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Academic literature on the topic 'Copper nanoparticles (colloidal solution)'

Author: Grafiati

Published: 10 January 2023

Last updated: 28 January 2023

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Journal articles on the topic "Copper nanoparticles (colloidal solution)"

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SEKIGUCHI, M., K. OIKAWA, M. NAKAHARA, Y. INABA, T. MAEDA, A. MATSUI, and H. ISHIZAKI. "Preparation of Cu nanoparticle colloid from a Cu ion solution by using protein surfactant." MRS Advances 4, no. 24 (2019): 1393–98. http://dx.doi.org/10.1557/adv.2019.72.

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ABSTRACTIn this paper, a colloidal solution of copper nanoparticles was prepared from a Cu ion aqueous solution with the protein casein surfactant by a liquid phase reduction method at low temperature below 373K. For the casein concentration ranging from 6g/L to 75g/L, the formation of copper nanoparticle colloid were observed. As a result, the peak was observed at the ranging of 450 to 650 nm corresponding to the copper nanoparticle colloid plasmon absorption. As the surfactant concentration increases, the absorption spectrum tends to blue-shift and the particle diameter decreases. Thus, it indicated that the optical property and particle diameter of copper nanoparticle colloidal solution will be controlled by the protein casein surfactant concentration.

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Krasochko, P. A., R. B. Korochkin, and M. A. Ponaskov. "Estimation of biocidal effect of metal and bioelement nanoparticles in a unicellular eukaryotic test system." Siberian Herald of Agricultural Science 52, no. 1 (March 28, 2022): 106–13. http://dx.doi.org/10.26898/0370-8799-2022-1-12.

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The results of the study of biocidal properties of silver, copper and silicon dioxide nanoparticles are presented. Questions about the safety of nanocomponents in connection with their unstudied impact on the environment are considered. To evaluate the biocidal effect of noble metal nanoparticles and bioelements, a unicellular eukaryotic test-system, represented by a ciliated protist microorganism Paramecium caudatum inhabiting pond water bodies, was used. It was found that solutions of noble metal nanoparticles and bioelements are not bioinert and biostimulating. Colloidal solutions of silver, copper and silicon dioxide nanoparticles have a biocidal effect and show a similar dosedependent effect if the concentration of nanoparticles in the initial colloidal solutions is the same (300 µg/ml). The colloidal silver solution is characterized by a more pronounced toxic activity in a unicellular protist biological model, since full biocidal activity against paramecium is provided by dilutions of the colloidal solution of nanoparticles to the value 1: 6 of the initial one. Compared to it, solutions of copper nanoparticles and silicon oxide have a biocidal index of 100% achieved only in values of two- or three-times dilution of the initial solution. Colloidal solutions of nanoparticles in concentrations that do not cause complete mortality of the infusoria (1: 5 of the original for copper and silicon oxide nanoparticles and 1: 7 of the original for silver nanoparticles) inhibit their reproduction intensity by approximately the same value of 55-61% (paramecium reproduction intensity index of 0.455 to 0.390 respectively).

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Krasochko, Petr, Rudolf Korochkin, Pavel Krasochko, Sergey Gvozdev, and Mikhail Ponaskov. "Optical properties of colloidal solutions of metal nanoparticles." Scientific Horizons 23, no. 10 (October 28, 2020): 47–53. http://dx.doi.org/10.48077/scihor.23(10).2020.47-53.

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Nanoparticles are finding more practical applications in various fields of human activity, including veterinary and medicine. Due to the fact that the effectiveness of colloidal solutions of nanoparticles is directly related to their aggregate state, convenient methods for assessing the physicochemical characteristics of such preparations is of high priority. Nanoparticles have unique optical properties that depend on their size and shape. They can be determined by the refractive index of light on the surface of nanoparticles in a phenomenon known as plasmon resonance, which makes the UV-Vis spectroscopy a valuable tool for studying and evaluating the properties of nanomaterials. Optical characteristics of NPs colloidal solutions of noble metals (silver) or bioelements (copper, silicon dioxide) were determined at various wavelengths (nm): 300-800 nm. The surface plasmon resonance has been found in all test preparations, while all of them exhibited obvious nonlinear optical properties. The most pronounced plasmon resonance peak was found in the colloidal solution of silver NPs within a wavelength of 420 nm. In the case of a colloidal solution of copper NPs, the peak of plasmon resonance was less pronounced and had a red shift (peak at 560 nm). In the colloidal solution of silicon dioxide, the plasmon resonance was less pronounced than in other test preparations, being shifted to the blue side of the spectrum (360 nm). UV-Vis spectroscopy of metal NPs requires further studies to assess their stability and influence of various external factors on their activity

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M Kareem, Mahmood. "The Effect of Laser Shots on Morphological and Optical Properties of Copper Oxide NPs Prepared by Nd-Yag Laser of 1064 nm Wavelengths in Distilled Water." Passer Journal of Basic and Applied Sciences 3, no. 2 (2019): 200–206. http://dx.doi.org/10.24271/psr.33.

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This study examines the synthesis of copper oxide nanoparticles (NPs) by using a Q-Switched Nd-Yag (1064 nm) laser on copper foil immersed in Distilled Water (DW). The solution color changed to light green refers to the production of copper oxide NPs. The generated nanoparticles were studied to determine their characteristics as a function of pulse laser shots and the NPs were obtained by taking 500 and 1000 laser pulse shots on Cu target. Thin films deposited on both (glass and silicon) substrates were characterized by X-Ray Diffraction (XRD), Field Emission-Scanning Electron Microscopy (FE-SEM), and Atomic Force Microscopy (AFM) techniques. Later, regarding the colloidal nanoparticles, NPs were instantly characterized by UV-vis spectroscopy and examined by TEM microscopy. The production rate of Cu-NPs concentration in the colloidal solution was measured by atomic absorption spectra type (ICP-OES), which increased by increasing the number of laser shots in the liquid volume. The Energy Dispersion Spectroscopy (EDS) analysis resulted in the presence of copper (Cu) and oxygen (O) elements in the film structure with a nearly stoichiometry ratio. The optical energy gap was decreased to (2.44 eV) with increasing the number of laser shots in the colloidal solution.

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Antipov, A. A., A. G. Putilov, A. V. Osipov, A. E. Shepelev, V. N. Glebov, and A. M. Maliutin. "Synthesis of copper nanoparticles by laser ablation." Journal of Physics: Conference Series 2316, no. 1 (August 1, 2022): 012004. http://dx.doi.org/10.1088/1742-6596/2316/1/012004.

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Abstract The synthesis of copper nanoparticles using a pulsed alexandrite laser is demonstrated. The laser operated in a free generation mode with a pulse duration of about 250 μs. The copper target was placed in distilled water and glycerin. The obtained colloidal solutions were investigated by dynamic light scattering, and the deposited structures were studied by atomic force and electron microscopy. The concentration of nanoparticles depended on the power of the laser radiation, the scanning speed and the exposure time. The smallest particles size was obtained at a frequency of 5 Hz at a wavelength of 750 nm. Colloids obtained in distilled water contain copper nanoparticles, which oxidize over time.

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Begletsova, N., E. Selifonova, A. Zakharevich, R. Chernova, and E. Glukhovskoy. "Preparation of Colloidal Solution of Copper Nanoparticles Using Cationic Surfactant." «Bulletin of the South Ural State University series "Chemistry"» 9, no. 4 (2017): 14–21. http://dx.doi.org/10.14529/chem170402.

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Ani, Hussam Nadum Abdalraheem Al, Anca Maria Cimbru, Corneliu Trisca-Rusu, Szidonia Katalin Tanczos, Adriana Cuciureanu, and Aurelia Cristina Nechifor. "Iono-molecular Separation with Composite Membranes II. Preparation and characterization of polysulphone and composite nanoparticles." Revista de Chimie 68, no. 2 (March 15, 2017): 203–9. http://dx.doi.org/10.37358/rc.17.2.5420.

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This paper illustrates the possibility of producing iono-molecular separations using ionic colloidal ultrafiltration membrane of polysulfone synthetic solutions of cupric ions and nitro phenols through ultrafiltration assisted by polymeric nanoparticle composites based on polysulfone. In the present work, in order to reduce the operating pressure and increase the flow of water we are using the process of ultrafiltration through a polysulfone membrane in N-methylpyrrolidone 10% prepared by coagulation in isopropanol. The nanoparticles needed in colloidal ultrafiltration had been obtained through the immersion technique of precipitation of a solution of 5% PSf in N-methyl pyrrolidone containing 3% aniline in lower alcohols: methanol, ethanol, and isopropanol, followed by the oxidation of the remaining aniline in a solution of 10% hydrochloric acid and ammonium persulfate. The Nanoparticles of polysulfone (NP-PSf) and The three obtained variants of nanoparticles composites (NP-PSf-PANI) were morphologically (SEM) and (AFM), structurally and compositionally (FTIR) characterized and the results show that nanoparticles polysulfone have a much lower range than the composites. The Possibility of copper complexation by both nitrophenols, and by nanoparticle surface probably lead to the formation of more stable aggregates in the supply, which can sufficiently justify the increased retention. The Retentions of the chemical species in question use in all the tests made the same series:R NP-PSf-PANI-M] R NP-PSf-PANI-E] R NP-PSf-PANI-P] R NP-PSf

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GAREEV, B. M., A. M. ABDRAKHMANOV, and G. L. SHARIPOV. "SONOLUMINESCENCE SPECTROSCOPY OF COLLOIDAL SUSPENSIONS: MOLECULAR, IONIC AND ATOMIC LUMINESCENCE DURING SONOCHEMICAL DECOMPOSITION OF SILICON DIOXIDE NANOPARTICLES CONTAINING RUTHENIUM AND COPPER COMPOUNDS." Izvestia Ufimskogo Nauchnogo Tsentra RAN, no. 4 (December 13, 2021): 16–21. http://dx.doi.org/10.31040/2222-8349-2021-0-4-16-21.

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The article is devoted to an example of the sonoluminescence spectroscopy use, which was previously known as a method for analyzing substances from the characteristic spectra of their sonoluminescence only in true solutions, for carrying out a similar analysis of substances contained in insoluble nanoparticles in colloidal suspensions. The solutions sonolysis, that is, their irradiation with ultrasound, is accompanied by the formation of cavitation bubbles that vibrate radially at the frequency of the ultrasonic field. Volatile components of the solution enter the bubbles, evaporating from the liquid-gas interface; nonvolatile components can penetrate into the bubble as a result of the injection of solution nanodroplets into the gas phase, which occurs during intense bubble movements accompanied by their deformation. In a nonequilibrium plasma periodically forming in cavitation bubbles, destruction occurs, as well as collisional excitation of these components, followed by luminescence. It has been shown that this mechanism of sonoluminescence also operates in colloidal suspensions, where substances are present in the form of nanoparticles with sizes less than 50 nm. Such nanoparticles penetrate into moving cavitation bubbles, without destroying them, as part of nanodroplets, and then undergo decomposition in bubble plasma with the excited particles generation as emitters of characteristic sonoluminescence. In this work, we synthesized colloidal suspensions in dodecane of porous SiO2 nanoparticles containing adsorbed Ru(bpy)3Cl2 and CuSO4 salts. During moving single-bubble sonolysis for these suspensions, characteristic emission spectra of Ru and Cu atoms, SiO molecules, and Ru(bpy)3 ions suitable for sonoluminescence spectroscopic analysis were recorded. By comparing the experimental and calculated (at different temperatures) luminescence spectra of Ru atoms, we estimated the electron temperature attained upon acoustic compression of single bubble in colloidal suspension in dodecane: Te = 7000 K.

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Yilleng, TM, NY Samuel, D. Stephen, JA Akande, ZM Agendeh, and LA Madaki. "Biosynthesis of Copper and Iron Nanoparticles using Neem (Azadirachta indica) Leaf Extract and their Anti-bacterial Activity." Journal of Applied Sciences and Environmental Management 24, no. 11 (January 11, 2021): 1987–91. http://dx.doi.org/10.4314/jasem.v24i11.20.

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Neem leaves extract was use to synthesize metal (iron and copper) nanoparticles. The nanoparticles were characterized using Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR) and UV-Vis spectrometer. The formation and stability of the reduced metal nanoparticles in the colloidal solution were monitored by UV–Vis spectrophotometer analysis. Their peaks of CuNPs and FeNPs were determined with a particles size in the range of 250nm-550nm and 250nm-350nm and have shapes of spherical and dendrimer respectively. The zone of inhibition by CuNP on gram negative bacteria (Staphylococcus Aureus) is 20mm ± 1 while on gram positive bacteria (Escherichia Coli) is 12.5mm ± 1. Thus, the synthesized metal nanoparticles prove to have very high anti-bacterial activity on both Staphylococci aureus and Escherichia coli. Copper nanoparticles exhibits high antibacterial activity compared to iron nanoparticles. Keywords: Copper, Iron, nanoparticles, Anti-bacterial activity

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Figueiredo, André Q., Carolina F. Rodrigues, Natanael Fernandes, Duarte de Melo-Diogo, Ilídio J. Correia, and André F. Moreira. "Metal-Polymer Nanoconjugates Application in Cancer Imaging and Therapy." Nanomaterials 12, no. 18 (September 13, 2022): 3166. http://dx.doi.org/10.3390/nano12183166.

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Metallic-based nanoparticles present a unique set of physicochemical properties that support their application in different fields, such as electronics, medical diagnostics, and therapeutics. Particularly, in cancer therapy, the plasmonic resonance, magnetic behavior, X-ray attenuation, and radical oxygen species generation capacity displayed by metallic nanoparticles make them highly promising theragnostic solutions. Nevertheless, metallic-based nanoparticles are often associated with some toxicological issues, lack of colloidal stability, and establishment of off-target interactions. Therefore, researchers have been exploiting the combination of metallic nanoparticles with other materials, inorganic (e.g., silica) and/or organic (e.g., polymers). In terms of biological performance, metal-polymer conjugation can be advantageous for improving biocompatibility, colloidal stability, and tumor specificity. In this review, the application of metallic-polymer nanoconjugates/nanohybrids as a multifunctional all-in-one solution for cancer therapy will be summarized, focusing on the physicochemical properties that make metallic nanomaterials capable of acting as imaging and/or therapeutic agents. Then, an overview of the main advantages of metal-polymer conjugation as well as the most common structural arrangements will be provided. Moreover, the application of metallic-polymer nanoconjugates/nanohybrids made of gold, iron, copper, and other metals in cancer therapy will be discussed, in addition to an outlook of the current solution in clinical trials.

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Dissertations / Theses on the topic "Copper nanoparticles (colloidal solution)"

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Yan, Hao. "Solubility phase transition behavior of gold nanoparticles in colloidal solution." Diss., Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2336.

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Batsmanova, L. M., L. M. Gonchar, N. Yu Taran, and A. A. Okanenko. "Using a Colloidal Solution of Metal Nanoparticles as Micronutrient Fertiliser for Cereals." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35441.

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We have developed the technology of using the colloidal solution of metal nanoparticles as fertilizers, which characterized by easiness to use, environmental safety and absence of corrosive properties. Colloidal solutions of biogenic metals, water-based, such as Fe, Mn, Zn, Mo, Co, Cu, and Ag, produced by a patented method of bittern natural colloidal solutions of the above metals were used. Seed treatment with colloidal solution of metal nanoparticles stored genetic purity grade, increased plant immune status via regulation of oxidative metabolism, photosynthetic activity, resistance to pathogens, and optimization of water regime of various winter wheat ecotypes during ontogenesis. Results of industrial tests proved that it is environ-mentally safe and economically feasible, since the cost of one liter of colloidal solutions of nanoparticles of metals ranges from 50-70 USD providing 500% level profitability. So, for the first time managed to opti-mize the function of biogenic metals through the use of physical and chemical characteristics of colloidal nanoparticle solutions to realize the productive potential of plants. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35441

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Bondarenko, I. S., О. Г. Аврунін, O. Gryshkov, B. Glasmacher, S. I. Bondarenko, A. V. Krevsun, and M. V. Rakhimova. "Acoustomagnetic detection of magnetic nanoparticles in a model." Thesis, The International Journal of Artificial Organs, 2019. http://openarchive.nure.ua/handle/document/9878.

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Magnetic nanoparticles (MNPs) are used in medicine for targeted drug delivyry to the area of the cancer. The installation consists of the ultrasound generator, the permanent magnet, the glass containerwith the colloidal mixture, the multi-turn coil about of the glass tube and the voltmeter. The experimental result corrilates with the calculated ones. It is suggested that AMM can used to detect MNPs in the real biological substance.

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Tegenaw, Ayenachew G. Ph D. "Environmental Implications of Cu-Based Nanoparticles and Biocides Products." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573573946625869.

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Darugar, Qusai A. "Surface effects on the ultrafast electronic relaxation of some semiconductor and metallic nanoparticles." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-06272006-160645/.

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Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007.
Zhang, John, Committee Member ; Wang, Zhong, Committee Member ; El-Sayed, Mostafa, Committee Chair ; Orlando, Thomas, Committee Member ; Lyon, Andrew, Committee Member.

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Yousef, Narin. "Solution-based and flame spray pyrolysis synthesis of cupric oxide nanostructures and their potential application in dye-sensitized solar cells." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-119329.

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The dye sensitized solar cell (DSSC) is a promising low-cost technology alternative to conventional solar cell in certain applications. A DSSC is a photo-electrochemical photovoltaic device, mainly composed of a working electrode, a dye sensitized semiconductor layer, an electrolyte and a counter electrode. Sunlight excites the dye, producing electrons and holes that can be transported by the semiconductor and electrolyte to the external circuit, converting the sunlight into an electrical current. A material that could be useful for DSSCs is the nanoscale cupric oxide, which can act as a p-type semiconductor and has interesting properties such as low thermal emittance and relatively good electrical properties. The goal of this project was to synthesize and characterize CuO nanoparticles using three different methods and look into each products potential use and efficiency in DSSCs. The particles were synthesized using two different solution based chemical precipitation methods and a flame spray pyrolysis method, yielding nanostructures with different compositions, structures and sizes ranging from ~20 to 1000 nm. The nanoparticle powder synthesized by the flame spray pyrolysis route was tested as semiconductor layer in the working electrode of the DSSC. Current-voltage measurements presented low solar conversion efficiencies with a reversed current, meaning that the cupric oxide cells did not work in a desirable way. Further studies of the cupric oxide synthesis and its suitability in DSSCs are needed to increases the future possibilities for gaining well working p-type DSSCs with higher efficiencies.

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Lopes, Filomeno Cleber. "Dispersions de nanoparticules magnétiques de type coeur-coquille MFe2O4@g-Fe2O3 dans des solvants polaires : réactivité électrochimique et rôle de l'interface oxyde/solution sur les propriétés colloïdales." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066673/document.

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Les dispersions de nanoparticules magnétiques (NPs) dans les solvants polaires sont utilisées dans de nombreuses applications dans des domaines variés, du biomédical à l'environnement ou à l'énergie. Aussi appelés ferrofluides (FFs), ces systèmes sont des dispersions de ferrites spinelle magnétiques pouvant être stabilisées par des répulsions électrostatiques. Cela nécessite une bonne compréhension de l'interface NPs/solvant porteur, qui contrôle les interactions entre NPs, la nanostructure et de nombreuses autres propriétés. Nous étudions ici en milieu aqueux la réactivité électrochimique de particules c¿ur/couronne de type MFe2O4@ Fe2O3 (M = Fe,Co,Mn,Cu,Zn), espèces électroactives non conventionnelles. La voltammétrie à signaux carrés et la coulométrie à potentiel contrôlé permettent d'étudier la coquille de maghémite ( Fe2O3), dont le rôle est la protection de l'oxyde mixte du c¿ur en milieu acide. D'autre part, un nouveau procédé d'élaboration de dispersions dans les solvants polaires, testé dans l'eau, est appliqué au diméthylsulfoxide (DMSO). A partir du point de charge nulle des NPs, un ajout connu d'acide ou de base permet de contrôler la charge des NPs, la nature des contreions et la quantité d'électrolyte libre. Des dispersions stabilisées par des répulsions électrostatiques sont obtenues dans le DMSO. La diffusion de rayons X aux petits angles et la diffusion dynamique de la lumière sont utilisées pour comprendre la nanostructure et quantifier les interactions entre particules. De forts effets spécifiques liés aux ions sont mis en évidence ainsi que le rôle de l'interface solide liquide, en particulier sur les propriétés de thermodiffusion
Dispersions of magnetic nanoparticles (NPs) in polar solvents have been inspiring many applications, to cite a few, biomedical, industrial and thermoelectrical ones. Also called ferrofluids (FFs), they are usually colloidal dispersions of magnetic spinel ferrite NPs, which can be stabilized thanks to electrostatic repulsion. A good understanding of the interface between NPs and the carrier solvent is thus a key point, which governs the interparticle interactions, the nanostructure and many other applicative properties. We study here the electrochemical reactivity of core-shell ferrite MFe2O4@ Fe2O3 (M=Fe,Co,Mn,Cu,Zn) NPs in aqueous medium. Square-wave voltammetry and potential controlled coulometry techniques are used on these non-conventional electroactive systems in order to evidence the shell of maghemite ( Fe2O3), the main function of which is to ensure the thermodynamical stability of NPs in acidic medium. We also present a new process for the elaboration of maghemite based FF in polar solvents, tested in water and applied to dimethyl sulfoxide (DMSO). Departing from the point of zero charge, the NPs are charged in a controlled way by adding acid or base, which enables us to better control the charge and the counter-ions nature, as well as the amount of free electrolyte in the dispersion. Stable dispersions are obtained thanks to electrostatic repulsion, also in DMSO. Small Angle X-ray scattering and Dynamic Light Scattering are used to understand the nanostructure and quantify the interparticle interactions. Specific ionic effects are evidenced as well as the strong influence of the solid/liquid interface on the migration of the NPs in a thermal gradient

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RIFI, EL HOUSSEINE. "Extraction metallique par des gels hydrophobes." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13158.

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Etude de l'extraction liquide-gel de cu, v et eu. On montre que les lois de la thermodynamique d'extraction de cu par les acyl-4 pyrazolones-5 ne sont pas pertubees par la presence du polymere, mais que la cinetique l'est fortement. L'impregnation des polybutadienes par la trilamylamine presente des difficultes; l'utilisation de pvc gonfle dans des solutions d'oxyde d'octylphenyl n,n-diisobutylcarbamoylmethylphosphine dans tbp est interessante

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Ider, Mina. "Elaboration et caractérisation des nanomatériaux à base de métaux nobles." Thesis, Le Mans, 2017. http://www.theses.fr/2017LEMA1022/document.

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Dans ce travail de thèse, la synthèse de nanoparticules d'argent (Ag) est réalisée par une méthode simple, efficace et rapide basée sur la réduction du nitrate d'argent (AgNO3) dans un milieu organique (éthanol) sous chauffage par irradiation micro-ondes (MW) pendant quelques secondes en présence d'une émulsion aqueuse de copolymère latex. Les expériences ont été effectuées soit de manière séquentielle en faisant varier les paramètres expérimentaux les uns après les autres (approche classique) ou bien en moyennant la méthodologie des plans d'expérience qui sert à varier simultanément ces conditions expérimentales dans le but à la fois d'optimiser et d'évaluer l'impact de ces facteurs sur les propriétés physico-chimiques des particules produites. L'objectif est d'arriver à préparer un maximum de concentration en nanoparticules d'argent avec un minimum de concentration en copolymère latex et en AgNO3. Les nanoparticules préparées sont trouvées extrêmement stables en solution colloïdale avec des distributions de taille très étroites, ce qui confirme la qualité élevée et le diamètre uniforme des nanoparticules obtenues par l'approche de synthèse micro-ondes. Ceci pourrait être probablement dû à l'effet de stabilisation produit par les molécules du latex, qui est un bon environnement pour contrôler efficacement la croissance de nanoparticules métalliques d'argent. En tant que principal objectif d'une telle réalisation de la synthèse de nanoparticules d'argent par la méthode MW ouvre la voie à l'exploitation d'effets plasmoniques de surface dans des réactions photocatalytiques en utilisant des structures semi-conductrices bien définies (Bi2O3, In2O3, TiO2...)
In this thesis work, the synthesis of silver nanoparticles (Ag) is carried out by a simple, efficient and fast method based on the reduction of silver nitrate (AgNO3) in an organic medium (ethanol) under heating by micro irradiation (MW) for a few seconds in the presence of an aqueous emulsion of latex copolymer. The experiments were performed either by varying the experimental parameters one after the other (classical approach) or by means of the experimental design methodology which serves to vary simultaneously these experimental conditions in order to both optimize and evaluate the impact of these factors on the physicochemical properties of the nanoparticles. The main goal is to prepare a maximum concentration of silver nanoparticles with a minimum concentration of latex copolymer and AgNO3. The prepared nanoparticles were found to be extremely stable in colloidal solution with very narrow size distributions, which confirms the high quality and the uniform diameter of the nanoparticles obtained by the microwave synthesis approach. This could possibly be due to the stabilizing effect produced by the latex molecules, which is a good environment for effectively controlling the growth of metallic silver nanoparticles. As the main objective of such realization of the silver nanoparticle synthesis by the MW method opens the way to the exploration of surface plasmonic effects in photocatalytic reactions using well-defined semiconducting structures (Bi2O3 , In2O3, TiO2 ...)

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Stockham, Katherine. "Antioxidants in food systems: influencing factors." Thesis, 2017. https://vuir.vu.edu.au/37865/.

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For well over 20 years the Oxygen Radical Absorbance Capacity (ORAC) assay has been an important research tool in identifying antioxidant candidates in food and serum samples. The ORAC value is derived from a series of fluorescence intensity measurements taken over a period of time, usually a few hours. The kinetics of this reaction is controlled by the sustained release of peroxyl radicals at 37°C by an azo compound (AAPH). The peroxyl radicals attack the fluorescent probe causing a gradual decrease in fluorescence intensity. Ultimately, the test yields fluorescence decay curves over time, with the presence of any antioxidants in a sample having a protective effect, delaying probe decay and resulting in a greater area under the decay curve. This forms the basis of the ORAC measurement. Concerns have been raised about the applicability of this assay, chemical interferences influencing the data, and the use of ORAC values to attribute health benefits of foods. In an effort to curb misrepresentation of health benefits from ORAC data, the USDA retracted its ORAC database in 2012 and published a statement by Dr Ronald Prior, a founding researcher for the ORAC assay. The explanatory statement by Dr Prior identified the misapplication of ORAC values and misleading perceived health benefits as major reasons for withdrawal of the database. Despite this, ORAC remains a popular assay, and the method is widely used as a product development and marketing tool. Some researchers have reported that ORAC values can be influenced by factors such as choice of solvent, chemical constituents in matrices, and pH conditions. However, little has been published on antioxidant synergies in food systems and their contribution to the ORAC value. Given the predisposition of the assay to interferences, a better understanding of antioxidant synergies is necessary to understand the contributing factors to measurement in real foods, and also to determine how these values may be manipulated. With the USDA caution in mind, this research was carried out to systematically investigate the factors influencing the ORAC measurement and its interpretation. Firstly, an alternative mode of reporting antioxidant activity to consumers on product labeling was proposed. Calculations needed to convert ORAC units from μM Trolox equivalents (μM T.E/kg or μM T.E/L) to mass units (g T.E/kg or g T.E/L) of Trolox equivalents per kg or per L of foodstuff are provided. We propose that mass units are less misleading to consumers, by not reporting very large and impressive-looking values when a simple conversion reveals most of them to be much more modest when viewed as a mass of vitamin E equivalent. For example, the antioxidant activity of blueberries when measured by the ORAC assay was equivalent to over 71,000 μM of Trolox equivalents. When converted, the blueberries can be said to have the same antioxidant activity as 17.9g of vitamin E per kg of fruit (17.9g T.E/kg). This new mode of reporting was successfully applied to a range of commodities including fruit, confection and beverages. Influencing factors, including environmental conditions, role of additives and nanoparticles and interactions between classes of chemical constituents were all investigated. Environmental conditions, specifically rainfall, were found to influence the levels of antioxidant compounds/bioactives in Australian wines. Six chemical constituents were identified as warranting further investigation; namely 6-methylcoumarin, protocatechuic acid, vanillic acid, p-coumaric acid, rutin and chlorogenic acid. Significant differences were also observed between the antioxidant capacity of wines by in vitro ORAC and ex vivo CAA-RBC assays, where wines with similar ORAC values had vastly different bioavailability and activity in the cellular system. Amino acids and CuNPs additives were found to greatly influence the antioxidant measurements of “superfoods”. Results indicated strong enhancements and synergies related to the properties of the amino acids and complexes formed with Cu(I) and essentially matrix independent.. The order of antioxidant enhancement in bilberry, coffee berry, and apple concentrates was Tryptophan > Tyrosine > Methionine ≥ Histidine ≥ 4-Hydroxyproline. This order was also consistent with the order of calculated bond dissociation energies (BDEs), reflecting the inherent antioxidant potentials of the amino acids studied. Density Functional Theory (DFT) was used to support a proposed “substrate zone” and “antioxidant zone” postulate for amino acids and related additives and this concept assists in demonstrating potential mechanisms involved in achieving such extraordinary enhancements and synergies. Histidine was used as a model system for DFT calculations, and allowable species had homolytic BDEs ranging from high (deactivated) to very low (activated), in the case of species (b) the BDE was at a level well below that of vitamin E, making it an excellent and potentially potent antioxidant. DFT calculations revealed that the histidine-Cu(I) complex had a comparable BDE to that of Trolox, again demonstrating how interactions between chemical constituents can influence, and in this case enhance antioxidant activity measurements. Synergies and antagonisms were also reported for eight classes of chemical constituents typically found in navel oranges. These mixtures were prepared based on the levels reported in nutritional data tables, and analyzed by ORAC and CAA-RBC assays. A correlation analysis revealed that the ORAC and CAA-RBC data did not correlate overall, however distinct clustering and several interesting outliers were noted. Cluster (a) had low ORAC and low CAA-RBC values, involving combinations of preservatives, sugars and CuNPs. Cluster (b) had low to moderate responses in both assays, and was made up primarily of vitamins in combination with CuNPs, preservatives, sugars and flavonoids. Cluster (c) was dominated by phenolics and their interactions with a number of groups, which gave high antioxidant activity in both ORAC and CAA-RBC assays, and amino acids are the main contributors in cluster (d). Organic acids featured in both outliers, firstly with a high antioxidant activity in both assays when combined with polyphenolics, and secondly as having an auto-oxidation effect in the CAA-RBC assay but a high ORAC value when analysed individually. Antioxidant activities of individual mixtures and combinations of classes of compounds showed antagonism/suppression of antioxidant activity between sugars and vitamins, and between polyphenolics and flavonoids in the ORAC assay. However, these same solutions resulted in antioxidant synergy in the CAA-RBC assay. In fact, the auto-oxidation effect of organic acids was reversed and synergies were noted in interaction with polyphenolics. A number of synergisms ex vivo involved polyphenolics in combination with other constituents such as vitamins, the amino acid Tryptophan, preservatives and CuNPs. These findings support the postulate that interactions at the “substrate zone” are influencing factors of antioxidant capacity at the molecular level. Computational chemistry was used to postulate mechanisms for antioxidant synergy, activation and deactivation of phenolic O-H groups, using quercetin and (-)-epicatechin-3-gallate as examples. It was concluded that factors including rainfall, amino acid and CuNPs addition, and interactions between common classes of food constituents influenced antioxidant activity in food systems. Computational chemical calculations were used to postulate mechanisms for antioxidant enhancement and synergy, a major influencing factor in antioxidant measurements. This research describes the potential for unlocking new and powerful antioxidant synergies in food systems, nutrition and health and the medical/pharmaceutical fields.

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Books on the topic "Copper nanoparticles (colloidal solution)"

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Rudolph, Martin. Nanoparticle-polymer-composites: The solution and spray drying process with an emphasis on colloidal interactions. Freiberg: Technische Universität Bergakademie, 2013.

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Book chapters on the topic "Copper nanoparticles (colloidal solution)"

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Hassinen, Antti, José C. Martins, and Zeger Hens. "Solution NMR Toolbox for Colloidal Nanoparticles." In Nanoparticles, 273–93. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44823-6_10.

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Destro, Priscila. "Synthesis of Gold-Copper Nanoparticles by Colloidal Method Varying the Compositions as a Function of the Synthesis Final Temperature." In Colloidal Nanoparticles for Heterogeneous Catalysis, 17–40. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-03550-1_2.

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Tabor, Christopher, Radha Narayanan, and Mostafa A. El-Sayed. "Catalysis with Transition Metal Nanoparticles in Colloidal Solution: Heterogeneous or Homogeneous?" In Model Systems in Catalysis, 395–414. New York, NY: Springer New York, 2009. http://dx.doi.org/10.1007/978-0-387-98049-2_18.

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Bhusari, Vivek, Amit Bansiwal, and Sadhana Rayalu. "Removal of Hexavalent Chromium from Aqueous Solution by Alumina-Supported Copper Aluminum Oxide Nanoparticles." In Smart Technologies for Energy, Environment and Sustainable Development, 291–97. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6148-7_30.

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Torre, J. García de la, F. G. Díaz Baños, and H. E. Pérez Sánchez. "Computational Methods for Dynamic Electro‐Optic Properties of Macromolecules and Nanoparticles in Solution." In Molecular and Colloidal Electro-Optics, 109–34. CRC Press, 2016. http://dx.doi.org/10.1201/9781420009859-5.

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Bugár, I., I. Capek, J. Ivan, L. Chitu, E. Majková, and D. Chorvát. "Time-resolved absorption spectroscopy of metal nanoparticles in colloidal solution." In Femtochemistry and Femtobiology, 545–48. Elsevier, 2004. http://dx.doi.org/10.1016/b978-044451656-5/50107-9.

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Lai, Chun-Feng. "Colloidal Photonic Crystals Containing Copper-Oxide and Silver Nanoparticles with Tunable Structural Colors." In Advances in Colloid Science. InTech, 2016. http://dx.doi.org/10.5772/65007.

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"Comparative Study of Production of Stable Colloidal Copper Nanoparticles Using Microreactor and Advanced-Flow Reactors®." In Chemical and Bioprocess Engineering, 427–45. Apple Academic Press, 2015. http://dx.doi.org/10.1201/b18402-43.

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Yadav, Sandhya, and P. K. Bajpai. "Role of processing parameters in solution routes for controlling size, shape, and morphology of chalcogenide nanoparticles." In Copper Nanostructures: Next-Generation of Agrochemicals for Sustainable Agroecosystems, 99–130. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-12-823833-2.00029-5.

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A.H. Alzahrani, Hassan. "CuO and MWCNTs Nanoparticles Filled PVA-PVP Nanocomposites: Morphological, Optical, Dielectric, and Electrical Characteristics." In Carbon Nanotubes - Recent Advances, New Perspectives and Potential Applications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105810.

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Copper dioxide (CuO) nanoparticles and multiwall carbon nanotubes (MWCNTs)-filled poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) blend matrix (50/50 wt%)-based polymer nanocomposites (PNCs) have been prepared employing the solution-cast method. The X-ray diffraction explores the semicrystalline morphologies of these PNCs. The FTIR, SEM, and AFM measurements of PNCs expose the development of the miscible mix, polymer-polymer and polymer-nanoparticle interactions, and the influence of CuO and MWCNTs nanofillers on the morphology aspects on the main chain of PVA/PVP blend. The nanofiller loading for x = 14 wt% in the PVA–PVP blend matrix significantly enhances the crystalline phase, diminishing the optical energy gap to 2.31 eV. The DC conductivity is found to be maximum for x = 14 wt% loading concentration. The dielectric and electrical characteristics of these PNCs are investigated for an applied frequency range from 1 kHz to 1 MHz. The dielectric permittivity values increase substantially, owing to the decrease in the nano-confinement phenomenon at low frequency. The rise in applied frequency reduces dielectric permittivity and impedance values and enhances AC electrical conductivity. These PNCs having good dielectric and electrical characteristics can be used as frequency tunable nano-dielectric material in electronic devices.

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Conference papers on the topic "Copper nanoparticles (colloidal solution)"

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Yuksel, Anil, Michael Cullinan, and Jayathi Murthy. "Thermal Energy Transport Below the Diffraction Limit in Close-Packed Metal Nanoparticles." In ASME 2017 Heat Transfer Summer Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/ht2017-4968.

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Fabrication of micro and nanoscale electronic components has become increasingly demanding due to device and interconnect scaling combined with advanced packaging and assembly for electronic, aerospace and medical applications. Recent advances in additive manufacturing have made it possible to fabricate microscale, 3D interconnect structures but heat transfer during the fabrication process is one of the most important phenomena influencing the reliable manufacturing of these interconnect structures. In this study, optical absorption and scattering by three-dimensional (3D) nanoparticle packings are investigated to gain insight into micro/nano heat transport within the nanoparticles. Because drying of colloidal solutions creates different configurations of nanoparticles, the plasmonic coupling in three different copper nanoparticle packing configurations were investigated: simple cubic (SC), face-centered cubic (FCC) and hexagonal close packing (HCP). Single-scatter albedo (ω) was analyzed as a function of nanoparticle size, packing density, and configuration to assess effect for thermo-optical properties and plasmonic coupling of the Cu nanoparticles within the nanoparticle packings. This analysis provides insight into plasmonically enhanced absorption in copper nanoparticle particles and its consequences for laser heating of nanoparticle assemblies.

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Han, Min, Zhilin Yang, and Ruomian Yang. "Research for Metallographic Organization of Gold Nanoparticles." In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21006.

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We used the solution of HAuCl4 and Na3 C6 H5 O7 to prepare the gold nanoparticles. The different shape and sizes of gold nanoparticles depends on the different amount of solution. We used gold nanoparticles with 35nm diameter to do experiments. Put the colloidal gold on a aluminum plate, copper plate and plastics plate, after dried, several items of tests had been done. we could see the mechanical property of gold nanoparticles such as hardness, extend rate was changed a lot than the common gold material. The reason was that the metallographic organization of gold nano materials was much tiny than common gold materia.

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Sanehira, Erin M., Chang-Ching Tu, and Lih Y. Lin. "Solution-processed photodetectors using colloidal germanium nanoparticles." In 2012 IEEE Photonics Conference (IPC). IEEE, 2012. http://dx.doi.org/10.1109/ipcon.2012.6358654.

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Sanehira, Erin M., Chang-Ching Tu, and Lih Y. Lin. "Solution-processed Photodetectors using Non-toxic, Colloidal ZnS-AgInS2 Nanoparticles." In CLEO: Science and Innovations. Washington, D.C.: OSA, 2013. http://dx.doi.org/10.1364/cleo_si.2013.cth4j.2.

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Rosso, Vanessa, Jerome Loicq, Z. Hens, Yvon Renotte, and Yves Lion. "Size-dependent third-order optical nonlinearity of InP nanoparticles colloidal solution." In Photonics Europe, edited by Richard M. De La Rue, Pierre Viktorovitch, Clivia M. Sotomayor Torres, and Michele Midrio. SPIE, 2004. http://dx.doi.org/10.1117/12.545881.

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Videla, Fabian A., Gustavo A. Torchia, Daniel S. Schinca, Lucía B. Scaffardi, Pablo Moreno, Cruz Méndez, Luis Roso, L. Giovanetti, and Jose Ramallo Lopez. "Role of supercontinuum in the fragmentation of colloidal gold nanoparticles in solution." In SPIE NanoScience + Engineering, edited by Michael T. Postek and John A. Allgair. SPIE, 2009. http://dx.doi.org/10.1117/12.831032.

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Malik, S. N., H. Ahmed, M. Shahid, N. Haider, M. A. Malik, and P. O'Brien. "Colloidal preparation of copper selenide and indium selenide nanoparticles by single source precursors approach." In 2013 10th International Bhurban Conference on Applied Sciences and Technology (IBCAST 2013). IEEE, 2013. http://dx.doi.org/10.1109/ibcast.2013.6512127.

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Helmy, A. S., J. Irizar, S. Rutledge, J. Dinglasan, D. Anderson, C. Goh, and J. Goh. "Photonic Crystal Fibers: A Platform for Raman Spectroscopy of Colloidal Nanoparticles in Solution." In 2008 IEEE PhotonicsGlobal@Singapore (IPGC). IEEE, 2008. http://dx.doi.org/10.1109/ipgc.2008.4781345.

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Budiati, Inayah Mumpuni, Fatkhiyatus Sa’adah, Nabila Dyah Rifani, and Ali Khumaeni. "Effect of solvent in the synthesis of colloidal copper nanoparticles by pulse laser ablation method." In INTERNATIONAL CONFERENCE ON SCIENCE AND APPLIED SCIENCE (ICSAS) 2019. AIP Publishing, 2019. http://dx.doi.org/10.1063/1.5141616.

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Holubnycha, V., M. Pogorielov, Viktoriia Korniienko, O. Kalinkevych, O. Ivashchenko, B. Peplinska, and M. Jarek. "Antibacterial activity of the new copper nanoparticles and Cu NPs/chitosan solution." In 2017 IEEE 7th International Conference "Nanomaterials: Application & Properties" (NAP). IEEE, 2017. http://dx.doi.org/10.1109/nap.2017.8190323.

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Reports on the topic "Copper nanoparticles (colloidal solution)"

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Chefetz, Benny, Baoshan Xing, and Yona Chen. Interactions of engineered nanoparticles with dissolved organic matter (DOM) and organic contaminants in water. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7699863.bard.

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Background: Engineered carbon nanotubes (CNTs) are expected to be increasingly released into the environment with the rapid increase in their production and use. The discharged CNTs may interact with coexisting contaminants and subsequently change environmental behaviors and ecological effects of both the CNTs themselves and the contaminants. Dissolved organic matter (DOM) plays a critical role in the transport of CNTs in the aquatic environment, affecting both CNT's surface properties through adsorption, and its colloidal stability in solution. Therefore, CNT-bound DOM complexes may interact with coexisting contaminants, thus affecting their environmental fate. With increasing production and use of CNTs, there is an increasing risk that humans could be exposed to CNTs mainly through ingestion and inhalation. Since CNTs can be carriers of contaminants due to their high adsorption affinity and capacity, the distribution of these nanoparticles in the environment holds a potential environmental and health risk. Project objectives: The overall goal of this project was to gain a better understanding of the environmental behavior of engineered nanoparticles with DOM and organic pollutant in aqueous systems. The scope of this study includes: characterizing various types of engineered nanoparticles and their interaction with DOM; binding studies of organic contaminants by nanoparticles and DOM-nanoparticle complexes; and examining interactions in DOM-nanoparticles-contaminant systems. Major conclusions, solutions and achievements: DOM has a pronounced effect on colloidal stability of CNTs in solution and on their surface chemistry and reactivity toward associated contaminants. The structure and chemical makeup of both CNTs and DOM determine their interactions and nature of formed complexes. CNTs, contaminants and DOM can co-occur in the aquatic environment. The occurrence of co-contaminants, as well as of co-introduction of DOM, was found to suppress the adsorption of organic contaminants to CNTs through both competition over adsorption sites and direct interactions in solution. Furthermore, the release of residual contaminants from CNTs could be enhanced by biomolecules found in the digestive as well as the respiratory tracts, thus increasing the bioaccessibility of adsorbed contaminants and possibly the overall toxicity of contaminant-associated CNTs. Contaminant desorption could be promoted by both solubilization and sorptive competition by biological surfactants. Scientific and agricultural implications: The information gained in the current project may assist in predicting the transport and fate of both CNTs and associated contaminants in the natural environment. Furthermore, the results imply a serious health risk from contaminant-associated CNTs.

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