the presence of different anions play a secondary role. X-ray diffraction, transmission electron microscopy, nuclear magnetic resonance, energy dispersive X-ray analysis, and UV-Vis-absorption spectroscopy are used to characterize the samples.

Copper-assisted shape control in colloidal synthesis of indium oxide nanoparticles

International Nuclear Information System (INIS)

Selishcheva, Elena; Parisi, Jürgen; Kolny-Olesiak, Joanna

2012-01-01

Indium oxide is an important n-type transparent semiconductor, finding application in solar cells, sensors, and optoelectronic devices. We present here a novel non-injection synthesis route for the preparation of colloidal indium oxide nanocrystals by using oleylamine (OLA) as ligand and as solvent. Indium oxide with cubic crystallographic structure is formed in a reaction between indium acetate and OLA, the latter is converted to oleylamide during the synthesis. The shape of the nanocrystals can be influenced by the addition of copper ions. When only indium (III) acetate is used as precursor flower-shaped indium oxide nanoparticles are obtained. Addition of copper salts such as copper (I) acetate, copper (II) acetate, copper (II) acetylacetonate, or copper (I) chloride, under otherwise identical reaction conditions changes the shape of nanoparticles to quasi-spherical or elongated. The anions, except for chloride, do not influence the shape of the resulting nanocrystals. This finding suggests that adsorption of copper ions on the In 2 O 3 surface during the nanoparticles growth is responsible for shape control, whereas changes in the reactivity of the In cations caused by the presence of different anions play a secondary role. X-ray diffraction, transmission electron microscopy, nuclear magnetic resonance, energy dispersive X-ray analysis, and UV–Vis-absorption spectroscopy are used to characterize the samples.

High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

International Nuclear Information System (INIS)

Tam, Sze Kee; Ng, Ka Ming

2015-01-01

This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10 −5  Ω cm.Graphical Abstract

High-concentration copper nanoparticles synthesis process for screen-printing conductive paste on flexible substrate

Energy Technology Data Exchange (ETDEWEB)

Tam, Sze Kee; Ng, Ka Ming, E-mail: kekmng@ust.hk [The Hong Kong University of Science and Technology, Department of Chemical and Biomolecular Engineering (Hong Kong)

2015-12-15

This study presents a method for the synthesis of copper nanoparticles, which are poised to replace silver nanoparticles in some application areas of printed electronics. This method offers three advantages. Firstly, copper loading in the synthesis reaction can be as high as 1 M, offering high productivity in large-scale production. Secondly, the size of the copper nanoparticles can be controlled from 12 to 99 nm. Thirdly, the surface polarity of the particles can be modified. Thus, a tailor-made product can be synthesized. The synthesis of copper nanoparticles coated with various capping agents, including dodecanethiol, lauric acid, nonanoic acid, polyacrylic acid, and polyvinyl pyrrolidone, was demonstrated. The nonanoic acid-coated copper nanoparticles were formulated as a screen-printing conductive paste. The particles were readily dispersed in terpineol, and the paste could be screen printed onto flexible polyester. The electrical resistivity of patterns after a low-temperature (120 °C) sintering treatment was around 5.8 × 10{sup −5} Ω cm.Graphical Abstract.

Expeditious low-temperature sintering of copper nanoparticles with thin defective carbon shells

Science.gov (United States)

Kim, Changkyu; Lee, Gyoungja; Rhee, Changkyu; Lee, Minku

2015-04-01

The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation. Isothermal oxidation and reduction treatment at 200 °C for only about 10 min yields an oxide-free copper network structure with an electrical resistivity of 25.1 μΩ cm (14.0 μΩ cm at 250 °C). Finally, conductive copper line patterns are achieved down to a 50 μm width with an excellent printing resolution (standard deviation ~4.0%) onto a polyimide substrate using screen printing of the optimized inks.The realization of air-stable nanoparticles, well-formulated nanoinks, and conductive patterns based on copper is a great challenge in low-cost and large-area flexible printed electronics. This work reports the synthesis of a conductively interconnected copper structure via thermal sintering of copper inks at a low temperature for a short period of time, with the help of thin defective carbon shells coated onto the copper nanoparticles. Air-stable copper/carbon core/shell nanoparticles (typical size ~23 nm, shell thickness ~1.0 nm) are prepared by means of an electric explosion of wires. Gaseous oxidation of the carbon shells with a defective structure occurs at 180 °C, impacting the choice of organic solvents as well as the sintering conditions to create a crucial neck formation

Facile and green synthesis of highly stable L-cysteine functionalized copper nanoparticles

Science.gov (United States)

Kumar, Nikhil; Upadhyay, Lata Sheo Bachan

2016-11-01

A simple eco-friendly method for L-cysteine capped copper nanoparticles (CCNPs) synthesis in aqueous solution has been developed. Glucose and L-cysteine were used as reducing agent and capping/functionalizing agent, respectively. Different parameters such as capping agent concentration, pH, reaction temperature, and reducing agent concentration were optimized during the synthesis. The L-cysteine capped copper nanoparticle were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, Particle size and zeta potential analyser, and high resolution transmission electron microscopy. Spherical shaped cysteine functionalized/capped copper nanoparticles with an average size of 40 nm were found to be highly stable at room temperature (RT) for a period of 1 month

Ultrahigh reactivity and grave nanotoxicity of copper nanoparticles

International Nuclear Information System (INIS)

Huan Meng; Zhen Chen; Chengcheng Zhang; Yun Wang; Yuliang Zhao

2007-01-01

Recently, it was reported that the toxicity of copper particles increases with the decrease of the particle size on a mass basis. To understand this phenomenon, inductively coupled plasma mass spectrometry (ICP-MS) techniques and in vitro chemical studies were carried out to explore how they produce toxicity in vivo. The results suggest that when the sizes of particles become small and down to a nanoscale, copper becomes extremely reactive in a simulative intracorporeal environment. The nanosized copper particles consume the hydrogen ions in stomach more quickly than micron ones. These processes further convert the copper nanoparticles into cupric ions whose toxicity is very high in vivo. (author)

Surface enhanced Raman scattering of gold nanoparticles supported on copper foil with graphene as a nanometer gap

International Nuclear Information System (INIS)

Xiang, Quan; Zhu, Xupeng; Chen, Yiqin; Duan, Huigao

2016-01-01

Gaps with single-nanometer dimensions (<10 nm) between metallic nanostructures enable giant local field enhancements for surface enhanced Raman scattering (SERS). Monolayer graphene is an ideal candidate to obtain a sub-nanometer gap between plasmonic nanostructures. In this work, we demonstrate a simple method to achieve a sub-nanometer gap by dewetting a gold film supported on monolayer graphene grown on copper foil. The Cu foil can serve as a low-loss plasmonically active metallic film that supports the imaginary charge oscillations, while the graphene can not only create a stable sub-nanometer gap for massive plasmonic field enhancements but also serve as a chemical enhancer. We obtained higher SERS enhancements in this graphene-gapped configuration compared to those in Au nanoparticles on Cu film or on graphene–SiO 2 –Si. Also, the Raman signals measured maintained their fine features and intensities over a long time period, indicating the stability of this Au–graphene–Cu hybrid configuration as an SERS substrate. (paper)

Durable and Washable Antibacterial Copper Nanoparticles Bridged by Surface Grafting Polymer Brushes on Cotton and Polymeric Materials

Directory of Open Access Journals (Sweden)

Chufeng Sun

2018-01-01

Full Text Available To increase the durability of antibacterial coating on cotton and polymeric substrates, surface initiated grafting polymer brushes are introduced onto the substrates surface to bridge copper nanoparticles coatings and substrate. The morphologies of the composites consisting of the copper nanoparticles and polymer brushes were characterized with scanning electron microscopy (SEM. It was found that copper nanoparticles were uniformly and firmly distributed on the surfaces of the substrates by the polymer brushes; meanwhile, the reinforced concrete-like structures were formed in the composite materials. The substrates coated by the copper nanoparticles showed the efficient antibacterial activity against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli even after washing by 30 cycles. The copper nanoparticles were tethered on the substrates by the strong chemical bonds, which led to the excellent washable fitness and durability. The change of the phase structure of the copper was analyzed to investigate the release mechanism of copper ions.

Bi-metallic nanoparticles as cathode electrocatalysts

Science.gov (United States)

Lu, Jun; Amine, Khalil; Wang, Xiaoping; Luo, Xiangyi; Myers, Deborah J.

2018-03-27

A lithium-air battery cathode catalyst includes core-shell nanoparticles on a carbon support, wherein: a core of the core-shell nanoparticles is platinum metal; and a shell of the core-shell nanoparticles is copper metal; wherein: the core-shell nanoparticles have a weight ratio of the copper metal to the platinum metal from about 4% to about 6% copper to from about 2% to about 12% platinum, with a remaining percentage being the carbon support.

Chitosan doped with nanoparticles of copper, nickel and cobalt.

Science.gov (United States)

Cárdenas-Triviño, Galo; Elgueta, Carolina; Vergara, Luis; Ojeda, Javier; Valenzuela, Ariel; Cruzat, Christian

2017-11-01

Metal colloids in 2 propanol using nanoparticles (NPs) of copper, nickel and cobalt were prepared by Chemical Liquid Deposition (CLD) method. The resulting colloidal dispersions were characterized by Transmission Electron Microscopy (TEM). The colloids were supported in chitosan. Then, microbiological assays were performed using E. coli and S. aureus in order to determine the bactericide/bacteriostatic activity of nanoparticles (NPs) trapped or chelated with chitosan. Finally, the toxicity of the metal colloids Cu, Ni and Co was tested. Bio-assays were conducted in three different animal species. First of all on earth warms (Eisenia foetida) to evaluate the toxicity and the biocompatibility of chitosan in lactic acid (1% and 0.5%). Secondly bio-assay done in fishes (rainbow trout), the liver toxicity of NPs in vivo was evaluated. Finally, a bio-assay was conducted in Sprange-Dawley rats of 100g weight, which were injected intraperitoneally with different solutions of chitosan metal colloids. Then, the minimum and maximum concentration were determined for copper, nickel and cobalt. The purpose of the use of chitosan was acting as a carrier for some magnetic NPs, which toxicity would allow to obtain new polymeric materials with potential applications as magnet future drugs carrier. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural and optical properties of pure and copper doped zinc oxide nanoparticles

Science.gov (United States)

Sajjad, Muhammad; Ullah, Inam; Khan, M. I.; Khan, Jamshid; Khan, M. Yaqoob; Qureshi, Muhammad Tauseef

2018-06-01

Pure and copper-doped zinc oxide nanoparticles (NPs) have been synthesized via chemical co-precipitation method where hydrazine is used as reducing agent and aqueous extract of Euphorbia milii plant as capping agent. Main objectives of the reported work are to investigate the effect of copper doping on crystal structure of ZnO nanoparticles; to study the effect of copper doping on optical band gap of ZnO nanoparticles and photoluminescence (PL) study of pure and copper-doped ZnO nanoparticles. To achieve the aforementioned objectives, XRD and SEM tests were performed for the identification and confirmation of crystal structure and morphology of the prepared samples. From XRD data the average grain size for pure ZnO was observed to be 24.62 nm which was first decreased to 18.95 nm for 5 wt% Cu-doped sample and then it was found to increase up to 37.80 nm as the Cu doping was increased to 7 wt%. Optical band gap of pure and Cu-doped ZnO nanoparticles was calculated from diffuse reflectance spectroscopy (DRS) spectra and was found to decrease from 3.13 eV to 2.94 eV as the amount of Cu increases up to 7 wt%. In photoluminescence study, PL technique was used and enhanced visible spectrum was observed. For further characterization FT-IR and EDX tests were also carried out.

High-speed collision of copper nanoparticle with aluminum surface: Molecular dynamics simulation

Science.gov (United States)

Pogorelko, Victor V.; Mayer, Alexander E.; Krasnikov, Vasiliy S.

2016-12-01

We investigate the effect of the high-speed collision of copper nanoparticles with aluminum surface by means of molecular dynamic simulations. Studied diameter of nanoparticles is varied within the range 7.2-22 nm and the velocity of impact is equal to 500 or 1000 m/s. Dislocation analysis shows that a large quantity of dislocations is formed within the impact area. Overall length of dislocations is determined, first of all, by the impact velocity and by the size of incident copper nanoparticle, in other words, by the kinetic energy of the nanoparticle. Dislocations occupy the total volume of the impacted aluminum single crystal layer (40.5 nm in thickness) in the form of intertwined structure in the case of large kinetic energy of the incident nanoparticle. Decrease in the initial kinetic energy or increase in the layer thickness lead to restriction of the penetration depth of the dislocation net; formation of separate dislocation loops is observed in this case. Increase in the initial system temperature slightly raises the dislocation density inside the bombarded layer and considerably decreases the dislocation density inside the nanoparticle. The temperature increase also leads to a deeper penetration of the copper atoms inside the aluminum. Additional molecular dynamic simulations show that the deposited particles demonstrate a very good adhesion even in the case of the considered relatively large nanoparticles. Medium energy of the nanoparticles corresponding to velocity of about 500 m/s and elevated temperature of the system about 700-900 K are optimal parameters for production of high-quality layers of copper on the aluminum surface. These conditions provide both a good adhesion and a less degree of the plastic deformation. At the same time, higher impact velocities can be used for combined treatment consisting of both the plastic deformation and the coating.

Amplification of light emission of chiral pyridine Eu(III) complex by copper nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Reisfeld, Renata; Levchenko, Viktoria [Institute of Chemistry, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904 (Israel); Piccinelli, Fabio; Bettinelli, Marco [Laboratorio Materiali Luminescenti, DB, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy)

2016-02-15

We outline the applications of lanthanides luminescence in a number of modern fields. The intensity of the luminescence of the expensive lanthanides can be increased by their interaction with nanoparticles of inexpensive copper. As a typical example the chiral pyridine-based Eu{sup 3+} complex was incorporated into amorphous films of polyvinyl alcohol with hydroxyethyl cellulose. The luminescence intensity of the complex is increased by three hundred percent by its interaction with copper nanoparticles. The synthesis and steady state spectroscopy of the materials are presented. - Highlights: • Nanoparticles of copper were for the first time synthesized at 80 °C. • Copper NPs were incorporated with a luminescent Eu{sup 3+} complex in a polymeric matrix. • The films produced were characterized by photoluminescence spectroscopy. • The luminescence of Eu{sup 3+} complex with Cu NPs is 3 times higher than the original one.

Identification of target organs of copper nanoparticles with ICP-MS technique

International Nuclear Information System (INIS)

Zhen Chen; Huan Meng; Yun Wang; Chengcheng Zhang; Yuliang Zhao

2007-01-01

Nanosized copper particles are widely used in fields of lubricants, polymers/plastic, metallic coating and ink. Recently, we found that copper particles in different sizes can lead to different toxicological effects. To clarify the target organs of copper particles of different sizes, the inductively coupled plasma mass spectroscopy (ICP-MS) was employed to evaluate the distribution of copper in different organs of mice after a single dose oral exposure. The results suggest that the main target organs for copper nanoparticles are kidney, liver and blood. Liver is the main damaged organ. (author)

[MORPHO-FUNCTIONAL CHARACTERISTIC OF THE THYROID GLAND AFTER ADMINISTRATION OF COPPER NANOPARTICLES].

Science.gov (United States)

Polyakova, V S; Sizova, Ye A; Miroshnikov, S A; Notova, S V; Zavaleyeva, S M

2015-01-01

The study was conducted on 15 male Wistar rats, which were injected intramuscularly with copper nanoparticle lyosols at a dose of 2.0 mg/kg body weight once a week for 3 months. Thyroid gland was removed 7 days after the last injection and was studied using histological, morphometric and immunohistochemical methods (demonstration of Ki-67 and caspase-3). Animals of the control group (n = 15) were administered distilled water at the same time intervals. It was found that after 1, 2, 3 and 4 injections of copper nanoparticles, the thyroid gland contained an increased number of large cyst-like follicles, while the average thyrocyte height of and the volume of their nuclei were reduced, which indicate a decline in hormone production. After 12 injections of copper nanoparticles, the hyperplastic thyroid gland demonstrated small follicles lined with columnar epithelium, which contained no or small amount of the colloid. The number of mitotically dividing thyrocytes was increased. Parafollicular cells demonstrated an apoptotic dominant. Morphological data suggest goitrogenic effect of multiple doses of copper nanopartides. The data received indicating the readiness of the thyroid cells to the programmed death and its possible depression (absence of signs of thyrocyte apoptosis) at different stages of the experiment confirm the modulating effect of copper on apoptosis.

Behavior of Copper Oxide Nanoparticles in Soil Pore Waters as Influenced by Soil Characteristics, Bacteria, and Wheat Roots

OpenAIRE

Hortin, Joshua

2017-01-01

The goal of this project was to study the behavior of copper oxide nanoparticles in soil environments. Copper oxide nanoparticles have antimicrobial properties and may also be used in agricultural settings to provide a source of copper for plant health, but accidental or misapplication of these nanoparticles to soil may be damaging to the plant and its associated bacteria. Dissolved soil organic matter that is present in soil pore waters dissolved nanoparticles, but did not dissolve the ex...

Synthesis of Copper Nanoparticles in Ethylene Glycol by Chemical Reduction with Vanadium (+2 Salts

Directory of Open Access Journals (Sweden)

Andrea Pietro Reverberi

2016-09-01

Full Text Available Copper nanoparticles have been synthesized in ethylene glycol (EG using copper sulphate as a precursor and vanadium sulfate as an atypical reductant being active at room temperature. We have described a technique for a relatively simple preparation of such a reagent, which has been electrolytically produced without using standard procedures requiring an inert atmosphere and a mercury cathode. Several stabilizing agents have been tested and cationic capping agents have been discarded owing to the formation of complex compounds with copper ions leading to insoluble phases contaminating the metallic nanoparticles. The elemental copper nanoparticles, stabilized with polyvinylpyrrolidone (PVP and sodium dodecyl sulphate (SDS, have been characterized for composition by energy dispersive X-ray spectroscopy (EDS, and for size by dynamic light scattering (DLS, and transmission electron microscopy (TEM, giving a size distribution in the range of 40–50 nm for both stabilizing agents. From a methodological point of view, the process described here may represent an alternative to other wet-chemical techniques for metal nanoparticle synthesis in non-aqueous media based on conventional organic or inorganic reductants.

Stage specific effects of soluble copper and copper oxide nanoparticles during sea urchin embryo development and their relation to intracellular copper uptake.

Science.gov (United States)

Torres-Duarte, Cristina; Ramos-Torres, Karla M; Rahimoff, René; Cherr, Gary N

2017-08-01

The effects of exposure to either soluble copper (copper sulfate) or copper oxide nanoparticles (nano-CuO) during specific early developmental stages of sea urchin embryos were analyzed. Soluble copper caused significant malformations in embryos (skeletal malformations, delayed development or gut malformations) when present at any given stage, while cleavage stage was the most sensitive to nano-CuO exposure causing skeletal malformations and decreased total antioxidant capacity. The stage specificity was linked to higher endocytic activity during the first hours of development that leads to higher accumulation of copper in specific cells critical for development. Results indicate that nano-CuO results in higher accumulation of copper inside of embryos and this intracellular copper is more persistent as compared to soluble copper. The possible implications later in development are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

Temperature and Copper Concentration Effects on the Formation of Graphene-Encapsulated Copper Nanoparticles from Kraft Lignin

Directory of Open Access Journals (Sweden)

Weiqi Leng

2017-06-01

Full Text Available The effects of temperature and copper catalyst concentration on the formation of graphene-encapsulated copper nanoparticles (GECNs were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy-attenuated total reflectance, and transmission electron microscopy. Results showed that higher amounts of copper atoms facilitated the growth of more graphene islands and formed smaller size GECNs. A copper catalyst facilitated the decomposition of lignin at the lowest temperature studied (600 °C. Increasing the temperature up to 1000 °C retarded the degradation process, while assisting the reconfiguration of the defective sites of the graphene layers, thus producing higher-quality GECNs.

Characterization and In Vitro Toxicity of Copper Nanoparticles (Cu-NPs) in Murine Neuroblastoma (N2A) Cells

Science.gov (United States)

2011-03-01

polymers and dendrimers ), 2) inorganic nanoparticles (e.g. metallic nanoparticles), 3) organic/inorganic hybrids (e.g. nanocomposites), 4) carbon...use, transport , and excretion of copper from the body. Copper is an essential nutrient because it is incorporated as one of many metalloenzymes...discover cellular copper transporters in the last decade or so. For those individuals lacking the proper copper exporter pump, diseases such as Menkes

Generation of copper, nickel, and CuNi alloy nanoparticles by spark discharge

International Nuclear Information System (INIS)

Muntean, Alex; Wagner, Moritz; Meyer, Jörg; Seipenbusch, Martin

2016-01-01

The generation of copper, nickel, and copper-nickel alloy nanoparticles by spark discharge was studied, using different bespoke alloy feedstocks. Roughly spherical particles with a primary particle Feret diameter of 2–10 nm were produced and collected in agglomerate form. The copper-to-nickel ratios determined by Inductively coupled plasma mass spectrometry (ICP-MS), and therefore averaged over a large number of particles, matched the nominal copper content quite well. Further investigations showed that the electrode compositions influenced the evaporation rate and the primary particle size. The evaporation rate decreased with increasing copper content, which was found to be in good accordance with the Llewellyn-Jones model. However, the particle diameter was increasing with an increasing copper content, caused by a decrease in melting temperature due to the lower melting point of copper. Furthermore, the alloy compositions on the nanoscale were investigated via EDX. The nanoparticles exhibited almost the same composition as the used alloy feedstock, with a deviation of less than 7 percentage points. Therefore, no segregation could be detected, indicating the presence of a true alloy even on the nanoscale.

Mesoporous silica nanoparticles supported copper(II) and nickel(II) Schiff base complexes: Synthesis, characterization, antibacterial activity and enzyme immobilization

Science.gov (United States)

Tahmasbi, Leila; Sedaghat, Tahereh; Motamedi, Hossein; Kooti, Mohammad

2018-02-01

Mesoporous silica nanoparticles (MSNs) were prepared by sol-gel method and functionalized with 3-aminopropyltriethoxysilane. Schiff base grafted mesoporous silica nanoparticle was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and amine-functionalized MSNs. The latter material was then treated with Cu(II) and Ni(II) salts separately to obtain copper and nickel complexes anchored mesoporous composites. The newly prepared hybrid organic-inorganic nanocomposites have been characterized by several techniques such as FT-IR, LA-XRD, FE-SEM, TEM, EDS, BET and TGA. The results showed all samples have MCM-41 type ordered mesoporous structure and functionalization occurs mainly inside the mesopore channel. The presence of all elements in synthesized nanocomposites and the coordination of Schiff base via imine nitrogen and phenolate oxygen were confirmed. MSNs and all functionalized MSNs have uniform spherical nanoparticles with a mean diameter less than 100 nm. The as-synthesized mesoporous nanocomposites were investigated for antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria, as carrier for gentamicin and also for immobilization of DNase, coagulase and amylase enzymes. MSN-SB-Ni indicated bacteriocidal effect against S.aureus and all compounds were found to be good carrier for gentamicin. Results of enzyme immobilization for DNase and coagulase and α-amylase revealed that supported metal complexes efficiently immobilized enzymes.

Flash light sintered copper precursor/nanoparticle pattern with high electrical conductivity and low porosity for printed electronics

International Nuclear Information System (INIS)

Chung, Wan-Ho; Hwang, Hyun-Jun; Kim, Hak-Sung

2015-01-01

In this work, the hybrid copper inks with precursor and nanoparticles were fabricated and sintered via flash light irradiation to achieve highly conductive electrode pattern with low porosity. The hybrid copper ink was made of copper nanoparticles and various copper precursors (e.g., copper(II) chloride, copper(II) nitrate trihydrate, copper(II) sulfate pentahydrate and copper(II) trifluoroacetylacetonate). The printed hybrid copper inks were sintered at room temperature and under ambient conditions using an in-house flash light sintering system. The effects of copper precursor weight fraction and the flash light irradiation conditions (light energy and pulse duration) were investigated. Surfaces of the sintered hybrid copper patterns were analyzed using a scanning electron microscope. Also, spectroscopic characterization techniques such as Fourier transform infrared spectroscopy and X-ray diffraction were used to investigate the crystal phases of the flash light sintered copper precursors. High conductivity hybrid copper patterns (27.3 μΩ cm), which is comparable to the resistivity of bulk copper (1.68 μΩ cm) were obtained through flash light sintering at room temperature and under ambient conditions. - Highlights: • The hybrid copper inks with precursor and nanoparticles were fabricated. • The hybrid copper ink was sintered via flash light irradiation. • The resistivity of sintered hybrid copper ink was 27.3 μΩ cm. • Highly conductive copper film with low porosity could be achieved

Flash light sintered copper precursor/nanoparticle pattern with high electrical conductivity and low porosity for printed electronics

Energy Technology Data Exchange (ETDEWEB)

Chung, Wan-Ho; Hwang, Hyun-Jun [Department of Mechanical Convergence Engineering, Hanyang University, 17 Haendang-Dong, Seongdong-Gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, 17 Haendang-Dong, Seongdong-Gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

2015-04-01

In this work, the hybrid copper inks with precursor and nanoparticles were fabricated and sintered via flash light irradiation to achieve highly conductive electrode pattern with low porosity. The hybrid copper ink was made of copper nanoparticles and various copper precursors (e.g., copper(II) chloride, copper(II) nitrate trihydrate, copper(II) sulfate pentahydrate and copper(II) trifluoroacetylacetonate). The printed hybrid copper inks were sintered at room temperature and under ambient conditions using an in-house flash light sintering system. The effects of copper precursor weight fraction and the flash light irradiation conditions (light energy and pulse duration) were investigated. Surfaces of the sintered hybrid copper patterns were analyzed using a scanning electron microscope. Also, spectroscopic characterization techniques such as Fourier transform infrared spectroscopy and X-ray diffraction were used to investigate the crystal phases of the flash light sintered copper precursors. High conductivity hybrid copper patterns (27.3 μΩ cm), which is comparable to the resistivity of bulk copper (1.68 μΩ cm) were obtained through flash light sintering at room temperature and under ambient conditions. - Highlights: • The hybrid copper inks with precursor and nanoparticles were fabricated. • The hybrid copper ink was sintered via flash light irradiation. • The resistivity of sintered hybrid copper ink was 27.3 μΩ cm. • Highly conductive copper film with low porosity could be achieved.

High-speed collision of copper nanoparticle with aluminum surface: Molecular dynamics simulation

Energy Technology Data Exchange (ETDEWEB)

Pogorelko, Victor V., E-mail: vik_ko83@mail.ru [Chelyabinsk State University, Bratiev Kashirinykh 129, 454001 Chelyabinsk (Russian Federation); South Ural State University (National Research University), Lenin Prospect 76, 454080 Chelyabinsk (Russian Federation); Mayer, Alexander E., E-mail: mayer@csu.ru [Chelyabinsk State University, Bratiev Kashirinykh 129, 454001 Chelyabinsk (Russian Federation); South Ural State University (National Research University), Lenin Prospect 76, 454080 Chelyabinsk (Russian Federation); Krasnikov, Vasiliy S., E-mail: vas.krasnikov@gmail.com [Chelyabinsk State University, Bratiev Kashirinykh 129, 454001 Chelyabinsk (Russian Federation); South Ural State University (National Research University), Lenin Prospect 76, 454080 Chelyabinsk (Russian Federation)

2016-12-30

Highlights: • High-speed nanoparticle impact induces shock waves and intensive plastic deformation. • Lattice orientation strongly influences on the deformation degree. • Plastic deformation goes through nucleation, growth and separation of semi-loops. • Medium impact energy and elevated temperature are optimal for high-quality coating. • High impact velocity and room temperature lead to plastic deformation and coating. - Abstract: We investigate the effect of the high-speed collision of copper nanoparticles with aluminum surface by means of molecular dynamic simulations. Studied diameter of nanoparticles is varied within the range 7.2–22 nm and the velocity of impact is equal to 500 or 1000 m/s. Dislocation analysis shows that a large quantity of dislocations is formed within the impact area. Overall length of dislocations is determined, first of all, by the impact velocity and by the size of incident copper nanoparticle, in other words, by the kinetic energy of the nanoparticle. Dislocations occupy the total volume of the impacted aluminum single crystal layer (40.5 nm in thickness) in the form of intertwined structure in the case of large kinetic energy of the incident nanoparticle. Decrease in the initial kinetic energy or increase in the layer thickness lead to restriction of the penetration depth of the dislocation net; formation of separate dislocation loops is observed in this case. Increase in the initial system temperature slightly raises the dislocation density inside the bombarded layer and considerably decreases the dislocation density inside the nanoparticle. The temperature increase also leads to a deeper penetration of the copper atoms inside the aluminum. Additional molecular dynamic simulations show that the deposited particles demonstrate a very good adhesion even in the case of the considered relatively large nanoparticles. Medium energy of the nanoparticles corresponding to velocity of about 500 m/s and elevated temperature of the

High-speed collision of copper nanoparticle with aluminum surface: Molecular dynamics simulation

International Nuclear Information System (INIS)

Pogorelko, Victor V.; Mayer, Alexander E.; Krasnikov, Vasiliy S.

2016-01-01

Highlights: • High-speed nanoparticle impact induces shock waves and intensive plastic deformation. • Lattice orientation strongly influences on the deformation degree. • Plastic deformation goes through nucleation, growth and separation of semi-loops. • Medium impact energy and elevated temperature are optimal for high-quality coating. • High impact velocity and room temperature lead to plastic deformation and coating. - Abstract: We investigate the effect of the high-speed collision of copper nanoparticles with aluminum surface by means of molecular dynamic simulations. Studied diameter of nanoparticles is varied within the range 7.2–22 nm and the velocity of impact is equal to 500 or 1000 m/s. Dislocation analysis shows that a large quantity of dislocations is formed within the impact area. Overall length of dislocations is determined, first of all, by the impact velocity and by the size of incident copper nanoparticle, in other words, by the kinetic energy of the nanoparticle. Dislocations occupy the total volume of the impacted aluminum single crystal layer (40.5 nm in thickness) in the form of intertwined structure in the case of large kinetic energy of the incident nanoparticle. Decrease in the initial kinetic energy or increase in the layer thickness lead to restriction of the penetration depth of the dislocation net; formation of separate dislocation loops is observed in this case. Increase in the initial system temperature slightly raises the dislocation density inside the bombarded layer and considerably decreases the dislocation density inside the nanoparticle. The temperature increase also leads to a deeper penetration of the copper atoms inside the aluminum. Additional molecular dynamic simulations show that the deposited particles demonstrate a very good adhesion even in the case of the considered relatively large nanoparticles. Medium energy of the nanoparticles corresponding to velocity of about 500 m/s and elevated temperature of the

Influence of Heat Treatment on the Morphologies of Copper Nanoparticles Based Films by a Spin Coating Method

Directory of Open Access Journals (Sweden)

Wei Liu

2017-01-01

Full Text Available We have investigated the influence of heat treatment on the morphologies of copper nanoparticles based films on glass slides by a spin coating method. The experiments show that heat treatment can modify the sizes and morphologies of copper nanoparticles based films on glass slides. We suggest that through changing the parameters of heat treatment process may be helpful to vary the scattering and absorbing intensity of copper nanoparticles when used in energy harvesting/conversion and optical devices.

Copper-gold nanoparticles: Fabrication, characteristic and application as drug carriers

Energy Technology Data Exchange (ETDEWEB)

Woźniak-Budych, Marta J., E-mail: marta.budych@amu.edu.pl; Langer, Krzysztof; Peplińska, Barbara; Przysiecka, Łucja; Jarek, Marcin; Jarzębski, Maciej; Jurga, Stefan

2016-08-15

In this investigation, the fabrication of porous core/shell nanostructures consisting of copper (core) and copper-gold nanoalloy (shell) for medical applications is presented. As a core triangular-shaped copper nanoparticles were used. The porous bimetallic nanoshell was prepared via galvanic reaction in the presence of oil-in water emulsion. It was proved that porous nanoalloy layer can be prepared at pH 7 and in the presence 0.1% and 0.5% oil-in water emulsion. The porous structure fabrication was mainly determined by volume fraction of hexadecane to acetone in the oil-in water emulsion and Zeta-potential of emulsion droplets (pH of emulsion). The influence of emulsion droplets size before galvanic reaction on porous structure preparation was negligible. It was found that doxorubicin could be easily introduced and released from porous core/shell nanostructures, due to spontaneous adsorption on the copper-gold nanoporous surface. The in vitro test showed that cytotoxic effect was more prominent once the doxorubicin was adsorbed on the porous copper-gold nanocarriers. It was demonstrated, that doxorubicin-loaded copper-gold nanostructures caused inhibition cell proliferation and viability of cancer cells, in a concentration-dependent manner. The results indicates that presented coper-gold nanocarrier have potential to be used in targeted cancer therapy, due to its porous structure and cytotoxic effect in cancer cells. - Highlights: • Porous copper-gold nanostructure as a cytostatic drug carrier was prepared. • Kinetics and thermodynamics of drug adsorption were studied. • DOX-loaded copper-gold nanoparticles showed a pH-controlled release rate. • DOX-loaded copper-gold NPs caused inhibition cell proliferation of cancer cells. • The Cu-Au NPs could serve as a theranostic platform for biomedical applications.

Examining mechanism of toxicity of copper oxide nanoparticles to Saccharomyces cerevisiae and Caenorhabditis elegans

Science.gov (United States)

Mashock, Michael J.

Copper oxide nanoparticles (CuO NPs) are an up and coming technology increasingly being used in industrial and consumer applications and thus may pose risk to humans and the environment. In the present study, the toxic effects of CuO NPs were studied with two model organisms Saccharomyces cerevisiae and Caenorhabditis elegans. The role of released Cu ions during dissolution of CuO NPs in growth media were studied with freshly suspended, aged NPs, and the released Cu 2+ fraction. Exposures to the different Cu treatments showed significant inhibition of S. cerevisiae cellular metabolic activity. Inhibition from the NPs was inversely proportional to size and was not fully explained by the released Cu ions. S. cerevisiae cultures grown under respiring conditions demonstrated greater metabolic sensitivity when exposed to CuO NPs compared to cultures undergoing fermentation. The cellular response to both CuO NPs and released Cu ions on gene expression was analyzed via microarray analysis after an acute exposure. It was observed that both copper exposures resulted in an increase in carbohydrate storage, a decrease in protein production, protein misfolding, increased membrane permeability, and cell cycle arrest. Cells exposed to NPs up-regulated genes related to oxidative phosphorylation but also may be inducing cell cycle arrest by a different mechanism than that observed with released Cu ions. The effect of CuO NPs on C. elegans was examined by using several toxicological endpoints. The CuO NPs displayed a more inhibitory effect, compared to copper sulfate, on nematode reproduction, feeding, and development. We investigated the effects of copper oxide nanoparticles and copper sulfate on neuronal health, a known tissue vulnerable to heavy metal toxicity. In transgenic C. eleganswith neurons expressing a green fluorescent protein reporter, neuronal degeneration was observed in up to 10% of the population after copper oxide nanoparticle exposure. Additionally, nematode

Copper nanoparticles synthesized in polymers by ion implantation

DEFF Research Database (Denmark)

Popok, Vladimir; Nuzhdin, Vladimir; Valeev, Valerij

2015-01-01

nanoparticles are observed to partly tower above the sample surface due to a side effect of high-fluence irradiation leading to considerable sputtering of polymers. Implantation and particle formation significantly change optical properties of both polymers reducing transmittance in the UV-visible range due...... as optical transmission spectroscopy. It is found that copper nanoparticles nucleation and growth are strongly fluence dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized...

In vitro susceptibility of filamentous fungi to copper nanoparticles assessed by rapid XTT colorimetry and agar dilution method.

Science.gov (United States)

Ghasemian, E; Naghoni, A; Tabaraie, B; Tabaraie, T

2012-12-01

Metal nanoparticles and their uses in various aspects have recently drawn a great deal of attention. One of the major applications is that it can be used as an antimicrobial agent. They can be considered in approaches targeted to decrease the harms caused by microorganisms, specifically fungi, threatening the medical and industrial areas. The aim of this study was to investigate the antifungal activity of synthesized copper nanoparticles (CuNPs) against four filamentous fungi including Alternaria alternata, Aspergillus flavus, Fusarium solani, and Penicillium chrysogenum. Zerovalent copper nanoparticles of mean size 8nm were synthesized by inert gas condensation (IGC) method. The antifungal activity of these synthesized copper nanoparticles was measured against selected fungi by using two different techniques including agar dilution method and XTT reduction assay. The minimal inhibitory concentrations (MICs) for copper nanoparticles by agar dilution method were less or equal to 40mg/L for P. chrysogenum, less or equal to 60mg/L for A. alternata, less or equal to 60mg/L for F. solani, and less or equal to 80mg/L for A. flavus. And also MICs obtained by XTT reduction assay ranged from 40 to 80mg/L. Our data demonstrated that the copper nanoparticles inhibited fungal growth, but the fungal sensitivity to copper nanoparticles varies depending on the fungal species. Therefore, it is advisable that the minimal inhibitory concentrations (MICs) be examined before using these compounds. It is hoped that, in future, copper nanoparticles could replace some antifungal agents, making them applicable to many different medical devices and antimicrobial control system. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Assessment of antifungal effects of copper nanoparticles on the growth of the fungus Saprolegnia sp. on white fish (Rutilus frisii kutum eggs

Directory of Open Access Journals (Sweden)

Pegah Kalatehjari

2015-12-01

Full Text Available This study was conducted to evaluate the in-vitro effects of copper nanoparticles on the growth of the fungus Saprolegnia sp. isolated from white fish (Rutilus frisii kutum eggs. The antifungal effects were measured by determining the minimum lethal concentration of copper nanoparticles on Saprolegnia sp. in yeast extract glucose chloramphenicol (YGC agar at 25 °C. Saprolegnia grown in YGC agar without added copper nanoparticles served as negative controls. Our study showed that copper nanoparticles at a minimum concentration of 10 ppm have antifungal effects on Saprolegnia sp. The antifungal effects of copper nanoparticles are positively correlated to both concentration and time of exposure. This study showed that the antifungal properties of copper nanoparticles make it a good alternative to malachite green, which is carcinogenic.

A new rapid chemical route to prepare reduced graphene oxide using copper metal nanoparticles

International Nuclear Information System (INIS)

Wu Tao; Gao Jianping; Xu Xiaoyang; Qiu Haixia; Wang Wei; Gao Chunjuan

2013-01-01

Copper metal nanoparticles were used as a reducing agent to reduce graphene oxide (GO). The reaction was complete in about 10 min and did not involve the use of any toxic reagents or acids that are typically used in the reduction of GO by Zn and Fe powders. The high reduction activity of the Cu nanoparticles, compared to Cu powder, may be the result of the formation of Cu 2 O nanoparticles. The effect of the mass ratio of the metal to GO for this reduction was also investigated. The reduction of the GO was verified by ultraviolet–visible absorption spectroscopy, x-ray diffraction, thermogravimetric analysis, Raman spectroscopy, x-ray photoelectron spectroscopy and transmission electron microscopy. After reduction, Cu 2 O supported on reduced GO was formed and showed superior catalytic ability for the degradation of a model dye pollutant, methylene blue. (paper)

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles.

Science.gov (United States)

Courant, T; Roullin, V G; Cadiou, C; Delavoie, F; Molinari, M; Andry, M C; Gafa, V; Chuburu, F

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Courant, T; Roullin, V G; Andry, M C [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR Pharmacie Reims, 51 rue Cognacq-Jay, F-51100 Reims (France); Cadiou, C; Chuburu, F [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR des Sciences Exactes et Naturelles, Batiment 18-Europol' Agro, BP 1039, F-51687 Reims Cedex 2 (France); Delavoie, F [Laboratoire de Microscopie Electronique Analytique, INSERM UMRS 926, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Molinari, M [Laboratoire de Microscopies et d' Etudes des Nanostructures, UFR des Sciences, Universite de Reims Champagne-Ardenne, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Gafa, V, E-mail: gaelle.roullin@univ-reims.fr, E-mail: francoise.chuburu@univ-reims.fr [EA4303 ' Inflammation et Immunite de l' Epithelium Respiratoire' , IFR53, UFR de Pharmacie, Universite de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, F-51100 Reims (France)

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

International Nuclear Information System (INIS)

Courant, T; Roullin, V G; Andry, M C; Cadiou, C; Chuburu, F; Delavoie, F; Molinari, M; Gafa, V

2010-01-01

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Facile preparation of monodisperse, impurity-free, and antioxidation copper nanoparticles on a large scale for application in conductive ink.

Science.gov (United States)

Zhang, Yu; Zhu, Pengli; Li, Gang; Zhao, Tao; Fu, Xianzhu; Sun, Rong; Zhou, Feng; Wong, Ching-ping

2014-01-08

Monodisperse copper nanoparticles with high purity and antioxidation properties are synthesized quickly (only 5 min) on a large scale (multigram amounts) by a modified polyol process using slightly soluble Cu(OH)2 as the precursor, L-ascorbic acid as the reductant, and PEG-2000 as the protectant. The resulting copper nanoparticles have a size distribution of 135 ± 30 nm and do not suffer significant oxidation even after being stored for 30 days under ambient conditions. The copper nanoparticles can be well-dispersed in an oil-based ink, which can be silk-screen printed onto flexible substrates and then converted into conductive patterns after heat treatment. An optimal electrical resistivity of 15.8 μΩ cm is achieved, which is only 10 times larger than that of bulk copper. The synthesized copper nanoparticles could be considered as a cheap and effective material for printed electronics.

Calculation of the surface free energy of fcc copper nanoparticles

International Nuclear Information System (INIS)

Jia Ming; Lai Yanqing; Tian Zhongliang; Liu Yexiang

2009-01-01

Using molecular dynamics simulations with the modified analytic embedded-atom method we calculate the Gibbs free energy and surface free energy for fcc Cu bulk, and further obtain the Gibbs free energy of nanoparticles. Based on the Gibbs free energy of nanoparticles, we have investigated the heat capacity of copper nanoparticles. Calculation results indicate that the Gibbs free energy and the heat capacity of nanoparticles can be divided into two parts: bulk quantity and surface quantity. The molar heat capacity of the bulk sample is lower compared with the molar heat capacity of nanoparticles, and this difference increases with the decrease in the particle size. It is also observed that the size effect on the thermodynamic properties of Cu nanoparticles is not really significant until the particle is less than about 20 nm. It is the surface atoms that decide the size effect on the thermodynamic properties of nanoparticles

Copper Nanoparticle Induced Cytotoxicity to Nitrifying Bacteria ...

Science.gov (United States)

With the inclusion of engineered nanomaterials in industrial processes and consumer products, wastewater treatments plants (WWTPs) will serve as a major sink for these emerging contaminants. Previous research has demonstrated that nanomaterials are potentially toxic to microbial communities utilized in biological wastewater treatment (BWT). Copper-based nanoparticles (CuNPs) are of particular interest based on their increasing use in wood treatment, paints, household products, coatings, and byproducts of semiconductor manufacturing. A critical step in BWT is nutrient removal via denitrification. This study examined the potential toxicity of bare and polyvinylpyrrolidone (PVP) coated CuO, and Cu2O nanoparticles, as well as Cu ions to microbial communities responsible for nitrogen removal in BWT. Inhibition was inferred from changes to the specific oxygen uptake rate (sOUR) in the absence and presence of Cu ions and CuNPs. X-ray absorption fine structure spectroscopy, with Linear Combination Fitting (LCF), was utilized to track changes to Cu speciation throughout exposure. Results indicate that the dissolution of Cu ions from CuNPs drive microbial inhibition. The presence of a PVP coating on CuNPs has little effect on inhibition. LCF fitting of the biomass combined with metal partitioning analysis supports the current hypothesis that Cu-induced cytotoxicity is primarily caused by reactive oxygen species formed from ionic Cu in solution via catalytic reaction inter

Cu and Cu-Based Nanoparticles: Synthesis and Applications in Catalysis.

Science.gov (United States)

Gawande, Manoj B; Goswami, Anandarup; Felpin, François-Xavier; Asefa, Tewodros; Huang, Xiaoxi; Silva, Rafael; Zou, Xiaoxin; Zboril, Radek; Varma, Rajender S

2016-03-23

The applications of copper (Cu) and Cu-based nanoparticles, which are based on the earth-abundant and inexpensive copper metal, have generated a great deal of interest in recent years, especially in the field of catalysis. The possible modification of the chemical and physical properties of these nanoparticles using different synthetic strategies and conditions and/or via postsynthetic chemical treatments has been largely responsible for the rapid growth of interest in these nanomaterials and their applications in catalysis. In addition, the design and development of novel support and/or multimetallic systems (e.g., alloys, etc.) has also made significant contributions to the field. In this comprehensive review, we report different synthetic approaches to Cu and Cu-based nanoparticles (metallic copper, copper oxides, and hybrid copper nanostructures) and copper nanoparticles immobilized into or supported on various support materials (SiO2, magnetic support materials, etc.), along with their applications in catalysis. The synthesis part discusses numerous preparative protocols for Cu and Cu-based nanoparticles, whereas the application sections describe their utility as catalysts, including electrocatalysis, photocatalysis, and gas-phase catalysis. We believe this critical appraisal will provide necessary background information to further advance the applications of Cu-based nanostructured materials in catalysis.

One pot synthesis of copper nanoparticles at room temperature and its catalytic activity

Directory of Open Access Journals (Sweden)

Nikhil V. Suramwar

2016-11-01

Full Text Available A facile reduction approach with sodium borohydride as a reducing agent and starch as a stabilizing agent leads to monodispersed Cu nanoparticles in aqueous medium at an ambient condition. The synthesized nanoparticles are highly pure with no traces of CuO found on surface. They are uniform in size in the range of 40–80 nm. The Cu nanoparticles have a FCC structure as characterized by powder X-ray diffraction (XRD. Transmission electron microscopy (TEM images show that they are arranged in a regular array which is separated by starch thin layer which controls the growth as well as stabilizes the Cu nanoparticles from air oxidation. The catalytic activity of prepared Cu nanomaterial was tested in Ullman reaction for the synthesis of biphenyl from iodobenzene. We have shown in this paper that the size as well as exposed surface area of the copper nanoparticles is responsible for the increase in yield of biphenyl up to 92%. This is higher compare to the 40% yield with the normal size copper powder under the same reaction condition.

Green synthesis of silver and copper nanoparticles using ascorbic acid and chitosan for antimicrobial applications.

Science.gov (United States)

Zain, N Mat; Stapley, A G F; Shama, G

2014-11-04

Silver and copper nanoparticles were produced by chemical reduction of their respective nitrates by ascorbic acid in the presence of chitosan using microwave heating. Particle size was shown to increase by increasing the concentration of nitrate and reducing the chitosan concentration. Surface zeta potentials were positive for all nanoparticles produced and these varied from 27.8 to 33.8 mV. Antibacterial activities of Ag, Cu, mixtures of Ag and Cu, and Ag/Cu bimetallic nanoparticles were tested using Bacillus subtilis and Escherichia coli. Of the two, B. subtilis proved more susceptible under all conditions investigated. Silver nanoparticles displayed higher activity than copper nanoparticles and mixtures of nanoparticles of the same mean particle size. However when compared on an equal concentration basis Cu nanoparticles proved more lethal to the bacteria due to a higher surface area. The highest antibacterial activity was obtained with bimetallic Ag/Cu nanoparticles with minimum inhibitory concentrations (MIC) of 0.054 and 0.076 mg/L against B. subtilis and E. coli, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nitrogen-doped graphene network supported copper nanoparticles encapsulated with graphene shells for surface-enhanced Raman scattering

Science.gov (United States)

Zhang, Xiang; Shi, Chunsheng; Liu, Enzuo; Li, Jiajun; Zhao, Naiqin; He, Chunnian

2015-10-01

In this study, we demonstrated nitrogen-doped graphene network supported few-layered graphene shell encapsulated Cu nanoparticles (NPs) (Cu@G-NGNs) as a sensing platform, which were constructed by a simple and scalable in situ chemical vapor deposition (CVD) technique with the assistance of a self-assembled three-dimensional (3D) NaCl template. Compared with pure Cu NPs and graphene decorated Cu NPs, the graphene shells can strengthen the plasmonic coupling between graphene and Cu, thereby contributing to an obvious improvement in the local electromagnetic field that was validated by finite element numerical simulations, while the 3D nitrogen-doped graphene walls with a large surface area facilitated molecule adsorption and the doped nitrogen atoms embedded in the graphene lattice can reduce the surface energy of the system. With these merits, a good surface enhanced Raman spectroscopy (SERS) activity of the 3D Cu@G-NGN painting film on glass was demonstrated using rhodamine 6G and crystal violet as model analytes, exhibiting a satisfactory sensitivity, reproducibility and stability. As far as we know, this is the first report on the in situ synthesis of nitrogen-doped graphene/copper nanocomposites and this facile and low-cost Cu-based strategy tends to be a good supplement to Ag and Au based substrates for SERS applications.In this study, we demonstrated nitrogen-doped graphene network supported few-layered graphene shell encapsulated Cu nanoparticles (NPs) (Cu@G-NGNs) as a sensing platform, which were constructed by a simple and scalable in situ chemical vapor deposition (CVD) technique with the assistance of a self-assembled three-dimensional (3D) NaCl template. Compared with pure Cu NPs and graphene decorated Cu NPs, the graphene shells can strengthen the plasmonic coupling between graphene and Cu, thereby contributing to an obvious improvement in the local electromagnetic field that was validated by finite element numerical simulations, while the 3D nitrogen

Transmission electron microscopy and Raman characterization of copper (I) oxide microspheres composed of nanoparticles

International Nuclear Information System (INIS)

Wang Wenzhong; Tu Ya; Wang Lijuan; Liang Yujie; Shi Honglong

2013-01-01

Highlights: ► Raman spectroscopy of copper (I) oxide microspheres were investigated. ► Infrared active mode is greatly activated in Raman scattering spectrum. ► Infrared active mode shows up in Raman spectrum of copper (I) oxide microspheres. ► The defects existed in spheres could be responsible for the observed Raman property. - Abstract: The high-resolution transmission electron microscope and Raman spectroscopy were used to investigate the microstructures and Raman scattering property of copper (I) oxide microspheres composed of nanoparticles. High-resolution transmission electron microscope images indicate that the copper (I) oxide microspheres are composed of nanoparticles with random growth direction, indicating that there are many defects in microspheres. The Raman spectrum shows that infrared active mode, which must be odd parity and is Raman forbidden for bulk crystal due to its inversion symmetry, is activated and shows up in Raman scattering spectrum. On the basis of investigations of the microstructure features of copper (I) oxide microspheres, we attribute the appearance of IR active mode in Raman scattering spectrum to the breakdown of the symmetry of the lattice due to the presence of defects in the prepared copper (I) oxide microspheres as observed in HRTEM images.

Inkjet printed electronics using copper nanoparticle ink

OpenAIRE

Kang, Jin Sung; Kim, Hak Sung; Ryu, Jongeun; Thomas Hahn, H.; Jang, Seonhee; Joung, Jae Woo

2010-01-01

Inkjet printing of electrode using copper nanoparticle ink is presented. Electrode was printed on a flexible glass epoxy composite substrate using drop on demand piezoelectric dispenser and was sintered at 200 °C of low temperature in N2 gas condition. The printed electrodes were made with various widths and thickness. In order to control the thickness of the printed electrode, number of printing was varied. Resistivity of printed electrode was calculated from the cross-sectional area measure...

Copper-based nanoparticles prepared from copper (II acetate bipyridine complex

Directory of Open Access Journals (Sweden)

Lastovina Tatiana A.

2016-01-01

Full Text Available We report the synthesis of CuO, Cu/Cu2O and Cu2O/CuO nanoparticles (NPs from the single copper (II acetate bipyridine complex by three different methods:microwave-assisted, solvothermal and borohydride. Presence of bipyridine ligand in the copper complex would impose no need in additional stabilization during synthesis. The phases of formed NPs were identified by X-ray diffraction. CuO NPs of ~11 nm were obtained via solvothermal synthesis from alkaline solution at 160°C. The Cu/Cu2O NPs of ~80 nm were produced via microwave-assisted polyol procedure at 185-200°C, where ethylene glycol can play a triple role as a solvent, a reducing agent and a surfactant. The Cu2O/CuO NPs of ~16 nm were synthesized by a borohydride method at room temperature. Interplanar spacing calculated from the selected-area electron diffraction data confirmed the formation of Cu, CuO and Cu2O phases in respective samples. All NPs are stable and can be used for various applications including biomedicine.

Microdistribution of copper-carbonate and iron oxide nanoparticles in treated wood

Energy Technology Data Exchange (ETDEWEB)

Matsunaga, Hiroshi, E-mail: mhiroshi@ffpri.affrc.go.jp; Kiguchi, Makoto [Forestry and Forest Products Research Institute (Japan); Evans, Philip D. [University of British Columbia, Centre for Advanced Wood Processing (Canada)

2009-07-15

Aqueous dispersions of copper-carbonate nanoparticles and microparticles have just begun to be exploited commercially for the preservative treatment of wood. The success of the new systems will depend, in part, on the uniform distribution of the preservative in wood and the ability of copper to penetrate cell walls. We examined the distribution of copper in wood treated with a nano-Cu preservative. Copper particles are not uniformly distributed in treated wood, but they accumulate in voids that act as the flow paths for liquids in wood. Particles are deposited on, but not within cell walls. Nevertheless, elemental copper is present within cell walls, but at a lower level than that in wood treated with a conventional wood preservative. These findings suggest that nano-Cu preservatives are able to deliver bioactive components into wood cell walls even though the majority of copper particles are too large to penetrate the cell wall's nanocapillary network.

Vacancy-Mediated Magnetism in Pure Copper Oxide Nanoparticles

Science.gov (United States)

2010-01-01

Room temperature ferromagnetism (RTF) is observed in pure copper oxide (CuO) nanoparticles which were prepared by precipitation method with the post-annealing in air without any ferromagnetic dopant. X-ray photoelectron spectroscopy (XPS) result indicates that the mixture valence states of Cu1+ and Cu2+ ions exist at the surface of the particles. Vacuum annealing enhances the ferromagnetism (FM) of CuO nanoparticles, while oxygen atmosphere annealing reduces it. The origin of FM is suggested to the oxygen vacancies at the surface/or interface of the particles. Such a ferromagnet without the presence of any transition metal could be a very good option for a class of spintronics. PMID:20671775

Structural, spectroscopic and biological investigation of copper oxides nanoparticles with various capping agents

Energy Technology Data Exchange (ETDEWEB)

Nowak, A., E-mail: ana.maria.nowak@gmail.com [A. Chelkowski Institute of Physics, University of Silesia, Katowice (Poland); Szade, J.; Talik, E.; Ratuszna, A. [A. Chelkowski Institute of Physics, University of Silesia, Katowice (Poland); Ostafin, M. [Agricultural University of Cracow, Department of Microbiology, Krakow (Poland); Peszke, J. [A. Chelkowski Institute of Physics, University of Silesia, Katowice (Poland)

2014-06-01

Powder composed of copper oxides nanoparticles with various capping agents has been synthesized and characterized with the use of X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Polyvinyl alcohol (PVA), glycol propylene, glycerin and glycerin plus ammonia were used as capping agents. The scanning electron microscopy (SEM) studies showed that nanoparticles form agglomerates with the size from 80 to 120 nm while particles size determined from the XRD experiment was in the range from 7 to 21 nm. XPS and XRD experiments revealed that depending on capping and reducing agents used in the synthesis nanoparticles are composed of Cu{sub 2}O, CuO or a mixture of them. The biological activity test performed for a selected sample where the capping agent was glycerin plus ammonia has shown promising killing/inhibiting behavior, very effective especially for Gram negatives bacteria. - Highlights: • We obtained copper oxide nanoparticles in a powder form. • Several capping agents were tested. • Structural and chemical tests showed that the main component were Cu{sub 2}O and CuO. • The size of nanoparticles was in the range 7–21 nm. • Nanoparticles with glycerin and ammonia capping agent showed good antibacterial properties.

Copper iodide nanoparticles on poly(4-vinylpyridine): A new and ...

Indian Academy of Sciences (India)

sustainable and competitive alternative to conventional catalysis since the nanoparticles possess a high surface- to-volume ratio, which enhances their activity and selectivity, while at the same time maintaining the intrinsic features of a heterogeneous catalyst.19 In par- ticular, the immobilization of copper(I) salts nanopar-.

Preparation methods of copper-ferrocyanide functionalized magnetic nanoparticles for selective removal of cesium in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Hee-Man Yang; Kune Woo Lee; Bum-Kyoung Seo; Jei Kwon Moon [KAERI, Daejeon (Korea, Republic of)

2013-07-01

Copper ferrocyanide functionalized magnetite nanoparticles (Cu-FC-MNPs) were successfully synthesized by the immobilization of copper and ferrocyanide on the surface of [1-(2 amino-ethyl)-3-aminopropyl] trimethoxysilane modified magnetite nanoparticles. A radioactive cesium (Cs) adsorption test was carried out to investigate the effectiveness of Cu-FC-MNPS for the removal of radioactive Cs. Furthermore, the Cu-FC-MNPs showed excellent separation ability by an external magnet in an aqueous solution. (authors)

Photocatalytic antibacterial activity of copper-based nanoparticles under visible light illumination

Science.gov (United States)

Wu, Zong-Yan; Abdullah, Hairus; Kuo, Dong-Hau

2018-04-01

Copper oxide and sulfide nanoparticles after annealing treatment at 400 °Chave been characterized and tested for their bactericidal properties toward Staphylococcus aureus and Escherichia coli under the dark and LED light illuminated conditions. It was found that the nanoparticles with the formation of CuS/Cu2S/CuO nanoheterostructuresexhibited a great capability of killing Staphylococcus aureus and Escherichia coli with or without light illumination. The antibacterial activity of the nanoparticles was demonstrated and simply observed with colony counting method. A mechanism of the antibacterial behaviour had been proposed and elucidated in this work.

Mechanism of silver nanoparticles action on insect pigmentation reveals intervention of copper homeostasis.

Directory of Open Access Journals (Sweden)

Najealicka Armstrong

Full Text Available Silver nanoparticles (AgNPs, like almost all nanoparticles, are potentially toxic beyond a certain concentration because the survival of the organism is compromised due to scores of pathophysiological abnormalities past that concentration. However, the mechanism of AgNP toxicity remains undetermined. Instead of applying a toxic dose, we attempted to monitor the effects of AgNPs at a nonlethal concentration on wild type Drosophila melanogaster by exposing them throughout their development. All adult flies raised in AgNP doped food showed that up to 50 mg/L concentration AgNP has no negative influence on median survival; however, these flies appeared uniformly lighter in body color due to the loss of melanin pigments in their cuticle. Additionally, fertility and vertical movement ability were compromised due to AgNP feeding. Determination of the amount of free ionic silver (Ag(+ led us to claim that the observed biological effects have resulted from the AgNPs and not from Ag(+. Biochemical analysis suggests that the activity of copper dependent enzymes, namely tyrosinase and Cu-Zn superoxide dismutase, are decreased significantly following the consumption of AgNPs, despite the constant level of copper present in the tissue. Consequently, we propose a mechanism whereby consumption of excess AgNPs in association with membrane bound copper transporter proteins cause sequestration of copper, thus creating a condition that resembles copper starvation. This model also explains the cuticular demelanization effect resulting from AgNP since tyrosinase activity is essential for melanin biosynthesis. Finally, we claim that Drosophila, an established genetic model system, can be well utilized for further understanding of the biological effects of nanoparticles.

Copper nanoparticles as an alternative feed additives in poultry diet

DEFF Research Database (Denmark)

Scott, A.; Vadalasetty, K. P.; Chwalibog, A.

2018-01-01

of the crucial health and environmental concerns. In recent years, many studies have reported copper nanoparticles (Cu-NP) as a promising alternative to antibacterial reagents and a growth promoter. Depending on the size, shape, dose and animal species, Cu-NP exhibit a variety of effects on animal performance...

Enhanced decolorization of methyl orange using zero-valent copper nanoparticles under assistance of hydrodynamic cavitation.

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Li, Pan; Song, Yuan; Wang, Shuai; Tao, Zheng; Yu, Shuili; Liu, Yanan

2015-01-01

The rate of reduction reactions of zero-valent metal nanoparticles is restricted by their agglomeration. Hydrodynamic cavitation was used to overcome the disadvantage in this study. Experiments for decolorization of methyl orange azo dye by zero-valent copper nanoparticles were carried out in aqueous solution with and without hydrodynamic cavitation. The results showed that hydrodynamic cavitation greatly accelerated the decolorization rate of methyl orange. The size of nanoparticles was decreased after hydrodynamic cavitation treatment. The effects of important operating parameters such as discharge pressure, initial solution pH, and copper nanoparticle concentration on the degradation rates were studied. It was observed that there was an optimum discharge pressure to get best decolorization performance. Lower solution pH were favorable for the decolorization. The pseudo-first-order kinetic constant for the degradation of methyl orange increased linearly with the copper dose. UV-vis spectroscopic and Fourier transform infrared (FT-IR) analyses confirmed that many degradation intermediates were formed. The results indicated hydroxyl radicals played a key role in the decolorization process. Therefore, the enhancement of decolorization by hydrodynamic cavitation could due to the deagglomeration of nanoparticles as well as the oxidation by the in situ generated hydroxyl radicals. These findings greatly increase the potential of the Cu(0)/hydrodynamic cavitation technique for use in the field of treatment of wastewater containing hazardous materials. Copyright © 2014 Elsevier B.V. All rights reserved.

Magnetic Properties of Copper Doped Nickel Ferrite Nanoparticles Synthesized by Co Precipitation Method

Science.gov (United States)

Anjana, V.; John, Sara; Prakash, Pooja; Nair, Amritha M.; Nair, Aravind R.; Sambhudevan, Sreedha; Shankar, Balakrishnan

2018-02-01

Nickel ferrite nanoparticles with copper atoms as dopant have been prepared using co-precipitation method with general formula Ni1-xCuxFe2O4 (x=0.2, 0.4, 0.6, 0.8 and 1) and are sintered at quite ambient temperature. Structural and magnetic properties were examined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction method (XRD) and Vibrating Sample Magnetometer (VSM) to study the influence of copper doping in nickel ferrite magnetic nanoparticles. X-ray studies proves that the particles are possessing single phase spinel structure with an average particle size calculated using Debye Scherer formula. Magnetic measurements reveal that saturation magnetization value (Ms) decreases while magnetic coercivity (Hc) increases upon doping.

Investigation of Industrial Polyurethane Foams Modified with Antimicrobial Copper Nanoparticles

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Maria Chiara Sportelli

2016-07-01

Full Text Available Antimicrobial copper nanoparticles (CuNPs were electrosynthetized and applied to the controlled impregnation of industrial polyurethane foams used as padding in the textile production or as filters for air conditioning systems. CuNP-modified materials were investigated and characterized morphologically and spectroscopically, by means of Transmission Electron Microscopy (TEM, and X-ray Photoelectron Spectroscopy (XPS. The release of copper ions in solution was studied by Electro-Thermal Atomic Absorption Spectroscopy (ETAAS. Finally, the antimicrobial activity of freshly prepared, as well as aged samples—stored for two months—was demonstrated towards different target microorganisms.

Effect of reduction enhancer on a radiolytic synthesis of carbon-supported Pt–Cu nanoparticles and their structural and electrochemical properties

Energy Technology Data Exchange (ETDEWEB)

Kugai, Junichiro, E-mail: jkugai@kobe-kosen.ac.jp [Kobe City College of Technology, Department of Applied Chemistry (Japan); Kubota, Chihiro; Okazaki, Tomohisa; Seino, Satoshi; Nakagawa, Takashi [Osaka University, Graduate School of Engineering (Japan); Nitani, Hiroaki [High Energy Accelerator Research Organization, Institute of Materials Structure Science (IMSS) (Japan); Yamamoto, Takao A. [Osaka University, Graduate School of Engineering (Japan)

2015-06-15

In order to clarify the effect of reduction enhancer on the nanoparticle formation process and their structural and catalytic properties, carbon-supported Pt–Cu nanoparticles were synthesized by electron beam irradiation on an aqueous precursor solution in the presence/absence of reduction enhancer. In the absence of reduction enhancer, tetravalent platinum oxide particles of approximately 1 nm in diameter were formed on carbon support with copper barely precipitated, while in the presence of 2-propanol or ethylene glycol or glucose both platinum and copper precipitated as few-nanometer-sized alloy particles together with copper oxides. It was suggested that the metal nuclei produced upon electron beam irradiation do not have enough lifetime without reduction enhancer due to fast oxidation of the nuclei by oxidizing radicals, while the reduction enhancer scavenges these oxidizing radicals preventing oxidation of metallic clusters and prolonging their lifetime. Ethylene glycol gave smaller and better alloyed particles with less copper oxides compared to 2-propanol since the carbonyl compounds derived from oxidation of ethylene glycol protect metallic clusters from oxidation further prolonging their lifetime. In the electrochemical measurements, the methanol oxidation activities of Pt–Cu/C catalysts were well explained by their structural characteristics.

Study of carbon-supported bimetallic PtCu nanoparticles by ASAXS

International Nuclear Information System (INIS)

Bulat, N.V.; Avakyan, L.A; Pryadchenko, V.V.; Srabionyan, V.V.; Belenov, S.V.; Bugaev, L.A.

2017-01-01

Bimetallic platinum-copper nanoparticles on carbon support are studied as a perspective electrochemical catalyst by anomalous small-angle X-ray scattering near the Pt absorption L 3 -edge. The simultaneous fitting of several diffraction patterns measured at different photon energies lead to a satisfactory agreement between experimental and model curves in the assumption of core-shell structure of the particles with Pt-rich shell and Cu-rich core. It is shown that the average size of as prepared nanoparticles is about 6 nm with distribution spread of about ±2 nm and with thickness of Pt-rich shell approximately 1.6 nm. After annealing at 350o C the average size of the particles increased by two times with additional enlargement of the Pt-rich shell thickness. (paper)

Thermally stable nanoparticles on supports

Science.gov (United States)

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2012-11-13

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity.

Science.gov (United States)

Chung, Wan-Ho; Hwang, Yeon-Taek; Lee, Seung-Hyun; Kim, Hak-Sung

2016-05-20

In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet-visible spectroscopy (UV-vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

Molecular dynamic simulation of Copper and Platinum nanoparticles Poiseuille flow in a nanochannels

Science.gov (United States)

Toghraie, Davood; Mokhtari, Majid; Afrand, Masoud

2016-10-01

In this paper, simulation of Poiseuille flow within nanochannel containing Copper and Platinum particles has been performed using molecular dynamic (MD). In this simulation LAMMPS code is used to simulate three-dimensional Poiseuille flow. The atomic interaction is governed by the modified Lennard-Jones potential. To study the wall effects on the surface tension and density profile, we placed two solid walls, one at the bottom boundary and the other at the top boundary. For solid-liquid interactions, the modified Lennard-Jones potential function was used. Velocity profiles and distribution of temperature and density have been obtained, and agglutination of nanoparticles has been discussed. It has also shown that with more particles, less time is required for the particles to fuse or agglutinate. Also, we can conclude that the agglutination time in nanochannel with Copper particles is faster that in Platinum nanoparticles. Finally, it is demonstrated that using nanoparticles raises thermal conduction in the channel.

A green synthesis of copper nanoparticles using native cyclodextrins as stabilizing agents

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Javier Suárez-Cerda

2017-03-01

Full Text Available In this work, a comparative study of the effect of the NCD size as a stabilizing agent, on the synthesis of copper nanoparticles (Cu-NPs by an easy green method was reported. The nanoparticles were synthesized through the chemical reduction of aqueous solutions of copper (II sulfate with ascorbic acid, using different native cyclodextrins (NCDs (α-, β-, or γ-NCD as stabilizing agents. Cu-NPs were characterized by scanning electron microscopy–energy dispersive spectroscopy (SEM–EDX, powder X-ray diffraction (XRD and transmission electron microscopy (TEM. The pattern showed in the typical selected area electron diffraction (SAED and lattice fringes, evidence that the crystalline structure of Cu-NPs is face-centered cubic (FCC with a (111, (200 and (220 lattice planes of Cu. The analysis of the TEM images show that the size of the Cu-NPs depends on the type of native cyclodextrin (NCD, also it was observed that the nanoparticles are spherical and with a size between ∼2 and 33 nm. The smaller Cu-NPs were obtained with α-NCD (mode 4 nm, while the nanoparticles obtained with β-NCD show the narrow size distribution (mode 6.5 nm. The average particle size and particle size distribution of Cu-NPs depend upon the type of CDs.

Synthesis of Copper Sulfide Nanoparticles Using Biogenic H2S Produced by a Low-pH Sulfidogenic Bioreactor

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Camila Colipai

2018-01-01

Full Text Available The application of acidophilic sulfate-reducing bacteria (SRB for the treatment of acidic mine water has been recently developed to integrate mine water remediation and selective biomineralization. The use of biogenic hydrogen sulfide (H2S produced from the dissimilatory reduction of sulfate to fabricate valuable products such as metallic sulfide nanoparticles has potential applications in green chemistry. Here we report on the operation of a low-pH sulfidogenic bioreactor, inoculated with an anaerobic sediment obtained from an acid river in northern Chile, to recover copper via the production of copper sulfide nanoparticles using biogenic H2S. The laboratory-scale system was operated as a continuous flow mode for up to 100 days and the bioreactor pH was maintained by the automatic addition of a pH 2.2 influent liquor to compensate for protons consumed by biosulfidogenesis. The “clean” copper sulfide nanoparticles, produced in a two-step process using bacterially generated sulfide, were examined using transmission electron microscopy, dynamic light scattering, energy dispersive (X-ray spectroscopy and UV-Vis spectroscopy. The results demonstrated a uniform nanoparticle size distribution with an average diameter of less than 50 nm. Overall, we demonstrated the production of biogenic H2S using a system designed for the treatment of acid mine water that holds potential for large-scale abiotic synthesis of copper sulfide nanoparticles.

Radiation induced deposition of copper nanoparticles inside the nanochannels of poly(acrylic acid)-grafted poly(ethylene terephthalate) track-etched membranes

Science.gov (United States)

Korolkov, Ilya V.; Güven, Olgun; Mashentseva, Anastassiya A.; Atıcı, Ayse Bakar; Gorin, Yevgeniy G.; Zdorovets, Maxim V.; Taltenov, Abzal A.

2017-01-01

Poly(ethylene terephthalate) PET, track-etched membranes (TeMs) with 400 nm average pore size were UV-grafted with poly(acrylic acid) (PAA) after oxidation of inner surfaces by H2O2/UV system. Carboxylate groups of grafted PAA chains were easily complexed with Cu2+ ions in aqueous solutions. These ions were converted into metallic copper nanoparticles (NPs) by radiation-induced reduction of copper ions in aqueous-alcohol solution by gamma rays in the dose range of 46-250 kGy. Copper ions chelating with -COOH groups of PAA chains grafted on PET TeMs form polymer-metal ion complex that prevent the formation of agglomerates during reduction of copper ions to metallic nanoparticles. The detailed analysis by X-Ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed the deposition of copper nanoparticles with the average size of 70 nm on the inner surface of nanochannels of PET TeMs. Samples were also investigated by FTIR, ESR spectroscopies to follow copper ion reduction.

Micronized copper wood preservatives: An efficiency and potential health risk assessment for copper-based nanoparticles

International Nuclear Information System (INIS)

Civardi, Chiara; Schwarze, Francis W.M.R.; Wick, Peter

2015-01-01

Copper (Cu) is an essential biocide for wood protection, but fails to protect wood against Cu-tolerant wood-destroying fungi. Recently Cu particles (size range: 1 nm–25 μm) were introduced to the wood preservation market. The new generation of preservatives with Cu-based nanoparticles (Cu-based NPs) is reputedly more efficient against wood-destroying fungi than conventional formulations. Therefore, it has the potential to become one of the largest end uses for wood products worldwide. However, during decomposition of treated wood Cu-based NPs and/or their derivate may accumulate in the mycelium of Cu-tolerant fungi and end up in their spores that are dispersed into the environment. Inhaled Cu-loaded spores can cause harm and could become a potential risk for human health. We collected evidence and discuss the implications of the release of Cu-based NPs by wood-destroying fungi and highlight the exposure pathways and subsequent magnitude of health impact. - Highlights: • We compared copper particulate wood preservatives with conventional ones. • We assessed the fungicidal activity of particulate copper wood preservatives. • We reviewed the Cu-tolerance mechanisms of some wood-destroying fungi. • Fungi colonizing wood treated with particulate copper may release Cu-loaded spores. - We assess the fungicidal activity of particulate copper wood preservatives and their possible release in the air by Cu-tolerant wood-destroying fungi

Toxicity of copper nanoparticles and CuCl2 salt to Enchytraeus albidus worms: Survival, reproduction and avoidance responses

International Nuclear Information System (INIS)

Amorim, Mónica João Barros; Scott-Fordsmand, Janeck James

2012-01-01

Environmental effects of copper nanoparticles are little studied in terrestrial ecosystems. In the present article, the toxicity of copper nanoparticles (Cu-NP) on the enchytraeid Enchytraeus albidus is compared to the toxicity of a copper-salt (CuCl 2 ). The effect parameters studied were survival, reproductive output and avoidance behaviour. The results show that Cu-NP were more toxic to E. albidus than the same concentrations of the CuCl 2 -salt. The physic-chemical analysis of the particles indicated that only a small fraction was released as ions. Hence, the results indicated a nanoparticle-specific effect – lower reproductive output and higher avoidance. This was observed as 2–8 fold (significant) lower ECx values for Cu-NP (EC 50-reprod = 95 mg Cu/kg; EC 50-avoid = 241 mg Cu/kg) exposed organisms compared to CuCl 2 (EC 50-reprod = 251 mg Cu/kg; EC 50-avoid = 475 mg Cu/kg) exposed organisms. These results corroborate with a nanoparticle-specific effect. - Highlights: ► Enchytraeus albidus were exposed to Cu-salt and Cu nanoparticles (80 nm) in soil. ► Survival, reproduction and avoidance behaviour were assessed. ► Particles characterization indicated very small ion release. ► Cu nanoparticles toxicity was higher than Cu-salt for reproduction and avoidance. - Toxicity of Cu chloride salt and Cu nanoparticles to Enchytraeus albidus indicated higher toxicity of Cu-NP.

Comparative effects of dissolved copper and copper oxide nanoparticle exposure to the sea anemone, Exaiptasia pallida

Energy Technology Data Exchange (ETDEWEB)

Siddiqui, Samreen; Goddard, Russell H.; Bielmyer-Fraser, Gretchen K., E-mail: gkbielmyer@valdosta.edu

2015-03-15

Highlights: • Differences between CuO NP and CuCl{sub 2} exposure were characterized. • Copper accumulation in E. pallida was concentration-dependent. • E. pallida exposed to CuCl{sub 2} accumulated higher copper tissue burdens. • The oxidative stress response was greater in E. pallida exposed to CuO NP. • Both forms of copper inhibited CA activity in E. pallida. - Abstract: Increasing use of metal oxide nanoparticles (NP) by various industries has resulted in substantial output of these NP into aquatic systems. At elevated concentrations, NP may interact with and potentially affect aquatic organisms. Environmental implications of increased NP use are largely unknown, particularly in marine systems. This research investigated and compared the effects of copper oxide (CuO) NP and dissolved copper, as copper chloride (CuCl{sub 2}), on the sea anemone, Exaiptasia pallida. Sea anemones were collected over 21 days and tissue copper accumulation and activities of the enzymes: catalase, glutathione peroxidase, glutathione reductase, and carbonic anhydrase were quantified. The size and shape of CuO NP were observed using a ecanning electron microscope (SEM) and the presence of copper was confirmed by using Oxford energy dispersive spectroscopy systems (EDS/EDX). E. pallida accumulated copper in their tissues in a concentration- and time-dependent manner, with the animals exposed to CuCl{sub 2} accumulating higher tissue copper burdens than those exposed to CuO NP. As a consequence of increased copper exposure, as CuO NP or CuCl{sub 2}, anemones increased activities of all of the antioxidant enzymes measured to some degree, and decreased the activity of carbonic anhydrase. Anemones exposed to CuO NP generally had higher anti-oxidant enzyme activities than those exposed to the same concentrations of CuCl{sub 2}. This study is useful in discerning differences between CuO NP and dissolved copper exposure and the findings have implications for exposure of aquatic

The effect of administration of copper nanoparticles to chickens in drinking water on estimated intestinal absorption of iron, zinc, and calcium.

Science.gov (United States)

Ognik, Katarzyna; Stępniowska, Anna; Cholewińska, Ewelina; Kozłowski, Krzysztof

2016-09-01

Copper nanoparticles used as a dietary supplement for poultry could affect the absorption of mineral elements. Hence the aim of the study was to determine the effect of administration of copper nanoparticles to chickens in drinking water on intestinal absorption of iron, zinc, and calcium. The experiment was carried out on 126 chicks assigned to seven experimental groups of 18 birds each (3 replications of 6 individuals each). The control group (G-C) did not receive copper nanoparticles. Groups: Cu-5(7), Cu-10(7), and Cu-15(7) received gold nanoparticles in their drinking water in the amounts of 5 mg/L for group Cu-5(7), 10 mg/L for group Cu-10(7), and 15 mg/L for group Cu-15(7) during 8 to 14, 22 to 28, and 36 of 42 days of the life of the chicks. The birds in groups Cu-5(3), Cu-10(3), and Cu-15(3) received copper nanoparticles in the same amounts, but only during 8 to 10, 22 to 24, and 36 to 38 days of life. Blood for analysis was collected from the wing vein of all chicks at the age of 42 days. After the rearing period (day 42), six birds from each experimental group with body weight similar to the group average were slaughtered. The carcasses were dissected and samples of the jejunum were collected for analysis of absorption of selected minerals. Mineral absorption was tested using the in vitro gastrointestinal sac technique. Oral administration of copper nanoparticles to chickens in the amount of 5, 10, and 15 mg/L led to accumulation of this element in the intestinal walls. The highest level of copper nanoparticles applied increased Cu content in the blood plasma of the birds. The in vitro study suggests that copper accumulated in the intestines reduces absorption of calcium and zinc, but does not affect iron absorption. © 2016 Poultry Science Association Inc.

Influences of surfactants on the preparation of copper nanoparticles by electron beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Zhou Ruimin [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China)], E-mail: zhourm47@staff.shu.edu.cn; Wu Xinfeng; Hao Xufeng; Zhou Fei [Shanghai Applied Radiation Institute, Shanghai University, Shanghai 201800 (China); Li Hongbin [Department of Chemical Engineering and Technology, Shanghai University, Shanghai 201800 (China); Rao Weihong [Shenzhen Tianding Fine Chemical Engineering Manufacturing Co., Ltd., Shenzhen, Guangdong 518057 (China)

2008-02-15

Electron beam radiation was applied to prepare nano-size copper in water system using polyvinyl alcohol, sodium dodecyl benzene sulfonate, gluten and polyethylene glycol as the surfactants, respectively. The irradiated products were characterized by XRD, TEM and LSPSDA. The XRD and TEM showed that relative pure copper products with an average size of 20 nm, 40 nm and 20 nm can be obtained by using gluten, PEG and SDBS as surfactant, respectively. An admixture of copper and cuprous oxide was obtained in PVA system. The LSPSDA showed that the size of the Cu nanoparticles decreased with increasing the glutin concentration.

Linear and nonlinear optical studies of bare and copper doped TiO2 nanoparticles via sol gel technique

Science.gov (United States)

Rajamannan, B.; Mugundan, S.; Viruthagiri, G.; Praveen, P.; Shanmugam, N.

2014-01-01

In general, the nanoparticles of TiO2 may exist in the phases of anatase, rutile and brookite. In the present work, we used titanium terta iso propoxide and 2-propanol as a common starting material to prepare the precursors of bare and copper doped nanosized TiO2. Then the synthesized products were calcinated at 500 °C and after calcination the pure TiO2 nanoparticles in anatase phase were harvested. The crystallite sizes of bare and copper doped TiO2 nanoparticles were calculated from X-ray diffraction analysis. The existence of functional groups of the samples was identified by Fourier transform infrared spectroscopy. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the copper doped TiO2 nanoparticles were studied by scanning electron microscope fitted with energy dispersive X-ray spectrometer arrangement. The nonlinear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP).

Enhanced reactive oxygen species through direct copper sulfide nanoparticle-doxorubicin complexation

Science.gov (United States)

Li, Yajuan; Cupo, Michela; Guo, Liangran; Scott, Julie; Chen, Yi-Tzai; Yan, Bingfang; Lu, Wei

2017-12-01

CuS-based nanostructures loading the chemotherapeutic agent doxorubicin (DOX) exerted excellent cancer photothermal chemotherapy under multi-external stimuli. The DOX loading was generally designed through electrostatic interaction or chemical linkers. However, the interaction between DOX molecules and CuS nanoparticles has not been investigated. In this work, we use PEGylated hollow copper sulfide nanoparticles (HCuSNPs) to directly load DOX through the DOX/Cu2+ chelation process. Distinctively, the synthesized PEG-HCuSNPs-DOX release the DOX/Cu2+ complexes into surrounding environment, which generate significant reactive oxygen species (ROS) in a controlled manner by near-infrared laser. The CuS nanoparticle-mediated photothermal ablation facilitates the ROS-induced cancer cell killing effect. Our current work reveals a DOX/Cu2+-mediated ROS-enhanced cell-killing effect in addition to conventional photothermal chemotherapy through the direct CuS nanoparticle-DOX complexation.

Synthesis of copper nanoparticles in a fluoropolymer matrix by annealing in vacuum

Energy Technology Data Exchange (ETDEWEB)

Safonov, Alexey, E-mail: safonov@itp.nsc.ru [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation); Sulyaeva, Veronica [Nikolaev Institute of Inorganic Chemistry SB RAS, Lavrentyev Ave. 3, 630090, Novosibirsk (Russian Federation); Timoshenko, Nikolay; Starinskiy, Sergey [Kutateladze Institute of Thermophysics SB RAS, Lavrentyev Ave. 1, 630090, Novosibirsk (Russian Federation)

2017-07-12

In this paper, a method for synthesizing copper nanoparticles in a fluoropolymer matrix is proposed which prevents the reduction in the plasmonic properties due to the oxidation of the metal. The basic idea of the proposed method of nanoparticle synthesis is to anneal of thin metal film coated with a thin layer of fluoropolymer. The morphology and optical properties of the resulting composites were determined. The optical properties remained unchanged after several months of storage under standard conditions. - Highlights: • The copper-fluoropolymer composites are obtained by a combination of GJD and HWCVD. • The annealing of thin Cu film covered with fluoropolymer leads to formation of NPs. • The dilution of the localized surface plasmon resonance due to oxidation was analyzed. • The plasmonic properties of the Cu NPs are saved in the fluoropolymer matrix. • The fluoropolymer matrix prevents oxidation of metal NPs.

Facile Synthesis of Copper Oxide Nanoparticles via Electrospinning

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Abdullah Khalil

2014-01-01

Full Text Available A novel approach for synthesizing copper oxide (CuO nanoparticles (NPs through electrospinning is reported. The approach is based on producing rough and discontinuous electrospun nanofibers from a precursor based on copper acetate salt and polyvinyl alcohol (PVA polymer. Selectively removing the polymeric phase from the fibers produced highly rough CuO nanofibers, which were composed of NPs that are weakly held together in a one-dimensional (1D manner. Sonication in a suitable liquid under controlled conditions completely disintegrated the nanofibers into NPs, resulting in the formation of uniform CuO NPs suspension. Aberration corrected high resolution transmission electron microscope (HRTEM showed that the obtained NPs are highly crystalline and nearly sphere-like with a diameter of 30 to 70 nm. Thus, electrospinning, which is a low cost and industrially scalable technique, can also be employed for economic and large scale synthesis of NPs.

Enhanced antifouling and antibacterial properties of poly (ether sulfone) membrane modified through blending with sulfonated poly (aryl ether sulfone) and copper nanoparticles

Science.gov (United States)

Zhang, Jingjing; Xu, Ya'nan; Chen, Shouwen; Li, Jiansheng; Han, Weiqing; Sun, Xiuyun; Wu, Dihua; Hu, Zhaoxia; Wang, Lianjun

2018-03-01

A series of novel blend ultrafiltration (UF) membranes have been successfully prepared from commercial poly (ether sulfone), lab-synthesized sulfonated poly (aryl ether sulfone) (SPAES, 1 wt%) and copper nanoparticles (0 ∼ 0.4 wt%) via immersion precipitation phase conversion. The micro-structure and separation performance of the membranes were characterized by field emission scanning electron microscopy (SEM) and cross-flow filtration experiments, respectively. Sodium alginate, bovine serum albumin and humic acid were chosen as model organic foulants to investigate the antifouling properties, while E. coil was used to evaluate the antibacterial property of the fabricated membranes. By the incorporation with SPAES and copper nanoparticles, the hydrophilicity, antifouling and antibacterial properties of the modified UF membranes have been profoundly improved. At a copper nanoparticles content of 0.4 wt%, the PES/SPAES/nCu(0.4) membrane exhibited a high pure water flux of 193.0 kg/m2 h, reaching the smallest contact angle of 52°, highest flux recovery ratio of 79% and largest antibacterial rate of 78.9%. Furthermore, the stability of copper nanoparticles inside the membrane matrix was also considerably enhanced, the copper nanoparticles were less than 0.08 mg/L in the effluent during the whole operation.

Bioaccumulation and effects of different-shaped copper oxide nanoparticles in the deposit-feeding snail Potamopyrgus antipodarum

DEFF Research Database (Denmark)

Ramskov, Tina; Selck, Henriette; Banta, Gary Thomas

2014-01-01

Copper oxide (CuO) nanoparticles (NPs) are among the most widely used engineered NPs and are thus likely to end up in the environment, predominantly in sediments. Copper oxide NPs have been found to be toxic to a variety of (mainly pelagic) organisms, but to differing degrees. In the present stud...

One-Pot Soft-Template Synthesis of Nanostructured Copper-Supported Mesoporous Carbon FDU-15 Electrocatalysts for Efficient CO2 Reduction.

Science.gov (United States)

Şahin, Nihat Ege; Comminges, Clément; Le Valant, Anthony; Kiener, Julien; Parmentier, Julien; Napporn, Teko W; Melinte, Georgian; Ersen, Ovidiu; Kokoh, Kouakou B

2018-03-14

Copper-supported mesoporous carbon nanocatalysts (Cu/FDU-15) were synthesized using an easy and convenient one-pot soft-template method for low-overvoltage CO 2 electroreduction. TEM imaging revealed the presence of large Cu nanoparticles (diameter 140 nm) with Cu 2 O nanoparticles (16 nm) as an additional phase. From the electron tomography observations, we found that the copper particles were placed inside and on the exterior surface of the porous FDU-15 support, providing an accessible surface for electrocatalytic reactions. CO 2 electrolyses showed that the mesostructured Cu/FDU-15-350 cathode materials were active towards CO 2 conversion to formic acid with 22 % Faradaic efficiency at a remarkably low overpotential of 290 mV, hydrogen being the only side-product. The catalyst's activity correlates to the calculated metallic surface area, as determined from a geometrical model, confirming that the mesoporous channels act as a diffusion path for the CO 2 molecule, and that the whole Cu surface is accessible to CO 2 , even if particles are entrapped in the carbon matrix. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Copper nanoparticles mediated by chitosan: synthesis and characterization via chemical methods.

Science.gov (United States)

Usman, Muhammad Sani; Ibrahim, Nor Azowa; Shameli, Kamyar; Zainuddin, Norhazlin; Yunus, Wan Md Zin Wan

2012-12-14

Herein we report a synthesis of copper nanoparticles (Cu-NPs) in chitosan (Cts) media via a chemical reaction method. The nanoparticles were synthesized in an aqueous solution in the presence of Cts as stabilizer and CuSO(4)·5H(2)O precursor. The synthesis proceeded with addition of NaOH as pH moderator, ascorbic acid as antioxidant and hydrazine( )as the reducing agent. The characterization of the prepared NPs was done using ultraviolet-visible spectroscopy, which showed a 593 nm copper band. The Field Emission Scanning Electron Microscope (FESEM) images were also observed, and found to be in agreement with the UV-Vis result, confirming the formation of metallic Cu-NPs. The mean size of the Cu-NPs was estimated to be in the range of 35-75 nm using X-ray diffraction. XRD was also used in analysis of the crystal structure of the NPs. The interaction between the chitosan and the synthesized NPs was studied using Fourier transform infrared (FT-IR) spectroscopy, which showed the capping of the NPs by Cts.

Water treatment with exceptional virus inactivation using activated carbon modified with silver (Ag) and copper oxide (CuO) nanoparticles.

Science.gov (United States)

Shimabuku, Quelen Letícia; Arakawa, Flávia Sayuri; Fernandes Silva, Marcela; Ferri Coldebella, Priscila; Ueda-Nakamura, Tânia; Fagundes-Klen, Márcia Regina; Bergamasco, Rosangela

2017-08-01

Continuous flow experiments (450 mL min -1 ) were performed in household filter in order to investigate the removal and/or inactivation of T4 bacteriophage, using granular activated carbon (GAC) modified with silver and/or copper oxide nanoparticles at different concentrations. GAC and modified GAC were characterized by X-ray diffractometry, specific surface area, pore size and volume, pore average diameter, scanning electron microscopy, transmission electron microscopy, zeta potential and atomic absorption spectroscopy. The antiviral activity of the produced porous media was evaluated by passing suspensions of T4 bacteriophage (∼10 5  UFP/mL) through filters. The filtered water was analyzed for the presence of the bacteriophage and the release of silver and copper oxide. The porous media containing silver and copper oxide nanoparticles showed high inactivation capacity, even reaching reductions higher than 3 log. GAC6 (GAC/Ag0.5%Cu1.0%) was effective in the bacteriophage inactivation, reaching 5.53 log reduction. The levels of silver and copper released in filtered water were below the recommended limits (100 ppb for silver and 1000 ppb for copper) in drinking water. From this study, it is possible to conclude that activated carbon modified with silver and copper oxide nanoparticles can be used as a filter for virus removal in the treatment of drinking water.

Green synthesis, characterization and catalytic activity of natural bentonite-supported copper nanoparticles for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol

Directory of Open Access Journals (Sweden)

Akbar Rostami-Vartooni

2015-12-01

Full Text Available In this study, Cu nanoparticles were immobilized on the surface of natural bentonite using Thymus vulgaris extract as a reducing and stabilizing agent. The natural bentonite-supported copper nanoparticles (Cu NPs/bentonite were characterized by FTIR spectroscopy, X-ray diffraction (XRD, X-ray fluorescence (XRF, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray spectroscopy (EDS, transmission electron microscopy (TEM, selected area electron diffraction (SAED and Brunauer–Emmett–Teller (BET analysis. Afterward, the catalytic performance of the prepared catalyst was investigated for the solvent-free synthesis of 1-substituted 1H-1,2,3,4-tetrazoles and reduction of 4-nitrophenol (4-NP in water. It was found that the Cu NPs/bentonite is a highly active and recyclable catalyst for related reactions.

Sublethal effects of copper nanoparticles on the histology of gill, liver and kidney of the Caspian roach, Rutilus rutilus caspicus

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Sh. Aghamirkarimi

2017-09-01

Full Text Available The current study has determined the toxicity effects of copper nanoparticles on the some vital organs such as gill, liver and kidney of Caspian Roach; Rutillus rutillus caspicus. For this purpose, 120 fishes were used as experimental samples and exposed to 0.1, 0.2 and 0.5 mg/L of Cu nanoparticles for 21 days, and 30 fishes assumed as the experiment control. The mean water temperature of the aquaria was 22±2 ºC, dissolved oxygen 5.2 mg/L, pH at 7±0.004 and the concentration of calcium carbonate was 270 ppm. On 7, 14 and 21 days after exposing the fishes to copper nanoparticles, three fishes were randomly selected from each aquaria, sacrificed and samples from their gill, liver and kidney were taken and fixed in cold 10 % buffered formalin. Then microscopic sections were prepared and examined by light microscope which showed histological alternations in the gill, liver and kidney tissues. Evaluation of these changes could be useful in estimating the harmful effects of copper nanoparticles. Histological alternation in gills included: hyperplasia, fusion and detachment of secondary lamellae, blood congestion in vascular axis of primary filaments, reduced secondary lamellae length and cellular degeneration. Histological changes in liver included blood congestion in the central veins, cytoplasmic vacuolation of the hepatocytes, cellular degeneration and congestion in the blood sinusoids and necrosis of the hepatocytes. Histological changes in kidneys included glomerular shrinkage, severe degeneration in the tubules cells, interstitial tissue and glomerulus, increase in interstitial tissue cells and macrophages aggregation. The degree of damages was more intensive at higher copper nanoparticles concentrations. The result of the study showed that copper nanoparticles could cause severe damages in the vital tissues of Caspian roach; Rutillus rutillus caspicus and have lethal effects for fish.

Growth graphene on silver-copper nanoparticles by chemical vapor deposition for high-performance surface-enhanced Raman scattering

Science.gov (United States)

Zhang, Xiumei; Xu, Shicai; Jiang, Shouzhen; Wang, Jihua; Wei, Jie; Xu, Shida; Gao, Shoubao; Liu, Hanping; Qiu, Hengwei; Li, Zhen; Liu, Huilan; Li, Zhenhua; Li, Hongsheng

2015-10-01

We present a graphene/silver-copper nanoparticle hybrid system (G/SCNPs) to be used as a high-performance surface-enhanced Raman scattering (SERS) substrate. The silver-copper nanoparticles wrapped by a monolayer graphene layer are directly synthesized on SiO2/Si substrate by chemical vapor deposition in a mixture of methane and hydrogen. The G/SCNPs shows excellent SERS enhancement activity and high reproducibility. The minimum detected concentration of R6G is as low as 10-10 M and the calibration curve shows a good linear response from 10-6 to 10-10 M. The date fluctuations from 20 positions of one SERS substrate are less than 8% and from 20 different substrates are less than 10%. The high reproducibility of the enhanced Raman signals could be due to the presence of an ultrathin graphene layer and uniform morphology of silver-copper nanoparticles. The use of G/SCNPs for detection of nucleosides extracted from human urine demonstrates great potential for the practical applications on a variety of detection in medicine and biotechnology field.

Synthesis and Biomedical Applications of Copper Sulfide Nanoparticles: From Sensors to Theranostics

Science.gov (United States)

Goel, Shreya; Chen, Feng; Cai, Weibo

2013-01-01

Copper sulfide (CuS) nanoparticles have attracted increasing attention from biomedical researchers across the globe, because of their intriguing properties which have been mainly explored for energy- and catalysis-related applications to date. This focused review article aims to summarize the recent progress made in the synthesis and biomedical applications of various CuS nanoparticles. After a brief introduction to CuS nanoparticles in the first section, we will provide a concise outline of the various synthetic routes to obtain different morphologies of CuS nanoparticles, which can influence their properties and potential applications. CuS nanoparticles have found broad applications in vitro, especially in the detection of biomolecules, chemicals, and pathogens which will be illustrated in detail. The in vivo uses of CuS nanoparticles have also been investigated in preclinical studies, including molecular imaging with various techniques, cancer therapy based on the photothermal properties of CuS, as well as drug delivery and theranostic applications. Research on CuS nanoparticles will continue to thrive over the next decade, and tremendous opportunities lie ahead for potential biomedical/clinical applications of CuS nanoparticles. PMID:24106015

Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption

Science.gov (United States)

Boruban, Cansu; Esenturk, Emren Nalbant

2018-03-01

Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (https://www.google.com.tr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.intertek.com%2Fanalytical-laboratories%2Fxrd%2F&ei=-5WZVYSCHISz7Aatqq-IAw&usg=AFQjCNFBlk-9wqy49foh8tskmbD-GGbG9g&sig2=eKrhYjO75rl_Id2sLGpq4w&bvm=bv.96952980,d.bGg) (XRD), X-ray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanoparticles are well-distributed on the activated carbon surface. The CO2 adsorption behavior of the activated carbon-supported CuO nanoparticles was observed by thermogravimetric analysis (TGA), temperature programmed desorption (TPD), Fourier transform infrared (FTIR), and BET analyses. The results showed that CuO nanoparticle loading on activated carbon led to about 70% increase in CO2 adsorption capacity of activated carbon under standard conditions (1 atm and 298 K). The main contributor to the observed increase is an improvement in chemical adsorption of CO2 due to the presence of CuO nanoparticles on activated carbon.

Green synthesis of copper nanoparticles by Citrus medica Linn. (Idilimbu) juice and its antimicrobial activity.

Science.gov (United States)

Shende, Sudhir; Ingle, Avinash P; Gade, Aniket; Rai, Mahendra

2015-06-01

We report an eco-friendly method for the synthesis of copper nanoparticles (CuNPs) using Citron juice (Citrus medica Linn.), which is nontoxic and cheap. The biogenic copper nanoparticles were characterized by UV-Vis spectrophotometer showing a typical resonance (SPR) at about 631 nm which is specific for CuNPs. Nanoparticles tracking analysis by NanoSight-LM20 showed the particles in the range of 10-60 nm with the concentration of 2.18 × 10(8) particles per ml. X-ray diffraction revealed the FCC nature of nanoparticles with an average size of 20 nm. The antimicrobial activity of CuNPs was determined by Kirby-Bauer disk diffusion method against some selected species of bacteria and plant pathogenic fungi. It was reported that the synthesized CuNPs demonstrated a significant inhibitory activity against Escherichia coli followed by Klebsiella pneumoniae, Pseudomonas aeruginosa, Propionibacterium acnes and Salmonella typhi. Among the plant pathogenic fungi tested, Fusarium culmorum was found to be most sensitive followed by F. oxysporum and F. graminearum. The novelty of this work is that for the first time citron juice was used for the synthesis of CuNPs.

Synthesis of Copper nanoparticles through vesicle template using gamma irradiation

International Nuclear Information System (INIS)

Noor Ezzah Rahimah Ahmad Samsuri

2012-01-01

Nano technology has gained attention for its application in life. This study was conducted to produce copper (Cu) nanoparticles using gamma ray irradiation through template vesicles. Cu nanoparticle has a variety of applications such as capacitor materials, catalyst, conductive coating, high thermal conductivity materials as well as lubricant additives. this study used gamma radiation compared to other methods because the use of gamma rays in producing nanoparticle is safer and environmental friendly. The purpose of this study was to see the effects of radiation on the formation of Cu nanoparticles. The radiation dose used was 80 kGy and 100 kGy. The vesicles were formed by mixing water, sodium n-lauroyl sarcosinat hydrated, 1-decanol and polyethylene glycol with certain ratio (85 %: 5 %: 7 %: 3 %). Analysis from the transmission electron microscopy (TEM) showed the production of multilammelar vesicles in size between 30 nm-80 nm. The formation of nanoparticles was analyzed using UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). Analysis of UV-Vis absorption spectroscopy showed no resonance peak around 600 nm. XRD analysis confirmed the presence of Cu, Cu 2 O and CuO. Analysis and characterisation using transmission electron microscopy (TEM) also confirmed that nanoparticles were produced with different sizes according to the radiation dose. At the radiation dose of 80 kGy, nanoparticles size is found vary between 30 nm to 90 nm. While at the radiation dose of 100 kGy, nanoparticles size is found vary between 3 nm to 7 nm. From this study it can be concluded that higher radiation dse will produce smaller nanoparticles. (author)

Investigation of Structure and Physico-Mechanical Properties of Composite Materials Based on Copper - Carbon Nanoparticles Powder Systems

Directory of Open Access Journals (Sweden)

Kovtun V.

2015-04-01

Full Text Available Physico-mechanical and structural properties of electrocontact sintered copper matrix- carbon nanoparticles composite powder materials are presented. Scanning electron microscopy revealed the influence of preliminary mechanical activation of the powder system on distribution of carbon nanoparticles in the metal matrix. Mechanical activation ensures mechanical bonding of nanoparticles to the surface of metal particles, thus giving a possibility for manufacture of a composite with high physico-mechanical properties.

Microfluidic Synthesis and Biological Evaluation of Photothermal Biodegradable Copper Sulfide Nanoparticles.

Science.gov (United States)

Ortiz de Solorzano, Isabel; Prieto, Martín; Mendoza, Gracia; Alejo, Teresa; Irusta, Silvia; Sebastian, Victor; Arruebo, Manuel

2016-08-24

The continuous synthesis of biodegradable photothermal copper sulfide nanoparticles has been carried out with the aid of a microfluidic platform. A comparative physicochemical characterization of the resulting products from the microreactor and from a conventional batch reactor has been performed. The microreactor is able to operate in a continuous manner and with a 4-fold reduction in the synthesis times compared to that of the conventional batch reactor producing nanoparticles with the same physicochemical requirements. Biodegradation subproducts obtained under simulated physiological conditions have been identified, and a complete cytotoxicological analysis on different cell lines was performed. The photothermal effect of those nanomaterials has been demonstrated in vitro as well as their ability to generate reactive oxygen species.

Controllable synthesis and characterization of novel copper-carbon core-shell structured nanoparticles

International Nuclear Information System (INIS)

Zhai, Jing; Tao, Xia; Pu, Yuan; Zeng, Xiao-Fei; Chen, Jian-Feng

2011-01-01

Highlights: → We reported a facile, green and cheap hydrothermal method to obtain novel copper-carbon core-shell nanoparticles. → The as-formed particles with controllable size and morphology are antioxidant. → The particles with organic-group-loaded surfaces and protective shells are expected to be applied in fields of medicine, electronics, sensors and lubricant. -- Abstract: A facile hydrothermal method was developed for preparing copper-carbon core-shell structured particles through a reaction at 160 o C in which glucose, copper sulfate pentahydrate and cetyltrimethylammonium bromide were used as starting materials. The original copper-carbon core-shell structured particles obtained were sized of 100-250 nm. The thickness of carbonaceous shells was controlled ranging from 25 to 100 nm by adjusting the hydrothermal duration time and the concentrations of glucose in the process. Products were characterized with transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, Fourier transform infrared spectroscopy. Since no toxic materials were involved in the preparation, particles with stable carbonaceous framework and reactive surface also showed promising applications in medicine, electronics, sensors, lubricant, etc.

Controllable synthesis and characterization of novel copper-carbon core-shell structured nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zhai, Jing [Sin-China Nano Technology Center, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, No. 15 Beisanhuan Dong Lu, Beijing 100029 (China); Tao, Xia; Pu, Yuan; Zeng, Xiao-Fei [Sin-China Nano Technology Center, Key Lab for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Chen, Jian-Feng, E-mail: chenjf@mail.buct.edu.cn [Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology, No. 15 Beisanhuan Dong Lu, Beijing 100029 (China)

2011-06-15

Highlights: {yields} We reported a facile, green and cheap hydrothermal method to obtain novel copper-carbon core-shell nanoparticles. {yields} The as-formed particles with controllable size and morphology are antioxidant. {yields} The particles with organic-group-loaded surfaces and protective shells are expected to be applied in fields of medicine, electronics, sensors and lubricant. -- Abstract: A facile hydrothermal method was developed for preparing copper-carbon core-shell structured particles through a reaction at 160 {sup o}C in which glucose, copper sulfate pentahydrate and cetyltrimethylammonium bromide were used as starting materials. The original copper-carbon core-shell structured particles obtained were sized of 100-250 nm. The thickness of carbonaceous shells was controlled ranging from 25 to 100 nm by adjusting the hydrothermal duration time and the concentrations of glucose in the process. Products were characterized with transmission electron microscopy, X-ray diffraction, energy dispersive spectroscopy, Fourier transform infrared spectroscopy. Since no toxic materials were involved in the preparation, particles with stable carbonaceous framework and reactive surface also showed promising applications in medicine, electronics, sensors, lubricant, etc.

Antibacterial effect of silk treated with silver and copper nanoparticles synthesized by pulsed laser ablation in distilled water

Science.gov (United States)

Baruah, Prahlad K.; Raman, Moghe A.; Chakrabartty, Ishani; Rangan, Latha; Sharma, Ashwini K.; Khare, Alika

2018-05-01

The antibacterial activity of three kinds of silks viz. Eri, Pat and Muga treated with silver and copper nanoparticles is reported in this paper. The nanoparticles have been synthesized by pulsed laser ablation of the respective metal targets in distilled water. Treatment of the silk pellets with the synthesized nanoparticles exhibited definite antibacterial activity whereas no such activity is observed in the untreated silk pellets.

Molecular dynamics simulations of aggregation of copper nanoparticles with different heating rates

Science.gov (United States)

Li, Qibin; Wang, Meng; Liang, Yunpei; Lin, Liyang; Fu, Tao; Wei, Peitang; Peng, Tiefeng

2017-06-01

Molecular dynamics simulations were employed to investigate the heating rates' effect on aggregation of two copper nanoparticles. The aggregation can be distinguished into three distinct regimes by the contacting and melting of nanoparticles. The nanoparticles contacting at a lower temperature during the sintering with lower heating rate, meanwhile, some temporary stacking fault exists at the contacting neck. The aggregation properties of the system, i.e. neck diameter, shrinkage ratio, potential energy, mean square displacement (MSD) and relative gyration radius, experience drastic changes due to the free surface annihilation. After the nanoparticles coalesced for a stable period, the shrinkage ratio, MSD, relative gyration radius and neck diameter of the system are dramatically changed during the melting process. It is shown that the shrinkage ratio and MSD have relative larger increasing ratio for a lower heating rate. While the evolution of the relative gyration radius and neck diameter is only sensitive to the temperature.

Catalytic Activity of Silicon Nanowires Decorated with Gold and Copper Nanoparticles Deposited by Pulsed Laser Ablation

Directory of Open Access Journals (Sweden)

Michele Casiello

2018-01-01

Full Text Available Silicon nanowires (SiNWs decorated by pulsed laser ablation with gold or copper nanoparticles (labeled as AuNPs@SiNWs and CuNPs@SiNWs were investigated for their catalytic properties. Results demonstrated high catalytic performances in the Caryl–N couplings and subsequent carbonylations for gold and copper catalysts, respectively, that have no precedents in the literature. The excellent activity, attested by the very high turn over number (TON values, was due both to the uniform coverage along the NW length and to the absence of the chemical shell surrounding the metal nanoparticles (MeNPs. A high recyclability was also observed and can be ascribed to the strong covalent interaction at the Me–Si interface by virtue of metal “silicides” formation.

L-cysteine protected copper nanoparticles as colorimetric sensor for mercuric ions.

Science.gov (United States)

Soomro, Razium A; Nafady, Ayman; Sirajuddin; Memon, Najma; Sherazi, Tufail H; Kalwar, Nazar H

2014-12-01

This report demonstrates a novel, simple and efficient protocol for the synthesis of copper nanoparticles in aqueous solution using L-cysteine as capping or protecting agent. UV-visible (UV-vis) spectroscopy was employed to monitor the LSPR band of L-cysteine functionalized copper nanoparticles (Cyst-Cu NPs) based on optimizing various reaction parameters. Fourier Transform Infrared (FTIR) spectroscopy provided information about the surface interaction between L-cysteine and Cu NPs. Transmission Electron Microscopy (TEM) confirmed the formation of fine spherical, uniformly distributed Cyst-Cu NPs with average size of 34 ± 2.1 nm. X-ray diffractometry (XRD) illustrated the formation of pure metallic phase crystalline Cyst-Cu NPs. As prepared Cyst-Cu NPs were tested as colorimetric sensor for determining mercuric (Hg(2+)) ions in an aqueous system. Cyst-Cu NPs demonstrated very sensitive and selective colorimetric detection of Hg(2+) ions in the range of 0.5 × 10(-6)-3.5 × 10(-6) mol L(-1) based on decrease in LSPR intensity as monitored by a UV-vis spectrophotometer. The developed sensor is simple, economic compared to those based on precious metal nanoparticles and sensitive to detect Hg(2+) ions with detection limit down to 4.3 × 10(-8) mol L(-1). The sensor developed in this work has a high potential for rapid and on-site detection of Hg(2+) ions. The sensor was successfully applied for assessment of Hg(2+) ions in real water samples collected from various locations of the Sindh River. Copyright © 2014 Elsevier B.V. All rights reserved.

Green Adeptness in the Synthesis and Stabilization of Copper Nanoparticles: Catalytic, Antibacterial, Cytotoxicity, and Antioxidant Activities

Science.gov (United States)

Din, Muhammad Imran; Arshad, Farhan; Hussain, Zaib; Mukhtar, Maria

2017-12-01

Copper nanoparticles (CuNPs) are of great interest due to their extraordinary properties such as high surface-to-volume ratio, high yield strength, ductility, hardness, flexibility, and rigidity. CuNPs show catalytic, antibacterial, antioxidant, and antifungal activities along with cytotoxicity and anticancer properties in many different applications. Many physical and chemical methods have been used to synthesize nanoparticles including laser ablation, microwave-assisted process, sol-gel, co-precipitation, pulsed wire discharge, vacuum vapor deposition, high-energy irradiation, lithography, mechanical milling, photochemical reduction, electrochemistry, electrospray synthesis, hydrothermal reaction, microemulsion, and chemical reduction. Phytosynthesis of nanoparticles has been suggested as a valuable alternative to physical and chemical methods due to low cytotoxicity, economic prospects, environment-friendly, enhanced biocompatibility, and high antioxidant and antimicrobial activities. The review explains characterization techniques, their main role, limitations, and sensitivity used in the preparation of CuNPs. An overview of techniques used in the synthesis of CuNPs, synthesis procedure, reaction parameters which affect the properties of synthesized CuNPs, and a screening analysis which is used to identify phytochemicals in different plants is presented from the recent published literature which has been reviewed and summarized. Hypothetical mechanisms of reduction of the copper ion by quercetin, stabilization of copper nanoparticles by santin, antimicrobial activity, and reduction of 4-nitrophenol with diagrammatic illustrations are given. The main purpose of this review was to summarize the data of plants used for the synthesis of CuNPs and open a new pathway for researchers to investigate those plants which have not been used in the past.

Poly(glycidyl methacrylate)-A soft template for the facile preparation of poly(glycidyl methacrylate) core-copper nanoparticle shell nanocomposite

Science.gov (United States)

Mohammed Safiullah, S.; Abdul Wasi, K.; Anver Basha, K.

2015-12-01

Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) was prepared by simple two step method (i) The synthesis of poly(glycidyl methacrylate) (PGMA) beads by free radical suspension polymerization followed by (ii) direct deposition of copper nanoparticles (CuNPs) on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. In this method the CuNPs were formed by chemical reduction of copper salts using sodium borohydride in water medium and deposited directly on the activated PGMA. Two different concentrations of copper salts were employed to know the effect of concentration on the shape and size of nanoparticles. The results showed that, the different sizes and shapes of CuNPs were deposited on the PGMA matrix. The X-ray Diffraction study results showed that the CuNPs were embedded on the surface of the PGMA matrix. The scanning electron microscopic images revealed that the fabrication of CuNPs on the PGMA matrix possess different shapes and changes the morphology and nature of PGMA beads significantly. The fluorescent micrograph also confirmed that the CuNPs were doped on the PGMA surface. The thermal studies have demonstrated that the CuNPs deposition on the surface of PGMA beads had a significant effect.

A new copper(I) coordination polymer with N.sub.2./sub.-donor schiff base and Its use as precursor for CuO nanoparticle: Spectroscopic, thermal and structural studies

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Rohlíček, Jan; Machek, Pavel; Das, D.

2014-01-01

Roč. 25, č. 5 (2014), s. 1425-1434 ISSN 1040-7278 Grant - others:AV ČR(CZ) Praemium Academiae Institutional support: RVO:68378271 Keywords : copper(I) complex * schiff base * spectroscopy * thermal study * nanoparticle * SEM * XRD Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.302, year: 2014

Impaired behavioural response to alarm substance in rainbow trout exposed to copper nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Sovová, Tereza [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, Plymouth University, Devon (United Kingdom); Department of Environmental Chemistry, Faculty of Environmental Technology, Institute of Chemical Technology, Prague (Czech Republic); Boyle, David, E-mail: david.boyle@ualberta.ca [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, Plymouth University, Devon (United Kingdom); Sloman, Katherine A. [School of Science, University of the West of Scotland, Paisley (United Kingdom); Vanegas Pérez, Cecilia [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, Plymouth University, Devon (United Kingdom); Laboratory of Animal Ecophysiology and Aquatic Ecotoxicology, National Autonomous University of Mexico, Mexico City (Mexico); Handy, Richard D. [Ecotoxicology Research and Innovation Centre, School of Biomedical and Biological Sciences, Plymouth University, Devon (United Kingdom)

2014-07-01

Highlights: • Copper nanoparticles impaired the behavioural response of trout to alarm substance. • This effect appeared to be greater than in trout exposed to copper sulphate. • Toxicity was mediated by interaction of materials at external surfaces of fish. • Copper nanoparticles did not affect the morphology of the olfactory rosette. • Copper nanoparticles caused a change in glutathione status in brains of fish. - Abstract: To date, studies of the toxicity of engineered nanoparticles (NPs) in fish have not fully considered effects on olfactory-mediated behaviours, despite their ecological importance. In this study the effects of copper NPs (Cu NPs) on the anti-predator behavioural responses of juvenile rainbow trout (Oncorhynchus mykiss) to trout alarm substance was investigated. Individual fish were exposed for 12 h to a control (no added Cu), 50 μg l⁻¹ of Cu as Cu NPs, or 50 μg l⁻¹ Cu as CuSO₄, after which fish behaviours were analyzed in 10 min periods before and after the addition of the alarm substance stimulus. The response of control fish to deionised water (negative control, no alarm substance stimulus) was also analyzed. The alarm substance elicited a behavioural response in the control fish characterized by an immediate freeze response and the slower resumption of swimming activity compared to negative controls exposed to the sham deionised water stimuli. In fish exposed to Cu NPs, the behavioural response to alarm substance was eliminated, with no significant difference in behaviours compared to negative controls. In comparison, exposure to 50 μg l⁻¹ Cu as CuSO₄ decreased, but did not eliminate the response of fish to alarm substance, which indicated a significantly greater effect of Cu NPs on olfactory mediated behaviours than of the equivalent concentration of Cu as CuSO₄. Measurement of total Cu concentrations in the tissues of fish demonstrated no significant accumulation of Cu from any treatment in gill, liver or brain

Support Functionalization To Retard Ostwald Ripening in Copper Methanol Synthesis Catalysts

NARCIS (Netherlands)

van den Berg, Roy; Parmentier, Tanja E.; Elkjaer, Christian F.; Gommes, Cedric J.; Sehested, Jens; Helveg, Stig; de Jongh, Petra E.; de Jong, Krijn P.

A main reason for catalyst deactivation in supported catalysts for methanol synthesis is copper particle growth. We have functionalized the support surface in order to suppress the formation and/or transport of mobile copper species and thereby catalyst deactivation. A Stober silica support was

A benchmark study of commercially available copper nanoparticle inks for application in organic electronic devices

NARCIS (Netherlands)

Polino, G.; Abbel, R.; Shanmugam, S.; Bex, G.J.P.; Hendriks, R.; Brunetti, F.; Di Carlo, A.; Andriessen, R.; Galagan, Y.

2016-01-01

A set of three commercial copper nanoparticle based inkjet inks has been benchmarked with respect to their potential to form conducting printed structures for future applications in organic electronic devices. Significant differences were observed in terms of jetting properties, spreading behaviour

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete, Part I

DEFF Research Database (Denmark)

Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noelle

2015-01-01

Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely...... unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L....... In nature, L. variegatus is potentially exposed to Cu via both water and sediment. However, sediment progressively becomes the predominant exposure route for Cu in L. variegatus as Cu partitioning to sediment increases...

Effect of Copper Nanoparticles Dispersion on Catalytic Performance of Cu/SiO2 Catalyst for Hydrogenation of Dimethyl Oxalate to Ethylene Glycol

Directory of Open Access Journals (Sweden)

Yajing Zhang

2013-01-01

Full Text Available Cu/SiO2 catalysts, for the synthesis of ethylene glycol (EG from hydrogenation of dimethyl oxalate (DMO, were prepared by ammonia-evaporation and sol-gel methods, respectively. The structure, size of copper nanoparticles, copper dispersion, and the surface chemical states were investigated by X-ray diffraction (XRD, transmission electron microscopy (TEM, temperature-programmed reduction (TPR, and X-ray photoelectron spectroscopy (XPS and N2 adsorption. It is found the structures and catalytic performances of the catalysts were highly affected by the preparation method. The catalyst prepared by sol-gel method had smaller average size of copper nanoparticles (about 3-4 nm, better copper dispersion, higher Cu+/C0 ratio and larger BET surface area, and higher DMO conversion and EG selectivity under the optimized reaction conditions.

Effect of different levels of copper nanoparticles and copper sulphate on performance, metabolism and blood biochemical profiles in broiler chicken

DEFF Research Database (Denmark)

Skot, Abdullah Talal Abdullah; Vadalasetty, Krishna Prasad; Lukasiewicz, M.

2018-01-01

the final body weight, average daily gain and feed conversion ratio in relation to the control group. Conversely, the provision of Cu in the drinking water had less of an effect on growth performance in comparison with the injected groups. A significant improvement was shown in energy and nitrogen......A study was conducted to investigate the influence of copper administration in ovo to chicken embryos and/or supplied in drinking water to growing chickens in the form copper nanoparticles (Cu-NP) or copper sulphate (CuSO4). The fertilised eggs were assigned to three groups (n = 50 per group......): control (not injected), injected with 50 mg/kg Cu-NP or with 50 mg/kg CuSO4 at day 1 of incubation. Thereafter, 126 one-day-old broiler chickens were randomly assigned to seven post-hatched groups: control not injected and not provided with Cu in the drinking water, injected with 50 mg/kg Cu-NP + 20 mg...

Optical Properties and Microstructure of Silver-Copper Nanoparticles Synthesized by Pulsed Laser Deposition

Science.gov (United States)

Hirai, Makoto; Kumar, Ashok

2007-12-01

Utilizing a pulsed laser deposition (PLD) method, silver-copper (Ag-Cu) nanoparticles have been synthesized by changing the surface area ratio of the target ( S R = S Cu/( S Ag + S Cu)) from 0 to 30%. The peak absorption attributed to surface plasmon resonance (SPR) increased when increasing S R up to 15%, above which it decreased. The peak shifts seem to be induced by the changes in the conductivity and morphology of the Ag-Cu nanoparticles. Additionally, the interplanar spacings of the Ag-Cu nanoparticles prepared at S R = 15% corresponded to the Ag {111}, {200}, {220}, and Cu {111} planes. However, since the interplanar spacings attributed to the Cu {200} and {220} planes were not detected, the Ag-Cu nanoparticles were believed to possess a lattice constant ( a) close not to the Cu phase ( a = 3.615 Å) but to the Ag phase ( a = 4.086 Å). Moreover, confirming the presence of Cu atoms in the nanoparticles using energy dispersive X-ray (EDX) spectra, Ag-Cu nanoparticles may be a solid solution in which Cu atoms partially replace Ag atoms in the fcc structure.

Extracellular Synthesis of Silver Nanoparticles by Ralstonia sp. SM8 Isolated from the Sarcheshmeh Copper Mine

Directory of Open Access Journals (Sweden)

Morahem Ashengroph

2014-04-01

Full Text Available Introduction: The biological synthesis of nanoparticles has gained enormous importance due to the development of clean and environmentally-friendly processes. Silver is highly toxic to microbial cells, Nevertheless, it has been reported that several microorganisms are silver resistance and corroborate the microbial reduction of water soluble Ag+ to Ag0 nanoparticles. In this study, native strains of bacteria screen for use as biocatalysts for extracellular synthesis of silver nanoparticles. Materials and methods: Eight different strains of bacteria exhibiting high silver tolerance were isolated from collecting soil samples from copper and gold mines and characterized using morphological observations and preliminary biochemical tests. The bacterial strains in the presence of 1 g/l Ag+ solution at pH 7 were incubated at 28º C for 48 h in an orbital shaker. The silver nanoparticles formation was investigated by visual observations (changing the color of the reaction solution, spectroscopic techniques and microscopic observations. Results: Among the 8 strains giving high Ag+ tolerance, the strain SM8, isolated from the Sarcheshmeh Copper Mine, Kerman, showed the capability of promoting the formation extracellular Ag nanoparticles. The strain was selected and identified as Ralstonia sp. SM8 (GenBank accession number KF264453 based on morphological and biochemical characteristics and its molecular phylogenetic analysis. Results obtained by visual observations, spectral data achieved from UV–vis, XRD spectrum and SEM micrographs revealed the extracellular formation of spherical silver nanoparticles in the size range of 20-50 nm with the culture supernatants of Ralstonia sp. SM8. Discussion and conclusion: Based on the results obtained, fast and extracellular synthesis of silver nanoparticles, without the need for complicated extraction steps, can be taken by using the culture supernatants of Ralstonia sp. SM8. The current study is the first report

Method for forming thermally stable nanoparticles on supports

Science.gov (United States)

Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

2013-08-20

An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

Effects of various polyoxyethylene sorbitan monooils (Tweens) and sodium dodecyl sulfate on reflux synthesis of copper nanoparticles

International Nuclear Information System (INIS)

Zhang Xifeng; Yin Hengbo; Cheng Xiaonong; Hu Huifeng; Yu Qi; Wang Aili

2006-01-01

Size-controlled synthesis of phase pure Cu nanoparticles was carried out by using copper sulfate pentahydrate as a precursor, ascorbic acid as a reductant, Tweens and sodium dodecyl sulfate (SDS) as modifiers in an aqueous solution at 80 deg. C. The as-prepared Cu nanoparticles were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and Fourier transform infrared (FT-IR). The stabilizing effects of SDS and Tweens on the Cu nanoparticles should be through the coordination between Cu nanoparticles and the respective sulfate group and oxygen-containing bond. The synergic effect of the composite SDS and Tweens on Cu nanoparticles was different from those arising from the individuals

As-grown graphene/copper nanoparticles hybrid nanostructures for enhanced intensity and stability of surface plasmon resonance

Science.gov (United States)

Li, Yun-Fei; Dong, Feng-Xi; Chen, Yang; Zhang, Xu-Lin; Wang, Lei; Bi, Yan-Gang; Tian, Zhen-Nan; Liu, Yue-Feng; Feng, Jing; Sun, Hong-Bo

2016-11-01

The transfer-free fabrication of the high quality graphene on the metallic nanostructures, which is highly desirable for device applications, remains a challenge. Here, we develop the transfer-free method by direct chemical vapor deposition of the graphene layers on copper (Cu) nanoparticles (NPs) to realize the hybrid nanostructures. The graphene as-grown on the Cu NPs permits full electric contact and strong interactions, which results in a strong localization of the field at the graphene/copper interface. An enhanced intensity of the localized surface plasmon resonances (LSPRs) supported by the hybrid nanostructures can be obtained, which induces a much enhanced fluorescent intensity from the dye coated hybrid nanostructures. Moreover, the graphene sheets covering completely and uniformly on the Cu NPs act as a passivation layer to protect the underlying metal surface from air oxidation. As a result, the stability of the LSPRs for the hybrid nanostructures is much enhanced compared to that of the bare Cu NPs. The transfer-free hybrid nanostructures with enhanced intensity and stability of the LSPRs will enable their much broader applications in photonics and optoelectronics.

A new metal electrocatalysts supported matrix: Palladium nanoparticles supported silicon carbide nanoparticles and its application for alcohol electrooxidation

International Nuclear Information System (INIS)

Dai Hong; Chen Yanling; Lin Yanyu; Xu Guifang; Yang Caiping; Tong Yuejin; Guo Longhua; Chen Guonan

2012-01-01

In this paper, we propose a facile approach for palladium nanoparticles load using silicon carbide nanoparticles as the new supported matrix and a familiar NaBH 4 as reducer. Detailed X-ray photoelectron spectrum (XPS) and transmission electron microscopy (TEM) analysis of the resultant products indicated that palladium nanoparticles are successfully immobilized onto the surface of the silicon carbide nanoparticles with uniform size distribution between 5 and 7 nm. The relative electrochemical characterization clearly demonstrated excellent electrocatalytic activity of this material toward alcohol in alkaline electrolytes. Investigation on the characteristics of the electrocatalytic activity of this material further indicated that the palladium nanoparticles supporting on SiC are very promising for direct alcohol fuel cells (DMFCs), biosensor and electronic devices. Moreover, it was proved that silicon carbide nanoparticles with outstanding properties as support for catalysis are of strong practical interest. And the silicon carbide could perform attractive role in adsorbents, electrodes, biomedical applications, etc.

Impaired behavioural response to alarm substance in rainbow trout exposed to copper nanoparticles

International Nuclear Information System (INIS)

Sovová, Tereza; Boyle, David; Sloman, Katherine A.; Vanegas Pérez, Cecilia; Handy, Richard D.

2014-01-01

Highlights: • Copper nanoparticles impaired the behavioural response of trout to alarm substance. • This effect appeared to be greater than in trout exposed to copper sulphate. • Toxicity was mediated by interaction of materials at external surfaces of fish. • Copper nanoparticles did not affect the morphology of the olfactory rosette. • Copper nanoparticles caused a change in glutathione status in brains of fish. - Abstract: To date, studies of the toxicity of engineered nanoparticles (NPs) in fish have not fully considered effects on olfactory-mediated behaviours, despite their ecological importance. In this study the effects of copper NPs (Cu NPs) on the anti-predator behavioural responses of juvenile rainbow trout (Oncorhynchus mykiss) to trout alarm substance was investigated. Individual fish were exposed for 12 h to a control (no added Cu), 50 μg l −1 of Cu as Cu NPs, or 50 μg l −1 Cu as CuSO 4 , after which fish behaviours were analyzed in 10 min periods before and after the addition of the alarm substance stimulus. The response of control fish to deionised water (negative control, no alarm substance stimulus) was also analyzed. The alarm substance elicited a behavioural response in the control fish characterized by an immediate freeze response and the slower resumption of swimming activity compared to negative controls exposed to the sham deionised water stimuli. In fish exposed to Cu NPs, the behavioural response to alarm substance was eliminated, with no significant difference in behaviours compared to negative controls. In comparison, exposure to 50 μg l −1 Cu as CuSO 4 decreased, but did not eliminate the response of fish to alarm substance, which indicated a significantly greater effect of Cu NPs on olfactory mediated behaviours than of the equivalent concentration of Cu as CuSO 4 . Measurement of total Cu concentrations in the tissues of fish demonstrated no significant accumulation of Cu from any treatment in gill, liver or brain

Preparation, characterization and toxicological investigation of copper loaded chitosan nanoparticles in human embryonic kidney HEK-293 cells

Energy Technology Data Exchange (ETDEWEB)

Arora, Divya [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Dhanwal, Vandna [Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Nayak, Debasis [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Saneja, Ankit [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Amin, Hina [Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Rasool, Reyaz ur [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Gupta, Prem Narayan [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Formulation and Drug Delivery Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India); Goswami, Anindya, E-mail: agoswami@iiim.ac.in [Academy of Scientific and Innovative Research (AcSIR), CSIR-Indian Institute of Integrative Medicine, Jammu (India); Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu (India)

2016-04-01

Metallic nanoparticles often attribute severe adverse effects to the various organs or tissues at the molecular level despite of their applications in medical, laboratory and industrial sectors. The present study highlights the preparation of copper adsorbed chitosan nanoparticles (CuCSNPs), its characterization and validation of cytotoxicity in human embryonic kidney HEK-293 cells. Particle size of the CuCSNPs was determined by using Zetasizer and the copper loading was quantified with the help of ICP/MS. Further characterization of CuCSNPs was carried out by FT-IR analysis to determine the formation of nanoparticles and SEM was conducted for the morphological analysis of the CuCSNPs. The CuCSNPs exhibited pronounced cytotoxic effects towards HEK-293 cells as analyzed by MTT assay. Moreover, the CuCSNPs inhibited the colony formation and induced nuclear damage at the dose of 100 μg/mL, much more effectively than the in built control copper sulfate (CuSO{sub 4}). At the molecular level, the CuCSNPs were found to be triggering reactive oxygen species (ROS), activating effector caspases and subsequent PARP cleavage to induce cell death in HEK-293 cells. - Highlights: • Subtoxic levels of CuCSNPs induce apoptosis in HEK-293 cells. • CuCSNPs mediate toxicity via nuclear cleavage and ROS generation. • CuCSNPs favor caspase activation and PARP cleavage to induce cell death.

Synthesis of carbon-supported copper catalyst and its catalytic performance in methanol dehydrogenation

Energy Technology Data Exchange (ETDEWEB)

Shelepova, Ekaterina V. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk, 634050 (Russian Federation); Vedyagin, Aleksey A., E-mail: vedyagin@catalysis.ru [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk, 634050 (Russian Federation); Ilina, Ludmila Yu.; Nizovskii, Alexander I. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk, 630090 (Russian Federation); Tsyrulnikov, Pavel G. [Institute of Hydrocarbon Processing SB RAS, Neftezavodskaya st., 54, Omsk, 644040 (Russian Federation)

2017-07-01

Highlights: • Carbon-supported copper catalyst was studied in dehydrogenation of methanol. • Reduction temperature affected size of Cu particles and Cu{sup 0}/Cu{sup 2+} ratio. • Reduction at 400 °C was required to obtain high methyl formate yield. - Abstract: Carbon-supported copper catalyst was prepared by incipient wetness impregnation of Sibunit with an aqueous solution of copper nitrate. Copper loading was 5 wt.%. Temperature of reductive pretreatment was varied within a range of 200–400 °C. The samples were characterized by transmission electron microscopy, X-ray diffraction analysis, X-ray photoelectron and X-ray absorption spectroscopies. Catalytic activity of the samples was studied in a reaction of methanol dehydrogenation. Silica-based catalyst with similar copper loading was used as a reference. It was found that copper is distributed over the surface of support in the form of metallic and partially oxidized particles of about 12–17 nm in size. Diminished interaction of copper with support was supposed to be responsible for high catalytic activity.

Multifunctional nanocomposites of chitosan, silver nanoparticles, copper nanoparticles and carbon nanotubes for water treatment: Antimicrobial characteristics.

Science.gov (United States)

Morsi, Rania E; Alsabagh, Ahmed M; Nasr, Shimaa A; Zaki, Manal M

2017-04-01

Multifunctional nanocomposites of chitosan with silver nanoparticles, copper nanoparticles and carbon nanotubes either as bi- or multifunctional nanocomposites were prepared. Change in the overall morphology of the prepared nanocomposites was observed; carbon nanotubes, Ag NPs and Cu NPs are distributed homogeneously inside the polymer matrix individually in the case of the bi-nanocomposites while a combination of different dimensional shapes; spherical NPs and nanotubes was observed in the multifunctional nanocomposite. Multifunctional nanocomposites has a higher antimicrobial activity, in relative short contact times, against both Gram negative and Gram positive bacteria; E. coli, Staphylococcus aureus; respectively in addition to the fungal strain; Aspergillus flavus isolated from local wastewater sample. The nanocomposites are highly differentiable at the low contact time and low concentration; 1% concentration of the multifunctional nanocomposite is very effective against the tested microbes at contact time of only 10min. Copyright © 2017 Elsevier B.V. All rights reserved.

Sustainable green catalysis by supported metal nanoparticles.

Science.gov (United States)

Fukuoka, Atsushi; Dhepe, Paresh L

2009-01-01

The recent progress of sustainable green catalysis by supported metal nanoparticles is described. The template synthesis of metal nanoparticles in ordered porous materials is studied for the rational design of heterogeneous catalysts capable of high activity and selectivity. The application of these materials in green catalytic processes results in a unique activity and selectivity arising from the concerted effect of metal nanoparticles and supports. The high catalytic performances of Pt nanoparticles in mesoporous silica is reported. Supported metal catalysts have also been applied to biomass conversion by heterogeneous catalysis. Additionally, the degradation of cellulose by supported metal catalysts, in which bifunctional catalysis of acid and metal plays the key role for the hydrolysis and reduction of cellulose, is also reported. Copyright 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

The role of copper nanoparticles in an etch-and-rinse adhesive on antimicrobial activity, mechanical properties and the durability of resin-dentine interfaces.

Science.gov (United States)

Gutiérrez, Mario F; Malaquias, Pamela; Hass, Viviane; Matos, Thalita P; Lourenço, Lucas; Reis, Alessandra; Loguercio, Alessandro D; Farago, Paulo Vitor

2017-06-01

To evaluate the effect of addition of copper nanoparticles at different concentrations into an etch-and-rinse adhesive (ER) on antimicrobial activity, Knoop microhardness (KHN), in vitro and in situ degree of conversion (DC), as well as the immediate (IM) and 2-year (2Y) resin-dentine bond strength (μTBS) and nanoleakage (NL). Seven experimental ER adhesives were formulated according to the amount of copper nanoparticles incorporated into the adhesives (0 [control], 0.0075 to 1wt.%). We tested the antimicrobial activity of adhesives against Streptococcus mutans using agar diffusion assay after IM and 2Y. The Knoop microhardness and in vitro DC were tested after IM and 2Y. The adhesives were applied to flat occlusal dentine surfaces after acid etching. After resin build-ups, specimens were longitudinally sectioned to obtain beam-like resin-dentine specimens (0.8mm 2 ), which were used for evaluation of μTBS and nanoleakage at the IM and 2Y periods. In situ DC was evaluated at the IM period in these beam-like specimens. Data were submitted to appropriate statistical analyses (α=0.05). The addition of copper nanoparticles provided antimicrobial activity to the adhesives only in the IM evaluation and slightly reduced the KHN, the in vitro and in situ DC (copper concentrations of 1wt.%). However, KHN increase for all concentrations after 2Y. After 2Y, no significant reductions of μTBS (0.06 to 1% wt.%) and increases of nanoleakage were observed for copper containing adhesives compared to the control group. Copper nanoparticles addition up to 0.5wt.% may provide antimicrobial properties to ER adhesives and prevent the degradation of the adhesive interface, without reducing the mechanical properties of the formulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fs–ns double-pulse Laser Induced Breakdown Spectroscopy of copper-based-alloys: Generation and elemental analysis of nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Guarnaccio, A.; Parisi, G.P.; Mollica, D. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy); De Bonis, A. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy); Dipartimento di Scienze, Università degli Studi della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Teghil, R. [Dipartimento di Scienze, Università degli Studi della Basilicata, Via dell' Ateneo Lucano 10, 85100 Potenza (Italy); Santagata, A. [CNR-ISM, U.O.S. Tito Scalo, Zona Industriale, 85050 Tito Scalo, PZ (Italy)

2014-11-01

Evolution of nanoparticles ejected during ultra-short (250 fs) laser ablation of certified copper alloys and relative calibration plots of a fs–ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration is presented. All work was performed in air at atmospheric pressure using certified copper-based-alloy samples irradiated by a fs laser beam and followed by a delayed perpendicular ns laser pulse. In order to evaluate possible compositional changes of the fs induced nanoparticles, it was necessary to consider, for all samples used, comparable features of the detected species. With this purpose the induced nanoparticles black-body-like emission evolution and their relative temperature decay have been studied. These data were exploited for defining the distance between the target surface and the successive ns laser beam to be used. The consequent calibration plots of minor constituents (i.e. Sn, Pb and Zn) of the certified copper-based-alloy samples have been reported by taking into account self-absorption effects. The resulting linear regression coefficients suggest that the method used, for monitoring and ruling the fs laser induced nanoparticles, could provide a valuable approach for establishing the occurrence of potential compositional changes of the detected species. All experimental data reveal that the fs laser induced nanoparticles can be used for providing a coherent composition of the starting target. In the meantime, the fs–ns double-pulse Laser Induced Breakdown Spectroscopy orthogonal configuration here used can be considered as an efficient technique for compositional determination of the nanoparticles ejected during ultra-short laser ablation processes. - Highlights: • Laser induced NP continuum black-body-like emission was used for T determination. • Invariable composition of generated NPs was assumed in the range of 20 μs. • Fs-ns DP-LIBS was employed for the compositional characterization of NPs. • NPs obtained by fs

Synthesis and characterization of Eichhornia-mediated copper oxide ...

Indian Academy of Sciences (India)

In this paper, we report the biosynthesis and characterization of copper oxide nanoparticles ... copper oxide nanoparticles by simple, cost-effective and ecofriendly method as an alternative to other available ... Currently, zinc oxide, gold, silver.

Spectral dependence of nonlinear optical absorption of silica glass with copper nanoparticles

International Nuclear Information System (INIS)

Golubev, A N; Nikitin, S I; Smirnov, M A; Stepanov, A L

2011-01-01

The nonlinear optical properties of silica glass with copper nanoparticles synthesized by ion implantation were investigated by z-scan method in nanosecond time scale. The reverse saturation absorption (RSA) at the wavelength range of 450–540 nm and saturation absorption (SA) at 550–585 nm were observed. It was supposed that the two-photon electron absorption from bound of d-states determined the RSA effect and the SA is due to saturation of plasmon excitation.

Different toxicity mechanisms between bare and polymer-coated copper oxide nanoparticles in Lemna gibba

International Nuclear Information System (INIS)

Perreault, François; Popovic, Radovan; Dewez, David

2014-01-01

In this report, we investigated how the presence of a polymer shell (poly(styrene-co-butyl acrylate) alters the toxicity of CuO NPs in Lemna gibba. Based on total Cu concentration, core–shell CuO NPs were 10 times more toxic than CuO NPs, inducing a 50% decrease of growth rate at 0.4 g l −1 after 48-h of exposure while a concentration of 4.5 g l −1 was required for CuO NPs for a similar effect. Toxicity of CuO NPs was mainly due to NPs solubilization in the media. Based on the accumulated copper content in the plants, core–shell CuO NPs induced 4 times more reactive oxygen species compared to CuO NPs and copper sulfate, indicating that the presence of the polymer shell changed the toxic effect induced in L. gibba. This effect could not be attributed to the polymer alone and reveals that surface modification may change the nature of NPs toxicity. -- Highlights: • Bare and polymer-coated CuO nanoparticles were toxic to Lemna gibba. • Toxicity of bare CuO was mainly due to solubilized soluble copper. • Coated CuO accumulated inside the plants four times more. • Formation of reactive oxygen species was increased by polymer coating. • Coating of nanomaterials modifies mechanisms of action at cellular level. -- Polymer coating increases oxidative stress effect by core–shell CuO nanoparticles

Effects of Copper Oxide Nanoparticles on Antioxidant Enzyme Activities and on Tissue Accumulation of Oreochromis niloticus.

Science.gov (United States)

Tunçsoy, Mustafa; Duran, Servet; Ay, Özcan; Cicik, Bedii; Erdem, Cahit

2017-09-01

Accumulation of copper oxide nanoparticles (CuO NPs) in gill, liver and muscle tissues of Oreochromis niloticus and its effects on superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities in gill and liver tissues were studied after exposing the fish to 20 µg/L Cu over 15 days. Copper levels and enzyme activities in tissues were determined using spectrophotometric (ICP-AES and UV) techniques respectively. No mortality was observed during the experiments. Copper levels increased in gill and liver tissues of O. niloticus compared to control when exposed to CuO NPs whereas exposure to metal had no effect on muscle level at the end of the exposure period. Highest accumulation of copper was observed in liver while no accumulation was detected in muscle tissue. SOD, CAT activities decreased and GPx activity increased in gill and liver tissues when exposed to CuO NPs.

Effects of supporting electrolytes on copper electroplating for filling through-hole

International Nuclear Information System (INIS)

Chen, Chien-Hung; Lu, Chun-Wei; Huang, Su-Mei; Dow, Wei-Ping

2011-01-01

Highlights: → The through-holes of a printed circuit boardare directly filled by copper electroplating using single organic additive. → The inhibiting strength of the additive on copper deposition is related to a supporting electrolyte. → H 2 SO 4 strongly enhances the inhibiting strength of the additive and results in a conformal deposition, whereas Na 2 SO 4 and K 2 SO 4 do not affect the inhibiting strength and lead to good filling capability. - Abstract: The filling of micron through-holes (THs) in a printed circuit board (PCB) by copper electroplating was investigated in this study. The role of supporting electrolytes, such as H 2 SO 4 , Na 2 SO 4 and K 2 SO 4 , was explored using practical TH filling plating and linear-sweep voltammetry (LSV) analysis of plating solutions. The copper could selectively fill THs using one organic additive, namely, tetranitroblue tetrazolium chloride (TNBT), as an inhibitor. The inhibiting strength of TNBT depended on the supporting electrolytes. Although H 2 SO 4 could enhance the inhibiting strength of TNBT, it also decreased the filling capability of the copper plating solution; Na 2 SO 4 and K 2 SO 4 did not enhance the inhibiting strength of TNBT but they increased the filling capability of the copper plating solution. Additionally, the protons could chemically interact with TNBT to form precipitate, whereas sodium and potassium ions did not easily interact with TNBT. The filling capability of the copper plating solution using Na 2 SO 4 and K 2 SO 4 as supporting electrolytes could be greatly improved by adding a small amount of bis(3-sulfopropyl)-disulfide (SPS) and poly(ethylene glycol) (PEG) with a molecular weight of 600.

Transport of Nanoparticles of Zerovalent Copper, Zinc Oxide, and Titanium Dioxide in Saturated Porous Media

Science.gov (United States)

Column tests show nanoparticles (NPs) of Cu(0) and ZnO were immobile at neutral pH in saturated sand.They became mobile in the presence of trizma, humic/fulvic, and citric/oxalic/formic acids. Copper NPs were mobile at pH 9. The deposition rates of TiO2 NP aggregates in both KCl ...

Cellular and molecular responses of adult zebrafish after exposure to CuO nanoparticles or ionic copper.

Science.gov (United States)

Vicario-Parés, Unai; Lacave, Jose M; Reip, Paul; Cajaraville, Miren P; Orbea, Amaia

2018-01-01

Due to their antimicrobial, electrical and magnetic properties, copper nanoparticles (NPs) are suitable for a vast array of applications. Copper can be toxic to biota, making it necessary to assess the potential hazard of copper nanomaterials. Zebrafish (Danio rerio) were exposed to 10 µg Cu/L of CuO NPs of ≈100 nm (CuO-poly) or ionic copper to compare the effects provoked after 3 and 21 days of exposure and at 6 months post-exposure (mpe). At 21 days, significant copper accumulation was only detected in fish exposed to ionic copper. Exposure to both copper forms caused histopathological alterations that could reduce gill functionality, more markedly in the case of ionic copper. Nevertheless, at 6 mpe higher prevalences of gill lesions were detected in fish previously exposed to CuO-poly NPs. No relevant histological alterations were detected in liver, but the lysosomal membrane stability test showed significantly impaired general health status after exposure to both metal forms that lasted up to 6 mpe. 69 transcripts appeared regulated after 3 days of exposure to CuO-poly NPs, suggesting that NPs could produce oxidative stress and reduce metabolism and transport processes. Thirty transcripts were regulated after 21 days of exposure to ionic copper, indicating possible DNA damage. Genes of the circadian clock were identified as the key genes involved in time-dependent differences between the two copper forms. In conclusion, each copper form showed a distinct pattern of liver transcriptome regulation, but both caused gill histopathological alterations and long lasting impaired health status in adult zebrafish.

RoomTtemperature Sulfidation of Copper Nanoparticles with Sulfur Yielding Covellite Nanoparticles

Czech Academy of Sciences Publication Activity Database

Urbanová, Markéta; Kupčík, Jaroslav; Bezdička, Petr; Šubrt, Jan; Pola, Josef

2012-01-01

Roč. 15, č. 6 (2012), s. 511-516 ISSN 1631-0748 R&D Projects: GA ČR GA203/09/0931 Institutional support: RVO:67985858 ; RVO:61388980 Keywords : nanoparticles * covelite * room-tempertaure reaction Subject RIV: CA - Inorganic Chemistry Impact factor: 1.920, year: 2012

Preparation of CuO nanoparticles by thermal decomposition of double-helical dinuclear copper(II Schiff-base complexes

Directory of Open Access Journals (Sweden)

Aliakbar Dehno Khalaji

2015-12-01

Full Text Available In this paper, two double helical dinuclear copper(II complexes of bis-N,O-bidentate Schiff base ligands bis(3-methoxy-N-salicylidene-4,4'-diaminodiphenylsulfone (L1 and bis(5-bromo-N-salicylidene-4,4'-diaminodiphenylsulfone (L2 were prepared and characterized by elemental analyses (CHN, as well as thermal analysis. Elemental analyses (CHN suggested that the reaction between ligands and copper salt has been occurred in 1:1 molar ratio. In these complexes the Schiff base ligands behaves as an anionic and bis-bidentate chelate and is coordinated to the copper(II ion via two phenolic oxygen and two iminic nitrogen atoms. In these double helical dinuclear complexes, each copper(II center has a pseudo-tetrahedral coordination sphere two-wrapped ligands. Thermal analysis of ligands and their complexes were studied in the range of room temperature to 750 °C with a heating rate of 10 °C min-1. TG plots show that the ligands and their complexes are thermally decomposed via 2 and 3 thermal steps, respectively. In addition, the complexes thermally decomposed in air at 520 °C for 3 h. The obtained solids characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The X-ray pattern result shows that the CuO nanoparticles are pure and single phase. The TEM result shows the as prepared CuO nanoparticles were very small and similar shape with particle size about

Poly(glycidyl methacrylate)—A soft template for the facile preparation of poly(glycidyl methacrylate) core-copper nanoparticle shell nanocomposite

International Nuclear Information System (INIS)

Mohammed Safiullah, S.; Abdul Wasi, K.; Anver Basha, K.

2015-01-01

Graphical abstract: - Highlights: • PGMA/Cu nanohybrids have been synthesized by Surface deposition method. • The CuNPs were deposited on the PGMA surface without surface modification. • CuNP deposition on PGMA has a significant effect on morphology and thermal stability. - Abstract: Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) was prepared by simple two step method (i) The synthesis of poly(glycidyl methacrylate) (PGMA) beads by free radical suspension polymerization followed by (ii) direct deposition of copper nanoparticles (CuNPs) on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. In this method the CuNPs were formed by chemical reduction of copper salts using sodium borohydride in water medium and deposited directly on the activated PGMA. Two different concentrations of copper salts were employed to know the effect of concentration on the shape and size of nanoparticles. The results showed that, the different sizes and shapes of CuNPs were deposited on the PGMA matrix. The X-ray Diffraction study results showed that the CuNPs were embedded on the surface of the PGMA matrix. The scanning electron microscopic images revealed that the fabrication of CuNPs on the PGMA matrix possess different shapes and changes the morphology and nature of PGMA beads significantly. The fluorescent micrograph also confirmed that the CuNPs were doped on the PGMA surface. The thermal studies have demonstrated that the CuNPs deposition on the surface of PGMA beads had a significant effect.

Poly(glycidyl methacrylate)—A soft template for the facile preparation of poly(glycidyl methacrylate) core-copper nanoparticle shell nanocomposite

Energy Technology Data Exchange (ETDEWEB)

Mohammed Safiullah, S., E-mail: safichem@gmail.com [Department of Chemistry, C. Abdul Hakeem College of Engineering & Technology, Melvisharam, Vellore District, Tamil Nadu 632509 (India); P.G. & Research Department of Chemistry, C. Abdul Hakeem College, Melvisharam, Vellore District, Tamil Nadu 632509 (India); Abdul Wasi, K. [P.G. & Research Department of Chemistry, C. Abdul Hakeem College, Melvisharam, Vellore District, Tamil Nadu 632509 (India); Anver Basha, K., E-mail: kanverbasha@gmail.com [P.G. & Research Department of Chemistry, C. Abdul Hakeem College, Melvisharam, Vellore District, Tamil Nadu 632509 (India)

2015-12-01

Graphical abstract: - Highlights: • PGMA/Cu nanohybrids have been synthesized by Surface deposition method. • The CuNPs were deposited on the PGMA surface without surface modification. • CuNP deposition on PGMA has a significant effect on morphology and thermal stability. - Abstract: Poly(glycidyl methacrylate) core/copper nanoparticle shell nanocomposite (PGMA/Cu nanohybrid) was prepared by simple two step method (i) The synthesis of poly(glycidyl methacrylate) (PGMA) beads by free radical suspension polymerization followed by (ii) direct deposition of copper nanoparticles (CuNPs) on activated PGMA beads. The PGMA beads were used as a soft template to host the CuNPs without surface modification of it. In this method the CuNPs were formed by chemical reduction of copper salts using sodium borohydride in water medium and deposited directly on the activated PGMA. Two different concentrations of copper salts were employed to know the effect of concentration on the shape and size of nanoparticles. The results showed that, the different sizes and shapes of CuNPs were deposited on the PGMA matrix. The X-ray Diffraction study results showed that the CuNPs were embedded on the surface of the PGMA matrix. The scanning electron microscopic images revealed that the fabrication of CuNPs on the PGMA matrix possess different shapes and changes the morphology and nature of PGMA beads significantly. The fluorescent micrograph also confirmed that the CuNPs were doped on the PGMA surface. The thermal studies have demonstrated that the CuNPs deposition on the surface of PGMA beads had a significant effect.

Selective growth of gold onto copper indium sulfide selenide nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Witt, Elena; Parisi, Juergen; Kolny-Olesiak, Joanna [Oldenburg Univ. (Germany). Inst. of Physics, Energy and Semiconductor Research

2013-05-15

Hybrid nanostructures are interesting materials for numerous applications in chemistry, physics, and biology, due to their novel properties and multiple functionalities. Here, we present a synthesis of metal-semiconductor hybrid nanostructures composed of nontoxic I-III-VI semiconductor nanoparticles and gold. Copper indium sulfide selenide (CuInSSe) nanocrystals with zinc blende structure and trigonal pyramidal shape, capped with dodecanethiol, serve as an original semiconductor part of a new hybrid nanostructure. Metallic gold nanocrystals selectively grow onto vertexes of these CuInSSe pyramids. The hybrid nanostructures were studied by transmission electron microscopy, energy dispersive X-ray analysis, X-ray diffraction, and UV-Vis-absorption spectroscopy, which allowed us conclusions about their growth mechanism. Hybrid nanocrystals are generated by replacement of a sacrificial domain in the CuInSSe part. At the same time, small selenium nanocrystals form that stay attached to the remaining CuInSSe/Au particles. Additionally, we compare the synthesis and properties of CuInSSe-based hybrid nanostructures with those of copper indium disulfide (CuInS{sub 2}). CuInS{sub 2}/Au nanostructures grow by a different mechanism (surface growth) and do not show any selectivity. (orig.)

Synthesis of silver nanoparticles stabilized with C-phycocyanin and for fluorimetric detection of copper ions

Science.gov (United States)

Wei, Nana; Hou, Yanhua; Lu, Zongbao; Yu, Huatong; Wang, Quanfu

2018-01-01

In this study, C-phycocyanin as protective agent, AgNO3 as raw material and NaBH4 as reducing agent synthesized C-phycocyanin-Ag nanoparticles (PC-AgNPs). The synthesis conditions of PC-AgNPs were determined by optimization. The maximum UV absorption peak of PC-AgNPs at 400 nm. The fluorescence excitation wavelength was 580 nm and the emission wavelength was 625 nm. PC-AgNPs was spherical in transmission electron microscope and the particles sizes were about 10-25 nm. In addition, fluorescence quenching was observed after adding copper ions to PC-AgNPs, which indicated that PC-AgNPs has potential applications in the detection of copper ions in diverse water environment.

Validity of Dynamic Light Scattering Method to Analyze a Range of Gold and Copper Nanoparticle Sizes Attained by Solids Laser Ablation in Liquid

Directory of Open Access Journals (Sweden)

Yu. V. Golubenko

2014-01-01

Full Text Available Nanoparticles of metals possess a whole series of features, concerned with it’s sizes, this leads to appearing or unusual electromagnetic and optical properties, which are untypical for particulates.An extended method of receiving nanoparticles by means of laser radiation is pulse laser ablation of hard targets in liquid medium.Varying the parameters of laser radiation, such as wavelength of laser radiation, energy density, etc., we can operate the size and shape of the resultant particles.The greatest trend of application in medicine have the nanoparticles of iron, copper, silver, silicon, magnesium, gold and zinc.The subject matter in this work is nanoparticles of copper and gold, received by means of laser ablation of hard targets in liquid medium.The aim of exploration, represented in the article, is the estimation of application of the dynamic light scattering method for determination of the range of nanoparticles sizes in the colloidal solution.For studying of the laser ablation process was chosen the second harmonic of Nd:YAG laser with the wavelength of 532 nm. Special attention was spared for the description of the experiment technique of receiving of nanoparticles.As the liquid medium ethanol and distillation water were used.For exploration of the received colloidal system have been used the next methods: DLS, transmission electron microscopy (TEM and scanning electron microscopy (SEM.The results of measuring by DLS method showed that colloidal solution of the copper in the ethanol is the steady system. Copper nanoparticle’s size reaches 200 nm and is staying in the same size for some time.Received system from the gold’s nanoparticles is polydisperse, unsteady and has a big range of the nanoparticle’s sizes. This fact was confirmed by means of photos, got from the TEM FEI Tecnai G2F20 + GIF and SEM Helios NanoLab 660. The range of the gold nanoparticle’s sizes is from 5 to 60 nm. So, it has been proved that the DLS method is

Effects of Au nanoparticle addition to hole transfer layer in organic solar cells based on copper naphthalocyanine and fullerene

Institute of Scientific and Technical Information of China (English)

Akihiko Nagata; Takeo Okun; Tsuyoshi Akiyaman; Atsushi Suzuki

2014-01-01

Organic solar cells based on copper naphthalocyanine (CuNc) and fullerene (C60) were fabricated, and their photovoltaic properties were investigated. C60 and CuNc were used as n-type and p-type semiconductors, respectively. In addition, the effect of Au nanoparticle addition on a hole transfer layer was investigated, and the power conversion efficiency of the devices was improved after blending the Au nanoparticles into the hole transport layer. Nanostructures of Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructure and electronic properties were discussed.

Influence of growth and photocatalytic properties of copper selenide (CuSe) nanoparticles using reflux condensation method

Energy Technology Data Exchange (ETDEWEB)

Sonia, S. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India); Kumar, P. Suresh [Thin Film and Nanomaterials Laboratory, Department of Physics, Bharathiar University, Coimbatore 641046 (India); Mangalaraj, D., E-mail: dmraj800@yahoo.com [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India); Ponpandian, N.; Viswanathan, C. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641046 (India)

2013-10-15

Influence of reaction conditions on the synthesis of copper selenide (CuSe) nanoparticles and their photo degradation activity is studied. Nearly monodispersed uniform size (23–44 nm) nanoparticles are synthesized by varying the reaction conditions using reflux condensation method. The obtained nanoparticles are characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and UV–visible absorption spectroscopy. The X-ray diffraction analysis of the sample shows the formation of nanoparticles with hexagonal CuSe structure. The result indicates that on increasing the reaction time from 4 to 12 h, the particle size decreases from 44 to 23 nm, but an increase in the reaction temperature increases the particle size. The calculated band gap E{sub g} is ranging from 2.34 to 3.05 eV which is blue shifted from the bulk CuSe (2.2 eV). The photocatalytic degradation efficiency of the CuSe nanoparticles on two organic dyes Methylene blue (MB) and Rhodamine-B (RhB) in aqueous solution under UV region is calculated as 76 and 87% respectively.

Layer-by-Layer Nanoassembly of Copper Indium Gallium Selenium Nanoparticle Films for Solar Cell Applications

Directory of Open Access Journals (Sweden)

A. Hemati

2012-01-01

Full Text Available Thin films of CIGS nanoparticles interdigited with polymers have been fabricated through a cost-effective nonvacuum film deposition process called layer-by-layer (LbL nanoassembly. CIGS nanoparticles synthesized by heating copper chloride, indium chloride, gallium chloride, and selenium in oleylamine were dispersed in water, and desired surface charges were obtained through pH regulation and by coating the particles with polystyrene sulfonate (PSS. Raising the pH of the nanoparticle dispersion reduced the zeta-potential from +61 mV at pH 7 to −51 mV at pH 10.5. Coating the CIGS nanoparticles with PSS (CIGS-PSS produced a stable dispersion in water with −56.9 mV zeta-potential. Thin films of oppositely charged CIGS nanoparticles (CIGS/CIGS, CIGS nanoparticles and PSS (CIGS/PSS, and PSS-coated CIGS nanoparticles and polyethylenimine (CIGS-PSS/PEI were constructed through the LbL nanoassembly. Film thickness and resistivity of each bilayer of the films were measured, and photoelectric properties of the films were studied for solar cell applications. Solar cell devices fabricated with a 219 nm CIGS film, when illuminated by 50 W light-source, produced 0.7 V open circuit voltage and 0.3 mA/cm2 short circuit current density.

Release of silver and copper nanoparticles from polyethylene nanocomposites and their penetration into Listeria monocytogenes

Energy Technology Data Exchange (ETDEWEB)

Tamayo, L.A., E-mail: laura.tamayo@usach.cl [Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Zapata, P.A. [Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Grupo de Polímeros, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Vejar, N.D.; Azócar, M.I.; Gulppi, M.A. [Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Zhou, X.; Thompson, G.E. [Corrosion and Protection Centre, School of Materials, The University of Manchester, Manchester, M13 9PL England (United Kingdom); Rabagliati, F.M. [Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Grupo de Polímeros, Facultad de Química y Biología, Universidad de Santiago de Chile, Av. L. B. O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); and others

2014-07-01

Since infection is a major cause of death in a patient whose immune responses have been compromised (immunocompromised patient), considerable attention has been focused on developing materials for the prevention of infections. This has been directed primarily at suppressing or eliminating the host's endogenous microbial burden and decreasing the acquisition of new organisms. In this study, the antibacterial properties of two nanocomposites, polyethylene modified with silver nanoparticles (PE-AgNps) or copper nanoparticles (PE-CuNps), against Listeria monocytogenes have been investigated. In order to elucidate the antibacterial mechanism, specifically whether this mechanism corresponds to bactericidal or bacteriolytic activities, we have determined the extent of release of metal ions (Ag{sup +} and Cu{sup 2+}) and, also, the morphology of the bacteria. The metal ion release from nanocomposites was followed by inductively coupled plasma spectrometry and the morphology of the bacteria was revealed through examination of ultramicrotomed sections of bacteria in a transmission electron microscope. The study of metal ion release from the nanocomposites shows that for both nanocomposites the amount of ions released varies with time, which initially displays a linear behavior until an asymptotic behavior is reached. Further, TEM images show that silver nanoparticles (AgNps) and copper nanoparticles (CuNps), which are released from the nanocomposites, can penetrate to the cell wall and the plasma membrane of bacteria. Resulting morphological changes involve separation of the cytoplasmic membrane from the cell wall, which is known to be an effect of plasmolysis. It was revealed that the antibacterial abilities of the two nanocomposites against L. monocytogenes are associated with both bactericidal and bacteriolytic effects. - Highlights: • Nanocomposites showed excellent antibacterial activity against L. monocytogenes. • The biocide abilities of nanocomposites

Copper Metal-Organic Framework Nanoparticles Stabilized with Folic Acid Improve Wound Healing in Diabetes.

Science.gov (United States)

Xiao, Jisheng; Zhu, Yunxiao; Huddleston, Samantha; Li, Peng; Xiao, Baixue; Farha, Omar K; Ameer, Guillermo A

2018-02-27

The successful treatment of chronic nonhealing wounds requires strategies that promote angiogenesis, collagen deposition, and re-epithelialization of the wound. Copper ions have been reported to stimulate angiogenesis; however, several applications of copper salts or oxides to the wound bed are required, leading to variable outcomes and raising toxicity concerns. We hypothesized that copper-based metal-organic framework nanoparticles (Cu-MOF NPs), referred to as HKUST-1, which are rapidly degraded in protein solutions, can be modified to slowly release Cu 2+ , resulting in reduced toxicity and improved wound healing rates. Folic acid was added during HKUST-1 synthesis to generate folic-acid-modified HKUST-1 (F-HKUST-1). The effect of folic acid incorporation on NP stability, size, hydrophobicity, surface area, and copper ion release profile was measured. In addition, cytotoxicity and in vitro cell migration processes due to F-HKUST-1 and HKUST-1 were evaluated. Wound closure rates were assessed using the splinted excisional dermal wound model in diabetic mice. The incorporation of folic acid into HKUST-1 enabled the slow release of copper ions, which reduced cytotoxicity and enhanced cell migration in vitro. In vivo, F-HKUST-1 induced angiogenesis, promoted collagen deposition and re-epithelialization, and increased wound closure rates. These results demonstrate that folic acid incorporation into HKUST-1 NPs is a simple, safe, and promising approach to control Cu 2+ release, thus enabling the direct application of Cu-MOF NPs to wounds.

Phytofabrication and characterization of monodisperse copper oxide nanoparticles using Albizia lebbeck leaf extract

Science.gov (United States)

Jayakumarai, G.; Gokulpriya, C.; Sudhapriya, R.; Sharmila, G.; Muthukumaran, C.

2015-12-01

Simple effective and rapid approach for the green synthesis of copper oxide nanoparticles (CONPs) using of Albizia lebbeck leaf extract was investigated in this study. Various instrumental techniques were adopted to characterize the synthesized CONPs, viz. UV-Vis spectroscopy, SEM, TEM, EDS and XRD. The synthesized CONPs were found to be spherical in shape and size less than 100 nm. It could be concluded that A. lebbeck leaf extract can be used as a cheap and effective reducing agent for CONPs production in large scale.

Carboxylate and amino group coated silver nanoparticles as joining materials for copper-to-copper silver joints.

Science.gov (United States)

Oestreicher, A; Röhrich, T; Lerch, M

2012-12-01

Organic silver complexes are introduced where silver is linked either with a carboxyl group or with an amino group. Upon heating, nanoparticles are generated if the respective ligands are long enough to act as stabilizing agents in the nanoparticulate regime. With decomposition and volatilization of the organic material, the sintering of silver occurs. The thermal characteristics of the carboxylates silver-n-octanoate, silver-n-decanoate, and AgOOC(CH2OCH2)2CH2OCH3 are compared with silver-n-alkylamines (n = 8, 9, and 12), and their thermal behavior is discussed based on thermogravimetry (TG) measurements. The consecutive stages of a metallization process are addressed based on the properties of AgOOC(CH2OCH2)2CH2OCH3, and the usable effects of the individual phases of this metal organic compound are analyzed by cross-sectional scanning electron microscope (SEM) images of silver joints. Selection criteria are addressed based on the thermal behavior. A mechanism for the joining process is proposed, considering formation and sintering of the nanoparticles. It was found that the bulk material can be used for low-temperature joining processes. Strong adherence to copper as a basic material can be achieved.

Effect of Silver or Copper Nanoparticles-Dispersed Silane Coatings on Biofilm Formation in Cooling Water Systems

Science.gov (United States)

Ogawa, Akiko; Kanematsu, Hideyuki; Sano, Katsuhiko; Sakai, Yoshiyuki; Ishida, Kunimitsu; Beech, Iwona B.; Suzuki, Osamu; Tanaka, Toshihiro

2016-01-01

Biofouling often occurs in cooling water systems, resulting in the reduction of heat exchange efficiency and corrosion of the cooling pipes, which raises the running costs. Therefore, controlling biofouling is very important. To regulate biofouling, we focus on the formation of biofilm, which is the early step of biofouling. In this study, we investigated whether silver or copper nanoparticles-dispersed silane coatings inhibited biofilm formation in cooling systems. We developed a closed laboratory biofilm reactor as a model of a cooling pipe and used seawater as a model for cooling water. Silver or copper nanoparticles-dispersed silane coating (Ag coating and Cu coating) coupons were soaked in seawater, and the seawater was circulated in the laboratory biofilm reactor for several days to create biofilms. Three-dimensional images of the surface showed that sea-island-like structures were formed on silane coatings and low concentration Cu coating, whereas nothing was formed on high concentration Cu coatings and low concentration Ag coating. The sea-island-like structures were analyzed by Raman spectroscopy to estimate the components of the biofilm. We found that both the Cu coating and Ag coating were effective methods to inhibit biofilm formation in cooling pipes. PMID:28773758

In Situ Production of Copper Oxide Nanoparticles in a Binary Molten Salt for Concentrated Solar Power Plant Applications.

Science.gov (United States)

Lasfargues, Mathieu; Stead, Graham; Amjad, Muhammad; Ding, Yulong; Wen, Dongsheng

2017-05-19

Seeding nanoparticles in molten salts has been shown recently as a promising way to improve their thermo-physical properties. The prospect of such technology is of interest to both academic and industrial sectors in order to enhance the specific heat capacity of molten salt. The latter is used in concentrated solar power plants as both heat transfer fluid and sensible storage. This work explores the feasibility of producing and dispersing nanoparticles with a novel one pot synthesis method. Using such a method, CuO nanoparticles were produced in situ via the decomposition of copper sulphate pentahydrate in a KNO₃-NaNO₃ binary salt. Analyses of the results suggested preferential disposition of atoms around produced nanoparticles in the molten salt. Thermal characterization of the produced nano-salt suspension indicated the dependence of the specific heat enhancement on particle morphology and distribution within the salts.

Gold-Copper alloy “nano-dumplings” with tunable compositions and plasmonic properties

International Nuclear Information System (INIS)

Verma, Manoj; Kedia, Abhitosh; Kumar, P. Senthil

2016-01-01

The unique yet tunable optical properties of plasmonic metal nanoparticles have made them attractive targets for a wide range of applications including nanophotonics, molecular sensing, catalysis etc. Such diverse applications that require precisely stable / reproducible plasmonic properties depend sensitively on the particle morphology ie. the shape, size and constituents. Herein, we systematically study the size / shape controlled synthesis of gold-copper “dumpling” shaped alloy nanoparticles by simultaneous reduction of gold and copper salts in the PVP-methanol solute-solvent system, by effectively utilizing the efficient but mild reduction as well as capping abilities of Poly (N-vinylpyrrolidone). Introduction of copper salts not only yielded the alloy nanoparticles, but also slowed down the growth process to maintain high mono-dispersity of the new shapes evolved. Copper and gold has different lattice constants (0.361 and 0.408 nm respectively) and hence doping/addition/replacement of copper atoms to gold FCC unit cell introduces strain into the lattice which is key parameter to the shape evolution in anisotropic nanoparticles. Synthesized alloy nanoparticles were characterized by UV-visible absorption spectroscopy, XRD and TEM imaging.

Synthesis of new copper nanoparticle-decorated anchored type ligands: Applications as non-enzymatic electrochemical sensors for hydrogen peroxide

Energy Technology Data Exchange (ETDEWEB)

Ensafi, Ali A., E-mail: Ensafi@cc.iut.ac.ir; Zandi-Atashbar, N.; Ghiaci, M.; Taghizadeh, M.; Rezaei, B.

2015-02-01

In this work, copper nanoparticles (CuNPs) decorated on two new anchored type ligands were utilized to prepare two electrochemical sensors. These ligands are made from bonding amine chains to silica support including SiO{sub 2}–pro–NH{sub 2} (compound I) and SiO{sub 2}–pro–NH–cyanuric–NH{sub 2} (compound II). The morphology of synthesized CuNPs was characterized by transmission electron microscopy (TEM). The nano-particles were in the range of 13–37 nm with the average size of 23 nm. These materials were used to modify carbon paste electrode. Different electrochemical techniques, including cyclic voltammetry, electrochemical impedance spectroscopy and hydrodynamic chronoamperometry, were used to study the sensor behavior. These electrochemical sensors were used as a model for non-enzymatic detection of hydrogen peroxide (H{sub 2}O{sub 2}). To evaluate the abilities of the modified electrodes for H{sub 2}O{sub 2} detection, the electrochemical signals were compared in the absence and presence of H{sub 2}O{sub 2}. From them, two modified electrodes showed significant responses vs. H{sub 2}O{sub 2} addition. The amperograms illustrated that the sensors were selective for H{sub 2}O{sub 2} sensing with linear ranges of 5.14–1250 μmol L{sup −1} and 1.14–1120 μmol L{sup −1} with detection limits of 0.85 and 0.27 μmol L{sup −1} H{sub 2}O{sub 2}, sensitivities of 3545 and 11,293 μA mmol{sup −1} L and with response times less than 5 s for I/CPE and II/CPE, respectively. As further verification of the selected sensor, H{sub 2}O{sub 2} contained in milk sample was analyzed and the obtained results were comparable with the ones from classical control titration method. - Highlights: • Copper nanoparticles decorating on two new anchored type ligands were prepared. • Ligands are bonding to silica support as SiO{sub 2}–pro–NH{sub 2} and SiO{sub 2}–pro–NH–cyanuric–NH{sub 2}. • These materials were used as electrochemical sensors for H

Improving Kinetics of “Click-Crosslinking” for Self-Healing Nanocomposites by Graphene-Supported Cu-Nanoparticles

Directory of Open Access Journals (Sweden)

Neda Kargarfard

2017-12-01

Full Text Available Investigation of the curing kinetics of crosslinking reactions and the development of optimized catalyst systems is of importance for the preparation of self-healing nanocomposites, able to significantly extend their service lifetimes. Here we study different modified low molecular weight multivalent azides for a capsule-based self-healing approach, where self-healing is mediated by graphene-supported copper-nanoparticles, able to trigger “click”-based crosslinking of trivalent azides and alkynes. When monitoring the reaction kinetics of the curing reaction via reactive dynamic scanning calorimetry (DSC, it was found that the “click-crosslinking” reactivity decreased with increasing chain length of the according azide. Additionally, we could show a remarkable “click” reactivity already at 0 °C, highlighting the potential of click-based self-healing approaches. Furthermore, we varied the reaction temperature during the preparation of our tailor-made graphene-based copper(I catalyst to further optimize its catalytic activity. With the most active catalyst prepared at 700 °C and the optimized set-up of reactants on hand, we prepared capsule-based self-healing epoxy nanocomposites.

Understanding the Formation of the Self-Assembly of Colloidal Copper Nanoparticles by Surfactant: A Molecular Velcro

Directory of Open Access Journals (Sweden)

Raquel Kely Bortoleto-Bugs

2013-01-01

Full Text Available Self-assembly procedure is employed to synthesize colloidal copper nanoparticles (ccNPs with cationic surfactant in an environmentally friendly method. Scanning electron microscopy images provide a clear view of the ccNPs formed having an approximate size of 15 nm. The X-ray diffraction reveals that the ccNPs have the two types of copper oxide as well as the metallic copper. The new procedure shows that the cationic surfactant CTAB plays an important role in the understanding and development of self-assembly. There is a strong relationship between the ccNPs formation with the critical micelle concentration of the CTAB which influences both shape and size. The outcomes allowed the development of a molecular model for the ccNPs synthesis showing that the CTAB monomer on the surface has the function of a molecular velcro making the linkage of ccNPs to form an agglomerate with size around 600 nm. Finally, with the emerging new technologies, the synthesis of copper oxide takes a new perspective for their applicability in diverse integrated areas such as the flexible electronics and energy.

Intracellular biosynthesis and removal of copper nanoparticles by dead biomass of yeast isolated from the wastewater of a mine in the Brazilian Amazonia.

Directory of Open Access Journals (Sweden)

Marcia R Salvadori

Full Text Available In this study was developed a natural process using a biological system for the biosynthesis of nanoparticles (NPs and possible removal of copper from wastewater by dead biomass of the yeast Rhodotorula mucilaginosa. Dead and live biomass of Rhodotorula mucilaginosa was used to analyze the equilibrium and kinetics of copper biosorption by the yeast in function of the initial metal concentration, contact time, pH, temperature, agitation and inoculum volume. Dead biomass exhibited the highest biosorption capacity of copper, 26.2 mg g(-1, which was achieved within 60 min of contact, at pH 5.0, temperature of 30°C, and agitation speed of 150 rpm. The equilibrium data were best described by the Langmuir isotherm and Kinetic analysis indicated a pseudo-second-order model. The average size, morphology and location of NPs biosynthesized by the yeast were determined by scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDS and transmission electron microscopy (TEM. The shape of the intracellularly synthesized NPs was mainly spherical, with an average size of 10.5 nm. The X-ray photoelectron spectroscopy (XPS analysis of the copper NPs confirmed the formation of metallic copper. The dead biomass of Rhodotorula mucilaginosa may be considered an efficiently bioprocess, being fast and low-cost to production of copper nanoparticles and also a probably nano-adsorbent of this metal ion in wastewater in bioremediation process.

Tannic acid promotes ion release of copper oxide nanoparticles: Impacts from solution pH change and complexation reactions.

NARCIS (Netherlands)

Zhao, Jing; Liu, Yang; Pan, Bo; Gao, Guoqian; Liu, Ying; Liu, Siqian; Liang, Ni; Zhou, Dandan; Vijver, Martina G; Peijnenburg, Willie J G M

2017-01-01

The increasing number of applications in which copper oxide nanoparticles (CuO NPs) are used, may lead to potential release of CuO NPs into the environment. However, the impact of natural organic matters on the behavior and fate of CuO NPs in aquatic media is still largely unknown. In this study,

Surface functionalization of copper via oxidative graft polymerization of 2,2'-bithiophene and immobilization of silver nanoparticles for combating biocorrosion.

Science.gov (United States)

Wan, Dong; Yuan, Shaojun; Neoh, K G; Kang, E T

2010-06-01

An environmentally benign approach to surface modification was developed to impart copper surface with enhanced resistance to corrosion, bacterial adhesion and biocorrosion. Oxidative graft polymerization of 2,2'-bithiophene from the copper surface with self-assembled 2,2'-bithiophene monolayer, and subsequent reduction of silver ions to silver nanoparticles (Ag NPs) on the surface, give rise to a homogeneous bithiophene polymer (PBT) film with densely coupled Ag NPs on the copper surface (Cu-g-PBT-Ag NP surface). The immobilized Ag NPs were found to significantly inhibit bacterial adhesion and enhance the antibacterial properties of the PBT modified copper surface. The corrosion inhibition performance of the functionalized copper substrates was evaluated by Tafel polarization curves and electrochemical impedance spectroscopy. Arising from the chemical affinity of thiols for the noble and coinage metals, the copper surface functionalized with both PBT brushes and Ag NPs also exhibits long-term stability, and is thus potentially useful for combating the combined problems of corrosion and biocorrosion in harsh marine and aquatic environments.

In Situ Production of Copper Oxide Nanoparticles in a Binary Molten Salt for Concentrated Solar Power Plant Applications

Directory of Open Access Journals (Sweden)

Mathieu Lasfargues

2017-05-01

Full Text Available Seeding nanoparticles in molten salts has been shown recently as a promising way to improve their thermo-physical properties. The prospect of such technology is of interest to both academic and industrial sectors in order to enhance the specific heat capacity of molten salt. The latter is used in concentrated solar power plants as both heat transfer fluid and sensible storage. This work explores the feasibility of producing and dispersing nanoparticles with a novel one pot synthesis method. Using such a method, CuO nanoparticles were produced in situ via the decomposition of copper sulphate pentahydrate in a KNO3-NaNO3 binary salt. Analyses of the results suggested preferential disposition of atoms around produced nanoparticles in the molten salt. Thermal characterization of the produced nano-salt suspension indicated the dependence of the specific heat enhancement on particle morphology and distribution within the salts.

Morphology of micro- and nanoparticles emitted by copper plants in Western Poland

International Nuclear Information System (INIS)

Konarski, P.; Cwil, M.; Iwanejko, I.; Mierzejewska, A.; Diduszko, R.

2004-01-01

Aerosol particles were collected in the vicinity of copper plants in Western Poland and analysed by mass spectrometry methods like secondary ion mass spectrometry (SIMS), spark source mass spectrometry (SSMS) and X-ray diffraction to characterise the possible dangers for the environment and health. The motivation of the work was to approach the toxicological mechanisms that are triggered when aerosol nanoparticles enter the human body. Different analytical techniques were used in order to compare bulk and surface properties of particles. The particle collection was performed with nine-stage cascade impactor with rotating plates and also with micro-fibre quartz filter collector. SSMS bulk analysis of copper plant emitted particles shows the presence of over 30 elements, the concentration in wt.% of Cu, Pb, Zn and Cl is 30, 5, 2 and 1, respectively. XRD analysis of these particles shows crystalline phases of quartz and probable phases containing copper CuS 2 , lead Pb 2 SiO 4 , PbO - massicot, Pb 5 [OH][PO 4 ] 3 , Pb 3 SiO 5 , iron and calcium Ca[Mg 0.67 Fe 0.33 ][CO 3 ] - dolomite, ferroan, Ca[FeMg][CO 3 ] 2 - ankerite, Ca[MgFe]Si 2 O 6 - augite. Surface sensitive SIMS depth profile analysis revealed the core-shell structure of copper plant emitted particles. The obtained structure of these particles shows that surfaces of the particles are enriched in elements like chlorine, fluorine, lead and chromium with respect to the core concentrations of these elements. The cores are composed mainly of copper, oxygen and carbon containing compounds. Lead concentration is nearly two times greater at the surface layers of particles than in the cores. SIMS analysis of urban aerosol particles collected in Legnica shows compositional dependence with size. Surface shell layer concentration of lead is three times greater for coarse 6-15 μm particles than for tiny 300 nm-1 μm particles. Such non-uniform particle morphology may enhance the toxic properties of particles suspended in

Antibacterial properties of copper iodide-doped glass ionomer-based materials and effect of copper iodide nanoparticles on collagen degradation.

Science.gov (United States)

Renné, Walter G; Lindner, Amanda; Mennito, Anthony S; Agee, Kelli A; Pashley, David H; Willett, Daniel; Sentelle, David; Defee, Michael; Schmidt, Michael; Sabatini, Camila

2017-01-01

This study investigated the antibacterial properties and micro-hardness of polyacrylic acid (PAA)-coated copper iodide (CuI) nanoparticles incorporated into glass ionomer-based materials, and the effect of PAA-CuI on collagen degradation. PAA-CuI nanoparticles were incorporated into glass ionomer (GI), Ionofil Molar AC, and resin-modified glass ionomer (RMGI), Vitrebond, at 0.263 wt%. The antibacterial properties against Streptococcus mutans (n = 6/group) and surface micro-hardness (n = 5/group) were evaluated. Twenty dentin beams were completely demineralized in 10 wt% phosphoric acid and equally divided in two groups (n = 10/group) for incubation in simulated body fluid (SBF) or SBF containing 1 mg/ml PAA-CuI. The amount of dry mass loss and hydroxyproline (HYP) released were quantified. Kruskal-Wallis, Student's t test, two-way ANOVA, and Mann-Whitney were used to analyze the antibacterial, micro-hardness, dry mass, and HYP release data, respectively (p glass ionomer matrix yielded significant reduction (99.999 %) in the concentration of bacteria relative to the control groups. While micro-hardness values of PAA-CuI-doped GI were no different from its control, PAA-CuI-doped RMGI demonstrated significantly higher values than its control. A significant decrease in dry mass weight was shown only for the control beams (10.53 %, p = 0.04). Significantly less HYP was released from beams incubated in PAA-CuI relative to the control beams (p glass ionomer-based materials as they greatly enhance their antibacterial properties and reduce collagen degradation without an adverse effect on their mechanical properties. The use of copper-doped glass ionomer-based materials under composite restorations may contribute to an increased longevity of adhesive restorations, because of their enhanced antibacterial properties and reduced collagen degradation.

Synthesis of polymer-stabilized monometallic Cu and bimetallic Cu/Ag nanoparticles and their surface-enhanced Raman scattering properties

Science.gov (United States)

Zhang, Danhui; Liu, Xiaoheng

2013-03-01

The present study demonstrates a facile process for the production of spherical-shaped Cu and Ag nanoparticles synthesized and stabilized by hydrazine and gelatin, respectively. Advantages of the synthetic method include its production of water dispersible copper and copper/silver nanoparticles at room temperature under no inert atmosphere. The resulting nanoparticles (copper or copper/silver) are investigated by X-ray diffraction (XRD), UV-vis spectroscopy, and transmission electron microscopy (TEM). The nanometallic dispersions were characterized by surface plasmon absorbance measuring at 420 and 572 nm for Ag and Cu nanoparticles, respectively. Transmission electron microscopy showed the formation of nanoparticles in the range of ˜10 nm (silver), and ˜30 nm (copper). The results also demonstrate that the reducing order of Cu2+/Ag+ is important for the formation of the bimetallic nanoparticles. The surface-enhanced Raman scattering effects of copper and copper/silver nanoparticles were also displayed. It was found that the enhancement ability of copper/silver nanoparticles was little higher than the copper nanoparticles.

Micronized copper wood preservatives: an efficiency and potential health risk assessment for copper-based nanoparticles.

Science.gov (United States)

Civardi, Chiara; Schwarze, Francis W M R; Wick, Peter

2015-05-01

Copper (Cu) is an essential biocide for wood protection, but fails to protect wood against Cu-tolerant wood-destroying fungi. Recently Cu particles (size range: 1 nm-25 μm) were introduced to the wood preservation market. The new generation of preservatives with Cu-based nanoparticles (Cu-based NPs) is reputedly more efficient against wood-destroying fungi than conventional formulations. Therefore, it has the potential to become one of the largest end uses for wood products worldwide. However, during decomposition of treated wood Cu-based NPs and/or their derivate may accumulate in the mycelium of Cu-tolerant fungi and end up in their spores that are dispersed into the environment. Inhaled Cu-loaded spores can cause harm and could become a potential risk for human health. We collected evidence and discuss the implications of the release of Cu-based NPs by wood-destroying fungi and highlight the exposure pathways and subsequent magnitude of health impact. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis and characterization of copper-infiltrated carbonized wood monoliths for supercapacitor electrodes

International Nuclear Information System (INIS)

Teng, Shiang; Siegel, Gene; Prestgard, Megan C.; Wang, Wei; Tiwari, Ashutosh

2015-01-01

Highlights: • Copper nanoparticles were embedded in the highly porous carbonized wood electrodes. • Copper nanoparticle serves as the pseudocapacitive specie to increase the energy density. • The porous copper-wood electrodes exhibit excellent electrochemical performances with high capacitance, excellent rate capability and stability. - Abstract: Copper nanoparticle-loaded carbonized wood electrodes were synthesized and characterized for the use as supercapacitor electrodes. The electrodes were fabricated by soaking beech wood samples in Cu(NO 3 ) 2 solution followed by carbonization at 800 °C under a N 2 atmosphere. The copper nanoparticle content in the electrodes was controlled by varying the concentration of the Cu(NO 3 ) 2 solution from 0.5 to 2 M. Subsequent X-ray diffraction and scanning electron microscopy measurements confirm that cubic copper was formed and the copper nanoparticles were anchored uniformly both on the surface as well as deep within the pores of the wood electrode. Cyclic voltammetry measurements showed that all of the electrodes had a typical pseudo-capacitive behavior, as indicated by the presence of redox reaction peaks. Charge–discharge testing also confirmed the pseudo-capacitive nature of the electrodes. The reversible oxidation of Cu into Cu 2 O and CuO was verified by performing X-ray photoelectron spectroscopy at different stages of the charge–discharge cycle. The Cu-loaded wood electrodes exhibited excellent cyclability and retaining 95% of their specific capacitance even after 2000 cycles. A maximum specific capacitance of 888 F/g was observed while discharging the 7 wt% Cu electrode at 200 mA/g in a 2 M KOH electrolyte solution. These results demonstrated the potential of the copper nanoparticle-loaded wood electrodes as cheap and high performance supercapacitor electrodes

Electro-oxidation nitrite based on copper calcined layered double hydroxide and gold nanoparticles modified glassy carbon electrode

Energy Technology Data Exchange (ETDEWEB)

Cui Lin; Meng Xiaomeng; Xu Minrong; Shang Kun [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Ai Shiyun, E-mail: ashy@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Liu Yinping [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China)

2011-11-30

Highlights: > A nitrite sensor fabricated based on copper calcined layered double hydroxides and gold nanoparticles modified electrode. > This sensor exhibited excellent electrocatalytic oxidation to nitrite. > This nitrite sensor exhibited very good analytical performance with low cost, convenient preparation and rapid detection. - Abstract: In this paper, a novel nitrite sensor was constructed based on electrodeposition of gold nanoparticles (AuNPs) on a copper calcined layered double hydroxide (Cu-CLDH) modified glassy carbon electrode. Electrochemical experiments showed that AuNPs/CLDH composite film exhibited excellent electrocatalytic oxidation activity with nitrite due to the synergistic effect of the Cu-CLDH with AuNPs. The fabricated sensor exhibited excellent performance for nitrite detection within a wide concentration interval of 1-191 {mu}M and with a detection limit of 0.5 {mu}M. The superior electrocatalytic response to nitrite was mainly attributed to the large surface area, minimized diffusion resistance, and enhanced electron transfer of the Cu-CLDH and AuNPs composition film. This platform offers a novel route for nitrite sensing with wide analytical applications and will supply the practical applications for a variety of simple, robust, and easy-to-manufacture analytical approaches in the future.

Electro-oxidation nitrite based on copper calcined layered double hydroxide and gold nanoparticles modified glassy carbon electrode

International Nuclear Information System (INIS)

Cui Lin; Meng Xiaomeng; Xu Minrong; Shang Kun; Ai Shiyun; Liu Yinping

2011-01-01

Highlights: → A nitrite sensor fabricated based on copper calcined layered double hydroxides and gold nanoparticles modified electrode. → This sensor exhibited excellent electrocatalytic oxidation to nitrite. → This nitrite sensor exhibited very good analytical performance with low cost, convenient preparation and rapid detection. - Abstract: In this paper, a novel nitrite sensor was constructed based on electrodeposition of gold nanoparticles (AuNPs) on a copper calcined layered double hydroxide (Cu-CLDH) modified glassy carbon electrode. Electrochemical experiments showed that AuNPs/CLDH composite film exhibited excellent electrocatalytic oxidation activity with nitrite due to the synergistic effect of the Cu-CLDH with AuNPs. The fabricated sensor exhibited excellent performance for nitrite detection within a wide concentration interval of 1-191 μM and with a detection limit of 0.5 μM. The superior electrocatalytic response to nitrite was mainly attributed to the large surface area, minimized diffusion resistance, and enhanced electron transfer of the Cu-CLDH and AuNPs composition film. This platform offers a novel route for nitrite sensing with wide analytical applications and will supply the practical applications for a variety of simple, robust, and easy-to-manufacture analytical approaches in the future.

Copper nitrate redispersion to arrive at highly active silica-supported copper catalysts

NARCIS (Netherlands)

Munnik, P.|info:eu-repo/dai/nl/328228524; Wolters, M.|info:eu-repo/dai/nl/304829560; Gabrielsson, A.; Pollington, S.D.; Headdock, G.; Bitter, J.H.|info:eu-repo/dai/nl/160581435; de Jongh, P.E.|info:eu-repo/dai/nl/186125372; de Jong, K.P.|info:eu-repo/dai/nl/06885580X

2011-01-01

In order to obtain copper catalysts with high dispersions at high copper loadings, the gas flow rate and gas composition was varied during calcination of silica gel impregnated with copper nitrate to a loading of 18 wt % of copper. Analysis by X-ray diffraction (XRD), N2O chemisorption, and

Work function measurements of copper nanoparticle intercalated polyaniline nanocomposite thin films

Science.gov (United States)

Patil, U. V.; Ramgir, Niranjan S.; Bhogale, A.; Debnath, A. K.; Muthe, K. P.; Gadkari, S. C.; Kothari, D. C.

2017-05-01

The nature of contact between the electrode and the sensing material plays a crucial role in governing the sensing mechanism. Thin films of polyaniline (PANI) and copper-polyaniline nanocomposite (NC) have been deposited at room temperatures by in-situ oxidative polymerization of aniline in the presence of Cu nanoparticles. For sensing applications a thin film Au (gold) ˜100 nm is deposited and used as a conducting electrode. To understand the nature of contact (i.e., ohmic or Schottky) the work function of the conducting polyaniline and nanocomposite films were measured using Kelvin Probe method. I-V characteristics of PANI and NC films investigated at room temperatures further corroborates and confirms the formation of Ohmic contact as evident from work function measurements.

Copper oxide nanoparticles induce the transcriptional modulation of oxidative stress-related genes in Arbacia lixula embryos.

Science.gov (United States)

Giannetto, Alessia; Cappello, Tiziana; Oliva, Sabrina; Parrino, Vincenzo; De Marco, Giuseppe; Fasulo, Salvatore; Mauceri, Angela; Maisano, Maria

2018-06-14

Copper oxide nanoparticles (CuO NPs) are widely used in various industrial applications, i.e. semiconductor devices, batteries, solar energy converter, gas sensor, microelectronics, heat transfer fluids, and have been recently recognized as emerging pollutants of increasing concern for human and marine environmental health. Therefore, the toxicity of CuO NPs needs to be thoroughly understood. In this study, we evaluated the potential role of oxidative stress in CuO NP toxicity by exploring the molecular response of Arbacia lixula embryos to three CuO NP concentrations (0.7, 10, 20 ppb) by investigating the transcriptional patterns of oxidative stress-related genes (catalase and superoxide dismutase) and metallothionein, here cloned and characterized for the first time. Time- and concentration-dependent changes in gene expression were detected in A. lixula embryos exposed to CuO NPs, up to pluteus stage (72 h post-fertilization, hpf), indicating that oxidative stress is one of the toxicity mechanisms for CuO NPs. These findings provide new insights into the comprehension of the molecular mechanisms underlying copper nanoparticle toxicity in A. lixula sea urchin and give new tools for monitoring of aquatic areas, thus corroborating the suitability of this embryotoxicity assay for future evaluation of impacted sites. Copyright © 2018 Elsevier B.V. All rights reserved.

Copper plasmonics and catalysis: role of electron-phonon interactions in dephasing localized surface plasmons

Science.gov (United States)

Sun, Qi-C.; Ding, Yuchen; Goodman, Samuel M.; H. Funke, Hans; Nagpal, Prashant

2014-10-01

Copper metal can provide an important alternative for the development of efficient, low-cost and low-loss plasmonic nanoparticles, and selective nanocatalysts. However, poor chemical stability and lack of insight into photophysics and plasmon decay mechanisms has impeded study. Here, we use smooth conformal ALD coating on copper nanoparticles to prevent surface oxidation, and study dephasing time for localized surface plasmons on different sized copper nanoparticles. Using dephasing time as a figure of merit, we elucidate the role of electron-electron, electron-phonon, impurity, surface and grain boundary scattering on the decay of localized surface plasmon waves. Using our quantitative analysis and different temperature dependent measurements, we show that electron-phonon interactions dominate over other scattering mechanisms in dephasing plasmon waves. While interband transitions in copper metal contributes substantially to plasmon losses, tuning surface plasmon modes to infrared frequencies leads to a five-fold enhancement in the quality factor. These findings demonstrate that conformal ALD coatings can improve the chemical stability for copper nanoparticles, even at high temperatures (>300 °C) in ambient atmosphere, and nanoscaled copper is a good alternative material for many potential applications in nanophotonics, plasmonics, catalysis and nanoscale electronics.Copper metal can provide an important alternative for the development of efficient, low-cost and low-loss plasmonic nanoparticles, and selective nanocatalysts. However, poor chemical stability and lack of insight into photophysics and plasmon decay mechanisms has impeded study. Here, we use smooth conformal ALD coating on copper nanoparticles to prevent surface oxidation, and study dephasing time for localized surface plasmons on different sized copper nanoparticles. Using dephasing time as a figure of merit, we elucidate the role of electron-electron, electron-phonon, impurity, surface and grain

Electrochemical properties and electrocatalytic activity of conducting polymer/copper nanoparticles supported on reduced graphene oxide composite

Science.gov (United States)

Ehsani, Ali; Jaleh, Babak; Nasrollahzadeh, Mahmoud

2014-07-01

Reduced graphene oxide (rGO) was used to support Cu nanoparticles. As electro-active electrodes for supercapacitors composites of reduced graphene oxide/Cu nanoparticles (rGO/CuNPs) and polytyramine (PT) with good uniformity are prepared by electropolymerization. Composite of rGO/CuNPs-PT was synthesized by cyclic voltammetry (CV) methods and electrochemical properties of film were investigated by using electrochemical techniques. The results show that, the rGO/CuNPs-PT/G has better capacitance performance. This is mainly because of the really large surface area and the better electronic and ionic conductivity of rGO/CuNPs-PT/G, which lead to greater double-layer capacitance and faradic pseudo capacitance. Modified graphite electrodes (rGO/CuNPs-PT/G) were examined for their redox process and electrocatalytic activities towards the oxidation of methanol in alkaline solutions. The methods of cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) were employed. In comparison with a Cu-PT/G (Graphite), rGO/CuNPs-PT/G modified electrode shows a significantly higher response for methanol oxidation. A mechanism based on the electro-chemical generation of Cu(III) active sites and their subsequent consumptions by methanol have been discussed.

Microbially supported synthesis of catalytically active bimetallic Pd-Au nanoparticles

DEFF Research Database (Denmark)

Hosseinkhani, Baharak; Søbjerg, Lina Sveidal; Rotaru, Amelia-Elena

2012-01-01

Transformation (FFT) analyses confirmed that the nanoparticles indeed were bimetallic. The bimetallic nanoparticles did not have a core-shell structure, but were superior to monometallic particles at reducing p-nitrophenol to p-aminophenol. Hence, formation of microbially supported nanoparticles may be a cheap......(II) to the bio-supported particles resulted in increased particle size. UV-Vis spectrophotometry and HR-TEM analyses indicated that the previously monometallic nanoparticles had become fully or partially covered by Au(0) or Pd(0), respectively. Furthermore, Energy Dispersive Spectrometry (EDS) and Fast Fourier...

Detention of copper by sulfur nanoparticles inhibits the proliferation of A375 malignant melanoma and MCF-7 breast cancer cells

Energy Technology Data Exchange (ETDEWEB)

Liu, Hao [Department of Chemistry, Jinan University, Guangzhou (China); Zhang, Yikai [Institute of Hematology, Jinan University, Guangzhou (China); Zheng, Shanyuan [School of Life Sciences, The Chinese University of Hong Kong, Hong Kong (China); Weng, Zeping; Ma, Jun [First Affiliated Hospital, Jinan University, Guangzhou (China); Li, Yangqiu [Institute of Hematology, Jinan University, Guangzhou (China); First Affiliated Hospital, Jinan University, Guangzhou (China); Key Laboratory for Regenerative Medicine of Ministry of Education, Jinan University, Guangzhou, 510632 (China); Xie, Xinyuan [Department of Chemistry, Jinan University, Guangzhou (China); Zheng, Wenjie, E-mail: tzhwj@jnu.edu.cn [Department of Chemistry, Jinan University, Guangzhou (China)

2016-09-02

Selective induction of cell death or growth inhibition of cancer cells is the future of chemotherapy. Clinical trials have found that cancer tissues are enriched with copper. Based on this finding, many copper-containing compounds and complexes have been designed to “copper” cancer cells using copper as bait. However, recent studies have demonstrated that copper boosts tumor development, and copper deprivation from serum was shown to effectively inhibit the promotion of cancer. Mechanistically, copper is an essential cofactor for mitogen-activated protein kinase (MAPK)/extracellular activating kinase (ERK) kinase (MEK), a central molecule in the BRAF/MEK/ERK pathway. Therefore, depleting copper from cancer cells by directly sequestering copper has a wider field for research and potential for combination therapy. Based on the affinity between sulfur and copper, we therefore designed sulfur nanoparticles (Nano-S) that detain copper, achieving tumor growth restriction. We found that spherical Nano-S could effectively bind copper and form a tighter surficial structure. Moreover, this Nano-S detention of copper effectively inhibited the proliferation of A375 melanoma and MCF-7 breast cancer cells with minimum toxicity to normal cells. Mechanistic studies revealed that Nano-S triggered inactivation of the MEK-ERK pathway followed by inhibition of the proliferation of the A375 and MCF-7 cells. In addition, lower Nano-S concentrations and shorter exposure stimulated the expression of a copper transporter as compensation, which further increased the cellular uptake and anticancer activities of cisplatin. Collectively, our results highlight the potential of Nano-S as an anticancer agent or adjuvant through its detention of copper. - Highlights: • Nano-S selectively inhibited the mitosis of A375 and MCF-7 cells by depleting copper. • Nano-S inactivated MEK/ERK pathway through the detention of copper. • Nano-S improved the cellular uptake and anticancer activities

Detention of copper by sulfur nanoparticles inhibits the proliferation of A375 malignant melanoma and MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Liu, Hao; Zhang, Yikai; Zheng, Shanyuan; Weng, Zeping; Ma, Jun; Li, Yangqiu; Xie, Xinyuan; Zheng, Wenjie

2016-01-01

Selective induction of cell death or growth inhibition of cancer cells is the future of chemotherapy. Clinical trials have found that cancer tissues are enriched with copper. Based on this finding, many copper-containing compounds and complexes have been designed to “copper” cancer cells using copper as bait. However, recent studies have demonstrated that copper boosts tumor development, and copper deprivation from serum was shown to effectively inhibit the promotion of cancer. Mechanistically, copper is an essential cofactor for mitogen-activated protein kinase (MAPK)/extracellular activating kinase (ERK) kinase (MEK), a central molecule in the BRAF/MEK/ERK pathway. Therefore, depleting copper from cancer cells by directly sequestering copper has a wider field for research and potential for combination therapy. Based on the affinity between sulfur and copper, we therefore designed sulfur nanoparticles (Nano-S) that detain copper, achieving tumor growth restriction. We found that spherical Nano-S could effectively bind copper and form a tighter surficial structure. Moreover, this Nano-S detention of copper effectively inhibited the proliferation of A375 melanoma and MCF-7 breast cancer cells with minimum toxicity to normal cells. Mechanistic studies revealed that Nano-S triggered inactivation of the MEK-ERK pathway followed by inhibition of the proliferation of the A375 and MCF-7 cells. In addition, lower Nano-S concentrations and shorter exposure stimulated the expression of a copper transporter as compensation, which further increased the cellular uptake and anticancer activities of cisplatin. Collectively, our results highlight the potential of Nano-S as an anticancer agent or adjuvant through its detention of copper. - Highlights: • Nano-S selectively inhibited the mitosis of A375 and MCF-7 cells by depleting copper. • Nano-S inactivated MEK/ERK pathway through the detention of copper. • Nano-S improved the cellular uptake and anticancer activities

Copper recovery in a bench-scale carrier facilitated tubular supported liquid membrane system

Directory of Open Access Journals (Sweden)

Makaka S.

2010-01-01

Full Text Available The extraction of copper ions in a tubular supported liquid membrane using LIX 984NC as a mobile carrier was studied, evaluating the effect of the feed characteristics (flowrate, density, viscosity on the feedside laminar layer of the membrane. A vertical countercurrent, double pipe perspex benchscale reactor consisting of a single hydrophobic PVDF tubular membrane mounted inside was used in all test work. The membrane was impregnated with LIX 984NC and became the support for this organic transport medium. Dilute Copper solution passed through the centre pipe and sulphuric acid as strippant passed through the shell side. Copper was successfully transported from the feedside to the stripside and from the data obtained, a relationship between Schmidt, Reynolds and Sherwood number was achieved of.

Synthesis, characterization and antibacterial activity of copper, nickel and bimetallic Cu–Ni nanoparticles for potential use in dental materials

Directory of Open Access Journals (Sweden)

Liliana Argueta-Figueroa

2014-08-01

Full Text Available The antibacterial effect is a desirable property in dental materials. Development of simple methods for the preparation of nanosized metal particles has attracted significant attention because of their future applications due to unusual size-dependent antibacterial properties. Copper (Cu, Nickel (Ni and bimetallic Cu–Ni nanoparticles were prepared by a simple chemical method and their antibacterial activity was tested against the widely used standard human pathogens Staphylococcus aureus (gram-negative and Escherichia coli (gram-positive. Additionally, these nanoparticles were tested against the dental pathogen Streptococcus mutans. Our results are promising for potential use in dental materials science.

Experimental and numerical optical characterization of plasmonic copper nanoparticles embedded in ZnO fabricated by ion implantation and annealing

Energy Technology Data Exchange (ETDEWEB)

Le, Khai Q. [Faculty of Science and Technology, Hoa Sen University, Ho Chi Minh City (Viet Nam); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia); Nguyen, Hieu P.T. [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, NJ 07102 (United States); Ngo, Quang Minh [Institute of Material Sciences, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay, Hanoi (Viet Nam); Canimoglu, Adil [Nigde University, Faculty of Arts and Sciences, Physics Department, Nigde (Turkey); Can, Nurdogan, E-mail: cannurdogan@yahoo.com [Celal Bayar University, Faculty of Arts and Sciences, Department of Physics, Muradiye, Manisa (Turkey); Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, 45142 Jazan (Saudi Arabia)

2016-06-05

Here we describe the successfully fabrication of metal nanoparticle crystals by implanting copper (Cu) ions into single zinc oxide (ZnO) crystals with ion energy of 400 keV at ion doses of 1 × 10{sup 16} to 1 × 10{sup 17} ions/cm{sup 2}. After implantation and post-annealing treatment, the Cu implanted ZnO produces a broad range of luminescence emissions, ranging from green to yellow. A green luminescence peak at 550 nm could be ascribed to the isolated Cu ions. The changes in luminescence emission bands between the initial implant and annealed suggest that the implants give rise to clustering Cu nanoparticles in the host matrix but that the annealing process dissociates these. Numerical modelling of the Cu nanoparticles was employed to simulate their optical properties including the extinction cross section, electron energy loss spectroscopy and cathodoluminescence. We demonstrate that the clustering of nanoparticles generates Fano resonances corresponding to the generation of multiple resonances, while the isolation of nanoparticles results in intensity amplification. - Highlights: • We present the fabrication of metal nanoparticle crystals by implanting Cu into ZnO. • The luminescence properties were studied at different annealing temperature. • Numerical modelling of the Cu nanoparticles was employed. • We demonstrate that the clustering of nanoparticles generates Fano resonances.

Modification of Titanium Dioxide Nanoparticles With Copper Oxide Co-Catalyst for Photo catalytic Degradation of 2,4-Dichlorophenoxyacetic Acid

International Nuclear Information System (INIS)

Leny Yuliati; Siah, W.R.; Nur Azmina Roslan; Mustaffa Shamsuddin

2016-01-01

2,4-dichlorophenoxyacetic acid (2,4-D) is a common herbicide that has been used widely. Due to its excessive usage, the 2,4-D herbicides can cause contamination over agricultural land and water bodies. In the present work, a simple impregnation method was used to modify the commercial titanium dioxide (P25 TiO_2) nanoparticles with the copper oxide. The prepared samples were characterized by X-ray Diffraction (XRD), reflectance UV-visible and fluorescence spectroscopies. It was observed that the incorporation of copper oxide did not significantly affect the crystal structure of P25 TiO_2. On the other hand, the presence of copper oxide was confirmed by reflectance UV-visible and fluorescence spectroscopies. The activity of the prepared sample was evaluated for photo catalytic removal of the 2,4-D. The photo catalytic activity of the TiO_2 increased with the increase of copper oxide loading up to 0.5 mol %. Unfortunately, the higher loading amount of copper oxide resulted in the lower photo catalytic activity. This study suggested that the higher photo catalytic activities obtained on the low loading samples were due to the lower electron-hole recombination. (author)

Effects of copper oxide nanoparticles on developing zebrafish embryos and larvae

Directory of Open Access Journals (Sweden)

Sun Y

2016-03-01

Full Text Available Yan Sun, Gong Zhang, Zizi He, Yajie Wang, Jianlin Cui, Yuhao Li Department of Pathology, Key Laboratory of Tumor Microenvironment and Neurovascular Regulation, Nankai University School of Medicine, Tianjin, People’s Republic of China Abstract: Copper oxide nanoparticles (CuO NPs are used for a variety of purposes in a wide range of commercially available products. Some CuO NPs probably end up in the aquatic systems, thus raising concerns about aqueous exposure toxicity, and the impact of CuO NPs on liver development and neuronal differentiation remains unclear. In this study, particles were characterized using Fourier transform infrared spectra, scanning electron microscopy, and transmission electron microscopy. Zebrafish embryos were continuously exposed to CuO NPs from 4 hours postfertilization at concentrations of 50, 25, 12.5, 6.25, or 1 mg/L. The expression of gstp1 and cyp1a was examined by quantitative reverse transcription polymerase chain reaction. The expression of tumor necrosis factor alpha and superoxide dismutase 1 was examined by quantitative reverse transcription polymerase chain reaction and Western blotting. Liver development and retinal neurodifferentiation were analyzed by whole-mount in situ hybridization, hematoxylin–eosin staining, and immunohistochemistry, and a behavioral test was performed to track the movement of larvae. We show that exposure of CuO NPs at low doses has little effect on embryonic development. However, exposure to CuO NPs at concentrations of 12.5 mg/L or higher leads to abnormal phenotypes and induces an inflammatory response in a dose-dependent pattern. Moreover, exposure to CuO NPs at high doses results in an underdeveloped liver and a delay in retinal neurodifferentiation accompanied by reduced locomotor ability. Our data demonstrate that short-term exposure to CuO NPs at high doses shows hepatotoxicity and neurotoxicity in zebrafish embryos and larvae. Keywords: copper oxide nanoparticles

Copper doped TiO2 nanoparticles characterized by X-ray absorption spectroscopy, total scattering, and powder diffraction--a benchmark structure-property study.

Science.gov (United States)

Lock, Nina; Jensen, Ellen M L; Mi, Jianli; Mamakhel, Aref; Norén, Katarina; Qingbo, Meng; Iversen, Bo B

2013-07-14

Metal functionalized nanoparticles potentially have improved properties e.g. in catalytic applications, but their precise structures are often very challenging to determine. Here we report a structural benchmark study based on tetragonal anatase TiO2 nanoparticles containing 0-2 wt% copper. The particles were synthesized by continuous flow synthesis under supercritical water-isopropanol conditions. Size determination using synchrotron PXRD, TEM, and X-ray total scattering reveals 5-7 nm monodisperse particles. The precise dopant structure and thermal stability of the highly crystalline powders were characterized by X-ray absorption spectroscopy and multi-temperature synchrotron PXRD (300-1000 K). The combined evidence reveals that copper is present as a dopant on the particle surfaces, most likely in an amorphous oxide or hydroxide shell. UV-VIS spectroscopy shows that copper presence at concentrations higher than 0.3 wt% lowers the band gap energy. The particles are unaffected by heating to 600 K, while growth and partial transformation to rutile TiO2 occur at higher temperatures. Anisotropic unit cell behavior of anatase is observed as a consequence of the particle growth (a decreases and c increases).

Carboxymethylated chitosan-stabilized copper nanoparticles: a promise to contribute a potent antifungal and antibacterial agent

Energy Technology Data Exchange (ETDEWEB)

Tantubay, Sangeeta, E-mail: sang.chem2@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Mukhopadhyay, Sourav K. [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Kalita, Himani; Konar, Suraj [Indian Institute of Technology Kharagpur, Department of Chemistry (India); Dey, Satyahari [Indian Institute of Technology Kharagpur, Department of Biotechnology (India); Pathak, Amita, E-mail: ami@chem.iitkgp.ernet.in; Pramanik, Panchanan, E-mail: ppramanik1946@yahoo.in, E-mail: pramanik1946@gmail.com [Indian Institute of Technology Kharagpur, Department of Chemistry (India)

2015-06-15

Carboxymethylated chitosan (CMC)-stabilized copper nanoparticles (Cu-NPs) have been synthesized via chemical reduction of copper(II)–CMC complex in aqueous medium by hydrazine under microwave irradiation in ambient atmosphere. Structural morphology, phase, and chemical compositions of CMC-stabilized Cu-NPs (CMC–Cu-NPs) have been analyzed through high-resolution transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Antifungal and antibacterial activities of CMC–Cu-NPs have been evaluated against Candida tropicalis and Escherichia coli through agar well diffusion method, broth microdilution assay, live–dead assay, and microscopic observation. Antimicrobial activity of spherical CMC–Cu-NPs (∼4–15 nm of diameters) has been observed to be significant for both C. tropicalis and E. coli. The cytotoxicity study indicates that CMC–Cu-NPs have no significant toxic effect against normal cell line, L929.

Preliminary study of copper oxide nanoparticles acoustic and magnetic properties for medical imaging

Science.gov (United States)

Perlman, Or; Weitz, Iris S.; Azhari, Haim

2015-03-01

The implementation of multimodal imaging in medicine is highly beneficial as different physical properties may provide complementary information, augmented detection ability, and diagnosis verification. Nanoparticles have been recently used as contrast agents for various imaging modalities. Their significant advantage over conventional large-scale contrast agents is the ability of detection at early stages of the disease, being less prone to obstacles on their path to the target region, and possible conjunction to therapeutics. Copper ions play essential role in human health. They are used as a cofactor for multiple key enzymes involved in various fundamental biochemistry processes. Extremely small size copper oxide nanoparticles (CuO-NPs) are readily soluble in water with high colloidal stability yielding high bioavailability. The goal of this study was to examine the magnetic and acoustic characteristics of CuO-NPs in order to evaluate their potential to serve as contrast imaging agent for both MRI and ultrasound. CuO-NPs 7nm in diameter were synthesized by hot solution method. The particles were scanned using a 9.4T MRI and demonstrated a concentration dependent T1 relaxation time shortening phenomenon. In addition, it was revealed that CuO-NPs can be detected using the ultrasonic B-scan imaging. Finally, speed of sound based ultrasonic computed tomography was applied and showed that CuO-NPs can be clearly imaged. In conclusion, the preliminary results obtained, positively indicate that CuO-NPs may be imaged by both MRI and ultrasound. The results motivate additional in-vivo studies, in which the clinical utility of fused images derived from both modalities for diagnosis improvement will be studied.

Ligand-Doped Copper Oxo-hydroxide Nanoparticles are Effective Antimicrobials

Science.gov (United States)

Bastos, Carlos A. P.; Faria, Nuno; Ivask, Angela; Bondarenko, Olesja M.; Kahru, Anne; Powell, Jonathan

2018-04-01

Bacterial resistance to antimicrobial therapies is an increasing clinical problem. This is as true for topical applications as it is for systemic therapy. Topically, copper ions may be effective and cheap antimicrobials that act through multiple pathways thereby limiting opportunities to bacteria for resistance. However, the chemistry of copper does not lend itself to facile formulations that will readily release copper ions at biologically compatible pHs. Here, we have developed nanoparticulate copper hydroxide adipate tartrate (CHAT) as a cheap, safe, and readily synthesised material that should enable antimicrobial copper ion release in an infected wound environment. First, we synthesised CHAT and showed that this had disperse aquated particle sizes of 2-5 nm and a mean zeta potential of - 40 mV. Next, when diluted into bacterial medium, CHAT demonstrated similar efficacy to copper chloride against Escherichia coli and Staphylococcus aureus, with dose-dependent activity occurring mostly around 12.5-50 mg/L of copper. Indeed, at these levels, CHAT very rapidly dissolved and, as confirmed by a bacterial copper biosensor, showed identical intracellular loading to copper ions derived from copper chloride. However, when formulated at 250 mg/L in a topically applied matrix, namely hydroxyethyl cellulose, the benefit of CHAT over copper chloride was apparent. The former yielded rapid sustained release of copper within the bactericidal range, but the copper chloride, which formed insoluble precipitates at such concentration and pH, achieved a maximum release of 10 ± 7 mg/L copper by 24 h. We provide a practical formulation for topical copper-based antimicrobial therapy. Further studies, especially in vivo, are merited.

A Study of the Influence of Percentage of Copper on the Structural and Optical Properties of Au-Cu Nanoparticle

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Parivash Mashayekhi Shams

2016-07-01

Full Text Available Here we present our experimental results in synthesizing Au-Cu nano-particles with tunable localized surface plasmon resonance frequency through wet-chemical at temperature room. The reaction is performed in the presence of ascorbic acid as a reducing agent and polyvinyl pyrrolidone as capping agent via four different procedures: (1 mixture of 90% HAuCl4 and 10% CuSO4.5H2O precursors, (2 mixture of 75% HAuCl4 and 25% CuSO4.5H2O precursors, (3 mixture of 50% HAuCl4 and 50% CuSO4.5H2O precursors (4 mixture of 25% HAuCl4 and 75% CuSO4.5H2O precursors. Effect of different percentages of Cu on Au nanoparticles has been analyzed using X-ray diffraction (XRD, scanning electron microscopy (SEM with EDAX analysis, DRS UV-Vis, and Fourier transform IR spectra (FTIR analysis. X-ray diffraction (XRD analysis revealed that the nanoparticles are of cubic structure without an impure phase. The successful doping of the Cu into the Au host was evident by XRD line shiftings. The increasing percentage of copper leads to the decreasing grain size. With the increase of Cu2+ to Au3+ ratio in the Cu2+/Au3+ mixed solution (> 50% Cu, XRD lines show no shifting. The average crystal sizes of the particles at room temperature were less than 9.9 nm. The surface plasmon resonance peak shifts from 380 to 340 nm, party due to the change in particle size. SEM images show a spherical shape and the size of nanoparticles becomes smaller with increasing the percentage of copper. Moreover, in the molar ratio of Cu2+/Au3+ = 75/25 (>50% Cu, mixture of spherical and trigonal nanoparticles were prepared. Fourier transform infrared spectroscopy (FT-IR showed the coordination and conjugation nanoparticles with N and O atoms of C-N and C=O bonds.

In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants

Energy Technology Data Exchange (ETDEWEB)

Banik, S.; Pérez-de-Luque, A.

2017-07-01

Copper-based chemicals are effectively used as antimicrobials in agriculture. However, with respect to its nanoparticulate form there has been limited number of studies. In this investigation, in vitro tests on effect of copper nanoparticles (CuNPs) against plant pathogenic fungi, oomycete, bacteria, beneficial microbes Trichoderma harzianum and Rhizobium spp., and wheat seeds were conducted. Integration of CuNPs with non-nano copper like copper oxychloride (CoC) at 50 mg/L concentration each recorded 76% growth inhibition of the oomycete Phytophthora cinnamomi in vitro compared to the control. CuNPs also showed synergistic inhibitory effect with CoC on mycelial growth and sporulation of A. alternata. Pseudomonas syringae was inhibited at 200 mg/L of CuNPs. CuNPs were not significantly biocidal against Rhizobium spp. and Trichoderma harzianum compared to CoC. Evaluation of the effect of CuNP on wheat revealed that rate of germination of wheat seeds was higher in presence of CuNPs and CoC compared to control. Germination vigor index, root length, shoot dry weight and seed metabolic efficiency of wheat were negatively affected. At low concentration, CuNPs promoted the growth of the plant pathogenic fungi Botrytis fabae, Fusarium oxysporum f.sp. ciceris, F.oxysporum f.sp. melonis, Alternaria alternate and P. syringae, and sporulation of T. harzianum. Synergistic effect of CuNPs and CoC in inhibiting P. cinnamomi offers a possibility of developing new fungicide formulation for better control of the oomycetes. Non-biocidal effect of CuNPs against beneficial microbes indicates its potential use in the agri-ecosystem.

In vitro effects of copper nanoparticles on plant pathogens, beneficial microbes and crop plants

International Nuclear Information System (INIS)

Banik, S.; Pérez-de-Luque, A.

2017-01-01

Copper-based chemicals are effectively used as antimicrobials in agriculture. However, with respect to its nanoparticulate form there has been limited number of studies. In this investigation, in vitro tests on effect of copper nanoparticles (CuNPs) against plant pathogenic fungi, oomycete, bacteria, beneficial microbes Trichoderma harzianum and Rhizobium spp., and wheat seeds were conducted. Integration of CuNPs with non-nano copper like copper oxychloride (CoC) at 50 mg/L concentration each recorded 76% growth inhibition of the oomycete Phytophthora cinnamomi in vitro compared to the control. CuNPs also showed synergistic inhibitory effect with CoC on mycelial growth and sporulation of A. alternata. Pseudomonas syringae was inhibited at 200 mg/L of CuNPs. CuNPs were not significantly biocidal against Rhizobium spp. and Trichoderma harzianum compared to CoC. Evaluation of the effect of CuNP on wheat revealed that rate of germination of wheat seeds was higher in presence of CuNPs and CoC compared to control. Germination vigor index, root length, shoot dry weight and seed metabolic efficiency of wheat were negatively affected. At low concentration, CuNPs promoted the growth of the plant pathogenic fungi Botrytis fabae, Fusarium oxysporum f.sp. ciceris, F.oxysporum f.sp. melonis, Alternaria alternate and P. syringae, and sporulation of T. harzianum. Synergistic effect of CuNPs and CoC in inhibiting P. cinnamomi offers a possibility of developing new fungicide formulation for better control of the oomycetes. Non-biocidal effect of CuNPs against beneficial microbes indicates its potential use in the agri-ecosystem.

Enhanced Photocatalytic Activity of TiO2 Nanoparticles Supported on Electrically Polarized Hydroxyapatite.

Science.gov (United States)

Zhang, Xuefei; Yates, Matthew Z

2018-05-23

Fast recombination of photogenerated charge carriers in titanium dioxide (TiO 2 ) remains a challenging issue, limiting the photocatalytic activity. This study demonstrates increased photocatalytic performance of TiO 2 nanoparticles supported on electrically polarized hydroxyapatite (HA) films. Dense and thermally stable yttrium and fluorine co-doped HA films with giant internal polarization were synthesized as photocatalyst supports. TiO 2 nanoparticles deposited on the support were then used to catalyze the photochemical reduction of aqueous silver ions to produce silver nanoparticles. It was found that significantly more silver nanoparticles were produced on polarized HA supports than on depolarized HA supports. In addition, the photodegradation of methyl orange with TiO 2 nanoparticles on polarized HA supports was found to be much faster than with TiO 2 nanoparticles on depolarized HA supports. It is proposed that separation of photogenerated electrons and holes in TiO nanoparticles is promoted by the internal polarization of the HA support, and consequently, the recombination of charge carriers is mitigated. The results imply that materials with large internal polarization can be used in strategies for enhancing quantum efficiency of photocatalysts.

Morphology of micro- and nanoparticles emitted by copper plants in Western Poland

Energy Technology Data Exchange (ETDEWEB)

Konarski, P.; Cwil, M.; Iwanejko, I.; Mierzejewska, A.; Diduszko, R

2004-07-01

Aerosol particles were collected in the vicinity of copper plants in Western Poland and analysed by mass spectrometry methods like secondary ion mass spectrometry (SIMS), spark source mass spectrometry (SSMS) and X-ray diffraction to characterise the possible dangers for the environment and health. The motivation of the work was to approach the toxicological mechanisms that are triggered when aerosol nanoparticles enter the human body. Different analytical techniques were used in order to compare bulk and surface properties of particles. The particle collection was performed with nine-stage cascade impactor with rotating plates and also with micro-fibre quartz filter collector. SSMS bulk analysis of copper plant emitted particles shows the presence of over 30 elements, the concentration in wt.% of Cu, Pb, Zn and Cl is 30, 5, 2 and 1, respectively. XRD analysis of these particles shows crystalline phases of quartz and probable phases containing copper CuS{sub 2}, lead Pb{sub 2}SiO{sub 4}, PbO - massicot, Pb{sub 5}[OH][PO{sub 4}]{sub 3}, Pb{sub 3}SiO{sub 5}, iron and calcium Ca[Mg{sub 0.67}Fe{sub 0.33}][CO{sub 3}] - dolomite, ferroan, Ca[FeMg][CO{sub 3}]{sub 2} - ankerite, Ca[MgFe]Si{sub 2}O{sub 6} - augite. Surface sensitive SIMS depth profile analysis revealed the core-shell structure of copper plant emitted particles. The obtained structure of these particles shows that surfaces of the particles are enriched in elements like chlorine, fluorine, lead and chromium with respect to the core concentrations of these elements. The cores are composed mainly of copper, oxygen and carbon containing compounds. Lead concentration is nearly two times greater at the surface layers of particles than in the cores. SIMS analysis of urban aerosol particles collected in Legnica shows compositional dependence with size. Surface shell layer concentration of lead is three times greater for coarse 6-15 {mu}m particles than for tiny 300 nm-1 {mu}m particles. Such non-uniform particle

Copper ferrocyanide functionalized magnetic nanoparticles using polyelectrolyte for the removal of cesium

Energy Technology Data Exchange (ETDEWEB)

Yang, Hee Man; Lee, Kune Woo; Seo, Bum Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

In the present study, magnetite nanoparticles were coated with copper ferrocyanide for the adsorption of radioactive Cs-137 in an aqueous solution through the grafting of polyethyleneimine. We describe the morphology, structure, and physical property of these nanoparticles. In addition, their ability to eliminate Cs-137 from water was also evaluated. Magnetic nanoadsorbents composed of a magnetic particles core and functional shell, which adsorb the contaminants, has attracted significant attention in environmental remediation owing to their high surface area and unique superparamagnetism. Since the nuclear accident at the Fukushima Daiichi nuclear power station in 2011, a huge amount of radioactive contaminants has been released into the environment. Among the various radioactive contaminants, cesium (Cs)-137 (137Cs) is the most apprehensive element owing to its long half-life (30.2 years), high solubility in water, and strong radiation emission in the form of gamma rays (γ-rays). Various methods such as ion exchange solvent extraction and precipitation are applied for the remediation of Cs-137 contaminated water. In particular, metal ferrocyanides show a high selectivity toward Cs-137. However, the very fine powder form of metal ferrocyanide causes a difficult separation from water through filtration.

Synthesis of Cu-Poor Copper-Indium-Gallium-Diselenide Nanoparticles by Solvothermal Route for Solar Cell Applications

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Chung Ping Liu

2014-01-01

Full Text Available Copper-indium-gallium-diselenide (CIGS thin films were fabricated using precursor nanoparticle ink and sintering technology. The precursor was a Cu-poor quaternary compound with constituent ratios of Cu/(In+Ga=0.603, Ga/(In+Ga=0.674, and Se/(Cu+In+Ga=1.036. Cu-poor CIGS nanoparticles of chalcopyrite for solar cells were successfully synthesized using a relatively simple and convenient elemental solvothermal route. After a fixed reaction time of 36 h at 180°C, CIGS nanocrystals with diameters in the range of 20–70 nm were observed. The nanoparticle ink was fabricated by mixing CIGS nanoparticles, a solvent, and an organic polymer. Analytical results reveal that the Cu-poor CIGS absorption layer prepared from a nanoparticle-ink polymer by sintering has a chalcopyrite structure and a favorable composition. For this kind of sample, its mole ratio of Cu : In : Ga : Se is equal to 0.617 : 0.410 : 0.510 : 2.464 and related ratios of Ga/(In+Ga and Cu/(In+Ga are 0.554 and 0.671, respectively. Under the condition of standard air mass 1.5 global illumination, the conversion efficiency of the solar cell fabricated by this kind of sample is 4.05%.

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO2 reforming of methane

KAUST Repository

Biausque, Gregory; Laveille, Paco; Anjum, Dalaver H.; Caps, Valerie; Basset, Jean-Marie

2015-01-01

Embodiments of the present disclosure provide for NiPt nanoparticles, compositions and supports including NiPt nanoparticles, methods of making NiPt nanoparticles, methods of supporting NiPt nanoparticles, methods of using NiPt nanoparticles, and the like.

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO2 reforming of methane

KAUST Repository

Biausque, Gregory

2015-09-24

Embodiments of the present disclosure provide for NiPt nanoparticles, compositions and supports including NiPt nanoparticles, methods of making NiPt nanoparticles, methods of supporting NiPt nanoparticles, methods of using NiPt nanoparticles, and the like.

Size control and catalytic activity of bio-supported palladium nanoparticles.

Science.gov (United States)

Søbjerg, Lina Sveidal; Lindhardt, Anders T; Skrydstrup, Troels; Finster, Kai; Meyer, Rikke Louise

2011-07-01

The development of nanoparticles has greatly improved the catalytic properties of metals due to the higher surface to volume ratio of smaller particles. The production of nanoparticles is most commonly based on abiotic processes, but in the search for alternative protocols, bacterial cells have been identified as excellent scaffolds of nanoparticle nucleation, and bacteria have been successfully employed to recover and regenerate platinum group metals from industrial waste. We report on the formation of bio-supported palladium (Pd) nanoparticles on the surface of two bacterial species with distinctly different surfaces: the gram positive Staphylococcus sciuri and the gram negative Cupriavidus necator. We investigated how the type of bacterium and the amount of biomass affected the size and catalytic properties of the nanoparticles formed. By increasing the biomass:Pd ratio, we could produce bio-supported Pd nanoparticles smaller than 10nm in diameter, whereas lower biomass:Pd ratios resulted in particles ranging from few to hundreds of nm. The bio-supported Pd nanoparticle catalytic properties were investigated towards the Suzuki-Miyaura cross coupling reaction and hydrogenation reactions. Surprisingly, the smallest nanoparticles obtained at the highest biomass:Pd ratio showed no reactivity towards the test reactions. The lack of reactivity appears to be caused by thiol groups, which poison the catalyst by binding strongly to Pd. Different treatments intended to liberate particles from the biomass, such as burning or rinsing in acetone, did not re-establish their catalytic activity. Sulphur-free biomaterials should therefore be explored as more suitable scaffolds for Pd(0) nanoparticle formation. Copyright © 2011 Elsevier B.V. All rights reserved.

Screening for cystic fibrosis via a magnetic and microfluidic immunoassay format with electrochemical detection using a copper nanoparticle-modified gold electrode

International Nuclear Information System (INIS)

Benuzzi, Maria Luz Scala; Pereira, Sirley V.; Raba, Julio; Messina, Germán A.

2016-01-01

This article describes a microfluidic electrochemical immunoassay that features two strategies, viz. (a), the incorporation of magnetic nanoparticles (MNPs) into the central microfluidic channel and acting as a bioaffinity support for the immobilization of the antibody against the immunoreactive trypsin (anti-IRT), and (b), the electrodeposition of copper nanoparticles (CuNPs) on a gold electrode. IRT, a marker for cystic fibrosis, is extracted from blood samples onto a disk using ultrasonication, eluted, and then injected into the detection system where it is captured by anti-IRT-loaded nanoparticles (anti-IRT-Ab-MNPs). Bound IRT is electrochemically quantified after addition of HRP-labeled anti-IRT-Ab which, in the presence of H 2 O 2 , catalyzes the oxidation of catechol to form o-benzoquinone which is detected at a working potential of −1 50 mV (vs. Ag/AgCl). The electrochemical response to benzoquinone is proportional to the concentration of IRT in the range from 0 to 580 ng⋅mL −1 . The coefficients of variation are <5 % for within-day assays, and <6.4 % for between-day assays. The method was compared to a commercial ELISA for IRT where is showed a correlation coefficient of close to 1. In our perception, this approach represents an attractive alternative to existing methods for screening newborns for cystic fibrosis. (author)

Colorimetric detection of trace copper ions based on catalytic leaching of silver-coated gold nanoparticles.

Science.gov (United States)

Lou, Tingting; Chen, Lingxin; Chen, Zhaopeng; Wang, Yunqing; Chen, Ling; Li, Jinhua

2011-11-01

A colorimetric, label-free, and nonaggregation-based silver coated gold nanoparticles (Ag/Au NPs) probe has been developed for detection of trace Cu(2+) in aqueous solution, based on the fact that Cu(2+) can accelerate the leaching rate of Ag/Au NPs by thiosulfate (S(2)O(3)(2-)). The leaching of Ag/Au NPs would lead to dramatic decrease in the surface plasmon resonance (SPR) absorption as the size of Ag/Au NPs decreased. This colorimetric strategy based on size-dependence of nanoparticles during their leaching process provided a highly sensitive (1.0 nM) and selective detection toward Cu(2+), with a wide linear detection range (5-800 nM) over nearly 3 orders of magnitude. The cost-effective probe allows rapid and sensitive detection of trace Cu(2+) ions in water samples, indicating its potential applicability for the determination of copper in real samples.

Sputtering and mixing of supported nanoparticles

International Nuclear Information System (INIS)

Jiménez-Sáez, J.C.; Pérez-Martín, A.M.C.; Jiménez-Rodríguez, J.J.

2013-01-01

Sputtering and mixing of Co nanoparticles supported in Cu(0 0 1) under 1-keV argon bombardment are studied using molecular-dynamics simulations. Particles of different initial size have been considered. The cluster height decreases exponentially with increasing fluence. In nanoparticles, sputtering yield is significantly enhanced compared to bulk. In fact, the value of this magnitude depends on the cluster height. A theoretical model for sputtering is introduced with acceptable results compared to those obtained by simulation. Discrepancies happen mainly for very small particles. Mixing rate at the interface is quantified; and besides, the influence of border effects for clusters of different initial size is assessed. Mixing rate and border length–surface area ratio for the initial interface show a proportionality relation. The phenomenon of ion-induced burrowing of metallic nanoparticles is analysed

Mechanism of the reduction of hexavalent chromium by organo-montmorillonite supported iron nanoparticles

International Nuclear Information System (INIS)

Wu, Pingxiao; Li, Shuzhen; Ju, Liting; Zhu, Nengwu; Wu, Jinhua; Li, Ping; Dang, Zhi

2012-01-01

Highlights: ► Organo-montmorillonite supported iron nanoparticles were found to be more efficient in the removal of Cr(VI) than unsupported iron nanoparticles. ► The iron nanoparticles were accommodated by the sectional structure of the clay minerals which were helpful to protect the nanoparticles from aggregating. ► XPS and XANES provided some direct information about the reduction mechanisms. ► The structure of the supported iron nanoparticles was stable in the reaction with Cr(VI). - Abstract: Iron nanoparticles exhibit greater reactivity than micro-sized Fe 0 , and they impart advantages for groundwater remediation. In this paper, supported iron nanoparticles were synthesized to further enhance the speed and efficiency of remediation. Natural montmorillonite and organo-montmorillonite were chosen as supporting materials. The capacity of supported iron nanoparticles was evaluated, compared to unsupported iron nanoparticles, for the reduction of aqueous Cr(VI). The reduction of Cr(VI) was much greater with organo-montmorillonite supported iron nanoparticles and fitted the pseudo-second order equation better. With a dose at 0.47 g/L, a total removal capacity of 106 mg Cr/g Fe 0 was obtained. Other factors that affect the efficiency of Cr(VI) removal, such as pH values, the initial Cr(VI) concentration and storage time of nanoparticles were investigated. X-ray photoelectron spectrometry (XPS) and X-ray absorption near edge structure (XANES) were used to figure out the mechanism of the removal of Cr(VI). XPS indicated that the Cr(VI) bound to the particle surface was completely reduced to Cr(III) under a range of conditions. XANES confirmed that the Cr(VI) reacted with iron nanoparticles was completely reduced to Cr(III).

Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

International Nuclear Information System (INIS)

Sujan, G.K.; Haseeb, A.S.M.A.; Afifi, A.B.M.

2014-01-01

Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu 6 Sn 5 from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping of flux

Effects of metallic nanoparticle doped flux on the interfacial intermetallic compounds between lead-free solder ball and copper substrate

Energy Technology Data Exchange (ETDEWEB)

Sujan, G.K., E-mail: sgkumer@gmail.com; Haseeb, A.S.M.A., E-mail: haseeb@um.edu.my; Afifi, A.B.M., E-mail: amalina@um.edu.my

2014-11-15

Lead free solders currently in use are prone to develop thick interfacial intermetallic compound layers with rough morphology which are detrimental to the long term solder joint reliability. A novel method has been developed to control the morphology and growth of intermetallic compound layers between lead-free Sn–3.0Ag–0.5Cu solder ball and copper substrate by doping a water soluble flux with metallic nanoparticles. Four types of metallic nanoparticles (nickel, cobalt, molybdenum and titanium) were used to investigate their effects on the wetting behavior and interfacial microstructural evaluations after reflow. Nanoparticles were dispersed manually with a water soluble flux and the resulting nanoparticle doped flux was placed on copper substrate. Lead-free Sn–3.0Ag–0.5Cu solder balls of diameter 0.45 mm were placed on top of the flux and were reflowed at a peak temperature of 240 °C for 45 s. Angle of contact, wetting area and interfacial microstructure were studied by optical microscopy, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. It was observed that the angle of contact increased and wetting area decreased with the addition of cobalt, molybdenum and titanium nanoparticles to flux. On the other hand, wettability improved with the addition of nickel nanoparticles. Cross-sectional micrographs revealed that both nickel and cobalt nanoparticle doping transformed the morphology of Cu{sub 6}Sn{sub 5} from a typical scallop type to a planer one and reduced the intermetallic compound thickness under optimum condition. These effects were suggested to be related to in-situ interfacial alloying at the interface during reflow. The minimum amount of nanoparticles required to produce the planer morphology was found to be 0.1 wt.% for both nickel and cobalt. Molybdenum and titanium nanoparticles neither appear to undergo alloying during reflow nor have any influence at the solder/substrate interfacial reaction. Thus, doping

Sustainable preparation of supported metal nanoparticles and their applications in catalysis.

Science.gov (United States)

Campelo, Juan M; Luna, Diego; Luque, Rafael; Marinas, José M; Romero, Antonio A

2009-01-01

Metal nanoparticles have attracted much attention over the last decade owing to their unique properties as compared to their bulk metal equivalents, including a large surface-to-volume ratio and tunable shapes. To control the properties of nanoparticles with particular respect to shape, size and dispersity is imperative, as these will determine the activity in the desired application. Supported metal nanoparticles are widely employed in catalysis. Recent advances in controlling the shape and size of nanoparticles have opened the possibility to optimise the particle geometry for enhanced catalytic activity, providing the optimum size and surface properties for specific applications. This Review describes the state of the art with respect to the preparation and use of supported metal nanoparticles in catalysis. The main groups of such nanoparticles (noble and transition metal nanoparticles) are highlighted and future prospects are discussed.

Plant Mediated Green Synthesis of CuO Nanoparticles: Comparison of Toxicity of Engineered and Plant Mediated CuO Nanoparticles towards Daphnia magna

Directory of Open Access Journals (Sweden)

Sadia Saif

2016-11-01

Full Text Available Research on green production methods for metal oxide nanoparticles (NPs is growing, with the objective to overcome the potential hazards of these chemicals for a safer environment. In this study, facile, ecofriendly synthesis of copper oxide (CuO nanoparticles was successfully achieved using aqueous extract of Pterospermum acerifolium leaves. P. acerifolium-fabricated CuO nanoparticles were further characterized by UV-Visible spectroscopy, field emission scanning electron microscopy (FE-SEM, energy dispersive X-ray (EDX, Fourier transform infrared spectroscopy (FTIR, X-ray photoelectron spectroscopy (XPS and dynamic light scattering (DLS. Plant-mediated CuO nanoparticles were found to be oval shaped and well dispersed in suspension. XPS confirmed the elemental composition of P. acerifolium-mediated copper nanoparticles as comprised purely of copper and oxygen. DLS measurements and ion release profile showed that P. acerifolium-mediated copper nanoparticles were more stable than the engineered CuO NPs. Copper oxide nanoparticles are used in many applications; therefore, their potential toxicity cannot be ignored. A comparative study was performed to investigate the bio-toxic impacts of plant-synthesized and engineered CuO nanoparticles on water flea Daphnia. Experiments were conducted to investigate the 48-h acute toxicity of engineered CuO NPs and plant-synthesized nanoparticles. Lower EC50 value 0.102 ± 0.019 mg/L was observed for engineered CuO NPs, while 0.69 ± 0.226 mg/L was observed for plant-synthesized CuO NPs. Additionally, ion release from CuO nanoparticles and 48-h accumulation of these nano CuOs in daphnids were also calculated. Our findings thus suggest that the contribution of released ions from nanoparticles and particles/ions accumulation in Daphnia needs to be interpreted with care.

Wrinkling instability in nanoparticle-supported graphene: implications for strain engineering

Science.gov (United States)

Cullen, William; Yamamoto, Mahito; Pierre-Louis, Olivier; Huang, Jia; Fuhrer, Michael; Einstein, Theodore

2013-03-01

We have carried out a systematic study of the wrinkling instability of graphene membranes supported on SiO2 substrates with randomly placed silica nanoparticles. At small nanoparticle density, monolayer graphene adheres to the substrate and is highly conformal over the nanoparticles. With increasing nanoparticle density, and decreasing nanoparticle separation to ~100 nm, graphene's elastic response dominates substrate adhesion, and elastic stretching energy is reduced by the formation of wrinkles which connect protrusions. Above a critical nanoparticle density, the wrinkles form a percolating network through the sample. As the graphene membrane is made thicker, delamination from the substrate is observed. Since the wrinkling instability acts to remove inhomogeneous in-plane elastic strains through out-of-plane buckling, our results can be used to place limits on the possible in-plane strain magnitudes that may be created in graphene to realized strain-engineered electronic structures.[2] Supported by the UMD NSF-MRSEC under Grant No. DMR 05-20471, the US ONR MURI and UMD CNAM.

Synthesis and Characterization of Pure Copper Nanostructures Using Wood Inherent Architecture as a Natural Template

Science.gov (United States)

Dong, Youming; Wang, Kaili; Tan, Yi; Wang, Qingchun; Li, Jianzhang; Mark, Hughes; Zhang, Shifeng

2018-04-01

The inherent sophisticated structure of wood inspires researchers to use it as a natural template for synthesizing functional nanoparticles. In this study, pure copper nanoparticles were synthesized using poplar wood as a natural inexpensive and renewable template. The crystal structure and morphologies of the copper nanoparticles were characterized by X-ray diffraction and field emission scanning electron microscopy. The optical properties, antibacterial properties, and stability of the hybrid wood materials were also tested. Due to the hierarchical and anisotropic structure and electron-rich components of wood, pure copper nanoparticles with high stability were synthesized with fcc structure and uniform sizes and then assembled into corncob-like copper deposits along the wood cell lumina. The products of nanoparticles depended strongly on the initial OH- concentration. With an increase in OH- concentration, Cu2O gradually decreased and Cu remained. Due to the restrictions inherent in wood structure, the derived Cu nanoparticles showed similar grain size in spite of increased Cu2+ concentration. This combination of Cu nanostructures and wood exhibited remarkable optical and antibacterial properties.

Low-cost optical fabrication of flexible copper electrode via laser-induced reductive sintering and adhesive transfer

Science.gov (United States)

Back, Seunghyun; Kang, Bongchul

2018-02-01

Fabricating copper electrodes on heat-sensitive polymer films in air is highly challenging owing to the need of expensive copper nanoparticles, rapid oxidation of precursor during sintering, and limitation of sintering temperature to prevent the thermal damage of the polymer film. A laser-induced hybrid process of reductive sintering and adhesive transfer is demonstrated to cost-effectively fabricate copper electrode on a polyethylene film with a thermal resistance below 100 °C. A laser-induced reductive sintering process directly fabricates a high-conductive copper electrode onto a glass donor from copper oxide nanoparticle solution via photo-thermochemical reduction and agglomeration of copper oxide nanoparticles. The sintered copper patterns were transferred in parallel to a heat-sensitive polyethylene film through self-selective surface adhesion of the film, which was generated by the selective laser absorption of the copper pattern. The method reported here could become one of the most important manufacturing technologies for fabricating low-cost wearable and disposable electronics.

Synthesis and structural studies of copper sulfide nanocrystals

Directory of Open Access Journals (Sweden)

Peter A. Ajibade

Full Text Available We report the synthesis and structural studies of copper sulfide nanocrystals from copper(II dithiocarbamate single molecule precursors. The optical studies of the as-prepared copper sulfide nanoparticles were carried out using UV–Visible and photoluminescence spectroscopy. The absorption spectra show absorption band edges at 287 nm and exhibit considerable blue shift that could be ascribed to the quantum confinement effects as a result of the small crystallite sizes of the nanoparticles and the photoluminescence spectra show emission curves that are red shifted with respect to the absorption band edges. The structural studies were carried out using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The XRD patterns revealed the formation of hexagonal structure of covellite CuS with estimated crystallite sizes of 17.3–18.6 nm. The TEM images showed particles with almost spherical or rod shapes with average crystallite sizes of 3–9.8 nm. SEM images showed morphology with ball-like microsphere on the surfaces and EDS spectra confirmed the presence of CuS nanoparticles. Keywords: CuS, Dithiocarbamate, Nanoparticles, Electron microscopy, AFM

Particle size effects in the thermal conductivity enhancement of copper-based nanofluids

Directory of Open Access Journals (Sweden)

Sahin Huseyin

2011-01-01

Full Text Available Abstract We present an analysis of the dispersion characteristics and thermal conductivity performance of copper-based nanofluids. The copper nanoparticles were prepared using a chemical reduction methodology in the presence of a stabilizing surfactant, oleic acid or cetyl trimethylammonium bromide (CTAB. Nanofluids were prepared using water as the base fluid with copper nanoparticle concentrations of 0.55 and 1.0 vol.%. A dispersing agent, sodium dodecylbenzene sulfonate (SDBS, and subsequent ultrasonication was used to ensure homogenous dispersion of the copper nanopowders in water. Particle size distribution of the copper nanoparticles in the base fluid was determined by dynamic light scattering. We found that the 0.55 vol.% Cu nanofluids exhibited excellent dispersion in the presence of SDBS. In addition, a dynamic thermal conductivity setup was developed and used to measure the thermal conductivity performance of the nanofluids. The 0.55 vol.% Cu nanofluids exhibited a thermal conductivity enhancement of approximately 22%. In the case of the nanofluids prepared from the powders synthesized in the presence of CTAB, the enhancement was approximately 48% over the base fluid for the 1.0 vol.% Cu nanofluids, which is higher than the enhancement values found in the literature. These results can be directly related to the particle/agglomerate size of the copper nanoparticles in water, as determined from dynamic light scattering.

Mechanism of the reduction of hexavalent chromium by organo-montmorillonite supported iron nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Wu, Pingxiao, E-mail: pppxwu@scut.edu.cn [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Li, Shuzhen [School of Chemical and Environmental Engineering, Wuyi University, Jiangmen, Guangdong Province 529020 (China); Ju, Liting [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Zhu, Nengwu [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China); Wu, Jinhua; Li, Ping [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); Dang, Zhi [College of Environmental Science and Engineering, South China University of Technology, Guangzhou 510006 (China); The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou 510006 (China); The Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Regular Higher Education Institutions (China)

2012-06-15

Highlights: Black-Right-Pointing-Pointer Organo-montmorillonite supported iron nanoparticles were found to be more efficient in the removal of Cr(VI) than unsupported iron nanoparticles. Black-Right-Pointing-Pointer The iron nanoparticles were accommodated by the sectional structure of the clay minerals which were helpful to protect the nanoparticles from aggregating. Black-Right-Pointing-Pointer XPS and XANES provided some direct information about the reduction mechanisms. Black-Right-Pointing-Pointer The structure of the supported iron nanoparticles was stable in the reaction with Cr(VI). - Abstract: Iron nanoparticles exhibit greater reactivity than micro-sized Fe{sup 0}, and they impart advantages for groundwater remediation. In this paper, supported iron nanoparticles were synthesized to further enhance the speed and efficiency of remediation. Natural montmorillonite and organo-montmorillonite were chosen as supporting materials. The capacity of supported iron nanoparticles was evaluated, compared to unsupported iron nanoparticles, for the reduction of aqueous Cr(VI). The reduction of Cr(VI) was much greater with organo-montmorillonite supported iron nanoparticles and fitted the pseudo-second order equation better. With a dose at 0.47 g/L, a total removal capacity of 106 mg Cr/g Fe{sup 0} was obtained. Other factors that affect the efficiency of Cr(VI) removal, such as pH values, the initial Cr(VI) concentration and storage time of nanoparticles were investigated. X-ray photoelectron spectrometry (XPS) and X-ray absorption near edge structure (XANES) were used to figure out the mechanism of the removal of Cr(VI). XPS indicated that the Cr(VI) bound to the particle surface was completely reduced to Cr(III) under a range of conditions. XANES confirmed that the Cr(VI) reacted with iron nanoparticles was completely reduced to Cr(III).

Synthesis of Supported NiPt Bimetallic Nanoparticles, Methods for Controlling the Surface Coverage of Ni Nanoparticles With Pt, Methods Of Making NiPt Multilayer Core-Shell Structures and Application of the Supported Catalysts for CO2 Reforming

KAUST Repository

Li, Lidong; Anjum, Dalaver H.; Zhou, Lu; Laveille, Paco; Basset, Jean-Marie

2015-01-01

Embodiments of the present disclosure provide for supported Ni/Pt bimetallic nanoparticles, compositions including supported NiPt nanoparticles, methods of making supported NiPt nanoparticles, methods of using supported NiPt nanoparticles

Catalytic Ammonia Decomposition Over Ruthenium Nanoparticles Supported on Nano-Titanates

DEFF Research Database (Denmark)

Klerke, Asbjørn; Klitgaard, Søren Kegnæs; Fehrmann, Rasmus

2009-01-01

Nanosized Na2Ti3O7, K2Ti6O13 and Cs2Ti6O13 materials were prepared and used as supports of ruthenium nanoparticles for catalytic ammonia decomposition. It is shown that these catalysts exhibit higher catalytic activity than ruthenium supported on TiO2 nanoparticles promoted with cesium. The diffe...

Synthesis of Supported NiPt Bimetallic Nanoparticles, Methods for Controlling the Surface Coverage of Ni Nanoparticles With Pt, Methods Of Making NiPt Multilayer Core-Shell Structures and Application of the Supported Catalysts for CO2 Reforming

KAUST Repository

Li, Lidong

2015-06-25

Embodiments of the present disclosure provide for supported Ni/Pt bimetallic nanoparticles, compositions including supported NiPt nanoparticles, methods of making supported NiPt nanoparticles, methods of using supported NiPt nanoparticles, and the like.

Sonochemical synthesis of copper II sulfide nanoparticles and their use as radiolytic stabilizer in poly(methyl methacrylate) matrix

International Nuclear Information System (INIS)

Albuquerque, Marilia Cordeiro C. de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S.

2011-01-01

Copper (II) sulfide (CuS) was synthesized by sonochemical method. Cu S crystals with hexagonal structure exhibit irregular particles with an average size in the range of 250-900 nm. Commercial Poly(methyl methacrylate) (PMMA) containing CuS nanoparticles (PMMA/Cu) at concentrations of 0.15; 0.30; 0.45 and 0.60 wt% were investigated. The samples were irradiated with gamma radiation ( 60 Co) at room temperature and air atmosphere. The viscosity-average molar mass (Mv) was measured for PMMA systems without nanoparticles and with nanoparticles. Decrease in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.3 wt% into PMMA matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 50% in PMMA matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PMMA systems. Changes in the infrared spectra of PMMA systems indicate that polymer molecules interact with CuS nanoparticles. Improvement of mechanical properties was found for PMMA/Cu films. An increase of 38% of Young's modulus value and a decrease of 22% on the elongation at break value were recorded for PMMA/Cu films exposed to gamma irradiation. (author)

Polymer supported gold nanoparticles: Synthesis and characterization of functionalized polystyrene-supported gold nanoparticles and their application in catalytic oxidation of alcohols in water

Science.gov (United States)

Kaboudin, Babak; Khanmohammadi, Hamid; Kazemi, Foad

2017-12-01

Sulfonated polystyrene microsphere were functionalized using ethylene diamine to introduce amine groups to the polymer chains. The amine functionalized polymers were used as a support for gold nanoparticles. A thorough structural characterization has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, EDS, CHN and atomic absorption spectroscopy. The polymer supported gold nanoparticles was found to be an efficient catalyst for the oxidation of alcohols in water.

Copper nanoparticle ensembles for selective electroreduction of CO2 to C2–C3 products

Science.gov (United States)

Kley, Christopher S.; Li, Yifan; Yang, Peidong

2017-01-01

Direct conversion of carbon dioxide to multicarbon products remains as a grand challenge in electrochemical CO2 reduction. Various forms of oxidized copper have been demonstrated as electrocatalysts that still require large overpotentials. Here, we show that an ensemble of Cu nanoparticles (NPs) enables selective formation of C2–C3 products at low overpotentials. Densely packed Cu NP ensembles underwent structural transformation during electrolysis into electrocatalytically active cube-like particles intermixed with smaller nanoparticles. Ethylene, ethanol, and n-propanol are the major C2–C3 products with onset potential at −0.53 V (vs. reversible hydrogen electrode, RHE) and C2–C3 faradaic efficiency (FE) reaching 50% at only −0.75 V. Thus, the catalyst exhibits selective generation of C2–C3 hydrocarbons and oxygenates at considerably lowered overpotentials in neutral pH aqueous media. In addition, this approach suggests new opportunities in realizing multicarbon product formation from CO2, where the majority of efforts has been to use oxidized copper-based materials. Robust catalytic performance is demonstrated by 10 h of stable operation with C2–C3 current density 10 mA/cm2 (at −0.75 V), rendering it attractive for solar-to-fuel applications. Tafel analysis suggests reductive CO coupling as a rate determining step for C2 products, while n-propanol (C3) production seems to have a discrete pathway. PMID:28923930

Synthesis of Mg2Cu nanoparticles on carbon supports with enhanced hydrogen sorption kinetics

NARCIS (Netherlands)

Au, Y.S.; Ponthieu, M.; van Zwienen, M.; Zlotea, C.; Cuevas, F.; de Jong, K.P.; de Jongh, P.E.

2013-01-01

The reaction kinetics and reversibility for hydrogen sorption were investigated for supported Mg2Cu nanoparticles on carbon. A new preparation method is proposed to synthesize the supported alloy nanoparticles. The motivation of using a support is to separate the nanoparticles to prevent sintering

Sugar-mediated ‘green’ synthesis of copper nanoparticles with high antifungal activity

International Nuclear Information System (INIS)

Ray, Debajyoti; Prasad Mandal, Ranju; De, Swati; Pramanik, Satadru; Chaudhuri, Sujata

2015-01-01

Herein we present a novel and facile approach to effectively synthesize and stabilize copper nanoparticles (CuNPs) using the sugars dextrose, dextrin and β-cyclodextrin. This approach adopts the fundamental principles of ‘green chemistry’ by usage of nontoxic, renewable chemicals and use of ambient temperature, normal pH and other mild conditions. This work shows that the amphiphilicity presented by the sugars determines the CuNP characteristics. One very important aspect of this work is that these CuNPs show significant antifungal activity towards a potent rice pathogen whose action is wide spread and difficult to control. Thus this work provides a biocompatible method to arrest the growth of a potent rice pathogen. This has widespread implications in areas where rice is the main food crop. (paper)

Copper-indium-gallium-diselenide nanoparticles synthesized by a solvothermal method for solar cell application

Directory of Open Access Journals (Sweden)

Chiou Chuan-Sheng

2017-01-01

Full Text Available Chalcopyrite copper-indium-gallium-diselenide (CIGS nanoparticles are useful for photovoltaic applications. In this study, the synthesis of CIGS powder was examined, and the powder was successfully synthesized using a relatively simple and convenient elemental solvothermal route. From the reactions of elemental Cu, In, Se and Ga(NO33 powders in an autoclave with ethylenediamine as a solvent, spherical CIGS nanoparticles, with diameters ranging from 20-40 nm, were obtained using a temperature of 200°C for 36h. The structure, morphology, chemical composition and optical properties of the as-synthesized CIGS were characterized using X-ray diffraction, transmission electron microscopy, selected area electron diffraction, scanning electron microscopy, inductively coupled plasma-mass spectrometry. In this sample, the mole ratio of Cu:In:Ga:Se was equal to 0.89:0.71:0.29:2.01, and the optical band gap was found to be 1.18 eV. The solar cell obtained a power conversion efficiency of 5.62% under standard air mass 1.5 global illumination.

Surface Functionalization of Thin-Film Composite Membranes with Copper Nanoparticles for Antimicrobial Surface Properties

KAUST Repository

Ben-Sasson, Moshe

2014-01-07

Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. © 2013 American Chemical Society.

Surface Functionalization of Thin-Film Composite Membranes with Copper Nanoparticles for Antimicrobial Surface Properties

KAUST Repository

Ben-Sasson, Moshe; Zodrow, Katherine R.; Genggeng, Qi; Kang, Yan; Giannelis, Emmanuel P.; Elimelech, Menachem

2014-01-01

Biofouling is a major operational challenge in reverse osmosis (RO) desalination, motivating a search for improved biofouling control strategies. Copper, long known for its antibacterial activity and relatively low cost, is an attractive potential biocidal agent. In this paper, we present a method for loading copper nanoparticles (Cu-NPs) on the surface of a thin-film composite (TFC) polyamide RO membrane. Cu-NPs were synthesized using polyethyleneimine (PEI) as a capping agent, resulting in particles with an average radius of 34 nm and a copper content between 39 and 49 wt.%. The positive charge of the Cu-NPs imparted by the PEI allowed a simple electrostatic functionalization of the negatively charged RO membrane. We confirmed functionalization and irreversible binding of the Cu-NPs to the membrane surface with SEM and XPS after exposing the membrane to bath sonication. We also demonstrated that Cu-NP functionalization can be repeated after the Cu-NPs dissolve from the membrane surface. The Cu-NP functionalization had minimal impact on the intrinsic membrane transport parameters. Surface hydrophilicity and surface roughness were also maintained, and the membrane surface charge became positive after functionalization. The functionalized membrane exhibited significant antibacterial activity, leading to an 80-95% reduction in the number of attached live bacteria for three different model bacterial strains. Challenges associated with this functionalization method and its implementation in RO desalination are discussed. © 2013 American Chemical Society.

Combined spectroscopy and microscopy of supported MoS2 nanoparticles

DEFF Research Database (Denmark)

Nielsen, Jane Hvolbæk; Bech, Lone; Nielsen, Kenneth

2009-01-01

Supported molybdenum-sulfide nanoparticles are known catalysts for petroleum hydrodesulfurization as well as for electrochemical hydrogen evolution. In this study, we investigate molybdenum-sulfide nanoparticles supported on Au(111) using X-ray photoelectron spectroscopy (XPS) and scanning...... tunneling microscopy (STM), aiming to correlate spectroscopically determined chemical states with atomically resolved nanostructure. The results of this study allow us to conclude the following: (1) the XPS results from our model system are in good agreement with previously published results on supported Mo...

Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4 and Zinc Ferrite (ZnFe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

Directory of Open Access Journals (Sweden)

Samikannu Kanagesan

2016-08-01

Full Text Available Spinel copper ferrite (CuFe2O4 and zinc ferrite (ZnFe2O4 nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

Role of different chelating agent in synthesis of copper doped tin oxide (Cu-SnO2) nanoparticles

Science.gov (United States)

Saravanakumar, B.; Anusiya, A.; Rani, B. Jansi; Ravi, G.; Yuvakkumar, R.

2018-05-01

An attempt was made to synthesis the copper doped tin oxide (Cu-SnO2) nanoparticles by adopting different chelating agents (NaOH, KOH and C2H2O4) by Sol-gel process. The synthesized products were characterized by XRD, Photoluminescence (PL), Infra- Red (FTIR) and SEM analysis. The XRD confirms the formation of Cu-SnO2 shows the maximum peak at 33.8° with lattice plane (101). The PL peak at 361 and 382 nm due to the recombination of electron in conduction band to valence band infers the optical properties. The IR spectra correspond to the peak at 551 and 620 cm-1 attributed to the characteristics peak for Cu-SnO2 nanoparticles. The SEM images for all three Cu-SnO2 nanoparticles formed by three chelating agent (NaOH, KOH and C2H2O4) facilitates the formation mechanism and the chelating agent Oxalic acid results in formation of nano flowers with diverse layers orientated in random direction. Further SEM studies reveal that, the Cu-SnO2 nanoparticles formed by oxalic acid could posses high surface area with large number layered structured enables the better electrochemical properties and its applications.

Wrinkling instability in graphene supported on nanoparticle-patterned SiO2

Science.gov (United States)

Cullen, William; Yamamoto, Mahito; Pierre-Louis, Olivier; Einstein, Theodore; Fuhrer, Michael

2012-02-01

Atomically-thin graphene is arguably the thinnest possible mechanical membrane: graphene's effective thickness (the thickness of an isotropic continuum slab which would have the same elastic and bending stiffness) is significantly less than 1 å, indicating that graphene can distort out-of-plane to conform to sub-nanometer features. Here we study the elastic response of graphene supported on a SiO2 substrate covered with SiO2 nanoparticles. At a low density of nanoparticles, graphene is largely pinned to the substrate due to adhesive interaction. However, with increasing nanoparticle density, graphene's elasticity dominates adhesion and strain is relieved by the formation of wrinkles which connect peaks introduced by the supporting nanoparticles. At a critical density, the wrinkles percolate, resulting in a wrinkle network. We develop a simple elastic model allowing for adhesion which accurately predicts the critical spacing between nanoparticles for wrinkle formation. This work has been supported by the University of Maryland NSF-MRSEC under Grant No. DMR 05-20471 with supplemental funding from NRI, and NSF-DMR 08-04976.

The use of biodegradable polymers for the stabilization of copper ...

Indian Academy of Sciences (India)

2017-08-03

Aug 3, 2017 ... nanoparticles synthesized by chemical reduction method ... and the reaction temperature on the size and size distribution of copper nanoparticles were investigated using the ..... on chemical and process engineering p 217.

Sonochemical synthesis of copper II sulfide nanoparticles and their use as radiolytic stabilizer in poly(methyl methacrylate) matrix

Energy Technology Data Exchange (ETDEWEB)

Albuquerque, Marilia Cordeiro C. de; Aquino, Katia Aparecida da Silva; Araujo, Elmo S., E-mail: aquino@ufpe.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear

2011-07-01

Copper (II) sulfide (CuS) was synthesized by sonochemical method. Cu S crystals with hexagonal structure exhibit irregular particles with an average size in the range of 250-900 nm. Commercial Poly(methyl methacrylate) (PMMA) containing CuS nanoparticles (PMMA/Cu) at concentrations of 0.15; 0.30; 0.45 and 0.60 wt% were investigated. The samples were irradiated with gamma radiation ({sup 60}Co) at room temperature and air atmosphere. The viscosity-average molar mass (Mv) was measured for PMMA systems without nanoparticles and with nanoparticles. Decrease in molar mass observed when the systems were gamma irradiated reflect the random scission effects that take place in the main chain. Degradation index (DI) value was also obtained by viscosity analysis. DI results showed that the addition of CuS nanoparticles at 0.3 wt% into PMMA matrix decreased the number of main chain scissions at dose of 25 kGy and was calculated a protection of 50% in PMMA matrix. CuS nanoparticles act as free radical scavenger into gamma-irradiated PMMA systems. Changes in the infrared spectra of PMMA systems indicate that polymer molecules interact with CuS nanoparticles. Improvement of mechanical properties was found for PMMA/Cu films. An increase of 38% of Young's modulus value and a decrease of 22% on the elongation at break value were recorded for PMMA/Cu films exposed to gamma irradiation. (author)

Copper laser diagnostics and kinetics support

International Nuclear Information System (INIS)

1981-12-01

In the effort MSNW participated with the LINL copper-Vapor Laser Program by providing a useful plasma diagnostic for interpretation of Copper-vapor laser kinetics. MSNW developed and delivered a pulsed interferometric diagnostic package to LLNL. Moreover MSNW provided personal services at the request and direction of LLL in the implementation of the diagnostic and interpretation of the data

Antimicrobial electrospun silver-, copper- and zinc-doped polyvinylpyrrolidone nanofibers

International Nuclear Information System (INIS)

Quirós, Jennifer; Borges, João P.; Boltes, Karina; Rodea-Palomares, Ismael; Rosal, Roberto

2015-01-01

Highlights: • Electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc. • Antimicrobial effect for the bacteria Staphylococcus aureus and Escherichia coli. • Silver strongly reduced colony forming units and bacterial viability. • Silver, copper, and zinc led to a significant increase of non-viable cells on mats. - Abstract: The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

Antimicrobial electrospun silver-, copper- and zinc-doped polyvinylpyrrolidone nanofibers

Energy Technology Data Exchange (ETDEWEB)

Quirós, Jennifer [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Borges, João P. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Boltes, Karina [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, E-28805, Alcalá de Henares, Madrid (Spain); Rodea-Palomares, Ismael [Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Rosal, Roberto [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, E-28805, Alcalá de Henares, Madrid (Spain)

2015-12-15

Highlights: • Electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc. • Antimicrobial effect for the bacteria Staphylococcus aureus and Escherichia coli. • Silver strongly reduced colony forming units and bacterial viability. • Silver, copper, and zinc led to a significant increase of non-viable cells on mats. - Abstract: The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

Synthesis and Bactericidal Properties of Hyaluronic Acid Doped with Metal Nanoparticles

Directory of Open Access Journals (Sweden)

Galo Cárdenas-Triviño

2017-01-01

Full Text Available A study on the nanoparticles size and the antibacterial properties of hyaluronic acid (HA doped with nanoparticles is reported. Nanoparticles from gold, silver, copper, and silver palladium with HA support were performed. The solvated metal atom dispersion (SMAD method with 2-propanol and HA was used. High-resolution transmission electron microscopy (HRTEM, infrared spectroscopy (FT-IR, and thermogravimetric analysis (TGA were conducted. The average sizes of nanoclusters were as follows: HA-Au = 17.88 nm; HA-Ag = 50.41 nm; HA-Cu = 13.33 nm; and HA-AgPd = 33.22 nm. The antibacterial activity of solutions and films containing nanoparticles against American Type Culture Collection (ATCC bacterial strains Escherichia coli (EC, Staphylococcus aureus (SA, Staphylococcus epidermidis (SE, and Pseudomonas aeruginosa (PA was determined. Inhibition was observed for HA-Ag, HA-Cu, and HA-AgPd. Toxicological tests were performed in rats that were injected intraperitoneally with two concentrations of gold, copper, silver, and silver-palladium nanoparticles. No alterations in hepatic parameters, including ALT (alanine aminotransferase, GGT (gamma-glutamyl transpeptidase bilirubin, and albumin, were observed after 14 days. These films could be used as promoters of skin recovery and Grades I and II cutaneous burns and as scaffolds.

Direct Write Processing of Multi-micron Thickness Copper Nano-particle Paste on Flexible Substrates with 532 nm Laser Wavelength

Science.gov (United States)

Lopez-Espiricueta, Dunia; Fearon, Eamonn; Edwardson, Stuart; Dearden, Geoffrey

The Laser Assisted Direct Write (LA-DW) method has been implemented in the development of different markets and material processing, recently also used for creating Printed Circuit Boards (PCB) or electrical circuitry. The process consists in the deposition of metallic nano-particle (NP) inks, which are afterwards cured or sintered by laser irradiation, thus creating conductive pathways; advantages are speed, accuracy and the protection of the heat affected zone (HAZ). This research will study the behaviour of the heat dissipation relatively within the Nano-particle Copper paste after being irradiated with 1064 nm and 532 nm wavelengths, research will be developed on different widths and depths deposited onto flat surfaces such as flexible PET. Comparisons to be made between resistivity results obtained from different wavelengths.

Polyurethane nanofibers containing copper nanoparticles as future materials

DEFF Research Database (Denmark)

Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Saran, Saurabh

2011-01-01

nanofibers. Typically, a colloidal gel consisting of copper NPs and polyurethane has been electrospun. SEM-EDX and TEM results confirmed well oriented nanofibers and good dispersion of pure copper NPs. Copper NPs have diameter in the range of 5–10nm. The thermal stability of the synthesized nanofibers...... the antimicrobial efficacy of these nanofiber mats. Subsequently, antimicrobial tests have indicated that the prepared nanofibers do posses good bactericidal effect. Accordingly, it is noted that the obtained nanofiber mats can be used as future filter membranes with good antimicrobial activities....

Cellulose gum and copper nanoparticles based hydrogel as antimicrobial agents against urinary tract infection (UTI) pathogens.

Science.gov (United States)

Al-Enizi, Abdullah M; Ahamad, Tansir; Al-Hajji, Abdullah Baker; Ahmed, Jahangeer; Chaudhary, Anis Ahmad; Alshehri, Saad M

2018-04-01

In the present study, stable copper nanoparticles (CuNPs) were successfully prepared in the hydrogel matrix. The prepared nanocomposite (HCuNPs) was characterized via x-ray diffraction (XRD), electron microscopy (TEM), and energy-dispersive (EDX) and x-ray photoelectron spectroscopic (XPS) studies. The wide scan XPS spectra support the presence of C, N and O in neat hydrogel; while, the XPS spectra of HCuNPs demonstrate the presence of Cu along with C, N, and O elements. TEM studies show the formation of spherical shaped CuNPs in the size range from 7 to 12nm. The rheology results reveal that the storage modulus (G') of the HCuNPs was found to be higher than the loss modulus (G"). Additionally, the antibacterial activities and cytotoxic were carried out against urinary tract infection (UTI) microbes and HeLa (cervical) cells respectively. The antibacterial results reveal that HCuNPs composites show higher zone of inhibition against these pathogens then that of corresponding hydrogel matrix. The cytotoxic effects suggest that the prepared nanocomposite could be used as promising candidates for biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Genotoxicity of copper oxide nanoparticles with different surface chemistry on rat bone marrow mesenchymal stem cells

DEFF Research Database (Denmark)

Zhang, Wenjing; Jiang, Pengfei; Chen, Wei

2016-01-01

The surface chemistry of nanoparticles (NPs) is one of the critical factors determining their cellular responses. In this study, the cytotoxicity and genotoxicity of copper oxide (CuO) NPs with a similar size but different surface chemistry to rat bone marrow mesenchymal stem cells (MSCs) were......V and showed a similar tendency to form agglomerates with a size of ∼200 nm in cell culture environment. The cytotoxicity of CuO NPs to MSCs at various concentrations and incubation periods were firstly evaluated. The CuO NPs showed dose-dependent and time-dependent toxicity to MSCs, and their surface...

Sensitive detection of copper ions via ion-responsive fluorescence quenching of engineered porous silicon nanoparticles

Science.gov (United States)

Hwang, Jangsun; Hwang, Mintai P.; Choi, Moonhyun; Seo, Youngmin; Jo, Yeonho; Son, Jaewoo; Hong, Jinkee; Choi, Jonghoon

2016-10-01

Heavy metal pollution has been a problem since the advent of modern transportation, which despite efforts to curb emissions, continues to play a critical role in environmental pollution. Copper ions (Cu2+), in particular, are one of the more prevalent metals that have widespread detrimental ramifications. From this perspective, a simple and inexpensive method of detecting Cu2+ at the micromolar level would be highly desirable. In this study, we use porous silicon nanoparticles (NPs), obtained via anodic etching of Si wafers, as a basis for undecylenic acid (UDA)- or acrylic acid (AA)-mediated hydrosilylation. The resulting alkyl-terminated porous silicon nanoparticles (APS NPs) have enhanced fluorescence stability and intensity, and importantly, exhibit [Cu2+]-dependent quenching of fluorescence. After determining various aqueous sensing conditions for Cu2+, we demonstrate the use of APS NPs in two separate applications - a standard well-based paper kit and a portable layer-by-layer stick kit. Collectively, we demonstrate the potential of APS NPs in sensors for the effective detection of Cu2+.

Copper oxide thin films anchored on glass substrate by sol gel spin coating technique

Science.gov (United States)

Krishnaprabha, M.; Venu, M. Parvathy; Pattabi, Manjunatha

2018-05-01

Owing to the excellent optical, thermal, electrical and photocatalytic properties, copper oxide nanoparticles/films have found applications in optoelectronic devices like solar/photovoltaic cells, lithium ion batteries, gas sensors, catalysts, magnetic storage media etc. Copper oxide is a p-type semiconductor material having a band gap energy varying from 1.2 eV-2.1 eV. Syzygium Samarangense fruit extract was used as reducing agent to synthesize copper oxide nanostructures at room temperature from 10 mM copper sulphate pentahydrate solution. The synthesized nanostructures are deposited onto glass substrate by spin coating followed by annealing the film at 200 °C. Both the copper oxide colloid and films are characterized using UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) techniques. Presence of 2 peaks at 500 nm and a broad peak centered around 800 nm in the UV-Vis absorbance spectra of copper oxide colloid/films is indicative of the formation of anisotropic copper oxide nanostructures is confirmed by the FESEM images which showed the presence of triangular shaped and rod shaped particles. The rod shaped particles inside island like structures were found in unannealed films whereas the annealed films contained different shaped particles with reduced sizes. The elemental analysis using EDS spectra of copper oxide nanoparticles/films showed the presence of both copper and oxygen. Electrical properties of copper oxide nanoparticles are affected due to quantum size effect. The electrical studies carried out on both unannealed and annealed copper oxide films revealed an increase in resistivity with annealing of the films.

Laser ablated copper plasmas in liquid and gas ambient

Science.gov (United States)

Kumar, Bhupesh; Thareja, Raj K.

2013-05-01

The dynamics of copper ablated plasma plumes generated using laser ablation of copper targets in both liquid (de-ionized water) and gas (air) ambients is reported. Using time and space resolved visible emission spectroscopy (450-650 nm), the plasma plumes parameters are investigated. The electron density (ne) determined using Stark broadening of the Cu I (3d104d1 2D3/2-3d104p1 2P3/2 at 521.8 nm) line is estimated and compared for both plasma plumes. The electron temperature (Te) was estimated using the relative line emission intensities of the neutral copper transitions. Field emission scanning electron microscopy and energy dispersive x-ray spectral analysis of the ablated copper surface indicated abundance of spherical nanoparticles in liquid while those in air are amalgamates of irregular shapes. The nanoparticles suspended in the confining liquid form aggregates and exhibit a surface plasmon resonance at ˜590 nm.

The Chemical Composition and Structure of Supported Sulfated Zirconia with Regulated Size Nanoparticles

Science.gov (United States)

Kanazhevskiy, V. V.; Shmachkova, V. P.; Kotsarenko, N. S.; Kochubey, D. I.; Vedrine, J. C.

2007-02-01

A set of model skeletal isomerization catalysts — sulfated zirconia nanoparticles of controlled thickness anchored on different supports — was prepared using colloidal solutions of Zr salt on titania as support. The nanoparticles of zirconia (1-5 nm) are epitaxially connected to the support surface, with S/Zr ratio equals to 1.3-1.5. It was shown by EXAFS that nanoparticles of non-stoichiometric zirconium sulfate Zr(SO4)1+x, where xlayers as zirconium hydroxide undergoes sulfation followed by thermal treatment.

Microstructure and Properties of Nanocrystalline Copper Strengthened by a Low Amount of Al2O3 Nanoparticles

Science.gov (United States)

Ďurišinová, Katarína; Ďurišin, Juraj; Ďurišin, Martin

2017-03-01

Dispersion-strengthened Cu-Al2O3 materials have been studied over recent years to find an optimum processing route to obtain a high strength, thermal-stable copper alloy designed for modern applications in electrical engineering. The study analyses the influence of 1 vol.% of alumina content on strengthening the copper matrix. Microstructure of the Cu-Al2O3 composite was studied by x-ray diffraction as well as scanning and transmission electron microscopy. The composite shows a homogeneous, thermal-stable nanostructure up to 900 °C due to dispersed alumina nanoparticles. The particles effectively strengthen crystallite/grain boundaries in processes of powder consolidation and annealing of the compact. In contrast to monolithic Cu, the Cu-1 vol.% Al2O3 exhibits more than double strength and hardness. The nanocrystalline matrix and the low amount of alumina particles result in a yield strength of 288 MPa and a ductility of 15% which is a good combination for practical utilization of the material.

Statistical analysis of support thickness and particle size effects in HRTEM imaging of metal nanoparticles

International Nuclear Information System (INIS)

House, Stephen D.; Bonifacio, Cecile S.; Grieshaber, Ross V.; Li, Long; Zhang, Zhongfan; Ciston, Jim; Stach, Eric A.; Yang, Judith C.

2016-01-01

High-resolution transmission electron microscopy (HRTEM) examination of nanoparticles requires their placement on some manner of support – either TEM grid membranes or part of the material itself, as in many heterogeneous catalyst systems – but a systematic quantification of the practical imaging limits of this approach has been lacking. Here we address this issue through a statistical evaluation of how nanoparticle size and substrate thickness affects the ability to resolve structural features of interest in HRTEM images of metallic nanoparticles on common support membranes. The visibility of lattice fringes from crystalline Au nanoparticles on amorphous carbon and silicon supports of varying thickness was investigated with both conventional and aberration-corrected TEM. Over the 1–4 nm nanoparticle size range examined, the probability of successfully resolving lattice fringes differed significantly as a function both of nanoparticle size and support thickness. Statistical analysis was used to formulate guidelines for the selection of supports and to quantify the impact a given support would have on HRTEM imaging of crystalline structure. For nanoparticles ≥1 nm, aberration-correction was found to provide limited benefit for the purpose of visualizing lattice fringes; electron dose is more predictive of lattice fringe visibility than aberration correction. These results confirm that the ability to visualize lattice fringes is ultimately dependent on the signal-to-noise ratio of the HRTEM images, rather than the point-to-point resolving power of the microscope. This study provides a benchmark for HRTEM imaging of crystalline supported metal nanoparticles and is extensible to a wide variety of supports and nanostructures. - Highlights: • The impact of supports on imaging nanoparticle lattice structure is quantified. • Visualization probabilities given particle size and support thickness are estimated. • Aberration-correction provided limited benefit

Statistical analysis of support thickness and particle size effects in HRTEM imaging of metal nanoparticles

Energy Technology Data Exchange (ETDEWEB)

House, Stephen D., E-mail: sdh46@pitt.edu [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Bonifacio, Cecile S.; Grieshaber, Ross V.; Li, Long; Zhang, Zhongfan [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Ciston, Jim [National Center of Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Stach, Eric A. [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States); Yang, Judith C. [Chemical and Petroleum Engineering, and Physics, University of Pittsburgh, Pittsburgh, PA 15261 (United States)

2016-10-15

High-resolution transmission electron microscopy (HRTEM) examination of nanoparticles requires their placement on some manner of support – either TEM grid membranes or part of the material itself, as in many heterogeneous catalyst systems – but a systematic quantification of the practical imaging limits of this approach has been lacking. Here we address this issue through a statistical evaluation of how nanoparticle size and substrate thickness affects the ability to resolve structural features of interest in HRTEM images of metallic nanoparticles on common support membranes. The visibility of lattice fringes from crystalline Au nanoparticles on amorphous carbon and silicon supports of varying thickness was investigated with both conventional and aberration-corrected TEM. Over the 1–4 nm nanoparticle size range examined, the probability of successfully resolving lattice fringes differed significantly as a function both of nanoparticle size and support thickness. Statistical analysis was used to formulate guidelines for the selection of supports and to quantify the impact a given support would have on HRTEM imaging of crystalline structure. For nanoparticles ≥1 nm, aberration-correction was found to provide limited benefit for the purpose of visualizing lattice fringes; electron dose is more predictive of lattice fringe visibility than aberration correction. These results confirm that the ability to visualize lattice fringes is ultimately dependent on the signal-to-noise ratio of the HRTEM images, rather than the point-to-point resolving power of the microscope. This study provides a benchmark for HRTEM imaging of crystalline supported metal nanoparticles and is extensible to a wide variety of supports and nanostructures. - Highlights: • The impact of supports on imaging nanoparticle lattice structure is quantified. • Visualization probabilities given particle size and support thickness are estimated. • Aberration-correction provided limited benefit

Influence of copper nanoparticles on the physical-chemical properties of activated sludge.

Directory of Open Access Journals (Sweden)

Hong Chen

Full Text Available The physical-chemical properties of activated sludge, such as flocculating ability, hydrophobicity, surface charge, settleability, dewaterability and bacteria extracellular polymer substances (EPS, play vital roles in the normal operation of wastewater treatment plants (WWTPs. The nanoparticles released from commercial products will enter WWTPs and can induce potential adverse effects on activated sludge. This paper focused on the effects of copper nanoparticles (CuNPs on these specific physical-chemical properties of activated sludge. It was found that most of these properties were unaffected by the exposure to lower CuNPs concentration (5 ppm, but different observation were made at higher CuNPs concentrations (30 and 50 ppm. At the higher CuNPs concentrations, the sludge surface charge increased and the hydrophobicity decreased, which were attributed to more Cu2+ ions released from the CuNPs. The carbohydrate content of EPS was enhanced to defense the toxicity of CuNPs. The flocculating ability was found to be deteriorated due to the increased cell surface charge, the decreased hydrophobicity, and the damaged cell membrane. The worsened flocculating ability made the sludge flocs more dispersed, which further increased the toxicity of the CuNPs by increasing the availability of the CuNPs to the bacteria present in the sludge. Further investigation indicated that the phosphorus removal efficiency decreased at higher CuNPs concentrations, which was consistent with the deteriorated physical-chemical properties of activated sludge. It seems that the physical-chemical properties can be used as an indicator for determining CuNPs toxicity to the bacteria in activated sludge. This work is important because bacteria toxicity effects to the activated sludge caused by nanoparticles may lead to the deteriorated treatment efficiency of wastewater treatment, and it is therefore necessary to find an easy way to indicate this toxicity.

Copper nanoparticles in zeolite Y

NARCIS (Netherlands)

Seidel, A.; Loos, J.; Boddenberg, B.

1999-01-01

CuCl has been dispersed in the supercages of a Y-type zeolite by heating a mechanical salt/host mixture in vacuo. The occluded salt was subsequently reduced to copper metal in a hydrogen atmosphere. Virtually complete reduction of the salt is achieved at 460°C. Under the same conditions,

Single step thermal decomposition approach to prepare supported γ-Fe2O3 nanoparticles

International Nuclear Information System (INIS)

Sharma, Geetu; Jeevanandam, P.

2012-01-01

γ-Fe 2 O 3 nanoparticles supported on MgO (macro-crystalline and nanocrystalline) were prepared by an easy single step thermal decomposition method. Thermal decomposition of iron acetylacetonate in diphenyl ether, in the presence of the supports followed by calcination, leads to iron oxide nanoparticles supported on MgO. The X-ray diffraction results indicate the stability of γ-Fe 2 O 3 phase on MgO (macro-crystalline and nanocrystalline) up to 1150 °C. The scanning electron microscopy images show that the supported iron oxide nanoparticles are agglomerated while the energy dispersive X-ray analysis indicates the presence of iron, magnesium and oxygen in the samples. Transmission electron microscopy images indicate the presence of smaller γ-Fe 2 O 3 nanoparticles on nanocrystalline MgO. The magnetic properties of the supported magnetic nanoparticles at various calcination temperatures (350-1150 °C) were studied using a superconducting quantum interference device which indicates superparamagnetic behavior.

Tunable shapes in supported metal nanoparticles: From nanoflowers to nanocubes

International Nuclear Information System (INIS)

Luque, Rafael; Balu, Alina Mariana; Campelo, Juan Manuel; Gonzalez-Arellano, Camino; Gracia, Maria Jose; Luna, Diego; Marinas, Jose Maria; Romero, Antonio Angel

2009-01-01

The facile preparation of a range of supported nanoparticles on porous materials was successfully accomplished through the use of a range of environmentally friendly protocols including a modified impregnation/reduction methodology, ultrasounds and microwave irradiation. Materials were characterised by transmission electron microscopy (TEM) and XPS. Different morphologies including conventional nanospheres, nanoflower aggregates, nanorod-like structures and nanocubes were achieved under different conditions. The reported supported nanoparticles are envisaged to have interesting applications in various areas including catalysis, optics and sensors.

Synthesis and Catalytic Evaluation of Dendrimer-Encapsulated Cu Nanoparticles: An Undergraduate Experiment Exploring Catalytic Nanomaterials

Science.gov (United States)

Feng, Z. Vivian; Lyon, Jennifer L.; Croley, J. Sawyer; Crooks, Richard M.; Vanden Bout, David A.; Stevenson, Keith J.

2009-01-01

Copper nanoparticles were synthesized using generation 4 hydroxyl-terminated (G4-OH) poly(amidoamine) (PAMAM) dendrimers as templates. The synthesis is conducted by coordinating copper ions with the interior amines of the dendrimer, followed by chemical reduction to form dendrimer-encapsulated copper nanoparticles (Cu-DEN). The catalytic…

Biological Mechanism of Silver Nanoparticle Toxicity

Science.gov (United States)

Armstrong, Najealicka Nicole

Silver nanoparticles (AgNPs), like almost all nanoparticles, are potentially toxic beyond a certain concentration because the survival of the organism is compromised due to scores of pathophysiological abnormalities above that concentration. However, the mechanism of AgNP toxicity remains undetermined. Instead of applying a toxic dose, these investigations were attempted to monitor the effects of AgNPs at a non-lethal concentration on wild type Drosophila melanogaster by exposing them to nanoparticles throughout their development. All adult flies raised in AgNP doped food indicated that of not more than 50 mg/L had no negative influence on median survival; however, these flies appeared uniformly lighter in body color due to the loss of melanin pigments in their cuticle. Additionally, fertility and vertical movement ability were compromised after AgNP feeding. The determination of the amount of free ionic silver (Ag+) indicated that the observed biological effects had resulted from the AgNPs and not from Ag+. Biochemical analysis suggests that the activity of copper dependent enzymes, namely tyrosinase and Cu-Zn superoxide dismutase, were decreased significantly following the consumption of AgNPs, despite the constant level of copper present in the tissue. Furthermore, copper supplementation restored the loss of AgNP induced demelanization, and the reduction of functional Ctr1 in Ctr1 heterozygous mutants caused the flies to be resistant to demelanization. Consequently, these studies proposed a mechanism whereby consumption of excess AgNPs in association with membrane bound copper transporter proteins cause sequestration of copper, thus creating a condition that resembles copper starvation. This model also explained the cuticular demelanization effect resulting from AgNP since tyrosinase activity is essential for melanin biosynthesis. Finally, these investigations demonstrated that Drosophila, an established genetic model system, can be well utilized for further

Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

Science.gov (United States)

An, Chongwei; Ding, Penghui; Ye, Baoyun; Geng, Xiaoheng; Wang, Jingyu

2017-03-01

Carbon-coated copper nanoparticles (CCNPs) were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and copper nitrate hydrate (Cu(NO3)2.3H2O) in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM), high resolution transmission electron microcopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP) were also investigated by differential scanning calorimeter (DSC). Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne), and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger's method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

Carbon-coated copper nanoparticles prepared by detonation method and their thermocatalysis on ammonium perchlorate

Directory of Open Access Journals (Sweden)

Chongwei An

2017-03-01

Full Text Available Carbon-coated copper nanoparticles (CCNPs were prepared by initiating a high-density charge pressed with a mixture of microcrystalline wax, hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX, and copper nitrate hydrate (Cu(NO32·3H2O in an explosion vessel filled with nitrogen gas. The detonation products were characterized by transmission electron microcopy (TEM, high resolution transmission electron microcopy (HRTEM, energy dispersive X-ray spectroscopy (EDX, X-ray diffraction (XRD, and Raman spectroscopy. The effects of CCNPs on thermal decomposition of ammonium perchlorate (AP were also investigated by differential scanning calorimeter (DSC. Results indicated that the detonation products were spherical, 25-40 nm in size, and had an apparent core-shell structure. In this structure, the carbon shell was 3-5 nm thick and mainly composed of graphite, C8 (a kind of carbyne, and amorphous carbon. When 5 wt.% CCNPs was mixed with 95 wt.% AP, the high-temperature decomposition peak of AP decreased by 95.97, 96.99, and 96.69 °Cat heating rates of 5, 10, and 20 °C/min, respectively. Moreover, CCNPs decreased the activation energy of AP as calculated through Kissinger’s method by 25%, which indicated outstanding catalysis for the thermal decomposition of AP.

Reduced graphene oxide supported gold nanoparticles for electrocatalytic reduction of carbon dioxide

Science.gov (United States)

Saquib, Mohammad; Halder, Aditi

2018-02-01

Electrochemical reduction of carbon dioxide is one of the methods which have the capability to recycle CO2 into valuable products for energy and industrial applications. This research article describes about a new electrocatalyst "reduced graphene oxide supported gold nanoparticles" for selective electrochemical conversion of carbon dioxide to carbon monoxide. The main aim for conversion of CO2 to CO lies in the fact that the latter is an important component of syn gas (a mixture of hydrogen and carbon monoxide), which is then converted into liquid fuel via well-known industrial process called Fischer-Tropsch process. In this work, we have synthesized different composites of the gold nanoparticles supported on defective reduced graphene oxide to evaluate the catalytic activity of reduced graphene oxide (RGO)-supported gold nanoparticles and the role of defective RGO support towards the electrochemical reduction of CO2. Electrochemical and impedance measurements demonstrate that higher concentration of gold nanoparticles on the graphene support led to remarkable decrease in the onset potential of 240 mV and increase in the current density for CO2 reduction. Lower impedance and Tafel slope values also clearly support our findings for the better performance of RGOAu than bare Au for CO2 reduction.

Pulsed electrodeposition of cobalt nanoparticles on copper: influence of the operating parameters on size distribution and morphology

International Nuclear Information System (INIS)

Pagnanelli, Francesca; Altimari, Pietro; Bellagamba, Marco; Granata, Giuseppe; Moscardini, Emanuela; Schiavi, Pier Giorgio; Toro, Luigi

2015-01-01

Cobalt nanoparticles were synthesized by pulsed electrodeposition on copper substrate. Scanning electron microscopy and image analysis were used to determine morphology and particle size distribution of nanoparticle populations obtained in different operating conditions. After preliminary tests, t on and t off were set at 50 and 300 ms respectively to obtain distinct nanoparticles and avoid dendritic structures. Experimental tests were performed according to two partially superimposed factorial designs with two factors at two levels. First factorial design investigated the effect of current density (I = 10 and 50 mA/cm 2 ) and discharged cobalt (Q = 2.5 × 10 −3 and 1.0 × 10 −2 C); second factorial design investigated the effect of cobalt concentration (C 0 = 0.01 and 0.1 M) for the same two levels of Q. For optimized value of t on /t off , square and hexagonal shaped nanoparticles were obtained. Statistical analysis evidenced that, for C 0 = 0.1 mol/L, current density is the most influencing factor on mean size: increasing I from 10 to 50 mA/cm 2 determined a diminution of mean size of 240 nm. For the same cobalt concentration, increasing the deposition time (Q) determined an increase of mean size of 60 nm. Diminishing the initial cobalt concentration from 0.1 to 0.01 mol/L determined an increase of mean size from 10 nm to 36 nm. For C 0 = 0.01 mol/L nanoparticles grow reaching an optimal size (36 nm) and then, increasing the time of deposition, optimal sized subunits tend to aggregate. As for polydispersity of nanoparticles, statistical tests denoted that increasing I determined significant reduction of variance, while increasing the time of deposition determined a significant increase of variance

Enhanced non-enzymatic glucose sensing based on copper nanoparticles decorated nitrogen-doped graphene.

Science.gov (United States)

Jiang, Ding; Liu, Qian; Wang, Kun; Qian, Jing; Dong, Xiaoya; Yang, Zhenting; Du, Xiaojiao; Qiu, Baijing

2014-04-15

Copper nanoparticles (NPs) decorated nitrogen-doped graphene (Cu-N-G) was prepared by a facile thermal treatment, and further employed as a novel sensing material for fabricating the sensitive non-enzymatic glucose sensor. Compared with pure Cu NPs, the Cu-N-G showed enhanced electrocatalytic activity to glucose oxidation due to the integration of N-G, which exhibited the oxidation peak current of glucose ca. 23-fold higher than that of pure Cu NPs. The presented sensor showed excellent performances for glucose detection including wide linear range of 0.004-4.5 mM, low detection limit (1.3 μM, S/N=3), high sensitivity (48.13 μA mM(-1)), fast response time (doped graphene as enhanced materials in fabricating sensors for chemical and biochemical analysis. © 2013 Published by Elsevier B.V.

Comparison of bacterial cells and amine-functionalized abiotic surfaces as support for Pd nanoparticle synthesis

DEFF Research Database (Denmark)

De Corte, Simon; Bechstein, Stefanie; Lokanathan, Arcot R.

2013-01-01

An increasing demand for catalytic Pd nanoparticles has motivated the search for sustainable production methods. An innovative approach uses bacterial cells as support material for synthesizing Pd nanoparticles by reduction of Pd(II) with e.g. hydrogen or formate. Nevertheless, drawbacks...... nanoparticles, and that abiotic surfaces could support the Pd particle synthesis as efficiently as bacteria. In this study, we explore the possibility of replacing bacteria with amine-functionalized materials, and we compare different functionalization strategies. Pd nanoparticles formed on the support...... on these surfaces was higher than for Pd particles formed on Shewanella oneidensis cells. Smaller Pd nanoparticles generally have better catalytic properties, and previous studies have shown that the particle size can be lowered by increasing the amount of support material used during Pd particle formation. However...

Sintering of oxide-supported Pt and Pd nanoparticles in air studied by in situ TEM

DEFF Research Database (Denmark)

Simonsen, Søren Bredmose

This thesis presents a fundamental study of the sintering of supported nanoparticles in relation to diesel oxidation catalysts. The sintering of supported nanoparticles is an important challenge in relation to this catalyst, as well as many other catalyst systems, and a fundamental understanding...... of Pt, Pd and bimetallic Pt-Pd nanoparticles supported on a flat and homogeneous Al2O3 or SiO2 surface. By using in situ TEM on the planar model catalysts it was possible to directly monitor the detailed dynamical changes of the individual nanoparticles during exposure to oxidizing conditions...

Kinetics of copper nanoparticle precipitation in phosphate glass: an isothermal plasmonic approach.

Science.gov (United States)

Sendova, Mariana; Jiménez, José A; Smith, Robert; Rudawski, Nicholas

2015-01-14

The kinetics of copper nanoparticle (NP) precipitation in melt-quenched barium-phosphate glass has been studied by in situ isothermal optical micro-spectroscopy. A spectroscopically based approximation technique is proposed to obtain information about the activation energies of nucleation and growth in a narrow temperature range (530-570 °C). Pre-plasmonic and plasmonic NP precipitation stages are identified separated in time. The process as a whole is discussed employing classical nucleation/growth theory and the Kolmogorov-Johnson-Mehl-Avrami phase change model. Activation energies of 3.9(7) eV and 2.6(5) eV have been estimated for the pre-plasmonic and plasmonic spectroscopically assessed stages, respectively. High resolution transmission electron microscopy, differential scanning calorimetry, and Raman spectroscopy were used as complementary techniques for studying the nanoparticulate phase and glass host structure. An empirical linear dependence of the diffusion activation energy on the glass transition temperature with broad applicability is suggested.

The antimicrobial effect of silicon nanowires decorated with silver and copper nanoparticles

International Nuclear Information System (INIS)

Fellahi, Ouarda; Marcon, Lionel; Coffinier, Yannick; Boukherroub, Rabah; Sarma, Rupak K; Saikia, Ratul; Das, Manash R; Hadjersi, Toufik; Maamache, Mustapha

2013-01-01

The paper reports on the preparation and antibacterial activity of silicon nanowire (SiNW) substrates coated with Ag or Cu nanoparticles (NPs) against Escherichia coli (E. coli) bacteria. The substrates are easily prepared using the metal-assisted chemical etching of crystalline silicon in hydrofluoric acid/silver nitrate (HF/AgNO 3 ) aqueous solution. Decoration of the SiNWs with metal NPs is achieved by simple immersion in HF aqueous solutions containing silver or copper salts. The SiNWs coated with Ag NPs are biocompatible with human lung adenocarcinoma epithelial cell line A549 while possessing strong antibacterial properties to E. coli. In contrast, the SiNWs decorated with Cu NPs showed higher cytotoxicity and slightly lower antibacterial activity. Moreover, it was also observed that leakage of sugars and proteins from the cell wall of E. coli in interaction with SiNWs decorated with Ag NPs is higher compared to SiNWs modified with Cu NPs. (paper)

Tailoring gas-phase CO2 electroreduction selectivity to hydrocarbons at Cu nanoparticles

Science.gov (United States)

Merino-Garcia, I.; Albo, J.; Irabien, A.

2018-01-01

Copper-based surfaces appear as the most active catalysts for CO2 electroreduction to hydrocarbons, even though formation rates and efficiencies still need to be improved. The aim of the present work is to evaluate the continuous gas-phase CO2 electroreduction to hydrocarbons (i.e. ethylene and methane) at copper nanoparticulated-based surfaces, paying attention to particle size influence (ranging from 25-80 nm) on reaction productivity, selectivity, and Faraday efficiency (FE) for CO2 conversion. The effect of the current density and the presence of a microporous layer within the working electrode are then evaluated. Copper-based gas diffusion electrodes are prepared by airbrushing the catalytic ink onto carbon supports, which are then coupled to a cation exchange membrane (Nafion) in a membrane electrode assembly. The results show that the use of smaller copper nanoparticles (25 nm) leads to a higher ethylene production (1148 μmol m-2 s-1) with a remarkable high FE (92.8%), at the same time, diminishing the competitive hydrogen evolution reaction in terms of FE. This work demonstrates the importance of nanoparticle size on reaction selectivity, which may be of help to design enhanced electrocatalytic materials for CO2 valorization to hydrocarbons.

Laser ablated copper plasmas in liquid and gas ambient

Energy Technology Data Exchange (ETDEWEB)

Kumar, Bhupesh; Thareja, Raj K. [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

2013-05-15

The dynamics of copper ablated plasma plumes generated using laser ablation of copper targets in both liquid (de-ionized water) and gas (air) ambients is reported. Using time and space resolved visible emission spectroscopy (450-650 nm), the plasma plumes parameters are investigated. The electron density (n{sub e}) determined using Stark broadening of the Cu I (3d{sup 10}4d{sup 1} {sup 2}D{sub 3/2}-3d{sup 10}4p{sup 1} {sup 2}P{sub 3/2} at 521.8 nm) line is estimated and compared for both plasma plumes. The electron temperature (T{sub e}) was estimated using the relative line emission intensities of the neutral copper transitions. Field emission scanning electron microscopy and energy dispersive x-ray spectral analysis of the ablated copper surface indicated abundance of spherical nanoparticles in liquid while those in air are amalgamates of irregular shapes. The nanoparticles suspended in the confining liquid form aggregates and exhibit a surface plasmon resonance at ∼590 nm.

Polymethacrylic acid as a new precursor of CuO nanoparticles

Science.gov (United States)

Hosny, Nasser Mohammed; Zoromba, Mohamed Shafick

2012-11-01

Polymethacrylic acid and its copper complexes have been synthesized and characterized. These complexes have been used as precursors to produce CuO nanoparticles by thermal decomposition in air. The stages of decompositions and the calcination temperature of the precursors have been determined from thermal analyses (TGA). The obtained CuO nanoparticles have been characterized by X-ray diffraction (XRD), scanning tunneling microscopy (STM) and transmission electron microscopy (TEM). XRD showed a monoclinic structure with particle size 8-20 nm for the synthesized copper oxide nanoparticles. These nanoparticles are catalytically active in decomposing hydrogen peroxide and a mechanism of decomposition has been suggested.

Multipath colourimetric assay for copper(II) ions utilizing MarR functionalized gold nanoparticles

Science.gov (United States)

Wang, Yulong; Wang, Limin; Su, Zhenhe; Xue, Juanjuan; Dong, Jinbo; Zhang, Cunzheng; Hua, Xiude; Wang, Minghua; Liu, Fengquan

2017-02-01

We use the multiple antibiotic resistance regulator (MarR), as a highly selective biorecognition elements in a multipath colourimetric sensing strategy for the fast detection of Cu2+ in water samples. The colourimetric assay is based on the aggregation of MarR-coated gold nanoparticles in the presence of Cu2+ ions, which induces a red-to-purple colour change of the solution. The colour variation in the gold nanoparticle aggregation process can be used for qualitative and quantitative detection of Cu2+ by the naked eye, and with UV-vis and smartphone-based approaches. The three analysis techniques used in the multipath colourimetric assay complement each other and provide greater flexibility for differing requirements and conditions, making the assay highly applicable for Cu2+ detection. Under optimal conditions, the Cu2+ concentration was quantified in less than 5 min with limits of detection for the naked eye, UV-vis and smartphone-based approaches of 1 μM, 405 nM and 61 nM, respectively. Moreover, the sensing system exhibited excellent selectivity and practical application for Cu2+ detection in real water samples. Thus, our strategy has great potential for application in on-site monitoring of Cu2+, and the unique response of MarR towards copper ions may provide a new approach to Cu2+ sensing.

Progress in controlling the size, composition and nanostructure of supported gold-palladium nanoparticles for catalytic applications

NARCIS (Netherlands)

Paalanen, P.P.|info:eu-repo/dai/nl/370602013; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397; Sankar, M.

2013-01-01

This review article gives an overview of the recent developments in the synthesis strategies of supported goldbased bimetallic nanoparticle catalysts. The catalytic efficiency of these supported bimetallic nanoparticles, similar to monometallic nanoparticles, depends on their structural

One-pot synthesis of graphene supported platinum–cobalt nanoparticles as electrocatalysts for methanol oxidation

International Nuclear Information System (INIS)

Kepenienė, V.; Tamašauskaitė-Tamašiūnaitė, L.; Jablonskienė, J.; Semaško, M.; Vaičiūnienė, J.; Vaitkus, R.; Norkus, E.

2016-01-01

In the present study the graphene supported platinum–cobalt nanoparticles were prepared via microwave synthesis. The composition of prepared catalysts was examined by Inductively Coupled Plasma Optical Emission Spectroscopy. The shape and size of catalyst particles were determined by Transmission Electron Microscopy. The electrocatalytic activity of the graphene supported platinum–cobalt nanoparticles was investigated towards the electro-oxidation of methanol in an alkaline medium. It has been found that the graphene supported platinum–cobalt nanoparticles having the Pt:Co molar ratio 1:7 show the highest activity towards the electro-oxidation of methanol among the catalysts with the Pt:Co molar ratios equal to 1:1 and 1:44, graphene supported bare Co and Pt/C catalysts. - Highlights: • Preparation of graphene supported Pt-Co nanoparticles by microwave synthesis. • Electrocatalysts for oxidation of methanol. • Higher activity of PtCo/graphene towards methanol oxidation.

One-pot synthesis of graphene supported platinum–cobalt nanoparticles as electrocatalysts for methanol oxidation

Energy Technology Data Exchange (ETDEWEB)

Kepenienė, V., E-mail: virginalisk@gmail.com [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania); Tamašauskaitė-Tamašiūnaitė, L.; Jablonskienė, J.; Semaško, M.; Vaičiūnienė, J. [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania); Vaitkus, R. [Faculty of Chemistry, Vilnius University, Vilnius LT 03225 (Lithuania); Norkus, E. [Department of Catalysis, Center for Physical Sciences and Technology, Vilnius LT 01108 (Lithuania)

2016-03-01

In the present study the graphene supported platinum–cobalt nanoparticles were prepared via microwave synthesis. The composition of prepared catalysts was examined by Inductively Coupled Plasma Optical Emission Spectroscopy. The shape and size of catalyst particles were determined by Transmission Electron Microscopy. The electrocatalytic activity of the graphene supported platinum–cobalt nanoparticles was investigated towards the electro-oxidation of methanol in an alkaline medium. It has been found that the graphene supported platinum–cobalt nanoparticles having the Pt:Co molar ratio 1:7 show the highest activity towards the electro-oxidation of methanol among the catalysts with the Pt:Co molar ratios equal to 1:1 and 1:44, graphene supported bare Co and Pt/C catalysts. - Highlights: • Preparation of graphene supported Pt-Co nanoparticles by microwave synthesis. • Electrocatalysts for oxidation of methanol. • Higher activity of PtCo/graphene towards methanol oxidation.

Antibacterial and Antimycotic Activity of Cotton Fabrics, Impregnated with Silver and Binary Silver/Copper Nanoparticles

Science.gov (United States)

Eremenko, A. M.; Petrik, I. S.; Smirnova, N. P.; Rudenko, A. V.; Marikvas, Y. S.

2016-01-01

Effective method of obtaining of the bactericidal bandage materials by impregnation of cotton fabric by aqueous solutions of silver and copper salts followed by a certain regime of heat treatment is developed. The study of obtained materials by methods of optical spectroscopy, electron microscopy, and X-ray phase analysis showed the formation of crystalline silver nanoparticles (NPs) and bimetallic Ag/Cu composites with the corresponding surface plasmon resonance (SPR) bands in the absorption spectra. High antimicrobial and antimycotic properties of tissues with low concentrations of Ag and Ag/Cu nanoparticles (Ag/Cu NPs) (in the range 0.06-0.25 weight percent (wt%) for Ag and 0.015-0.13 wt% for Ag/Cu) is confirmed in experiments with a wide range of multidrug-resistant bacteria and fungi: Escherichia coli, Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, Candida albicans yeasts, and micromycetes . Textile materials with Ag NPs demonstrate high antibacterial activity, while fabrics doped with bimetallic composite Ag/Cu have pronounced antimycotic properties. Bactericidal and antifungal properties of the obtained materials do not change after a washing. Production of such materials is extremely fast, convenient, and cost-effective.

Zircon Supported Copper Catalysts for the Steam Reforming of Methanol

Science.gov (United States)

Widiastri, M.; Fendy, Marsih, I. N.

2008-03-01

Steam reforming of methanol (SRM) is known as one of the most favorable catalytic processes for producing hydrogen. Current research on zirconia, ZrO2 supported copper catalyst revealed that CuO/ZrO2 as an active catalyst for the SRM. Zircon, ZrSiO4 is available from the by-product of tin mining. In the work presented here, the catalytic properties of CuO/ZrSiO4 with various copper oxide compositions ranging from 2.70% (catalyst I), 4.12% (catalyst II), and 7.12%-mass (catalyst III), synthesized by an incipient wetness impregnation technique, were investigated to methanol conversion, selectivity towards CO formation, and effect of ZnO addition (7.83%CuO/8.01%ZnO/ZrSiO4 = catalyst V). The catalytic activity was obtained using a fixed bed reactor and the zircon supported catalyst activity was compared to those of CuO/ZnO/Al2O3 catalyst (catalyst IV) and commercial Kujang LTSC catalyst. An X-ray powder diffraction (XRD) analysis was done to identify the abundant phases of the catalysts. The catalysts topography and particle diameter were measured with scanning electron microscopy (SEM) and composition of the catalysts was measured by SEM-EDX, scanning electron microscope-energy dispersive using X-ray analysis. The results of this research provide information on the possibility of using zircon (ZrSiO4) as solid support for SRM catalysts.

Combined TEM and NC-AFM study of Al2O3-supported Pt nanoparticles

DEFF Research Database (Denmark)

Jensen, Thomas Nørregaard; Simonsen, Søren Bredmose; Chorkendorff, Ib

Sintering, the growth of large particles at the expense of smaller ones, is one of the main causes of catalysts deactivation, since the physicochemical properties of a nanoparticle may depend strongly on its size, shape and composition. For application as heterogeneous catalysts, the nanoparticle...... kinks and edges often play an important role for the catalytic activity. In order to preserve these sites, it is important to stabilize the supported nanoparticles with sizes of a few nanometers during operational conditions at often high temperatures and in the relevant gas environments. A prototypical...... nanocatalyst system for studying coarsening consists of Pt nanoparticles supported on an Al2O3 material which is relevant as an oxidation catalyst in diesel and lean-burn engine exhaust after-treatment technologies. In this study we address the effect on sintering of the shape of Pt nanoparticles supported...

Optical and thermal response of single-walled carbon nanotube–copper sulfide nanoparticle hybrid nanomaterials

International Nuclear Information System (INIS)

Tseng, Yi-Hsuan; He Yuan; Que Long; Lakshmanan, Santana; Yang Chang; Chen Wei

2012-01-01

This paper reports the optical and thermal response of a single-walled carbon nanotube–copper sulfide nanoparticle (SWNT–CuS NP) hybrid nanomaterial and its application as a thermoelectric generator. The hybrid nanomaterial was synthesized using oleylamine molecules as the linker molecules between SWNTs and CuS NPs. Measurements found that the hybrid nanomaterial has significantly increased light absorption (up to 80%) compared to the pure SWNT. Measurements also found that the hybrid nanomaterial thin-film devices exhibit a clear optical and thermal switching effect, which can be further enhanced up to 10 × by asymmetric illumination of light and thermal radiation on the thin-film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials is demonstrated, indicating a new route for achieving thermoelectricity. (paper)

Novel strategies for ultrahigh specific activity targeted nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Zhou, Dong

2012-12-13

We have developed novel strategies optimized for preparing high specific activity radiolabeled nanoparticles, targeting nuclear imaging of low abundance biomarkers. Several compounds have been labeled with F-18 and Cu-64 for radiolabeling of SCK-nanoparticles via Copper(I) catalyzed or copper-free alkyne-azide cyclolization. Novel strategies have been developed to achieve ultrahigh specific activity with administrable amount of dose for human study using copper-free chemistry. Ligands for carbonic anhydrase 12 (CA12), a low abundance extracellular biomarker for the responsiveness of breast cancer to endocrine therapie, have been labeled with F-18 and Cu-64, and one of them has been evaluated in animal models. The results of this project will lead to major improvements in the use of nanoparticles in nuclear imaging and will significantly advance their potential for detecting low abundance biomarkers of medical importance.

Growth of CdS nanoparticles by chemical method and its ...

Indian Academy of Sciences (India)

carbon film supported on the copper grid and was kept for some time for drying. Transmission electron ... Wang et al obtained CdS nanoparticles having a band gap of. 2.79 eV [21]. .... [16] S Yu, Y Wu, J Yang, Z Han, Y Quan, X Liu and Y Xie, Chem. Matter 10 ... [22] U K Gautam, R Seshadri and C N R Rao, Chem. Phys. Lett.

Preparation of single-crystal copper ferrite nanorods and nanodisks

International Nuclear Information System (INIS)

Du Jimin; Liu Zhimin; Wu Weize; Li Zhonghao; Han Buxing; Huang Ying

2005-01-01

This article, for the first time, reports the preparation of single-crystal copper ferrite nanorods and nanodisks. Using amorphous copper ferrite nanoparticles synthesized by reverse micelle as reaction precursor, single-crystal copper ferrite nanorods were synthesized via hydrothermal method in the presence of surfactant polyethylene glycol (PEG), however, copper ferrite nanodisks were prepared through the same procedures except the surfactant PEG. The resulting nanomaterials have been characterized by powder X-ray diffraction (XRD), selected electron area diffraction (SEAD), and transmission electron microscopy (TEM). The bulk composition of the samples was determined by means of X-ray photoelectron spectroscopy (XPS)

Green synthesis of copper oxide nanoparticles using gum karaya as a biotemplate and their antibacterial application

Directory of Open Access Journals (Sweden)

Thekkae Padil VV

2013-02-01

Full Text Available Vinod Vellora Thekkae Padil, Miroslav ČerníkLaboratory of Chemical Remediation Processes, Institute for Nanomaterials, Advanced Technology and Innovation, Technical University of Liberec, Studentská 1402/2, Liberec, Czech RepublicBackground: Copper oxide (CuO nanoparticles have attracted huge attention due to catalytic, electric, optical, photonic, textile, nanofluid, and antibacterial activity depending on the size, shape, and neighboring medium. In the present paper, we synthesized CuO nanoparticles using gum karaya, a natural nontoxic hydrocolloid, by green technology and explored its potential antibacterial application.Methods: The CuO nanoparticles were synthesized by a colloid-thermal synthesis process. The mixture contained various concentrations of CuCl2 · 2H2O (1 mM, 2 mM, and 3 mM and gum karaya (10 mg/mL and was kept at 75°C at 250 rpm for 1 hour in an orbital shaker. The synthesized CuO was purified and dried to obtain different sizes of the CuO nanoparticles. The well diffusion method was used to study the antibacterial activity of the synthesized CuO nanoparticles. The zone of inhibition, minimum inhibitory concentration, and minimum bactericidal concentration were determined by the broth microdilution method recommended by the Clinical and Laboratory Standards Institute.Results: Scanning electron microscopy analysis showed CuO nanoparticles evenly distributed on the surface of the gum matrix. X-ray diffraction of the synthesized nanoparticles indicates the formation of single-phase CuO with a monoclinic structure. The Fourier transform infrared spectroscopy peak at 525 cm−1 should be a stretching of CuO, which matches up to the B2u mode. The peaks at 525 cm−1 and 580 cm−1 indicated the formation of CuO nanostructure. Transmission electron microscope analyses revealed CuO nanoparticles of 4.8 ± 1.6 nm, 5.5 ± 2.5 nm, and 7.8 ± 2.3 nm sizes were synthesized with various concentrations of CuCl2 · 2H2O (1 mM, 2 mM, and

Copper(II) Schiff base complexes and their mixed thin layers with ...

Indian Academy of Sciences (India)

Thin layer; ZnO nanoparticles; copper complexes; AFM; SEM; fluorescence. 1. Introduction ... ZnO nanopowders29,30 and ZnO nanoparticles doped by different metal ...... Roy S, Choubey S, Bhar K, Khan S, Mitra P and Ghosh. B K 2013 J. Mol ...

Anionic solid lipid nanoparticles supported on protamine/DNA complexes

International Nuclear Information System (INIS)

Ye Jiesheng; Liu Chunxi; Chen Zhijin; Zhang Na; Wang Aihua

2008-01-01

The objective of this study was to design novel anionic ternary nanoparticles for gene delivery. These ternary nanoparticles were equipped with protamine/DNA binary complexes (150-200 nm) as the support, and the anionic formation was achieved by absorption of anionic solid lipid nanoparticles (≤20 nm) onto the surface of the binary complexes. The small solid lipid nanoparticles (SLNs) were prepared by a modified film dispersion-ultrasonication method, and adsorption of the anionic SLNs onto the binary complexes was typically carried out in water via electrostatic interaction. The formulated ternary nanoparticles were found to be relatively uniform in size (257.7 ± 10.6 nm) with a 'bumpy' surface, and the surface charge inversion from 19.28 ± 1.14 mV to -17.16 ± 1.92 mV could be considered as evidence of the formation of the ternary nanoparticles. The fluorescence intensity measurements from three batches of the ternary nanoparticles gave a mean adsorption efficiency of 96.75 ± 1.13%. Circular dichroism spectra analysis showed that the protamine/DNA complexes had been coated by small SLNs, and that the anionic ternary nanoparticles formed did not disturb the construction of the binary complexes. SYBR Green I analysis suggested that the ternary nanoparticles could protect the DNA from nuclease degradation, and cell viability assay results showed that they exhibit lower cytotoxicity to A549 cells compared with the binary complexes and lipofectamine. The transfection efficiency of the ternary nanoparticles was better than that of naked DNA and the binary complexes, and almost equal to that of lipofectamine/DNA complexes, as revealed by inversion fluorescence microscope observation. These results indicated that the anionic ternary nanoparticles could facilitate gene transfer in cultured cells, and might alleviate the drawbacks of the conventional cationic vector/DNA complexes for gene delivery in vivo

Piper betle-mediated synthesis, characterization, antibacterial and rat splenocyte cytotoxic effects of copper oxide nanoparticles.

Science.gov (United States)

Praburaman, Loganathan; Jang, Jum-Suk; Muthusamy, Govarthanan; Arumugam, Sengottaiyan; Manoharan, Koildhasan; Cho, Kwang-Min; Min, Cho; Kamala-Kannan, Seralathan; Byung-Taek, Oh

2016-09-01

The study reports a simple, inexpensive, and eco-friendly synthesis of copper oxide nanoparticles (CuONPs) using Piper betle leaf extract. Formation of CuONPs was confirmed by UV-visible spectroscopy at 280 nm. Transmission electron microscopy (TEM) images showed that the CuONPs were spherical, with an average size of 50-100 nm. The scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS) peak was observed approximately at 1 and 8 keV. The X-ray diffraction (XRD) studies indicated that the particles were crystalline in nature. CuONPs effectively inhibited the growth of phytopathogens Ralstonia solanacearum and Xanthomonas axonopodis. The cytotoxic effect of the synthesized CuONPs was analyzed using rat splenocytes. The cell viability was decreased to 94% at 300 μg/mL.

Comparative toxicity and biodistribution of copper nanoparticles and cupric ions in rats

Directory of Open Access Journals (Sweden)

Lee IC

2016-06-01

Full Text Available In-Chul Lee,1 Je-Won Ko,1 Sung-Hyeuk Park,1 Je-Oh Lim,1 In-Sik Shin,1 Changjong Moon,1 Sung-Hwan Kim,2 Jeong-Doo Heo,3 Jong-Choon Kim1 1College of Veterinary Medicine BK21 Plus Project Team, Chonnam National University, Gwangju, 2Jeonbuk Department of Inhalation Research, Korea Institute of Toxicology, Jeongeup, 3Gyeongnam Department of Environment and Toxicology, Korea Institute of Toxicology, Gyeongnam, Republic of Korea Abstract: Despite widespread use and prospective biomedical applications of copper nanoparticles (Cu NPs, their biosafety issues and kinetics remain unclear. Thus, the aim of this study was to compare the detailed in vivo toxicity of Cu NPs and cupric ions (CuCl2; Cu ions after a single oral dose. We determined the physicochemical characteristics of Cu NPs, including morphology, hydrodynamic size, zeta potential, and dissolution in gastric (pH 1.5, vehicle (pH 6.5, and intestinal (pH 7.8 conditions. We also evaluated the kinetics of Cu following a single equivalent dose (500 mg/kg of Cu NPs and Cu ions. Cu NPs had highest dissolution (84.5% only in gastric conditions when compared with complete dissolution of Cu ions under various physiological milieus. Kinetic analysis revealed that highest Cu levels in blood and tested organs of Cu NP-treated rats were 15%–25% lower than that of Cu ions. Similar to the case of Cu ions, Cu levels in the tested organs (especially liver, kidney, and spleen of Cu NP-treated rats increased significantly when compared with the vehicle control. However, delay in reaching the highest level and biopersistence of Cu were observed in the blood and tested organs of Cu NP-treated rats compared with Cu ions. Extremely high levels of Cu in feces indicated that unabsorbed Cu NPs or absorbed Cu ions were predominantly eliminated through liver/feces. Cu NPs exerted apparent toxicological effects at higher dose levels compared with Cu ions and showed sex-dependent differences in mortality, biochemistry, and

Cissus quadrangularis mediated ecofriendly synthesis of copper oxide nanoparticles and its antifungal studies against Aspergillus niger, Aspergillus flavus.

Science.gov (United States)

Devipriya, Duraipandi; Roopan, Selvaraj Mohana

2017-11-01

Recently, non-toxic source mediated synthesis of metal and a metal oxide nanoparticle attains more attention due to key applicational responsibilities. This present report stated that the eco-friendly synthesis of copper oxide nanoparticles (CuO NPs) using Cissus quadrangularis (C. quadrangularis) plant extract. Further the eco-friendly synthesized CuO NPs were characterized using a number of analytical techniques. The observed results stated that the synthesized CuO NPs were spherical in shape with 30±2nm. Then the eco-friendly synthesized CuO NPs were subjected for anti-fungal against two strains namely Aspergillus niger (A. niger) resulted in 83% at 500ppm, 86% of inhibition at 1000ppm and Aspergillus flavus (A. flavus) resulted in 81% at 500ppm, 85% of inhibition at 1000ppm respectively. Despite the fact that compared to standard Carbendazim, eco-friendly synthesized CuO NPs exhibits better results were discussed in this manuscript. Copyright © 2017 Elsevier B.V. All rights reserved.

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

KAUST Repository

Biausque, Gregory; Laveille, Paco; Anjum, Dalaver H.; Caps, Valerie; Basset, Jean-Marie

2015-01-01

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

KAUST Repository

Biausque, Gregory

2015-04-28

Methods to synthesize NiPt bimetallic nanoparticles by a reversed-phase microemulsion, deposition of NiPt bimetallic nanoparticles on a support, and application of the supported catalyst for CO.sub.2 reforming of methane

The importance of surface morphology in controlling the selectivity of polycrystalline copper for CO(2) electroreduction

DEFF Research Database (Denmark)

Tang, Wei; Peterson, Andrew A; Varela Gasque, Ana Sofia

2012-01-01

This communication examines the effect of the surface morphology of polycrystalline copper on electroreduction of CO(2). We find that a copper nanoparticle covered electrode shows better selectivity towards hydrocarbons compared with the two other studied surfaces, an electropolished copper elect...

Aptamer-based electrochemical assay of 17β-estradiol using a glassy carbon electrode modified with copper sulfide nanosheets and gold nanoparticles, and applying enzyme-based signal amplification

International Nuclear Information System (INIS)

Huang, Ke-Jing; Liu, Yu-Jie; Zhang, Ji-Zong

2015-01-01

We have developed an electrochemical method for the determination of 17β-estradiol. A glassy carbon electrode was modified with a composite made from copper sulfide nanosheets, gold nanoparticles, and glucose oxidase. The copper sulfide nanosheet was prepared by a single-step hydrothermal process, and its properties were characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. Finally, an estradiol-specific aptamer was assembled on the electrode. The copper sulfide nanosheet on the electrode surface acts as a relatively good electrical conductor. Glucose oxidase acts as an indicator, and the dual modification of glucose oxidase and gold nanoparticles for signal amplification. The determination of 17β-estradiol was performed by differential pulse voltammetry of glucose oxidase because the signal measured at typically −0.43 V depends on the concentration of 17β-estradiol because addition of 17β-estradiol at electrode hinders electron transfer. A linear relationship exists between the peak current and the logarithm of concentration of 17β-estradiol in the 0.5 pM to 5 nM range, with a 60 f. detection limit (at 3σ/S). The method displays good selectivity over bisphenol A, 1-aminoanthraquinone and naphthalene even if present in 100-fold concentrations. (author)

Predicting catalyst-support interactions between metal nanoparticles and amorphous silica supports

Science.gov (United States)

Ewing, Christopher S.; Veser, Götz; McCarthy, Joseph J.; Lambrecht, Daniel S.; Johnson, J. Karl

2016-10-01

Metal-support interactions significantly affect the stability and activity of supported catalytic nanoparticles (NPs), yet there is no simple and reliable method for estimating NP-support interactions, especially for amorphous supports. We present an approach for rapid prediction of catalyst-support interactions between Pt NPs and amorphous silica supports for NPs of various sizes and shapes. We use density functional theory calculations of 13 atom Pt clusters on model amorphous silica supports to determine linear correlations relating catalyst properties to NP-support interactions. We show that these correlations can be combined with fast discrete element method simulations to predict adhesion energy and NP net charge for NPs of larger sizes and different shapes. Furthermore, we demonstrate that this approach can be successfully transferred to Pd, Au, Ni, and Fe NPs. This approach can be used to quickly screen stability and net charge transfer and leads to a better fundamental understanding of catalyst-support interactions.

Green synthesis, characterization and antibacterial activity of copper ...

African Journals Online (AJOL)

Green synthesis, characterization and antibacterial activity of copper nanoparticles using L -ascorbic ... Journal Home > Vol 10, No 3 (2017) > ... In this study, simple, economical, convenient and environmentally-friendly chemical reduction ...

Synthesis, characterization and fabrication of copper nanoparticles in N-isopropylacrylamide based co-polymer microgels for degradation of p-nitrophenol

Directory of Open Access Journals (Sweden)

Farooqi Zahoor H.

2015-03-01

Full Text Available Poly(N-isopropylacrylamide-co-acrylic acid [P(NIPAM-co-AAc] microgels were synthesized by precipitation polymerization. Copper nanoparticles were successfully fabricated inside the microgels by in-situ reduction of copper ions in an aqueous medium. The microgels were characterized by Fourier Transform Infrared Spectroscopy (FT-IR and Dynamic Light Scattering (DLS. Hydrodynamic radius of P(NIPAM-co-AAc microgel particles increased with an increase in pH in aqueous medium at 25 °C. Copper-poly(N-isopropylacrylamide-co-acrylic acid [Cu-P(NIPAM-co-AAc] hybrid microgels were used as a catalyst for the reduction of 4-nitrophenol (4-NP. Effect of temperature, concentration of sodium borohydride (NaBH4 and catalyst dosage on the value of apparent rate constant (kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc hybrid microgels were investigated by UV-Vis spectrophotometry. It was found that the value of kapp for catalytic reduction of 4-NP in the presence of Cu-P(NIPAM-co-AAc hybrid microgel catalyst increased with an increase in catalyst dosage, temperature and concentration of NaBH4 in aqueous medium. The results were discussed in terms of diffusion of reactants towards catalyst surface and swelling-deswelling of hybrid microgels.

Wrinkling of graphene membranes supported by silica nanoparticles on substrates

Science.gov (United States)

Yamamoto, Mahito; Cullen, William; Fuhrer, Michael; Einstein, Theodore; Department of Physics, University of Maryland Team

2011-03-01

The challenging endeavor of modulating the morphology of graphene via a patterned substrate to produce a controlled deformation has great potential importance for strain engineering the electronic properties of graphene. An essential step in this direction is to understand the response of graphene to substrate features of known geometry. Here we employ silica nanoparticles with a diameter of 10-100 nm to uniformly decorate Si O2 and mica substrates before depositing graphene, to promote nanoscale modulation of graphene geometry. The morphology of graphene on this modified substrate is then characterized by atomic force spectroscopy. We find that graphene on the substrate is locally raised by the supporting nanoparticles, and wrinkling propagates radially from the protrusions to form a ridge network which links the protrusions. We discuss the dependence of the wrinkled morphology on nanoparticle diameter and graphene thickness in terms of graphene elasticity and adhesion energy. Supported by NSF-MRSEC, Grant DMR 05-20471

In ovo administration of copper nanoparticles and copper sulfate positively influences chicken performance

DEFF Research Database (Denmark)

Mroczek-Sosnowska, Natalia; Łukasiewicz, Monika; Wnuk, Agnieszka

2016-01-01

BACKGROUND: Copper (Cu) is a key trace mineral involved in a variety of physiological processes, and is commonly used in poultry production. However, regardless of the inclusion level the majority of Cu is excreted with poultry faeces. We hypothesise that in ovo administration will allow for better...... utilisation of Cu during embryo development than when supplied post-natally with feed to growing chickens. Thus, the objective of this study was to evaluate effects of in ovo administration of NanoCu and copper sulfate (CuSO4 ) on broiler chicken performance. RESULTS: The study showed the positive influences...

Effect of Particle Morphology on the Ripening of Supported Pt Nanoparticles

DEFF Research Database (Denmark)

Simonsen, Søren Bredmose; Chorkendorff, Ib; Dahl, Søren

2012-01-01

To improve the understanding of sintering in diesel and lean-burn engine exhaust after-treatment catalysts, we examined oxygen-induced sintering in a model catalyst consisting of Pt nanoparticles supported on a planar, amorphous Al2O3 substrate. After aging at increasing temperatures, a transmiss......To improve the understanding of sintering in diesel and lean-burn engine exhaust after-treatment catalysts, we examined oxygen-induced sintering in a model catalyst consisting of Pt nanoparticles supported on a planar, amorphous Al2O3 substrate. After aging at increasing temperatures...

The Chemical Composition and Structure of Supported Sulfated Zirconia with Regulated Size Nanoparticles

International Nuclear Information System (INIS)

Kanazhevskiy, V. V.; Shmachkova, V. P.; Kotsarenko, N. S.; Kochubey, D. I.; Vedrine, J. C.

2007-01-01

A set of model skeletal isomerization catalysts - sulfated zirconia nanoparticles of controlled thickness anchored on different supports - was prepared using colloidal solutions of Zr salt on titania as support. The nanoparticles of zirconia (1-5 nm) are epitaxially connected to the support surface, with S/Zr ratio equals to 1.3-1.5. It was shown by EXAFS that nanoparticles of non-stoichiometric zirconium sulfate Zr(SO4)1+x, where x<0.5, are formed on the support surface. Its structure looks like half-period shifted counterdirected chains built-up by zirconium atoms linked by triangle pyramids of sulfate groups. Considering catalytic data of skeletal n-butane isomerisation at 150 deg. C, one can suggest that these species behave as the active component of sulfated zirconia. They are formed in subsurface layers as zirconium hydroxide undergoes sulfation followed by thermal treatment

Charge carrier transport and collection enhancement of copper indium diselenide photoactive nanoparticle-ink by laser crystallization

Energy Technology Data Exchange (ETDEWEB)

Nian, Qiong; Cheng, Gary J., E-mail: gjcheng@purdue.edu [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Zhang, Martin Y. [School of Industrial Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Wang, Yuefeng [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); School of Materials Engineering, Purdue University, West Lafayette, Indiana 47906 (United States); Das, Suprem R.; Bhat, Venkataprasad S. [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47906 (United States); Huang, Fuqiang [Shanghai Institute of Ceramics, Chinese Academy of Science, Shanghai 200050 (China)

2014-09-15

There has been increasing needs for cost-effective and high performance thin film deposition techniques for photovoltaics. Among all deposition techniques, roll-to-roll printing of nanomaterials has been a promising method. However, the printed thin film contains many internal imperfections, which reduce the charge-collection performance. Here, direct pulse laser crystallization (DPLC) of photoactive nanoparticles-inks is studied to meet this challenge. In this study, copper indium selenite (CIS) nanoparticle-inks is applied as an example. Enhanced crystallinity, densified structure in the thin film is resulted after DLPC under optimal conditions. It is found that the decreased film internal imperfections after DPLC results in reducing scattering and multi-trapping effects. Both of them contribute to better charge-collection performance of CIS absorber material by increasing extended state mobility and carrier lifetime, when carrier transport and kinetics are coupled. Charge carrier transport was characterized after DPLC, showing mobility increased by 2 orders of magnitude. Photocurrent under AM1.5 illumination was measured and shown 10 times enhancement of integrated power density after DPLC, which may lead to higher efficiency in photo-electric energy conversion.

Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete

DEFF Research Database (Denmark)

Thit, Amalie; Ramskov, Tina; Croteau, Marie-Noële Croteau

2016-01-01

the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically...

Nonenzymatic glucose sensor based on disposable pencil graphite electrode modified by copper nanoparticles

Directory of Open Access Journals (Sweden)

Sima Pourbeyram

2016-10-01

Full Text Available A nonenzymatic glucose sensor based on a disposable pencil graphite electrode (PGE modified by copper nanoparticles [Cu(NP] was prepared for the first time. The prepared Cu(NP exhibited an absorption peak centered at ∼562 nm using UV-visible spectrophotometry and an almost homogenous spherical shape by scanning electron microscopy. Cyclic voltammetry of Cu(NP-PGE showed an adsorption controlled charge transfer process up to 90.0 mVs−1. The sensor was applied for the determination of glucose using an amperometry technique with a detection limit of [0.44 (±0.01 μM] and concentration sensitivity of [1467.5 (±1.3 μA/mMcm−2]. The preparation of the Cu(NP-PGE sensor was reproducible (relative standard deviation = 2.10%, n = 10, very simple, fast, and inexpensive, and the Cu(NP-PGE is suitable to be used as a disposable glucose sensor.

Synthesis of Cu Nanoparticles Using Copper Carbonate as Cu Source Toward Versatile Applications.

Science.gov (United States)

Yano, Kazuhisa; Ishizaki, Toshitaka; Sugiyama, Hidehiko

2018-07-01

Cu nanoparticles (NPs) coated with polyvinylpyrrolidone (PVP) were fabricated by polyol method using copper carbonate as a raw material. To increase the reaction temperature, glycol multimers such as diethylene glycol, triethylene glycol, or tetraethylene glycol were examined as a solvent. With increasing degree of multimerization, average diameter of Cu NPs decreased. The synthesis of Cu NPs was further investigated by changing reaction temperature, the amount and molecular weight of PVP in triethylene glycol as a solvent. Average diameter and standard deviation of Cu NPs were found to be highly dependent on those factors. As a result, fine Cu NPs ranging from 28 to 67 nm in average size with narrow size distribution (standard deviation: 16-28%) were obtained. The obtained Cu NPs were applied to a nanofluid, which showed higher thermal conductivity than the theoretical value. The antibacterial activity of Cu NPs was also demonstrated, and found to have strong antibacterial activity.

Changes induced by gamma radiation in nanocomposites based on copper II and antimony sulfides in commercial poly(methyl methacrylate) matrix

International Nuclear Information System (INIS)

Albuquerque, M.C.C. de; Garcia, O.P.; Aquino, K.A.S.; Araujo, E.S.

2010-01-01

Poly (methyl methacrylate) (PMMA) is a polymer with wide application in the manufacture of medical devices that is exposed to gamma irradiation. Currently the use of composite materials has been disseminated and PMMA is an excellent polymer matrix to package various materials. This study aimed to analyze the changes induced by gamma irradiation (25 kGy) on the properties of PMMA nanocomposites with nanoparticles of copper II sulfide (250nm-900nm) and antimony sulfite (300-500 nm). The nanoparticles were added to the polymer in different concentrations and synthesized by ultrasonic irradiation from the corresponding chlorides with thioacetamide. Viscometric results showed a good radioprotective effect of nanoparticles of copper and antimony. It was found a good protection of nanoparticles on PMMA matrix in the concentration of 0.3% wt. The protections of 75% and 50% were calculated for nanoparticles of antimony and copper II, respectively. (author)

Adsorption of environmental pollutants using magnetic hybrid nanoparticles modified with β-cyclodextrin

International Nuclear Information System (INIS)

Wang, Niejun; Zhou, Lilin; Guo, Jun; Ye, Qiquan; Lin, Jin-Ming; Yuan, Jinying

2014-01-01

Graft through strategy was utilized to coat magnetic Fe 3 O 4 nanoparticles with poly(glycidyl methacrylate) using ordinary radical polymerization and then β-cyclodextrin was linked onto the surface of nanoparticles. With these nanoparticles modified with cyclodextrin groups, adsorption of two model environmental pollutants, bisphenol A and copper ions, was studied. Host–guest interactions between cyclodextrin and aromatic molecules had a great contribution to the adsorption of bisphenol A, while multiple hydroxyls of cyclodextrin also helped the adsorption of copper ions. These magnetic nanoparticles could be applied in the elimination, enrichment and detection of some environmental pollutants.

Physical properties of Cu nanoparticles: A molecular dynamics study

International Nuclear Information System (INIS)

Kart, H.H.; Yildirim, H.; Ozdemir Kart, S.; Çağin, T.

2014-01-01

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. - Highlights: • Solid and liquid properties of Cu nanoparticles are studied. • Molecular dynamics utilizing the Quantum Sutton Chen potential is used in this work. • Melting temperatures of nanoparticles are strongly depended on nanoparticle sizes. • Heat capacity, radial distribution function and diffusion coefficients are studied. • Structures of nanoparticles are analyzed by Lindemann and Honeycutt–Andersen index

Mechanistic studies of formic acid oxidation at polycarbazole supported Pt nanoparticles

International Nuclear Information System (INIS)

Moghaddam, Reza B.; Pickup, Peter G.

2013-01-01

Highlights: •A polycarbazole support decreases the accumulation of adsorbed intermediates on Pt during formic acid oxidation. •Polycarbazole causes a bilayer of Cu to form on Pt nanoparticles during Cu underpotential deposition. •XPS suggests that both of these effects are due to electron donation from the metal (Pt or Cu) into the polymer π-system. -- Abstract: Mechanistic aspects of the promotion of formic acid oxidation at Pt nanoparticles supported on a thin layer of polycarbazole (PCZ) have been investigated by voltammetry and X-ray photoelectron spectroscopy (XPS). The Pt nanoparticles were drop coated onto a glassy carbon (GC) electrode coated with a ca. 9 nm layer of electrochemically deposited polycarbazole. After 500 s of formic acid oxidation at 0 V vs. SCE, the current at a GC/PCZ/Pt electrode was 25 times higher than at a GC/Pt electrode. Voltammetry in formic acid free H 2 SO 4 following potentiostatic oxidation of formic acid revealed that there was less accumulation of adsorbed intermediates for the polycarbazole supported Pt nanoparticles than for those deposited directly onto the glassy carbon with, 50% more Pt sites remaining available for the GC/PCZ/Pt electrode relative to the GC/Pt electrode. Independent CO stripping experiments revealed only slight differences, while Cu underpotential deposition surprisingly resulted in the deposition of a ca. two-fold excess of Cu on the polycarbazole supported particles. This observation was supported by XPS which also revealed a second Cu signal at a higher binding energy, suggesting electron donation into the conjugated π system of the polymer. Such an interaction of Pt with the polycarbazole may be responsible for its higher activity for formic acid oxidation

Enhancement of Degradation and Dechlorination of Trichloroethylene via Supporting Palladium/Iron Bimetallic Nanoparticles onto Mesoporous Silica

Directory of Open Access Journals (Sweden)

Jianjun Wei

2016-07-01

Full Text Available This study is aimed to prevent the agglomeration of Pd/Fe bimetallic nanoparticles and thus improve the efficiency toward degradation and dechlorination of chlorinated organic contaminants. A mesoporous silica with a primary pore diameter of 8.3 nm and a specific surface area of 688 m2/g was prepared and used as the host of Pd/Fe nanoparticles. The Pd/Fe nanoparticles were deposited onto or into the mesoporous silica by reduction of ferrous ion and hexachloropalladate ion in aqueous phase. Batch degradation and dechlorination reactions of trichloroethylene were conducted with initial trichloroethylene concentration of 23.7 mg/L, iron loading of 203 or 1.91 × 103 mg/L and silica loading of 8.10 g/L at 25 °C. Concentration of trichloroethylene occurs on the supported Pd/Fe nanoparticles, with trichloroethylene degrading to 56% and 59% in 30 min on the supported Pd/Fe nanoparticles with weight percentage of palladium to iron at 0.075% and 0.10% respectively. The supported Pd/Fe nanoparticles exhibit better dechlorination activity. When the supported Pd/Fe nanoparticles with a weight percentage of palladium to iron of 0.10% were loaded much less than the bare counterpart, the yield of ethylene plus ethane in 10 h on them was comparable, i.e., 19% vs. 21%. This study offers a future approach to efficiently combine the reactivity of supported Pd/Fe nanoparticles and the adsorption ability of mesoporous silica.

Luminescence of polyethylene glycol coated CdSeTe/ZnS and InP/ZnS nanoparticles in the presence of copper cations.

Science.gov (United States)

Beaune, Grégory; Tamang, Sudarsan; Bernardin, Aude; Bayle-Guillemaud, Pascale; Fenel, Daphna; Schoehn, Guy; Vinet, Françoise; Reiss, Peter; Texier, Isabelle

2011-08-22

The use of click chemistry for quantum dot (QD) functionalization could be very promising for the development of bioconjugates dedicated to in vivo applications. Alkyne-azide ligation usually requires copper(I) catalysis. The luminescence response of CdSeTe/ZnS nanoparticles coated with polyethylene glycol (PEG) is studied in the presence of copper cations, and compared to that of InP/ZnS QDs coated with mercaptoundecanoic acid (MUA). The quenching mechanisms appear different. Luminescence quenching occurs without any wavelength shift in the absorption and emission spectra for the CdSeTe/ZnS/PEG nanocrystals. In this case, the presence of copper in the ZnS shell is evidenced by energy-filtered transmission electron microscopy (EF-TEM). By contrast, in the case of InP/ZnS/MUA nanocrystals, a redshift of the excitation and emission spectra, accompanied by an increase in absorbance and a decrease in photoluminescence, is observed. For CdSeTe/ZnS/PEG nanocrystals, PL quenching is enhanced for QDs with 1) smaller inorganic-core diameter, 2) thinner PEG shell, and 3) hydroxyl terminal groups. Whereas copper-induced PL quenching can be interesting for the design of sensitive cation sensors, copper-free click reactions should be used for the efficient functionalization of nanocrystals dedicated to bioapplications, in order to achieve highly luminescent QD bioconjugates. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Responses of Wetland Plant Carex vulpina to Copper and Iron Nanoparticles

Czech Academy of Sciences Publication Activity Database

Cyrusová, Tereza; Petrová, Šárka; Vaněk, Tomáš; Podlipná, Radka

2017-01-01

Roč. 228, č. 7 (2017), č. článku 258. ISSN 0049-6979 R&D Projects: GA MŠk(CZ) LD14100; GA MŠk(CZ) LD13028 Institutional support: RVO:61389030 Keywords : Carex vulpina * Metal nanoparticles * Phytotoxicity Subject RIV: DJ - Water Pollution ; Quality OBOR OECD: Bioremediation, diagnostic biotechnologies (DNA chips and biosensing devices) in environmental management Impact factor: 1.702, year: 2016

Neo-Geometric Copper Nanocrystals by Competitive, Dual Surfactant-Mediated Facet Adsorption Controlling Skin Permeation

Directory of Open Access Journals (Sweden)

Karmani Murugan

2016-11-01

Full Text Available Neogeometric copper nanoparticles (CuNPs have various applications yet its synthesis still proves to be challenging with regards to self-assembly and uniformity control. This study aimed to synthesize shape-specific CuNPs in the biomedical application of ascertaining skin permeation and retention of the CuNPs as a drug delivery system. The approach to the shape design involved the dual control of two surfactants to direct the shape organisation of the nanoparticles (NPs while an interesting aspect of the study showed the competitive adsorption of the surfactants onto the nanocrystal facets to direct facet growth. The resulting copper nanoparticles were characterised using X-ray diffraction (XRD and electron diffraction spectra analysis (EDS for elemental and crystalline analysis. Thermogravimetric Analysis (TGA identified the degradation of the surfactant coat and the synthesis of a novel copper-polymer complex and extensive transmission electron microscopy (TEM was conducted to determine the nanoparticle morphology. Epidermal skin tissue served as the model for permeation studies of five idealistic nano-geometries and investigated its application in drug delivery with regards to cellular internalisation and transbarrier transport of the geometric CuNPs. A mechanistic consideration for shape control is discussed.

A two step method to synthesize palladium-copper nanoparticles on reduced graphene oxide and their extremely high electrocatalytic activity for the electrooxidation of methanol and ethanol

Science.gov (United States)

Na, HeYa; Zhang, Lei; Qiu, HaiXia; Wu, Tao; Chen, MingXi; Yang, Nian; Li, LingZhi; Xing, FuBao; Gao, JianPing

2015-08-01

Palladium-copper nanoparticles (Pd-Cu NPs) supported on reduced graphene oxide (RGO) with different Pd/Cu ratios (Pd-Cu/RGO) were prepared by a two step method. The Pd-Cu/RGO hybrids were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and thermogravimetric analyses. Cyclic voltammetry and chronoamperometry were used to investigate the electrochemical activities and stabilities of the Pd-Cu/RGO catalysts for the electro-oxidation of methanol and ethanol in alkaline media. The Pd-Cu/RGO catalysts exhibited high catalytic activities and good stabilities. This is because the catalysts have a bimetallic structure consisting of a small Pd-Cu core surrounded by a thin Pd-rich shell which improves the catalytic activities of the Pd-Cu/RGO hybrids. Thus they should be useful in direct methanol and ethanol fuel cells.

Comparison study of catalyst nanoparticle formation and carbon nanotube growth: Support effect

International Nuclear Information System (INIS)

Wang Yunyu; Luo Zhiquan; Li Bin; Ho, Paul S.; Yao Zhen; Shi Li; Bryan, Eugene N.; Nemanich, Robert J.

2007-01-01

A comparison study has been conducted on the formation of catalyst nanoparticles on a high surface tension metal and low surface tension oxide for carbon nanotube (CNT) growth via catalytic chemical vapor deposition (CCVD). Silicon dioxide (SiO 2 ) and tantalum have been deposited as supporting layers before deposition of a thin layer of iron catalyst. Iron nanoparticles were formed after thermal annealing. It was found that densities, size distributions, and morphologies of iron nanoparticles were distinctly different on the two supporting layers. In particular, iron nanoparticles revealed a Volmer-Weber growth mode on SiO 2 and a Stranski-Krastanov mode on tantalum. CCVD growth of CNTs was conducted on iron/tantalum and iron/SiO 2 . CNT growth on SiO 2 exhibited a tip growth mode with a slow growth rate of less than 100 nm/min. In contrast, the growth on tantalum followed a base growth mode with a fast growth rate exceeding 1 μm/min. For comparison, plasma enhanced CVD was also employed for CNT growth on SiO 2 and showed a base growth mode with a growth rate greater than 2 μm/min. The enhanced CNT growth rate on tantalum was attributed to the morphologies of iron nanoparticles in combination with the presence of an iron wetting layer. The CNT growth mode was affected by the adhesion between the catalyst and support as well as CVD process

Influence of the Support of Copper Catalysts on Activity and 1,2-dichloroethane Selectivity in Ethylene Oxychlorination.

Czech Academy of Sciences Publication Activity Database

Vajglová, Zuzana; Kumar, N.; Eränen, K.; Tokarev, A.; Peurla, M.; Peltonen, J.; Murzin, D.Yu.; Salmi, T.

2018-01-01

Roč. 556 (2018), s. 41-51 ISSN 0926-860X Institutional support: RVO:67985858 Keywords : oxychlorination * copper * support effect Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 4.339, year: 2016

Interfacial bonding stabilizes rhodium and rhodium oxide nanoparticles on layered Nb oxide and Ta oxide supports.

Science.gov (United States)

Strayer, Megan E; Binz, Jason M; Tanase, Mihaela; Shahri, Seyed Mehdi Kamali; Sharma, Renu; Rioux, Robert M; Mallouk, Thomas E

2014-04-16

Metal nanoparticles are commonly supported on metal oxides, but their utility as catalysts is limited by coarsening at high temperatures. Rhodium oxide and rhodium metal nanoparticles on niobate and tantalate supports are anomalously stable. To understand this, the nanoparticle-support interaction was studied by isothermal titration calorimetry (ITC), environmental transmission electron microscopy (ETEM), and synchrotron X-ray absorption and scattering techniques. Nanosheets derived from the layered oxides KCa2Nb3O10, K4Nb6O17, and RbTaO3 were compared as supports to nanosheets of Na-TSM, a synthetic fluoromica (Na0.66Mg2.68(Si3.98Al0.02)O10.02F1.96), and α-Zr(HPO4)2·H2O. High surface area SiO2 and γ-Al2O3 supports were also used for comparison in the ITC experiments. A Born-Haber cycle analysis of ITC data revealed an exothermic interaction between Rh(OH)3 nanoparticles and the layered niobate and tantalate supports, with ΔH values in the range -32 kJ·mol(-1) Rh to -37 kJ·mol(-1) Rh. In contrast, the interaction enthalpy was positive with SiO2 and γ-Al2O3 supports. The strong interfacial bonding in the former case led to "reverse" ripening of micrometer-size Rh(OH)3, which dispersed as 0.5 to 2 nm particles on the niobate and tantalate supports. In contrast, particles grown on Na-TSM and α-Zr(HPO4)2·H2O nanosheets were larger and had a broad size distribution. ETEM, X-ray absorption spectroscopy, and pair distribution function analyses were used to study the growth of supported nanoparticles under oxidizing and reducing conditions, as well as the transformation from Rh(OH)3 to Rh nanoparticles. Interfacial covalent bonding, possibly strengthened by d-electron acid/base interactions, appear to stabilize Rh(OH)3, Rh2O3, and Rh nanoparticles on niobate and tantalate supports.

Molecular recognition by gold, silver and copper nanoparticles

Science.gov (United States)

Tauran, Yannick; Brioude, Arnaud; Coleman, Anthony W; Rhimi, Moez; Kim, Beonjoom

2013-01-01

The intrinsic physical properties of the noble metal nanoparticles, which are highly sensitive to the nature of their local molecular environment, make such systems ideal for the detection of molecular recognition events. The current review describes the state of the art concerning molecular recognition of Noble metal nanoparticles. In the first part the preparation of such nanoparticles is discussed along with methods of capping and stabilization. A brief discussion of the three common methods of functionalization: Electrostatic adsorption; Chemisorption; Affinity-based coordination is given. In the second section a discussion of the optical and electrical properties of nanoparticles is given to aid the reader in understanding the use of such properties in molecular recognition. In the main section the various types of capping agents for molecular recognition; nucleic acid coatings, protein coatings and molecules from the family of supramolecular chemistry are described along with their numerous applications. Emphasis for the nucleic acids is on complementary oligonucleotide and aptamer recognition. For the proteins the recognition properties of antibodies form the core of the section. With respect to the supramolecular systems the cyclodextrins, calix[n]arenes, dendrimers, crown ethers and the cucurbitales are treated in depth. Finally a short section deals with the possible toxicity of the nanoparticles, a concern in public health. PMID:23977421

Catalytic degradation of brominated flame retardants by copper oxide nanoparticles

Science.gov (United States)

Dror, I.; Yecheskel, Y.; Berkowitz, B.

2013-12-01

Brominated flame retardants (BFRs) have been added to various products like plastic, textile, electronics and synthetic polymers at growing rates. In spite of the clear advantages of reducing fire damages, many of these BFRs may be released to the environment after their beneficial use which may lead to contamination of water resources. In this work we present the catalytic degradation of two brominated flame retardants (BFRs), tribromoneopentyl alcohol (TBNPA) and 2,4 dibromophenol (2,4-DBP) by copper oxide nanoparticles (nCuO) in aqueous solution. The degradation kinetics, the debromination, and the formation of intermediates by nCuO catalysis are compared to Fenton oxidation and to reduction by nano zero-valent iron (nZVI). The two studied BFRs are shown to degrade fully by the nCuO system within hours to days. Shorter reaction times showed differences in reaction pathways and kinetics for the two compounds. The 2,4-DBP showed faster degradation than TBNPA, by nCuO catalysis. Relatively high resistance to degradation was recorded for 2,4-DBP with nZVI, yielding 20% degradation after 24 h, while the TBNPA was degraded by 85% within 12 hours. A catalytic mechanism for radical generation and BFR degradation by nCuO is proposed. It is further suggested that H2O2 plays an essential role in the activation of the catalyst.

Three-dimensional structure of Au nanoparticles supported on amorphous silica and carbon substrates

International Nuclear Information System (INIS)

Bruma, A; Li, Z Y

2012-01-01

Scanning Transmission Electron Microscope (STEM) has been employed to study the three-dimensional structure of gold (Au) nanoparticles deposited by means of thermal evaporation in high vacuum on amorphous silica (a-SiO 2 ) and amorphous carbon (a-C) supports. By performing quantitative analysis on the evolution of the high angle annular dark field (HAADF) images, we studied the influence of the nature and the temperature of support on the growth mode of gold nanoparticles.

Basic metal carbonate supported gold nanoparticles: enhanced performance in aerobic alcohol oxidation

NARCIS (Netherlands)

Yang, J.; Guan, Y.; Verhoeven, M.W.G.M.; Santen, van R.A.; Li, Can; Hensen, E.J.M.

2009-01-01

Gold nanoparticles supported by basic hydrozincite or bismuth carbonate are excellent catalysts for liquid-phase aerobic alcohol oxidation: the performance of a series of metal (Zn, Bi, Ce, La, Zr) carbonate supported gold catalysts depends strongly on the basicity of the support material.

Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Yuan Peng, E-mail: yuanpeng@gig.ac.cn [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Liu Dong; Fan Mingde; Yang Dan [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Zhu Runliang; Ge Fei [College of Chemical Engineering, Xiangtan University, Xiangtan 411105 (China); Zhu Jianxi; He Hongping [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

2010-01-15

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.

Removal of hexavalent chromium [Cr(VI)] from aqueous solutions by the diatomite-supported/unsupported magnetite nanoparticles.

Science.gov (United States)

Yuan, Peng; Liu, Dong; Fan, Mingde; Yang, Dan; Zhu, Runliang; Ge, Fei; Zhu, JianXi; He, Hongping

2010-01-15

Diatomite-supported/unsupported magnetite nanoparticles were prepared by co-precipitation and hydrosol methods, and characterized by X-ray diffraction, nitrogen adsorption, elemental analysis, differential scanning calorimetry, transmission electron microscopy and X-ray photoelectron spectroscopy. The average sizes of the unsupported and supported magnetite nanoparticles are around 25 and 15 nm, respectively. The supported magnetite nanoparticles exist on the surface or inside the pores of diatom shells, with better dispersing and less coaggregation than the unsupported ones. The uptake of hexavalent chromium [Cr(VI)] on the synthesized magnetite nanoparticles was mainly governed by a physico-chemical process, which included an electrostatic attraction followed by a redox process in which Cr(VI) was reduced into trivalent chromium [Cr(III)]. The adsorption of Cr(VI) was highly pH-dependent and the kinetics of the adsorption followed a pseudo-second-order model. The adsorption data of diatomite-supported/unsupported magnetite fit well with the Langmuir isotherm equation. The supported magnetite showed a better adsorption capacity per unit mass of magnetite than unsupported magnetite, and was more thermally stable than their unsupported counterparts. These results indicate that the diatomite-supported/unsupported magnetite nanoparticles are readily prepared, enabling promising applications for the removal of Cr(VI) from aqueous solution.

Selective liquid phase oxidation of benzyl alcohol to benzaldehyde by tert-butyl hydroperoxide over γ-Al2O3 supported copper and gold nanoparticles

International Nuclear Information System (INIS)

Ndolomingo, Matumuene Joe; Meijboom, Reinout

2017-01-01

Highlights: • Cu and Au on γ-Al 2 O 3 catalysts were prepared and characterized. • Benzyl alcohol oxidation to benzaldehyde was performed by tert-butyl hydroperoxide in the absence of any solvent using the prepared catalysts. • The as prepared catalysts exhibited good performance in terms of conversion and selectivity towards benzaldehyde. • The kinetics of the reaction was investigated; k app was proportional to the amount of nano catalyst and oxidant present in the system. • The catalysts was recycled and reused with neither significant loss of activity nor selectivity. - Abstract: Benzyl alcohol oxidation to benzaldehyde was performed by tert-butyl hydroperoxide (TBHP) in the absence of any solvent using γ-Al 2 O 3 supported copper and gold nanoparticles. Li 2 O and ionic liquids were used as additive and stabilizers for the synthesis of the catalysts. The physico-chemical properties of the catalysts were characterized by atomic absorption spectroscopy (AAS), X-ray diffraction spectroscopy (XRD), N 2 absorption/desorption (BET), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and temperature programmed reduction (TPR), whereas, the oxidation reaction was followed by gas chromatography with a flame ionization detector (GC-FID). The as prepared catalysts exhibited good catalytic performance in terms of conversion and selectivity towards benzaldehyde. The performance of the Au-based catalysts is significantly higher than that of the Cu-based catalysts. For both Cu and Au catalysts, the conversion of benzyl alcohol increased as the reaction proceeds, while the selectivity for benzaldehyde decreased. Moreover, the catalysts can be easily recycled and reused with neither significant loss of activity nor selectivity. A kinetic study for the Cu and Au-catalyzed oxidation of benzyl alcohol to benzyldehyde is reported. The rate at which the oxidation of benzyl alcohol is occurring as a function of

Electrochemical detection of C-reactive protein using Copper nanoparticles and hybridization chain reaction amplifying signal.

Science.gov (United States)

Zhang, Junjun; Zhang, Wenjuan; Guo, Jinjin; Wang, Junchun; Zhang, Yuzhong

2017-12-15

In this study, a sandwich-type electrochemical immunosensor for the detection of C-reactive protein (CRP) is described. In design, Copper nanoparticles (Cu NPs) were used for signal tag and hybridization chain reaction (HCR)amplified output signal. The immunosensor fabrication involved three steps: (i) primary antibodies (Ab 1 ) were immobilized on the surface of gold nanoparticles (Au NPs); (ii) the sandwich-type structure formation contained "primary antibodies-antigen-secondary antibodies conjugated with primer (Ab 2 -S 0 )"; and (iii) long DNA concatemers intercalating amounts of Cu NPs was linked to the sandwich-type structure via hybridization reaction. Differential pulse voltammetry (DPV) was used to record the response signal of the immunosensor in phosphate-buffered saline (PBS). Under optimal conditions, the anodic peak currents of Cu NPs at the peak potential of about 0.08V(VS.SCE) were linear with the logarithm of CRP concentration in the range of 1.0 fg mL -1 to 100 ng mL -1 with a detection limit of 0.33 fg mL -1 (at signal/noise [S/N] = 3). In addition, the practical application of immunosensor was evaluated by analyzing CRP in real human serum samples, the recoveries obtained were within 95.3%-103.8%, indicating the immunosensor possessed potential application ability for practical disease diagnosis. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of trace labile copper in environmental waters by magnetic nanoparticle solid phase extraction and high-performance chelation ion chromatography.

Science.gov (United States)

Wei, Z; Sandron, S; Townsend, A T; Nesterenko, P N; Paull, B

2015-04-01

Cobalt magnetic nanoparticles surface functionalised with iminodiacetic acid were evaluated as a nano-particulate solid phase extraction absorbent for copper ions (Cu(2+)) from environmental water samples. Using an external magnetic field, the collector nanoparticles could be separated from the aqueous phase, and adsorbed ions simply decomplexed using dilute HNO3. Effects of pH, buffer concentration, sample and sorbent volume, extraction equilibrium time, and interfering ion concentration on extraction efficiency were investigated. Optimal conditions were then applied to the extraction of Cu(2+) ions from natural water samples, prior to their quantitation using high-performance chelation ion chromatography. The limits of detection (LOD) of the combined extraction and chromatographic method were ~0.1 ng ml(-1), based upon a 100-fold preconcentration factor (chromatographic performance; LOD=9.2 ng ml(-1) Cu(2+)), analytical linear range from 20 to 5000 ng mL(-1), and relative standard deviations=4.9% (c=1000 ng ml(-1), n=7). Accuracy and precision of the combined approach was verified using a certified reference standard estuarine water sample (SLEW-2) and comparison of sample determinations with sector field inductively coupled plasma mass spectrometry. Recoveries from the addition of Cu(2+) to impacted estuarine and rain water samples were 103.5% and 108.5%, respectively. Coastal seawater samples, both with and without prior UV irradiation and dissolved organic matter removal were also investigated using the new methodology. The effect of DOM concentration on copper availability was demonstrated. Copyright © 2015. Published by Elsevier B.V.

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

International Nuclear Information System (INIS)

McCormick, Stephen F.

2016-01-01

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/

Annual Copper Mountain Conferences on Multigrid and Iterative Methods, Copper Mountain, Colorado

Energy Technology Data Exchange (ETDEWEB)

McCormick, Stephen F. [Front Range Scientific, Inc., Lake City, CO (United States)

2016-03-25

This project supported the Copper Mountain Conference on Multigrid and Iterative Methods, held from 2007 to 2015, at Copper Mountain, Colorado. The subject of the Copper Mountain Conference Series alternated between Multigrid Methods in odd-numbered years and Iterative Methods in even-numbered years. Begun in 1983, the Series represents an important forum for the exchange of ideas in these two closely related fields. This report describes the Copper Mountain Conference on Multigrid and Iterative Methods, 2007-2015. Information on the conference series is available at http://grandmaster.colorado.edu/~copper/.

DNA Three-Way Junction for Differentiation of Single-Nucleotide Polymorphisms with Fluorescent Copper Nanoparticles.

Science.gov (United States)

Sun, Feifei; You, Ying; Liu, Jie; Song, Quanwei; Shen, Xiaotong; Na, Na; Ouyang, Jin

2017-05-23

A label- and enzyme-free fluorescent sensor for the detection of single-nucleotide polymorphisms (SNPs) at room temperature is proposed, using new copper nanoparticles (CuNPs) as fluorescent reporters. The CuNPs were constructed by using a DNA three-way junction (3WJ) template. In this assay, two complementary adenine/thymine-rich probes can hybridize with the wild-type target simultaneously to construct a 3WJ structure, serving as an efficient scaffold for the generation of CuNPs. However, the CuNPs produce weak fluorescence when the probes bind with a mutant-type target. SNPs can be identified by the difference in fluorescence intensity of the CuNPs. This SNPs detection strategy is straightforward, cost-effective, and avoids the complicated procedures of labeling or enzymatic reactions. The fluorescent sensor is versatile and can be applied to all types of mutation because the probes are programmable. Moreover, the sensor exhibits good detection performance in biological samples. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sol–gel synthesis of palladium nanoparticles supported on reduced ...

Indian Academy of Sciences (India)

average particle size of the Pd nanoparticles supported on rGO obtained from TEM is ... Ag|AgCl|KCl3M, the current is .... was used for chemical characterization of a specimen. The ... mer's method.36 In a typical procedure, about 20 mg of GO.

Synthesis and Characterization of Phase-pure Copper Zinc Tin Sulfide (Cu2ZnSnS4) Nanoparticles

Science.gov (United States)

Monahan, Bradley Michael

Semiconductor nanoparticles have been an important area of research in many different disciplines. A substantial amount of this work has been put toward advancing the field of photovoltaics. However, current p-type photovoltaic materials can not sustain the large scale production needed for future energy demands due to their low elemental abundance. Therefore, Earth abundant semiconductor materials have become of great interest to the photovoltaic community especially, the material copper zinc tin sulfide (CZTS), also known by its mineral name kesterite. CZTS exhibits desirable properties for photovoltaics, such as elemental abundance, high absorption coefficient (~104 cm-1 ), high carrier concentration, and optimum direct band gap (1.5 eV). To date, solution based approaches for making CZTS have yielded the most promising conversion efficiencies in solar cells. To that end, the motivation of nanoparticle based inks that can be used in high throughput production are an attractive route for large scale deployment. This has driven the need to make high quality CZTS nanoparticles that possess the properties of the pure kesterite phase with high monodispersity that can be deposited into dense thin films. The inherent challenge of making a quaternary compound of a single phase has made this a difficult task; however, some of those fundamental problems are addressed in this thesis. This had resulted in the synthesis of phase-pure k-CZTS confirmed by powder X-ray diffraction, Raman spectroscopy, UV-visible absorption spectroscopy and energy dispersive x-ray spectroscopy. Furthermore, ultra-fast laser spectroscopy was done on CZTS thin films made from phase-pure kesterite nanoparticles synthesized in this work. This thesis provides new data that directly probes the lifetime of photogenerated free carriers in kesterite CZTS (k-CZTS) thin films.

A structure study of copper oxide for monolayer dispersion of anatase supported

International Nuclear Information System (INIS)

Zi Fenlan; Yu Xiaofeng; Guo Hongyou; Cai Xiaohai; Yang Pengcheng; Wu Nianzu; Xie Yaning; Zang Jing; Hu Tiandou

2002-01-01

The monolayer dispersion of copper oxide on the surface of anatase and its effect on the properties have been studied by X-ray photoelectron spectroscopy (XPS) and X-ray extended absorption fine structure (EXAFS). XPS results give an utmost dispersion capacity of 7.2 mg/gTiO 2 . Strong interactions between copper oxide and anatase can be seen from EXAFS results. The structure of the supported CuO species is strongly dependent on the amount of CuO loading. When the content of CuO loading is below the utmost dispersion capacity, the surface of CuO/TiO 2 is dominated by the highly dispersed CuO species having no -Cu-O-Cu- chains. The copper ion is located in an octahedral coordination environment, and the Cu-O coordination distance is much longer than that in pure crystalline CuO. When CuO loading is exceeds the utmost dispersion capacity, crystalline CuO is formed on the surface of CuO/TiO 2 . From the result of the structure study, it is Cu-O octahedral coordination and coordination distance change in comparison with pure crystalline CuO on the surface CuO/TiO 2 that have catalytic activity

Copper-doped titanium dioxide nanoparticles as dual-functional labels for fabrication of electrochemical immunosensors.

Science.gov (United States)

Zhang, Sen; Ma, Hongmin; Yan, Liangguo; Cao, Wei; Yan, Tao; Wei, Qin; Du, Bin

2014-09-15

Constructions of versatile electroactive labels are key issues in the development of electrochemical immunosensors. In this study, copper-doped titanium dioxide nanoparticle (Cu@TiO2) was synthesized and used as labels for fabrication of sandwich-type electrochemical immunosensors on glassy carbon electrode (GCE). Due to the presence of copper ions, Cu@TiO2 shows a strong response current when coupled to an electrode. The prepared nanocomposite also shows high electrocatalytic activity towards reduction of hydrogen peroxide (H2O2). The dual functionality of Cu@TiO2 enables the fabrication of immunosensor using different detection modes, that is, square wave voltammetry (SWV) or chronoamperometry (CA). While Cu@TiO2 was used as labels of secondary antibodies (Ab2), carboxyl functionalized graphene oxide (CFGO) was used as electrode materials to immobilize primary antibodies (Ab1). Using human immunoglobulin G (IgG) as a model analyte, the immunosensor shows high sensitivity, acceptable stability and good reproducibility for both detection modes. Under optimal conditions, a linear range from 0.1 pg/mL to 100 ng/mL with a detection limit of 0.052 pg/mL was obtained for SWV analysis. For CA analysis, a wider linear range from 0.01 pg/mL to 100 ng/mL and a lower detection limit of 0.0043 pg/mL were obtained. The proposed metal ion-based enzyme-free and noble metal-free immunosensor may have promising applications in clinical diagnoses and many other fields. Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanical and microbiological properties and drug release modeling of an etch-and-rinse adhesive containing copper nanoparticles.

Science.gov (United States)

Gutiérrez, M F; Malaquias, P; Matos, T P; Szesz, A; Souza, S; Bermudez, J; Reis, A; Loguercio, A D; Farago, P V

2017-03-01

To evaluate the effect of addition of copper nanoparticles (CN) at different concentrations into a two-step etch-and-rinse (2-ER) adhesive on antimicrobial activity (AMA), copper release (CR), ultimate tensile strength (UTS), degree of conversion (DC), water sorption (WS), solubility (SO), as well as the immediate (IM) and 1-year resin-dentin bond strength (μTBS) and nanoleakage (NL). Seven adhesives were formulated according to the addition of CN (0, 0.0075, 0.015, 0.06, 0.1, 0.5 and 1wt%) in adhesive. The AMA was evaluated against Streptococcus mutans using agar diffusion assay. For CR, WS and SO, specimens were constructed and tested for 28 days. For UTS, specimens were tested after 24h and 28 days. For DC, specimens were constructed and tested after 24h by FTIR. After enamel removal, the ER was applied to dentin. After composite resin build-ups, specimens were sectioned to obtain resin-dentin sticks. For μTBS and NL, specimens were tested after 24h and 1-year periods. All data were submitted to statistical analysis (α=0.05). The addition of CN provided AMA to the adhesives at all concentrations. Higher CR was observed in adhesives with higher concentration of CN. UTS, DC, WS and SO were not influenced. For μTBS an increase was observed in 0.1 and 0.5% copper group. For NL, a significant decrease was observed in all groups in comparison with control group. After 1-year, no significant reductions of μTBS and no significant increases of NL were observed for copper containing adhesives compared to the control group. The addition of CN in concentrations up to 1wt% in the 2-ER adhesive may be an alternative to provide AMA and preserve the bonding to dentin, without reducing adhesives' mechanical properties evaluated. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Size control and supporting of palladium nanoparticles made by laser ablation in saline solution as a facile route to heterogeneous catalysts

International Nuclear Information System (INIS)

Marzun, Galina; Nakamura, Junji; Zhang, Xiaorui; Barcikowski, Stephan; Wagener, Philipp

2015-01-01

Graphical abstract: - Highlights: • We studied laser-generated, size-controlled palladium nanoparticles in saline solution. • Palladium nanoparticles were electrostatically stabilized by anions. • Photo- and electrocatalyst are prepared by supporting Pd nanoparticles to TiO 2 and graphene. • Particle size does not change during supporting process, while 18 wt% load has been achieved. • Palladium nanoparticles and graphene undergo a redox-reaction during adsorption. - Abstract: In the literature many investigations on colloidal stability and size control of gold nanoparticles are shown but less for ligand-free palladium nanoparticles, which can be promising materials in various applications. Palladium nanoparticles are perspective materials for a manifold of energy application like photo- and electrocatalysis or hydrogen storage. For this purpose, size-controlled nanoparticles with clean surfaces and facile immobilization on catalyst supports are wanted. Laser ablation in saline solution yields ligand-free, charged colloidal palladium nanoparticles that are supported by titania and graphene nanosheets as model systems for photo- and electrocatalysis, respectively. By adjusting the ionic strength during laser ablation in liquid, it is possible to control stability and particle size without compromising subsequent nanoparticle adsorption of supporting materials. A quantitative deposition of nearly 100% yield with up to 18 wt% nanoparticle load was achieved. The average size of the laser-generated nanoparticles remains the same after immobilization on a support material, in contrast to other preparation methods of catalysts. The characterization by X-ray photoelectron spectroscopy reveals a redox reaction between the immobilized nanoparticles and the graphene support

Functionalized Natural Carbon-Supported Nanoparticles as Excellent Catalysts for Hydrocarbon Production.

Science.gov (United States)

Sun, Jian; Guo, Lisheng; Ma, Qingxiang; Gao, Xinhua; Yamane, Noriyuki; Xu, Hengyong; Tsubaki, Noritatsu

2017-02-01

We report a one-pot and eco-friendly synthesis of carbon-supported cobalt nanoparticles, achieved by carbonization of waste biomass (rice bran) with a cobalt source. The functionalized biomass provides carbon microspheres as excellent catalyst support, forming a unique interface between hydrophobic and hydrophilic groups. The latter, involving hydroxyl and amino groups, can catch much more active cobalt nanoparticles on surface for Fischer-Tropsch synthesis than chemical carbon. The loading amount of cobalt on the final catalyst is much higher than that prepared with a chemical carbon source, such as glucose. The proposed concept of using a functionalized natural carbon source shows great potential compared with conventional carbon sources, and will be meaningful for other fields concerning carbon support, such as heterogeneous catalysis or electrochemical fields. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electronic cigarette aerosols and copper nanoparticles induce mitochondrial stress and promote DNA fragmentation in lung fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Lerner, Chad A.; Rutagarama, Pierrot; Ahmad, Tanveer; Sundar, Isaac K.; Elder, Alison; Rahman, Irfan, E-mail: irfan_rahman@urmc.rochester.edu

2016-09-02

Oxidants or nanoparticles have recently been identified as constituents of aerosols released from various styles of electronic cigarettes (E-cigs). Cells in the lung may be directly exposed to these constituents and harbor reactive properties capable of incurring acute cell injury. Our results show mitochondria are sensitive to both E-cig aerosols and aerosol containing copper nanoparticles when exposed to human lung fibroblasts (HFL-1) using an Air-Liquid Interface culture system, evident by elevated levels of mitochondrial ROS (mtROS). Increased mtROS after aerosol exposure is associated with reduced stability of OxPhos electron transport chain (ETC) complex IV subunit and nuclear DNA fragmentation. Increased levels of IL-8 and IL-6 in HFL-1 conditioned media were also observed. These findings reveal both mitochondrial, genotoxic, and inflammatory stresses are features of direct cell exposure to E-cig aerosols which are ensued by inflammatory duress, raising a concern on deleterious effect of vaping. - Graphical abstract: Oxidants and possibly reactive properties of metal particles in E-cig aerosols impart mitochondrial oxidative stress and DNA damage. These biological effects accompany inflammatory response which may raise concern regarding long term E-cig use. Mitochondria may be particularly sensitive to reactive properties of E-cig aerosols in addition to the potential for them to induce genotoxic stress by generating increased ROS. - Highlights: • Mitochondria are sensitive to both E-cig aerosols and metal nanoparticles. • Increased mtROS by E-cig aerosol is associated with disrupted mitochondrial energy. • E-cig causes nuclear DNA fragmentation. • E-cig aerosols induce pro-inflammatory response in human fibroblasts.

Electronic cigarette aerosols and copper nanoparticles induce mitochondrial stress and promote DNA fragmentation in lung fibroblasts

International Nuclear Information System (INIS)

Lerner, Chad A.; Rutagarama, Pierrot; Ahmad, Tanveer; Sundar, Isaac K.; Elder, Alison; Rahman, Irfan

2016-01-01

Oxidants or nanoparticles have recently been identified as constituents of aerosols released from various styles of electronic cigarettes (E-cigs). Cells in the lung may be directly exposed to these constituents and harbor reactive properties capable of incurring acute cell injury. Our results show mitochondria are sensitive to both E-cig aerosols and aerosol containing copper nanoparticles when exposed to human lung fibroblasts (HFL-1) using an Air-Liquid Interface culture system, evident by elevated levels of mitochondrial ROS (mtROS). Increased mtROS after aerosol exposure is associated with reduced stability of OxPhos electron transport chain (ETC) complex IV subunit and nuclear DNA fragmentation. Increased levels of IL-8 and IL-6 in HFL-1 conditioned media were also observed. These findings reveal both mitochondrial, genotoxic, and inflammatory stresses are features of direct cell exposure to E-cig aerosols which are ensued by inflammatory duress, raising a concern on deleterious effect of vaping. - Graphical abstract: Oxidants and possibly reactive properties of metal particles in E-cig aerosols impart mitochondrial oxidative stress and DNA damage. These biological effects accompany inflammatory response which may raise concern regarding long term E-cig use. Mitochondria may be particularly sensitive to reactive properties of E-cig aerosols in addition to the potential for them to induce genotoxic stress by generating increased ROS. - Highlights: • Mitochondria are sensitive to both E-cig aerosols and metal nanoparticles. • Increased mtROS by E-cig aerosol is associated with disrupted mitochondrial energy. • E-cig causes nuclear DNA fragmentation. • E-cig aerosols induce pro-inflammatory response in human fibroblasts.

Silica-supported Preyssler Nanoparticles as New Catalysts in the ...

African Journals Online (AJOL)

A new and efficient method for the preparation of 4(3H)-quinazolinones from the condensation of anthranilic acid, orthoester and substituted anilines, in the presence of catalytic amounts of silica-supported Preyssler nanoparticles is reported. The catalyst performs very well in comparison with other catalysts reported before.

Cuprous oxide nanoparticles dispersed on reduced graphene oxide as an efficient electrocatalyst for oxygen reduction reaction.

Science.gov (United States)

Yan, Xiao-Yan; Tong, Xi-Li; Zhang, Yue-Fei; Han, Xiao-Dong; Wang, Ying-Yong; Jin, Guo-Qiang; Qin, Yong; Guo, Xiang-Yun

2012-02-11

Cuprous oxide (Cu(2)O) nanoparticles dispersed on reduced graphene oxide (RGO) were prepared by reducing copper acetate supported on graphite oxide using diethylene glycol as both solvent and reducing agent. The Cu(2)O/RGO composite exhibits excellent catalytic activity and remarkable tolerance to methanol and CO in the oxygen reduction reaction. This journal is © The Royal Society of Chemistry 2012

Strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy

International Nuclear Information System (INIS)

Shi, Guodong; Chen, Xiaohua; Jiang, Han; Wang, Zidong; Tang, Hao; Fan, Yongquan

2015-01-01

A single crystal Cu–Fe alloy with finely dispersed precipitate Fe nanoparticles was fabricated in this study. The interface relationship of iron nanoparticle and copper matrix was analyzed with a high-resolution transmission electron microscope (HRTEM), and the effect of Fe nanoparticles on mechanical properties of single crystal Cu–Fe alloy was discussed. Results show that, the finely dispersed Fe nanoparticles can be obtained under the directional solidification condition, with the size of 5–50 nm and the coherent interface between the iron nanoparticle and the copper matrix. Single crystal Cu–Fe alloy possesses improved tensile strength of 194.64 MPa, and total elongation of 44.72%, respectively, at room temperature, in contrast to pure Cu sample. Nanoparticles which have coherent interface with matrix can improve the dislocation motion state. Some dislocations can slip through the nanoparticle along the coherent interface and some dislocations can enter into the nanoparticles. Thus to improve the tensile strength of single crystal Cu–Fe alloy without sacrificing the ductility simultaneously. Based on the above analyses, strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy was described

Magnetically recoverable catalyst for the asymmetric Henry reaction based on a substituted imidazolidine-4-one copper(II) complex supported by Fe3O4 center dot SiO2 nanoparticles

Czech Academy of Sciences Publication Activity Database

Bhosale, D. S.; Drabina, P.; Kincl, Miloslav; Vlček, Milan; Sedlák, M.

2015-01-01

Roč. 26, 21-22 (2015), s. 1300-1306 ISSN 0957-4166 Institutional support: RVO:61389013 Keywords : transition - metal - complexes * nanoparticle * adsorption Subject RIV: CC - Organic Chemistry Impact factor: 2.108, year: 2015

CTAB assisted microwave synthesis of ordered mesoporous carbon supported Pt nanoparticles for hydrogen electro-oxidation

International Nuclear Information System (INIS)

Zhou, Jian-Hua; He, Jian-Ping; Ji, Ya-Jun; Dang, Wang-Juan; Liu, Xiao-Lei; Zhao, Gui-Wang; Zhang, Chuan-Xiang; Zhao, Ji-Shuang; Fu, Qing-Bin; Hu, Huo-Ping

2007-01-01

Mesoporous carbon with ordered hexagonal structure derived from the co-assembly of triblock copolymer F127 and resol was employed as the carbon support of Pt catalysts for hydrogen electro-oxidation. Structural characterizations revealed that the mesoporous carbon exhibited large surface area and uniform mesopores. The Pt nanoparticles supported on the novel mesoporous carbon were fabricated by a facile CTAB assisted microwave synthesis process, wherein CTAB was expected to improve the wettability of carbon support as well as the dispersion of Pt nanoparticles. X-ray diffraction and transmission electron microscopy were applied to characterize the Pt catalysts. It was found that the Pt nanoparticles were uniform in size and highly dispersed on the mesoporous carbon supports. The cyclic voltammograms in sulfuric acid demonstrated that the electrochemical active surface area of Pt catalysts prepared with CTAB was two times than that without CTAB

Antimicrobial Effect of Copper Oxide Nanoparticles on Some Oral Bacteria and Candida Species

Directory of Open Access Journals (Sweden)

Amiri M

2017-03-01

Full Text Available Statement of Problem: Acid producing bacteria including Streptococcus mutans and lactobacilli cause tooth demineralization and lead to tooth decay. Also, oral colonization of the species of Candida has been reported in many studies that are resistant to antifungal agents. Objectives: In this study, antibacterial and antifungal effects of nano-CuO were studied against some oral bacteria and yeast fungi. Materials and Methods: The minimum inhibitory concentrations (MICs of copper oxide nanoparticles (CuO NPs for oral bacterial and fungal test strains were determined in 96-well microtiter plate technique. The agar diffusion test (ADT was employed to assess the antifungal properties of nystatin. Results: The MIC50 value of CuO NPs was determined at the range of 1–10 µg/ml for S. mutans, < 1 µg/ml for L. acidophilus, and 10 µg/ml for L. casei. Higher concentrations of CuO NPs (100-1000 µg/ml were effective on the bacterial cell growth, resulting in 100% reduction in the optical density in TSB medium. The cells of Candida albicans, C. krusei and C. glabrata were treated with CuO NPs and the results showed a decrease in fungal growth at a concentration of 1-1000 µg/ml in TSB medium. The MIC50 value of CuO NPs was determined 1000 µg/ml for three species of Candida. The diameter of growth inhibition zones of 1100 µg/ml nystatin was obtained 15-21 mm for clinical isolates of three species of Candida. Conclusions: With respect to the potential bactericidal activity of CuO NPs on various cariogenic bacteria examined in this study, these NPs could be introduce as a candidate control agent for preventing dental caries or dental infections. In our study, on the other hand, Nano copper oxide had a weak effect on the candida species.

One-step green route to narrowly dispersed copper nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Wu Chunwei; Mosher, Brian P.; Zeng Taofang [North Carolina State University, Mechanical and Aerospace Engineering (United States)], E-mail: tzeng2@unity.ncsu.edu

2006-12-15

We report a total 'green' chemical method in aqueous solution for synthesizing stable narrowly distributed copper nanoparticles with average diameter less than 5 nm in the presence of Polyvinylpyrrolidone (PVP) as a stabilizer and without any inert gas protection. In our synthesis route, ascorbic acid, natural vitamin C (VC), an excellent oxygen scavenger, acts as both reducing agent and antioxidant, to reduce the metallic ion precursor, and to effectively prevent the common oxidation process of the newborn pure copper nanoclusters.

Physicochemical and antibacterial characterization of ionocity Ag/Cu powder nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Nowak, A., E-mail: ana.maria.nowak@gmail.com [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Szade, J. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Talik, E. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Zubko, M. [Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1a, 41-500 Chórzow (Poland); Wasilkowski, D. [Department of Biochemistry, University of Silesia, Jagiellońska 28, 40-032 Katowice (Poland); Dulski, M. [Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); Institute of Material Science, University of Silesia, 75 Pułku Piechoty 1a, 41-500 Chórzow (Poland); Balin, K. [A. Chełkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland); Silesian Center for Education and Interdisciplinary Research, 75 Pułku Piechoty 1A, 41-500 Chorzów (Poland); and others

2016-07-15

Metal ion in bimetallic nanoparticles has shown vast potential in a variety of applications. In this paper we show the results of physical and chemical investigations of powder Ag/Cu nanoparticles obtained by chemical synthesis. Transmission electron microscopy (TEM) experiment indicated the presence of bimetallic nanoparticles in the agglomerated form. The average size of silver and copper nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu) basing on the X-ray diffraction (XRD) data. X-ray photoelectron (XPS) and Raman spectroscopies revealed the existence of metallic silver and copper as well as Cu{sub 2}O and CuO being a part of the nanoparticles. Moreover, UV–Vis spectroscopy showed surface alloy of Ag and Cu while Time of Flight Secondary Ion Mass Spectroscopy (ToF-SIMS) and Energy Dispersive X-ray Spectroscopy (EDX) showed heterogeneously distributed Ag structures placed on spherical Cu nanoparticles. The tests of antibacterial activity show promising killing/inhibiting growth behaviour for Gram positive and Gram negative bacteria. - Highlights: • Ag/Cu nanoparticles were obtained in the powder form. • The average size of nanoparticles is 17.1(4) nm (Ag) and 28.9(2) nm (Cu). • Ag/Cu powder nanoparticle shows promising antibacterial properties.

Antimicrobial Polymers with Metal Nanoparticles

Science.gov (United States)

Palza, Humberto

2015-01-01

Metals, such as copper and silver, can be extremely toxic to bacteria at exceptionally low concentrations. Because of this biocidal activity, metals have been widely used as antimicrobial agents in a multitude of applications related with agriculture, healthcare, and the industry in general. Unlike other antimicrobial agents, metals are stable under conditions currently found in the industry allowing their use as additives. Today these metal based additives are found as: particles, ions absorbed/exchanged in different carriers, salts, hybrid structures, etc. One recent route to further extend the antimicrobial applications of these metals is by their incorporation as nanoparticles into polymer matrices. These polymer/metal nanocomposites can be prepared by several routes such as in situ synthesis of the nanoparticle within a hydrogel or direct addition of the metal nanofiller into a thermoplastic matrix. The objective of the present review is to show examples of polymer/metal composites designed to have antimicrobial activities, with a special focus on copper and silver metal nanoparticles and their mechanisms. PMID:25607734

Water-soluble PEGylated silicon nanoparticles and their assembly into swellable nanoparticle aggregates

International Nuclear Information System (INIS)

Xu, Zejing; Li, Yejia; Zhang, Boyu; Purkait, Tapas; Alb, Alina; Mitchell, Brian S.; Grayson, Scott M.; Fink, Mark J.

2015-01-01

Water-soluble silicon nanoparticles were synthesized by grafting PEG polymers onto functionalized silicon nanoparticles with distal alkyne or azide moieties. The surface-functionalized silicon nanoparticles were produced in one step from the reactive high-energy ball milling (RHEBM) of silicon wafers with a mixture of either 5-chloro-1-pentyne in 1-pentyne or 1,7 octadiyne in 1-hexyne to afford air and water-stable chloroalkyl or alkynyl-terminated nanoparticles, respectively. Nanoparticles with the ω-chloroalkyl substituents were easily converted to ω-azidoalkyl groups through the reaction of the Si nanoparticles with sodium azide in DMF. The azido-terminated nanoparticles were then grafted with mono-alkynyl-PEG polymers using a copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction to afford core–shell silicon nanoparticles with a covalently attached PEG shell. Covalently linked Si nanoparticle clusters were synthesized via the CuAAC “click” reaction of functional Si NPs with α,ω-functional PEG polymers of various lengths. Dynamic light scattering studies show that the flexible globular nanoparticle aggregates undergo a solvent-dependent change in volume (ethanol > dichloromethane > toluene) similar in behavior to hydrogel nanocomposites

Tuning the reactivity of Ru nanoparticles by defect engineering of the reduced graphene oxide support

KAUST Repository

Liu, Xin; Sui, Yanhui; Meng, Changgong; Han, Yu

2014-01-01

We systematically investigated the electronic structure of Ru nanoparticles supported on various local structures on reduced graphene oxide (rGO) by first-principles-based calculations. We showed that Ru nanoparticles prefer to nucleate

Electrochemical detection of copper ions leached from CuO nanoparticles in saline buffers and biological media using a gold wire working electrode

Energy Technology Data Exchange (ETDEWEB)

Baldisserri, Carlo, E-mail: carlo.baldisserri@istec.cnr.it; Costa, Anna Luisa [ISTEC-CNR (Italy)

2016-04-15

We performed explorative cyclic voltammetry in phosphate-buffered saline buffers, Dulbecco’s modified Eagle’s medium (DMEM), and fetal bovine serum-added DMEM using Au wire as working electrode, both in the absence and in the presence of known nominal concentrations of Cu{sup 2+} ions or 15 nm CuO nanoparticles. Addition of either Cu{sup 2+} ions or aqueous suspension of CuO nanoparticles caused a single anodic peak to appear in the double-layer region of all three pristine media. The height of the anodic peak was found to increase in a monotonic fashion vs. Cu{sup 2+} concentration in Cu{sup 2+}-added media, and versus time since CuO addition in CuO-added media. Stepwise addition of glycine to Cu{sup 2+}-added phosphate-buffered saline buffer caused an increasing cathodic shift of the anodic peak accompanied by decreasing peak currents. Results indicate that preparing Cu{sup 2+}-free suspensions of CuO nanoparticles in such media is difficult, owing to the presence of leached copper ions. The implications on results of experiments in which CuO nanoparticle-added biological media are used as cell culture substrates are discussed. Literature data on the interactions between Cu{sup 2+} ions, dissolved carbon dioxide in aqueous CuO suspensions, and amino acids present in such media are compared to our results.

Electrochemical detection of copper ions leached from CuO nanoparticles in saline buffers and biological media using a gold wire working electrode

Science.gov (United States)

Baldisserri, Carlo; Costa, Anna Luisa

2016-04-01

We performed explorative cyclic voltammetry in phosphate-buffered saline buffers, Dulbecco's modified Eagle's medium (DMEM), and fetal bovine serum-added DMEM using Au wire as working electrode, both in the absence and in the presence of known nominal concentrations of Cu2+ ions or 15 nm CuO nanoparticles. Addition of either Cu2+ ions or aqueous suspension of CuO nanoparticles caused a single anodic peak to appear in the double-layer region of all three pristine media. The height of the anodic peak was found to increase in a monotonic fashion vs. Cu2+ concentration in Cu2+-added media, and versus time since CuO addition in CuO-added media. Stepwise addition of glycine to Cu2+-added phosphate-buffered saline buffer caused an increasing cathodic shift of the anodic peak accompanied by decreasing peak currents. Results indicate that preparing Cu2+-free suspensions of CuO nanoparticles in such media is difficult, owing to the presence of leached copper ions. The implications on results of experiments in which CuO nanoparticle-added biological media are used as cell culture substrates are discussed. Literature data on the interactions between Cu2+ ions, dissolved carbon dioxide in aqueous CuO suspensions, and amino acids present in such media are compared to our results.

Tuning the Chemoselective Hydrogenation of Nitrostyrenes Catalyzed by Ionic Liquid-Supported Platinum Nanoparticles

DEFF Research Database (Denmark)

Beier, Matthias Josef; Andanson, Jean-Michel; Baiker, Alfons

2012-01-01

Pt nanoparticles (NPs) in the range of 1.7–3.4 nm were synthesized in an ionic liquid (IL). Subsequent immobilization on various solid supports (silica, alumina, titania, carbon nanotubes (CNTs)) in some cases proved to be beneficial. These catalysts exhibited excellent performance in the chemose......Pt nanoparticles (NPs) in the range of 1.7–3.4 nm were synthesized in an ionic liquid (IL). Subsequent immobilization on various solid supports (silica, alumina, titania, carbon nanotubes (CNTs)) in some cases proved to be beneficial. These catalysts exhibited excellent performance...

Speciation of copper diffused in a bi-porous molecular sieve

International Nuclear Information System (INIS)

Huang, C.-H.; Paul Wang, H.; Wei, Y.-L.; Chang, J.-E.

2010-01-01

To better understand diffusion of copper in the micro- and mesopores, speciation of copper in a bi-porous molecular sieve (BPMS) possessing inter-connecting 3-D micropores (0.50-0.55 nm) and 2-D mesopores (4.1 nm) has been studied by X-ray absorption near edge structure (XANES) spectroscopy. It is found that about 77% (16% of CuO nanoparticles and 61% of CuO clusters) and 23% (CuO ads ) of copper can be diffused into the meso- and micropores, respectively, in the BPMS. At least two diffusion steps in the BPMS may be involved: (i) free diffusion of copper in the mesopores and (ii) diffusion-controlled copper migrating into the micropores of the BPMS. The XANES data also indicate that diffusion rate of copper in the BPMS (4.68x10 -5 g/s) is greater than that in the ZSM-5 (1.11x10 -6 g/s) or MCM-41 (1.17x10 -5 g/s).

Speciation of copper diffused in a bi-porous molecular sieve

Science.gov (United States)

Huang, C.-H.; Paul Wang, H.; Wei, Y.-L.; Chang, J.-E.

2010-07-01

To better understand diffusion of copper in the micro- and mesopores, speciation of copper in a bi-porous molecular sieve (BPMS) possessing inter-connecting 3-D micropores (0.50-0.55 nm) and 2-D mesopores (4.1 nm) has been studied by X-ray absorption near edge structure (XANES) spectroscopy. It is found that about 77% (16% of CuO nanoparticles and 61% of CuO clusters) and 23% (CuO ads) of copper can be diffused into the meso- and micropores, respectively, in the BPMS. At least two diffusion steps in the BPMS may be involved: (i) free diffusion of copper in the mesopores and (ii) diffusion-controlled copper migrating into the micropores of the BPMS. The XANES data also indicate that diffusion rate of copper in the BPMS (4.68×10 -5 g/s) is greater than that in the ZSM-5 (1.11×10 -6 g/s) or MCM-41 (1.17×10 -5 g/s).

Synthesis of copper polyacrylate nanocomposites by gamma irradiation

International Nuclear Information System (INIS)

Casalme, Loida Olores

2005-04-01

This research involves the synthesis of copper nanoparticles with controlled size by the application of gamma radiation with varying polyacrylic acid (PAA) and CuSO 4 concentration. An alternative and convenient method was done which employs Co 60 irradiation of solutions of copper salt and PAA with irradiation dose of 1.6, 3.6, 6.4, and 9.2 MRad. The effect of polymer and copper sulfate's initial concentrations as well as the effect of the presence of alcohol as radical scavenger and the presence of ethylenediaminetetraacetic acid as stabilizer were evaluated. Characterization of nanocomposite properties such as plasmon resonance band, fluorescence, and particle morphology and size were determined. Layer-by-layer assembly of Cu-PAA nanocomposites and polydiallyl dimethyl ammonium chloride (PDDA) was also constructed. Stability of the synthesized copper-PAA nanocomposites in terms of the disappearance of plasmon band with time was evaluated. (Author)

Tuning the reactivity of Ru nanoparticles by defect engineering of the reduced graphene oxide support

KAUST Repository

Liu, Xin

2014-01-01

We systematically investigated the electronic structure of Ru nanoparticles supported on various local structures on reduced graphene oxide (rGO) by first-principles-based calculations. We showed that Ru nanoparticles prefer to nucleate at these localized defect structures on rGO, which act as strong trapping sites for Ru nanoparticles and inhibit their aggregation. The binding of Ru nanoparticles to rGO, which is dependent on these local defect structures and correlates with the interfacial charge transfer, determines the electronic structure of the composites. Further study reveals that the performance of these composites against oxygen adsorption changes proportionally with the shift of the d-band center of the nanoparticles. The correlation between the defect structures on rGO and the reactivity of the composites suggests that controlled modification of the graphenic support by defect engineering would be an efficient way to fabricate new transition metal/rGO composites with high stability and desired reactivity. This journal is © the Partner Organisations 2014.

Ag-Cu Bimetallic Nanoparticles Prepared by Microemulsion Method as Catalyst for Epoxidation of Styrene

Directory of Open Access Journals (Sweden)

Hong-Kui Wang

2012-01-01

Full Text Available Ag/Cu bimetallic nanocatalysts supported on reticulate-like γ-alumina were prepared by a microemulsion method using N2H4·H2O as the reducing agent. The catalysts were activated by calcination followed with hydrogen reduction at 873K, and the properties were confirmed using various characterization techniques. Compared with metal oxides particles, Ag-Cu particles exhibited smaller sizes (<5 nm after calcination in H2 at 873K. XPS results indicated that the binding energies changed with the Ag/Cu ratios, suggesting that increasing the copper content gave both metals a greater tendency to lose electrons. Furthermore, Ag-Cu bimetallic nanoparticles supported on γ-alumina showed better catalytic activity on the epoxidation of styrene as compared with the corresponding monometallic silver or copper. The styrene oxide selectivity could reach 76.6% at Ag/Cu molar ratio of 3/1, while the maximum conversion (up to 94.6% appeared at Ag/Cu molar ratio of 1/1 because of the maximum interaction between silver and copper.

Copper-assisted, anti-reflection etching of silicon surfaces

Science.gov (United States)

Toor, Fatima; Branz, Howard

2014-08-26

A method (300) for etching a silicon surface (116) to reduce reflectivity. The method (300) includes electroless deposition of copper nanoparticles about 20 nanometers in size on the silicon surface (116), with a particle-to-particle spacing of 3 to 8 nanometers. The method (300) includes positioning (310) the substrate (112) with a silicon surface (116) into a vessel (122). The vessel (122) is filled (340) with a volume of an etching solution (124) so as to cover the silicon surface (116). The etching solution (124) includes an oxidant-etchant solution (146), e.g., an aqueous solution of hydrofluoric acid and hydrogen peroxide. The silicon surface (116) is etched (350) by agitating the etching solution (124) with, for example, ultrasonic agitation, and the etching may include heating (360) the etching solution (124) and directing light (365) onto the silicon surface (116). During the etching, copper nanoparticles enhance or drive the etching process.

Synthesis and shape control of copper tin sulphide nanocrystals and formation of gold-copper tin sulphide hybrid nanostructures

International Nuclear Information System (INIS)

Kruszynska, Marta; Parisi, Juergen; Kolny-Olesiak, Joanna

2014-01-01

Hexagonal prismatic Cu 3 SnS 4 nanoparticles and nanorods were synthesized by a hot-injection procedure. Changing the reaction conditions leads to the formation of different shapes. When oleylamine is used as a solvent, hexagonal prismatic particles are obtained, while a reaction in octadecene results in the formation of nanorods. The growth process of copper tin sulphide starts with the formation of djurleite copper sulphide seeds. Their reaction with Sn 4+ ions leads to the formation of Cu 3 SnS 4 . These Cu 3 SnS 4 nanocrystals form Au-Cu 3 SnS 4 hybrid nanostructures by reaction with gold seeds.

Electrodeposition of copper nanoparticles using pectin scaffold at graphene nanosheets for electrochemical sensing of glucose and hydrogen peroxide

International Nuclear Information System (INIS)

Mani, Veerappan; Devasenathipathy, Rajkumar; Chen, Shen-Ming; Wang, Sea-Fue; Devi, Parvathy; Tai, Yian

2015-01-01

A simple electrodeposition approach has been described for the preparation of copper nanoparticles (CuNPs) using biopolymer pectin as a scaffold and graphene as a support. The formation of graphene/pectin-CuNPs was confirmed by scanning electron microscopy, UV-Visible spectroscopy and X-ray diffraction studies. The graphene/pectin-CuNPs film modified electrode was prepared and its electrocatalytic applications to the oxidation of glucose and reduction of H 2 O 2 have been explored. An amperometric glucose sensor was fabricated which exhibited excellent sensor performance in terms of wide linear range (10 μM–5.5 mM), low detection limit (2.1 μM) and high sensitivity (0.0457 μAμM −1 cm −2 ). Likewise, an amperometric sensor has been fabricated for the determination of H 2 O 2 which displayed linear range of 1 μM–1 mM, detection limit of 0.35 μM and sensitivity of 0.391 μAμM −1 cm −2 . The sensor displayed appreciable repeatability, reproducibity and stability. Furthermore, practical feasibility of the sensor has been demonstrated in human serum and contact lens cleaning solution to determine glucose and H 2 O 2 , respectively. The main advantages of sensor include simple and green fabrication approach, roughed and stable electrode matrix, high sensitivity and stability, fast in sensing and highly reproducible

Bioinspired green synthesis of copper oxide nanoparticles from Syzygium alternifolium (Wt.) Walp: characterization and evaluation of its synergistic antimicrobial and anticancer activity

Science.gov (United States)

Yugandhar, Pulicherla; Vasavi, Thirumalanadhuni; Uma Maheswari Devi, Palempalli; Savithramma, Nataru

2017-10-01

In recent times, nanoparticles are attributed to green nanotechnology methods to know the synergistic biological activities. To accomplish this phenomenon, present study was aimed to synthesize copper oxide nanoparticles (CuO NPs) by using Syzygium alternifolium stem bark, characterized those NPs using expository tools and to elucidate high prioritized antimicrobial and anticancer activities. Synthesized particles exhibited a color change pattern upon synthesis and affirmed its respective broad peak at 285 nm which was analyzed through UV-vis spectroscopy. FT-IR study confirmed that phenols and primary amines were mainly involved in capping and stabilization of nanoparticles. DLS and Zeta potential studies revealed narrow size of particles with greater stability. XRD studies revealed the crystallographic nature of particles with 17.2 nm average size. Microscopic analysis by using TEM revealed that particle size range from 5-13 nm and most of them were spherical in shape, non-agglomerated and poly-dispersed in condition. Antimicrobial studies of particles showed highest inhibitory activity against E. coli and T. harzianum among bacterial and fungal strains, respectively. The scope of this study is extended by examining anticancer activity of CuO NPs. This study exhibited potential anticancer activity towards MDA-MB-231 human breast cancer lines. Overall, these examinations relate that the S. alternifolium is described as efficient well-being plant and probabilistically for the design and synthesis of nanoparticles for human health. This study paves a way to better understand antimicrobial and anticancer therapeutic drug potentials of nanoparticles to design and analysis of pharmaceuticals by in vivo and in vitro approaches.

Effect of structure, size and copper doping on the luminescence properties of ZnS

Energy Technology Data Exchange (ETDEWEB)

Kamal, Ch. Satya [Crystal Growth and Nanoscience Research Centre, Government College (A), Rajahmundry, Andhra Pradesh 533 105 (India); Mishra, R.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Patel, Dinesh K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, 9190401 (Israel); Rao, K. Ramachandra, E-mail: drkrcr@gmail.com [Crystal Growth and Nanoscience Research Centre, Government College (A), Rajahmundry, Andhra Pradesh 533 105 (India); Sudarsan, V., E-mail: vsudar@barc.gov.in [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Vatsa, R.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

2016-09-15

Highlights: • Blue and green emission intensity form ZnS is sensitive to crystallographic form. • For ZnS nanoparticles, emission characteristics are not affected by copper doping. • Cu solubility poor in ZnS nanoparticles compared to corresponding bulk. - Abstract: Luminescence properties of wurtzite and cubic forms of bulk ZnS have been investigated in detail and compared with that of ZnS nanoparticles. Blue emission observed in both hexagonal and cubic forms of undoped bulk ZnS is explained based on electron–hole recombination involving electron in conduction band and hole trapped in Zn{sup 2+} vacancies where as green emission arises due to electron hole recombination from Zn{sup 2+} and S{sup 2−} vacancies. Conversion of wurtzite form to cubic form is associated with relative increase in intensity of green emission due to increased defect concentration brought about by high temperature heat treatment. Copper doping in ZnS, initially leads to formation of both Cu{sub Zn} and Cu{sub i} (interstitial copper) centers, and latter to mainly Cu{sub Zn} centers as revealed by variation in relative intensities of blue and green emission from the samples.

Copper and copper-nickel-alloys - An overview

Energy Technology Data Exchange (ETDEWEB)

Klassert, Anton; Tikana, Ladji [Deutsches Kupferinstitut e.V. Am Bonneshof 5, 40474 Duesseldorf (Germany)

2004-07-01

With the increasing level of industrialization the demand for and the number of copper alloys rose in an uninterrupted way. Today, the copper alloys take an important position amongst metallic materials due to the large variety of their technological properties and applications. Nowadays there exist over 3.000 standardized alloys. Copper takes the third place of all metals with a worldwide consumption of over 15 millions tons per year, following only to steel and aluminum. In a modern industrial society we meet copper in all ranges of the life (electro-technology, building and construction industry, mechanical engineering, automotive, chemistry, offshore, marine engineering, medical applications and others.). Copper is the first metal customized by humanity. Its name is attributed to the island Cyprus, which supplied in the antiquity copper to Greece, Rome and the other Mediterranean countries. The Romans called it 'ore from Cyprus' (aes cyprium), later cuprum. Copper deposited occasionally also dapper and could be processed in the recent stone age simply by hammering. Already in early historical time copper alloys with 20 to 50 percent tin was used for the production of mirrors because of their high reflecting power. Although the elementary nickel is an element discovered only recently from a historical perspective, its application in alloys - without any knowledge of the alloy composition - occurred at least throughout the last 2.000 years. The oldest copper-nickel coin originates from the time around 235 B.C.. Only around 1800 AD nickel was isolated as a metallic element. In particular in the sea and offshore technology copper nickel alloys found a broad field of applications in piping systems and for valves and armatures. The excellent combination of characteristics like corrosion resistance, erosion stability and bio-fouling resistance with excellent mechanical strength are at the basis of this success. An experience of many decades supports the use

Acute and sub-lethal exposure to copper oxide nanoparticles causes oxidative stress and teratogenicity in zebrafish embryos.

Science.gov (United States)

Ganesan, Santhanamari; Anaimalai Thirumurthi, Naveenkumar; Raghunath, Azhwar; Vijayakumar, Savitha; Perumal, Ekambaram

2016-04-01

Nano-copper oxides are a versatile inorganic material. As a result of their versatility, the immense applications and usage end up in the environment causing a concern for the lifespan of various beings. The ambiguities surround globally on the toxic effects of copper oxide nanoparticles (CuO-NPs). Hence, the present study endeavored to study the sub-lethal acute exposure effects on the developing zebrafish embryos. The 48 hpf LC50 value was about 64 ppm. Therefore, we have chosen the sub-lethal dose of 40 and 60 ppm for the study. Accumulation of CuO-NPs was evidenced from the SEM-EDS and AAS analyzes. The alterations in the AChE and Na(+)/K(+)-ATPase activities disrupted the development process. An increment in the levels of oxidants with a concomitant decrease in the antioxidant enzymes confirmed the induction of oxidative stress. Oxidative stress triggered apoptosis in the exposed embryos. Developmental anomalies were observed with CuO-NPs exposure in addition to oxidative stress in the developing embryos. Decreased heart rate and hatching delay hindered the normal developmental processes. Our work has offered valuable data on the connection between oxidative stress and teratogenicity leading to lethality caused by CuO-NPs. A further molecular mechanism unraveling the uncharted connection between oxidative stress and teratogenicity will aid in the safe use of CuO-NPs. Copyright © 2015 John Wiley & Sons, Ltd.

Reversing Size-Dependent Trends in the Oxidation of Copper Clusters through Support Effects: Reversing Size-Dependent Trends in the Oxidation of Copper Clusters through Support Effects

Energy Technology Data Exchange (ETDEWEB)

Mammen, Nisha [Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, -560064 Bangalore India; Spanu, Leonardo [Shell Technology Center, Shell India Markets Private Limited, -560048 Bangalore India; Tyo, Eric C. [Materials Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Yang, Bing [Materials Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Halder, Avik [Materials Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Seifert, Sönke [X-ray Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Pellin, Michael J. [Materials Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Vajda, Stefan [Materials Science Division, Argonne National Laboratory, 60439 Argonne IL USA; Institute for Molecular Engineering, The University of Chicago, 60637 Chicago IL USA; Narasimhan, Shobhana [Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, -560064 Bangalore India

2017-12-22

Having the ability to tune the oxidation state of Cu nanoparticles is essential for their utility as catalysts. The degree of oxidation that maximizes product yield and selectivity is known to vary, depending on the particular reaction. Using first principles calculations and XANES measurements, we show that for subnanometer sizes in the gas phase, smaller Cu clusters are more resistant to oxidation. However, this trend is reversed upon deposition on an alumina support. We are able to explain this result in terms of strong cluster-support interactions, which differ significantly for the oxidized and elemental clusters. The stable cluster phases also feature novel oxygen stoichiometries. Our results suggest that one can tune the degree of oxidation of Cu catalysts by optimizing not just their size, but also the support they are deposited on.

Thiols make for better catalysts: Au nanoparticles supported on functional SBA-15 for catalysis of Ullmann-type homocouplings

KAUST Repository

Chen, Tianyou

2017-09-21

A strategy for arraying small gold nanoparticles on a mesoporous support modified with single-component or mixed self-assembled monolayers is described. The use of mixed surface modifiers allows easy access to a range of surface chemistries and modalities of interaction between nanoparticles and supports. A combination of thiol groups and linear semifluorinated chains effectively stabilized the nanoparticles against aggregation, while preserving their catalytic activity. The thiol-fluorous-supported catalyst was found active in Ullmann-type homocoupling of aryl halides and showed exceptional selectivity in this reaction.

Thiols make for better catalysts: Au nanoparticles supported on functional SBA-15 for catalysis of Ullmann-type homocouplings

KAUST Repository

Chen, Tianyou; Chen, Batian; Bukhriakov, Konstantin; Rodionov, Valentin

2017-01-01

A strategy for arraying small gold nanoparticles on a mesoporous support modified with single-component or mixed self-assembled monolayers is described. The use of mixed surface modifiers allows easy access to a range of surface chemistries and modalities of interaction between nanoparticles and supports. A combination of thiol groups and linear semifluorinated chains effectively stabilized the nanoparticles against aggregation, while preserving their catalytic activity. The thiol-fluorous-supported catalyst was found active in Ullmann-type homocoupling of aryl halides and showed exceptional selectivity in this reaction.

Carbon-based coating containing ultrafine MoO2 nanoparticles as an integrated anode for high-performance lithium-ion batteries

Science.gov (United States)

Li, Quanyi; Yang, Qi; Zhao, Yanhong; Wan, Bin

2017-10-01

Copper-supported MoO2-C composite as an integrated anode with excellent battery performance was synthesized by a facile knife coating technique followed by heat treatment in a vacuum. The obtained samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal analysis, nitrogen adsorption and desorption analysis, field emission scanning microscopy (FESEM), and transmission electron microscopy (TEM). The results show the MoO2-C composite coating is comprised of a porous carbon matrix with a pore size of 1-3 nm and ultrafine MoO2 nanoparticles with a size of 5-10 nm encapsulated inside, the coating is tightly attached on the surface of copper foil, and the interface between them is free of cracks. Stable PAN-DMF-H2O system containing ammonium molybdate suitable for knife coating technique and the MoO2-C composite with ultrafine MoO2 nanoparticles encapsulated in the carbon matrix can be prepared through controlling amount of added ammonium molybdate solution. The copper-supported MoO2-C composite coating can be directly utilized as the integrated anode for lithium-ion batteries (LIBs). It delivers a capacity of 814 mA h g-1 at a current density of 100 mA g-1 after 100 cycles without apparent capacity fading. Furthermore, with increase of current densities to 200, 500, 1000, 2000, and 5000 mA g-1, it exhibits average capacities of 809, 697, 568, 383, and 188 mA h g-1. Its outstanding electrochemical performance is attributed to combined merits of integrated anode and structure with ultrafine MoO2 nanoparticles embedded in the porous carbon matrix.

Effect of Bed Temperature on the Laser Energy Required to Sinter Copper Nanoparticles

Science.gov (United States)

Roy, N. K.; Dibua, O. G.; Cullinan, M. A.

2018-03-01

Copper nanoparticles (NPs), due to their high electrical conductivity, low cost, and easy availability, provide an excellent alternative to other metal NPs such as gold, silver, and aluminum in applications ranging from direct printing of conductive patterns on metal and flexible substrates for printed electronics applications to making three-dimensional freeform structures for interconnect fabrication for chip-packaging applications. Lack of research on identification of optimum sintering parameters such as fluence/irradiance requirements for sintering of Cu NPs serves as the primary motivation for this study. This article focuses on the identification of a good sintering irradiance window for Cu NPs on an aluminum substrate using a continuous wave (CW) laser. The study also includes the comparison of CW laser sintering irradiance windows obtained with substrates at different initial temperatures. The irradiance requirements for sintering of Cu NPs with the substrate at 150-200°C were found to be 5-17 times smaller than the irradiance requirements for sintering with the substrate at room temperature. These findings were also compared against the results obtained with a nanosecond (ns) laser and a femtosecond (fs) laser.

In situ TEM study of the coarsening of carbon black supported Pt nanoparticles in hydrogen

DEFF Research Database (Denmark)

Simonsen, Søren Bredmose; Wang, Yan; Jensen, Jens Oluf

2017-01-01

The control of sizes and shapes of nanostructures is of tremendous importance for the catalytic activity in electrochemistry and in catalysis more generally. However, due to relatively large surface free energies, nanostructures often sinter to form coarser and more stable structures that may...... not have the intended physicochemical properties. Pt is known to be a very active catalyst in several chemical reactions and for example as carbon supported nanoparticles in fuel cells. The presentation focusses on coarsening mechanisms of Pt nanoparticles supported on carbon black during exposure...... to hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 % H2/Ar while ramping up the temperature to ca. 900 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in the pure hydrogen environment...

Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics.

Science.gov (United States)

Farraj, Yousef; Grouchko, Michael; Magdassi, Shlomo

2015-01-31

Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks.

Stacked dipole line source excitation of active nano-particles

DEFF Research Database (Denmark)

Arslanagic, Samel

This work investigates electromagnetic properties of cylindrical active coated nano-particles excited by a stac- ked electric dipole line source. The nano-particles consist of a silica nano-core, layered by silver, gold, or copper nano-shell. Attention is devoted to the influence of the source...... location and dipole orientation, the gain constant, and the nano-particle material composition on the electromagnetic field distributions and radiated powers. The results are contrasted to those for the magnetic line source illumination of the nano-particles....

Synthesis of Thermally Spherical CuO Nanoparticles

Directory of Open Access Journals (Sweden)

Nittaya Tamaekong

2014-01-01

Full Text Available Copper oxide (CuO nanoparticles were successfully synthesized by a thermal method. The CuO nanoparticles were further characterized by thermogravimetric analysis (TGA, differential thermal analysis (DTA, X-ray diffraction (XRD, scanning electron microscopy (SEM, energy dispersive X-ray spectrometry (EDS, and high resolution transmission electron microscopy (HRTEM, respectively. The specific surface area (SSABET of CuO nanoparticles was determined by nitrogen adsorption. The SSABET was found to be 99.67 m2/g (dBET of 9.5 nm. The average diameter of the spherical CuO nanoparticles was approximately 6–9 nm.

The molecular dynamic simulation on impact and friction characters of nanofluids with many nanoparticles system

Directory of Open Access Journals (Sweden)

Bai Minli

2011-01-01

Full Text Available Abstract Impact and friction model of nanofluid for molecular dynamics simulation was built which consists of two Cu plates and Cu-Ar nanofluid. The Cu-Ar nanofluid model consisted of eight spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid. The Lennard-Jones potential function was adopted to deal with the interactions between atoms. Thus motion states and interaction of nanoparticles at different time through impact and friction process could be obtained and friction mechanism of nanofluids could be analyzed. In the friction process, nanoparticles showed motions of rotation and translation, but effected by the interactions of nanoparticles, the rotation of nanoparticles was trapped during the compression process. In this process, agglomeration of nanoparticles was very apparent, with the pressure increasing, the phenomenon became more prominent. The reunited nanoparticles would provide supporting efforts for the whole channel, and in the meantime reduced the contact between two friction surfaces, therefore, strengthened lubrication and decreased friction. In the condition of overlarge positive pressure, the nanoparticles would be crashed and formed particles on atomic level and strayed in base liquid.

Hydroxyapatite supported Ag3PO4 nanoparticles with higher visible light photocatalytic activity

International Nuclear Information System (INIS)

Hong Xiaoting; Wu Xiaohui; Zhang Qiuyun; Xiao Mingfeng; Yang Gelin; Qiu Meirong; Han Guocheng

2012-01-01

Hydroxyapatite supported Ag 3 PO 4 nanocomposites have been synthesized by a wet impregnation process. UV-vis absorption spectra show a red shift of the absorption edges for the composite systems compared to pure hydroxyapatite support. The surface structure and morphology of the nanocomposites were characterized by Brunauer-Emmett-Teller (BET) apparatus, X-ray diffraction (XRD), transmission electron microscopy (TEM). The results suggest that Ag 3 PO 4 nanoparticles (6-17 nm in diameter) are well dispersed on the hydroxyapatite support and Ag 3 PO 4 nanoparticles density is larger for the higher Ag + loading sample. The as-prepared nanocomposite photocatalysts showed a pronounced photocatalytic activity upon decomposition of methylene blue dye in aqueous solution under both visible light (wavelength > 400 nm) and UV-vis light irradiation. A synergic mechanism of inherent photocatalytic capability of Ag 3 PO 4 and the accelerated electron/hole separation resulting from the photoinduced electrons captured by the slow-released Ag + at the interface of Ag 3 PO 4 and hydroxyapatite is proposed for the nanocomposites on the enhancement of photocatalytic performance in comparison to that of pure Ag 3 PO 4 nanoparticles. The support of hydroxyapatite may also act as an absorbent which favors the mass transfer in heterogeneous photocatalysis reaction.

Effects of the silica nanoparticles (NPSiO2 on the stabilization and transport of hazardous nanoparticle suspensions into landfill soil columns

Directory of Open Access Journals (Sweden)

Elizabeth Mendes de Oliveira

Full Text Available Abstract This study evaluates the stability and transport behaviors of hazardous nanoparticles into soil landfills using experimental procedures to simulate the effects of natural silica nanoparticle suspensions during their percolation into the soil layers of municipal waste landfills. For this, we prepared stabilized suspensions of nanoparticle oxides containing silicon (NPSiO2, titanium (NPTiO2, copper (NPCuO and zinc (NPZnO, which are recognized as hazardous to the environment, and we conducted leaching experiments within the soil column by simulating landfills layers and simulating the capture and attenuation of nanomaterials into municipal waste landfills. The results demonstrated that the presence of NPSiO2 in suspensions increases the stable concentrations of copper, zinc and titanium oxides and strongly decreases soil layer effectiveness. In contrast, NPZnO improves effectiveness due to its ability to promote agglomeration and setting conditions, allowing further complexation.

Selective liquid phase oxidation of benzyl alcohol to benzaldehyde by tert-butyl hydroperoxide over γ-Al{sub 2}O{sub 3} supported copper and gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Ndolomingo, Matumuene Joe; Meijboom, Reinout, E-mail: rmeijboom@uj.ac.za

2017-03-15

Highlights: • Cu and Au on γ-Al{sub 2}O{sub 3} catalysts were prepared and characterized. • Benzyl alcohol oxidation to benzaldehyde was performed by tert-butyl hydroperoxide in the absence of any solvent using the prepared catalysts. • The as prepared catalysts exhibited good performance in terms of conversion and selectivity towards benzaldehyde. • The kinetics of the reaction was investigated; k{sub app} was proportional to the amount of nano catalyst and oxidant present in the system. • The catalysts was recycled and reused with neither significant loss of activity nor selectivity. - Abstract: Benzyl alcohol oxidation to benzaldehyde was performed by tert-butyl hydroperoxide (TBHP) in the absence of any solvent using γ-Al{sub 2}O{sub 3} supported copper and gold nanoparticles. Li{sub 2}O and ionic liquids were used as additive and stabilizers for the synthesis of the catalysts. The physico-chemical properties of the catalysts were characterized by atomic absorption spectroscopy (AAS), X-ray diffraction spectroscopy (XRD), N{sub 2} absorption/desorption (BET), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and temperature programmed reduction (TPR), whereas, the oxidation reaction was followed by gas chromatography with a flame ionization detector (GC-FID). The as prepared catalysts exhibited good catalytic performance in terms of conversion and selectivity towards benzaldehyde. The performance of the Au-based catalysts is significantly higher than that of the Cu-based catalysts. For both Cu and Au catalysts, the conversion of benzyl alcohol increased as the reaction proceeds, while the selectivity for benzaldehyde decreased. Moreover, the catalysts can be easily recycled and reused with neither significant loss of activity nor selectivity. A kinetic study for the Cu and Au-catalyzed oxidation of benzyl alcohol to benzyldehyde is reported. The rate at which the oxidation of benzyl alcohol