Journal articles: '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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BAZYLYAK, Liliya, Andriy KYTSYA, Pavlo LYUTYI, Orest KUNTYI, Alla PROKOPALO, and Olena KARPENKO. "SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF COLLOIDAL SOLUTIONS OF BICOMPONENT Ag/CuO NANOPARTICLES STABILIZED BY RAMNOLIPID." Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2022, no. 70 (September 30, 2022): 159–68. http://dx.doi.org/10.37827/ntsh.chem.2022.70.159.

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Despite the extremely high activity of researchers in the direction of green synthesis of nano-particles of silver, copper, as well as bimetallic nanoparticles Ag/Cu-NPs, the many aspects of the synthesis of nanoparticles based on silver and copper remain unexplored, in particular, the studies on the influence of the nature of biosurfactants on the characteristics are relevant obtained nano¬particles, in particular their size, shape, etc., as well as the influence of the morphology and compo¬sition of nanoparticles on their antimicrobial properties. Therefore, the purpose of this work was to synthesize colloidal solutions of bicomponent Ag/CuO-NPs nanoparticles of different composition and to investigate their antimicrobial activity. Bicomponent Ag/CuO nanoparticles of different composition were obtained by the method of coprecipitation of Ag+ and Cu2+ cations in solution of rhamnolipid. It was found that the process of formation of monocomponent CuO nanoparticles is completed within 2.5 hours but the reduction of silver ions in aqueous solutions of RL occurs within a few minutes. The obtained Ag/CuO-NPs were studied using UV-visible spectroscopy and the method of powder diffraction of X-rays. It was found that the absorption spectra of Ag/CuO-NPs solutions are characterized by two maxima at 280 and 410 nm, which correspond to the surface plasmon resonance bands of CuO and Ag-NPs, res-pectively. Based on the obtained data, it is reasonable to assume that the obtained Ag/CuO-NPs can form core-shell structures in which the role of the core will be played by silver surrounded by a CuO shell. Taking into account the prospects of using the nanoparticles based on silver and copper as antimicrobial agents for the plant protection, the antimicrobial activity of the synthesized Ag/CuO-NPs was investigated. The gram-negative bacteria-phytopathogens were used as test microorganisms, namely Agrobacterium tumefaciens, which is the causative agent of crown gall disease of a wide range of agricultural crops and Xanthomonas campestris, which is the causative agent of the "black rot" disease in cruciferous vegetables. The antimicrobial activity of the synthesized colloidal solutions of Ag/CuO was evaluated by the minimum inhibitory concentration values. The results of the studies of antimicrobial activity of the synthesized Ag/CuO colloidal solutions showed that the obtained preparations effectively inhibit the growth of phytopathogenic bacteria Agrobacterium tumefaciens and Xanthomonas campestris and it was found that the obtained drugs are more active against the Xanthomonas campestris.

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Svetlichnyi, Valery A., Darya A. Goncharova, Anastasiia V. Shabalina, Ivan N. Lapin, and Anna L. Nemoykina. "Cu₂O Water Dispersions and Nano-Cu₂O/Fabric Composite: Preparation by Pulsed Laser Ablation, Characterization and Antibacterial Properties." Nano Hybrids and Composites 13 (January 2017): 75–81. http://dx.doi.org/10.4028/www.scientific.net/nhc.13.75.

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Colloidal solutions of copper (I) oxide, Cu2O, were obtained by pulsed laser ablation of metallic copper target in distilled water using fundamental harmonic of Nd:YAG laser (1064 nm, 7 ns, 20 Hz). Nanocolloids obtained were applied to cotton fabric. Nanoparticles composition and structure were studied by UV-Vis and Raman spectroscopy, transmission and scanning electron microscopy, and XRD. Antibacterial activity of Cu2O nanoparticles on cotton fabric to E.coli bacteria was demonstrated in comparison with zinc oxide nanoparticles.

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Hao, Hoang Minh, Cao Van Du, Duong Thi Ngoc Dung, Cao Xuan Chuong, Nguyen Thi Phuong Phong, Nguyen Huu Tri, and Pham Thi Bich Van. "Synthesis, characterization and evaluation of copper nanoparticles as agrochemicals against Phytophthora spp." Science and Technology Development Journal - Natural Sciences 2, no. 6 (September 17, 2019): 48–56. http://dx.doi.org/10.32508/stdjns.v2i6.843.

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By using water as a solvent, copper nanoparticles (CuNPs) have been synthesized from copper sulfate via chemical reduction method in the presence of trisodium citrate dispersant and polyvinylpyrrolidone (PVP) as capping agent. The effects of the experimental parameters such as the concentration of reducing agent (NaBH4), reaction temperature, molar ratio of citrate/Cu2+ and weight percentage ratios of Cu2+/PVP on the CuNP sizes were studied. The size of CuNPs in a range of 31 nm was obtained at NaBH4 concentration of 0.2 M, 50oC, citrate/Cu2+ molar ratio of 1.0 and Cu2+/PVP weight percentage of 5%. The colloidal CuNPs were characterized by using UV–Visible spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. The colloidal solution of CuNPs (3±1 nm) was investigated the potential against Phytophthora spp. which cause economically crop diseases. Under in vitro test conditions, the inhibition of Phytophthora spp. mycelia growth at three concentrations of CuNPs (10, 20, 30 ppm) after 48 hours are 90.18%, 91.87% and 100%, respectively. These results provided a simple and economical method to develop the CuNPs-based-fungicide.

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Shuliak, S. V., O. S. Haidei, O. V. Kaminska, and L. V. Shevchenko. "Effect of different concentrations of colloidal silver on the chemical composition of quail meat." Sučasne ptahìvnictvo, no. 3-4 (April 16, 2020): 10–14. http://dx.doi.org/10.31548/poultry2020.03-04.010.

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The search for an alternative to antibiotics in quail breeding involves theevelopment of new agents with antibacterial properties and a study of their effect on the quality and safety of the resulting product. Among the promising drugs on the market of new antimicrobial agents, related to nanotechnology, one of the first positions is nanosilver preparations, which have a wide range of antibacterial, antiviral, antiparasitic, and potent inflammatory drugs. At the same time, the use of colloidal silver in poultry farming certainly has corresponding consequences on the main consumer product – meat, offal and eggs, which, in turn, affect human health. It has been established that with oral administration of various concentrations of solutions of colloidal silver in quail, the liver and tubular bones have the highest cumulative ability, of all the studied tissues. Also, the distribution and cumulation of silver nanoparticles in various quail tissues indicate a dose-dependent accumulation of silver. The effect of various concentrations of colloidal silver solutions on some indicators of the quality and safety of quail meat was studied. It has been established that boiling quails over the period of growing solutions of colloidal silver in doses of 0.02-2.0 mg/l improves the quality of meat in terms of protein, calcium and phosphorus. Boiling quail of a colloidal silver solution in doses of 0.02-2.0 mg/l leads to an increase in copper contentin muscles by 1.2-2.1 times, does not depend on the dose and period of drinking. The content of zinc and cobalt in the muscles of quail is not significantlydependent on the dose of boiling of a colloidal silver solution. Boiling quails of a solution of colloidal silver in doses of 1.0 and 2.0 mg /l does not affect the level of iron, and in doses of 0.02 and 0.2 mg/l it contributes to an increase in its content by 1.3-3.5 times the muscles.

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Мусская, Ольга Николаевна, Валентина Константиновна Крутько, Анатолий Иосифович Кулак, and Евгений Николаевич Крутько. "COMPOSITES BASED ON CALCIUM PHOSPHATES AND COPPER NANOPARTICLES." Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, no. 13 (December 23, 2021): 320–28. http://dx.doi.org/10.26456/pcascnn/2021.13.320.

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Боргидридным методом с использованием полимерных стабилизаторов (полиэтиленгликоля, поливинилпирролидона) синтезированы наночастицы меди. Методом оптической спектроскопии установлено, что наибольшей стабильностью (до 1,5 месяца) обладают наночастицы меди, полученные при мольном соотношении Cu /полимер 1:3 - 6. Показано, что в отсутствии полимера либо при его небольшом содержании (мольное соотношение Cu /полимер 1:1) происходит агрегирование образующихся наночастиц и выпадение осадка, содержащего медь и ее оксиды (CuO, CuO). Механическим смешиванием аморфизированных фосфатов кальция (в порошковой и гелевой форме) и наночастиц меди (в виде коллоидного раствора) получен порошковый композит, содержащий фазы CaCuH(PO) и CuPOOH . Выявлено, что при совместном осаждении фосфатов кальция и наночастиц меди происходит встраивание ионов меди в кристаллическую решетку фосфатов кальция с образованием смешанных кислых и средних солей. Copper nanoparticles were synthesized by the borohydride method using polymer stabilizers (polyethylene glycol, polyvinylpyrrolidone). It was found by optical spectroscopy that copper nanoparticles obtained at a molar ratio Cu / polymer of 1: (3 - 6) have the highest stability (up to 1.5 months). It was shown that in the absence of polymer or at its low content (molar ratio Cu / polymer 1:1), the resulting nanoparticles aggregate and a precipitate forms containing copper and its oxides (CuO, CuO). By mechanical mixing of amorphized calcium phosphates (in powder and gel form) and copper nanoparticles (in the form of a colloidal solution), a powder composite containing CaCuH(PO) and CuPOOH phases was obtained. It was shown that during the coprecipitation of calcium phosphates and copper nanoparticles, copper ions are incorporated into the crystal lattice of calcium phosphates with the formation of mixed acidic and medium salts.

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Patel, Kamakshi, Anastasiya Sergievskaya, Samir Chauhan, and Stephanos Konstantinidis. "Heating of liquid substrate by low-pressure sputtering plasma." Journal of Applied Physics 131, no. 20 (May 28, 2022): 203301. http://dx.doi.org/10.1063/5.0089214.

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The heating of the liquid substrate by low-pressure (∼1 Pa) sputtering plasma has been investigated by in situ temperature measurements. The combination of “green” non-toxic solvent, castor oil, copper target, and direct current magnetron sputtering was chosen as a model system. The temperature increase induced by plasma was registered with two thermocouples placed immediately under the liquid surface and in the bulk solution. The effect of the working gas pressure and sputter power was studied. It was shown that the liquid temperature increases at a rate of up to 1 °C/min, depending on the sputtering conditions. The experimental data were compared with numerical calculations and COMSOL simulation. Provided information is essential data for the detailed explanation of the formation of nanoparticles during sputtering onto liquids, a clean approach for production of colloidal solutions of “naked” nanoparticles.

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Faizullayeva, S., S. M. Klimentov, and A. A. Popov. "Evolution of the properties of nanomaterials obtained by pulsed laser ablation." Journal of Physics: Conference Series 2058, no. 1 (October 1, 2021): 012014. http://dx.doi.org/10.1088/1742-6596/2058/1/012014.

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Abstract The synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as gold, silver, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this work, gold colloids were prepared by pulsed laser ablation of high purity gold plate immersed in deionized water and 10μM NaCl solution. After ablation process, we study the change in the size distribution of nanoparticles after the ablation process for a month.

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Piplai, Tropita, Arun Kumar, and Babu J. Alappat. "Removal of mixture of ZnO and CuO nanoparticles (NPs) from water using activated carbon in batch kinetic studies." Water Science and Technology 75, no. 4 (December 10, 2016): 928–43. http://dx.doi.org/10.2166/wst.2016.521.

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The aim of this study was to understand the effects of pH (5, 6, 7, 8, 9) and activated carbon (AC) concentration (0.01, 0.1, 1, 10, 100 g/L) on the removal of a colloidal solution of nanoparticles (NPs) (ZnO + CuO) using AC in batch kinetic studies. Results revealed that adsorption capacities of AC for Zn and Cu (individually) were 0.9 ± 0.028 mg/g (91.3% removal) and 0.95 ± 0.036 mg/g (95.6% removal) in deionized water and 0.6 ± 0.038 mg/g (78% removal) and 0.75 ± 0.078 mg/g (83% removal) in wastewater at pH 8 (Zn) and pH 6 (Cu) respectively. In a colloidal solution mixture of zinc oxide nanoparticles (ZnONPs) and copper oxide nanoparticles (CuONPs), adsorption capacity of AC for Zn in deionized water was 0.71 ± 0.051 mg/g (74.7% removal) and in wastewater was 0.576 ± 0.019 mg/g (69% removal) and for Cu in deionized water was 0.82 ± 0.017 mg/g (81.2% removal) and in wastewater was 0.6 ± 0.032 mg/g (71.5% removal). Overall, this study provided a detailed analysis of the removal capacity of AC and indicated that AC can be used as an efficient adsorbent filter for removing engineered NPs like ZnONPs and CuONPs (single and mixture) from water. As there is a need for removing NPs from wastewater, removal of NPs using an AC-based adsorptive-filter might become a promising method.

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Millien, Kawira. "Characterization of Local Nano-Heat Transfer Fluids for Solar Thermal Collection." Advances in Materials Science and Engineering 2020 (August 7, 2020): 1–8. http://dx.doi.org/10.1155/2020/6105879.

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Performance of organic oils in solar thermal collection is limited due to their low thermal conductivity when they are compared to molten salt solutions. Extraction of organic oils from plants can be locally achieved. The purpose of this study was to investigate the effect of use of copper nanoparticles in some base local heat transfer fluids (HTFs). Addition of volume fraction of 1.2% of the copper nanoparticles to oil-based heat transfer fluids improved their thermal conductivity as deduced from the thermal heat they conducted from solar radiation. The oil-based copper nanofluids were obtained by preparation of a colloidal solution of the nanoparticles. Impurities were added to increase the boiling point of the nano-heat transfer fluids. Stabilizers were used to keep the particles suspended in the oil-based fluids. The power output of the oil-based copper nano-heat transfer fluids was in the range of 475.4 W to 1130 W. The heat capacity of the steam in the heat exchanger was 93.7% dry and had a thermal capacity of 5.71 × 103 kJ. The heat rate of flow of the oil-based copper nano-heat transfer fluids was an average of 72.7 Js−1·kg−1 to 89.1 Js−1·kg−1. The thermal efficiency for the oil-based copper nano-heat transfer fluids ranged from 0.85 to 0.91. The average solar thermal solar intensity was in the range 700 Wm−2 to 1180 Wm−2. The heat exchanger used in this study was operating at 4.15 × 103 kJ and a temperature of 500.0°C. The heat transfer fluids entered the exchanger at an average temperature of 381°C and exited at 96.3°C and their heat coefficient ranged between 290.1 Wm−2°C and 254.1 Wm−2°C. The average temperatures of operation ranged between 394.1°C and 219.7°C with respective temperature efficiencies ranging between 93.4% and 64.4%. It was established that utilization of copper nanoparticles to enhance heat transfer in oil-based local heat transfer fluids can mitigate energy demand for meeting the world’s increasing energy uses, especially for areas inaccessible due to poor land terrain.

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BAZYLYAK, Liliya, Andriy KYTSYA, Ilona KARPENKO, and Olena KARPENKO. "SYNTHESIS AND ANTIMICROBIAL ACTIVITY OF SILVER NANOPARTICLES STABILIZED BY CITRATE ANIONS." Proceedings of the Shevchenko Scientific Society. Series Сhemical Sciences 2020, no. 60 (February 25, 2020): 127–35. http://dx.doi.org/10.37827/ntsh.chem.2020.60.127.

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Widespread use of synthetic antimicrobial drugs leads to the development of antibiotic resistance of pathogenic strains of microorganisms. Therefore, today researchers are very interested in drugs based on nanoparticles of metals, in particular silver and copper, which have antibacterial, antifungal and antiviral activity. One of the reasons for the high interest of researchers in AgNPs as an antimicrobial agent is the significantly lower toxicity of AgNPs compared to Ag+ ions. High antibacterial efficiency of silver nano¬particles is achieved due to their developed surface, which provides maximum contact with the environment. In addition, such nanoparticles are quite small and are able to penetrate cell membranes, to affect intracellular processes from within. Therefore, the aim of this work was to obtain concentrated colloidal silver solutions stabilized by citrate anions, which simultaneously provide satisfactory stabilization of colloidal silver solutions and are non-toxic, as well as to investigate the antimicrobial action of synthesized AgNPs. The solution of citrate stabilized silver nanoparticles (AgNPs) have been obtained via the reaction of reduction of silver nitrate by hydrazine in alkaline medium in the presence of sodium citrate. AgNPs were investigated using transmission electron microscopy (TEM) and UV-vis spectroscopy and the particles size and particles size distribution (PSD) were determined. It was observed that obtained AgNPs are mainly spherical shape. It was found that the mean diameter and PSD of AgNPs determined using TEM and UV-vis spectroscopy are close and equal to 14 and 5 nm and 15 and 4 nm respectively. Obtained solution was concentrated by evaporation at 70 C under reduced pressure up to achievement of AgNPs concentration equal to 200 mg/L. On the base of comparison of optical properties of initial silver sol and concentrated solution the minority of agglomeration of AgNPs was statement. At the same time AgNO3 test showed no change of UV-vis spectrum of concentrate that points on the absence of reducing agent in the solution; this fact indicate that hydrazine was eliminated from during the evaporation of initial AgNPs solution and obtained concentrate did not consist the toxic impurities. Antimicrobial activity of obtained citrate stabilised AgNPs against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli bacterium was tested using disk diffusion method. It was found that AgNPs shown significant bactericidal effect even at low (25 mg/L) concentration as well as some higher efficiency against Gram-negative bacterium. There was also a slightly higher antimicrobial activity of the drug against gram-negative bacteria Escherichia coli compared with gram-positive bacteria Bacillus subtilis, due to the different structure of cell walls. In particular, the walls of gram-positive bacteria consist mainly of peptidoglycan (murein), and gram-negative bacteria have cell walls with a layer of peptidoglycan and an outer membrane with a lipopolysaccharide component, which is not present in gram-positive bacteria. Based on the studies, it can be concluded that the proposed method of synthesis of AgNPs is suitable for obtaining highly concentrated silver sols. This method of synthesis is simple in hardware design, scalable, and the resulting colloidal solutions are stable and do not contain harmful impurities. Therefore, due to the high antibacterial activity of citrate-anion-stabilized AgNPs against certain types of gram-positive and gram-negative bacteria, it can be recommended for the manufacture of bactericidal drugs for biomedical purposes.

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Sportelli, Maria C., Antonio Ancona, Rosaria A. Picca, Adriana Trapani, Annalisa Volpe, Giuseppe Trapani, and Nicola Cioffi. "Laser Ablation Synthesis in Solution of Nanoantimicrobials for Food Packaging Applications." MRS Proceedings 1804 (2015): 37–42. http://dx.doi.org/10.1557/opl.2015.611.

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ABSTRACTDesigning bioactive materials, with controlled metal ion release, exerting significant bioactivity and associated low toxicity for humans, is nowadays one of the most important challenges for the scientific community. In this work, we propose a new material combining the well-known antimicrobial properties of copper nanoparticles (CuNPs) with those of bioactive chitosan (CS), a cheap natural polymer widely exploited for its biodegradability and nontoxicity. Here, we used ultrafast femtosecond laser pulses to finely fragment, via laser ablation, a Cu solid target immersed into aqueous CS solutions. Homogeneously dispersed copper-chitosan (Cu-CS) colloids were obtained by tuning the Cu/CS molar ratios, according to the initial chitosan concentration, as well as other experimental parameters. Cu-CS colloids were characterized by several techniques, like UV-Vis and X-ray Photoelectron spectroscopies (XPS). Transmission Electron Microscopy (TEM) was used to morphologically characterize the novel nanocomposites.

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Wang, William B., and Jude C. Clapper. "Antibacterial Activity of Electrospun Polyacrylonitrile Copper Nanoparticle Nanofibers on Antibiotic Resistant Pathogens and Methicillin Resistant Staphylococcus aureus (MRSA)." Nanomaterials 12, no. 13 (June 22, 2022): 2139. http://dx.doi.org/10.3390/nano12132139.

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Bacteria induced diseases such as community-acquired pneumonia (CAP) are easily transmitted through respiratory droplets expelled from a person’s nose or mouth. It has become increasingly important for researchers to discover materials that can be implemented in in vitro surface contact settings which disrupt bacterial growth and transmission. Copper (Cu) is known to have antibacterial properties and have been used in medical applications. This study investigates the antibacterial properties of polyacrylonitrile (PAN) based nanofibers coated with different concentrations of copper nanoparticles (CuNPs). Different concentrations of copper sulfate (CuSO4) and polyacrylonitrile (PAN) were mixed with dimethylformamide (DMF) solution, an electrospinning solvent that also acts as a reducing agent for CuSO4, which forms CuNPs and Cu ions. The resulting colloidal solutions were electrospun into nanofibers, which were then characterized using various analysis techniques. Methicillin-Resistant isolates of Staphylococcus aureus, an infective strain that induces pneumonia, were incubated with cutouts of various nanocomposites using disk diffusion methods on Luria-Bertani (LB) agar to test for the polymers’ antibacterial properties. Herein, we disclose that PAN-CuNP nanofibers have successfully demonstrated antibacterial activity against bacteria that were otherwise resistant to highly effective antibiotics. Our findings reveal that PAN-CuNP nanofibers have the potential to be used on contact surfaces that are at risk of contracting bacterial infections, such as masks, in vivo implants, or surgical intubation.

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Khan, Umair, Aurang Zaib, Iskandar Waini, Anuar Ishak, El-Sayed M. Sherif, Wei-Feng Xia, and Noor Muhammad. "Impact of Smoluchowski Temperature and Maxwell Velocity Slip Conditions on Axisymmetric Rotated Flow of Hybrid Nanofluid past a Porous Moving Rotating Disk." Nanomaterials 12, no. 2 (January 15, 2022): 276. http://dx.doi.org/10.3390/nano12020276.

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Colloidal suspensions of regular fluids and nanoparticles are known as nanofluids. They have a variety of applications in the medical field, including cell separation, drug targeting, destruction of tumor tissue, and so on. On the other hand, the dispersion of multiple nanoparticles into a regular fluid is referred to as a hybrid nanofluid. It has a variety of innovative applications such as microfluidics, heat dissipation, dynamic sealing, damping, and so on. Because of these numerous applications of nanofluids in minds, therefore, the objective of the current exploration divulged the axisymmetric radiative flow and heat transfer induced by hybrid nanofluid impinging on a porous stretchable/shrinkable rotating disc. In addition, the impact of Smoluchowski temperature and Maxwell velocity slip boundary conditions are also invoked. The hybrid nanofluid was formed by mixing the copper (Cu) and alumina (Al2O3) nanoparticles scattered in the regular (viscous) base fluid (H2O). Similarity variables are used to procure the similarity equations, and the numerical outcomes are achieved using bvp4c in MATLAB software. According to the findings, double solutions are feasible for stretching (λ>0) and shrinking cases (λ<0). The heat transfer rate is accelerated as the hybrid nanoparticles increases. The suction parameter enhances the friction factors as well as heat transfer rate. Moreover, the friction factor in the radial direction and heat transfer enrich for the first solution and moderate for the second outcome due to the augmentation δ1, while the trend of the friction factor in the radial direction is changed only in the case of stretching for both branches.

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Pootawang, Panuphong, Nagahiro Saito, and Sang Yul Lee. "Discharge time dependence of a solution plasma process for colloidal copper nanoparticle synthesis and particle characteristics." Nanotechnology 24, no. 5 (January 16, 2013): 055604. http://dx.doi.org/10.1088/0957-4484/24/5/055604.

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Sliem, Mahmoud A., Todor Hikov, Zi-An Li, Marina Spasova, Michael Farle, Diedrich A. Schmidt, Martina Havenith-Newen, and Roland A. Fischer. "Interfacial Cu/ZnO contact by selective photodeposition of copper onto the surface of small ZnO nanoparticles in non-aqueous colloidal solution." Physical Chemistry Chemical Physics 12, no. 33 (2010): 9858. http://dx.doi.org/10.1039/c003861j.

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Fuseini, Mohammed, Moustafa Mahmoud Yousry Zaghloul, Marwa F. Elkady, and Ahmed H. El-Shazly. "Evaluation of synthesized polyaniline nanofibres as corrosion protection film coating on copper substrate by electrophoretic deposition." Journal of Materials Science 57, no. 10 (March 2022): 6085–101. http://dx.doi.org/10.1007/s10853-022-06994-3.

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AbstractIn this current paper, we report the use of inexpensive, simple electrophoretic deposition (EPD) technique in developing polyaniline (PANI) aqueous colloidal suspension coating on copper (Cu) substrate. Polyaniline nanoparticle films were deposited electrophoretically on the surface of copper sheet electrode. A colloidal suspension with high stability was produced by a liquid polyaniline in the presence of formic acid and acetonitrile as electrolyte for the EPD process. The suspension of the PANI was characterized by measuring the zeta potential of the suspension using zeta-sizer analyser. The PANI coating was used as barrier for corrosion protection of the Cu sheet. Operating parameters such as operating time, applied voltage, and the concentration were used with deposition at the cathode. Characterization such as XRD, SEM, FT-IR, and UV–Vis was carried out, and the corrosion protection offered by the PANI on the Cu surface was examined using potentiodynamic (Tafel) polarization in 3.5% NaCl solution at room temperature. As a result, the optimum parameters for obtaining a homogenous coating on the Cu sheet were attained at the voltage of 15 V and deposition time of 180 s with 50 mg/mL PANI concentration. The attained results indicated inhibition efficiency for PANI deposit of 92.92% indicating protection against corrosion.

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Kudriavtseva, E. V., and A. A. Burinskaya. "INVESTIGATION OF THE EFFECT OF STABILIZERS ON THE STABILITY OF COLLOIDAL SOLUTIONS OF BIMETALLIC COPPER-SILVER NANOPARTICLES." Вестник Санкт-Петербургского государственного университета технологии и дизайна. Серия 1: Естественные и технические науки, no. 2 (2021): 101–6. http://dx.doi.org/10.46418/2079-8199_2021_2_16.

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Kudriavtseva, E. V., and A. A. Burinskaya. "INVESTIGATION OF THE EFFECT OF STABILIZERS ON THE STABILITY OF COLLOIDAL SOLUTIONS OF BIMETALLIC COPPER-SILVER NANOPARTICLES." Вестник Санкт-Петербургского государственного университета технологии и дизайна. Серия 1: Естественные и технические науки, no. 2 (2021): 101–6. http://dx.doi.org/10.46418/2079-8199_2021_2_16.

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Мусская, Ольга Николаевна, Валентина Константиновна Крутько, Анатолий Иосифович Кулак, and Евгений Николаевич Крутько. "MODIFICATION OF FIBER CELLULOSE MATERIALS WITH AMORPHIZED CALCIUM PHOSPHATES AND COPPER NANOPARTICLES." Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, no. 14 (December 15, 2022): 811–19. http://dx.doi.org/10.26456/pcascnn/2022.14.811.

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Этерификацией поверхности целлюлозных носителей фосфорной кислотой в присутствии мочевины получены волоконные материалы, характеризующиеся повышенной степенью набухания в водных средах (в 1,1-1,5 раза). Боргидридным методом с использованием натриевой соли карбоксиметилцеллюлозы в качестве полимера-стабилизатора синтезированы наночастицы меди и их композиты с аморфизированными фосфатами кальция. Полученные коллоидные растворы меди и их композиты с гидроксиапатитом характеризуются стабильностью от нескольких суток до 2 месяцев. Выявлено, что модифицирование целлюлозных (исходных и фосфорилированных) материалов иммерсионным методом с использованием водных составов, содержащих аморфизированные фосфаты кальция, наночастицы меди либо композиты на их основе, в присутствии натриевой соли карбоксиметилцеллюлозы и аскорбиновой кислоты при величине pH 6 и 11 приводит к снижению кристалличности полимерного носителя. Методом ИК-спектроскопии показано, что аморфизация модифицированных волоконных целлюлозных материалов обусловлена изменением статической однородности системы водородных связей в структуре полимера. Etherification of the surface of cellulose carriers with phosphoric acid in the presence of urea yielded fiber materials characterized by an increased degree of swelling in aqueous media (by a factor of 1,1-1,5). The copper nanoparticles and their composites with amorphized calcium phosphates were synthesized by the borohydride method using the sodium salt of carboxymethyl cellulose as a stabilizer polymer. The obtained colloidal solutions of copper and their composites with hydroxyapatite are characterized by stability from several days to 2 months. It was found that the modification of cellulose materials (initial and phosphorylated) by the immersion method using aqueous compositions containing amorphized calcium phosphates, copper nanoparticles or composites based on them in the presence of sodium carboxymethylcellulose and ascorbic acid at pH 6 and 11 leads to a decrease in the crystallinity of the polymer carrier. It has been shown by IR spectroscopy that the amorphization of modified fiber cellulose materials is due to a change in the static homogeneity of the system of hydrogen bonds in the polymer structure.

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Bagatskaya, H. M., R. V. Mazurenko, S. M. Makhno, and P. P. Gorbyk. "Influence of copper iodide particles of different dispersity on the fermentation activity of yeast cells Saccharomyces cerevisiae." Himia, Fizika ta Tehnologia Poverhni 13, no. 2 (June 30, 2022): 150–59. http://dx.doi.org/10.15407/hftp13.02.150.

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The effect of different dispersity copper iodide (CuI) particles on vital activity in an aqueous yeast suspension of organisms of the species Saccharomyces cerevisiae under anaerobic conditions under endogenous metabolism was studied by differential microcalorimetry. It has been found that an increase in the concentration of Cu+ to certain values leads to activation of the protective functions of cellular organisms, which is manifested in an increase in the energy costs of the yeast cell on the structural reorganization of the plasmolemma and possibly other membrane structures in order to counter the penetration of the bactericidal agent into the organism and its internal membrane structures. Upon reaching certain concentrations of Cu+, the yeast organism loses its original vitality, so that at its extreme values the organism completely stops its vital activity. The equilibrium concentration of Cu+ ions in aqueous solution for copper iodide nanoparticles is significantly higher in comparison with their microparticles, which is explained by the lower work function of CuI in the solution at the solid-liquid interface due to the increase in the curvature of the surface of the nanoparticle and the change in the surface tension at the interface.

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Karekar, Neha, Anik Karan, Elnaz Khezerlou, Neela Prajapati, Chelsea D. Pernici, Teresa A. Murray, and Mark A. DeCoster. "Self-Assembled Metal–Organic Biohybrids (MOBs) Using Copper and Silver for Cell Studies." Nanomaterials 9, no. 9 (September 8, 2019): 1282. http://dx.doi.org/10.3390/nano9091282.

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The novel synthesis of metal-containing biohybrids using self-assembly methods at physiological temperatures (37 °C) was compared for copper and silver using the amino acid dimer cystine. Once assembled, the copper containing biohybrid is a stable, high-aspect ratio structure, which we call CuHARS. Using the same synthesis conditions, but replacing copper with silver, we have synthesized cystine-capped silver nanoparticles (AgCysNPs), which are shown here to form stable colloid solutions in contrast to the CuHARS, which settle out from a 1 mg/mL solution in 90 min. Both the copper and silver biohybrids, as synthesized, demonstrate very low agglomeration which we have applied for the purpose of applications with cell culture methods, namely, for testing as anti-cancer compounds. AgCysNPs (1000 ng/mL) demonstrated significant toxicity (only 6.8% viability) to glioma and neuroblastoma cells in vitro, with concentrations as low as 20 ng/mL causing some toxicity. In contrast, CuHARS required at least 5 μg/mL. For comparative purposes, silver sulfate at 100 ng/mL decreased viability by 52% and copper sulfate at 100 ng/mL only by 19.5% on glioma cells. Using these methods, the novel materials were tested here as metal–organic biohybrids (MOBs), and it is anticipated that the functionalization and dynamics of MOBs may result in building a foundation of new materials for cellular applications, including cell engineering of both normal and diseased cells and tissue constructs.

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Omiri, Jessim, Youssef Snoussi, Arvind K. Bhakta, Stéphanie Truong, Souad Ammar, Ahmed M. Khalil, Mohamed Jouini, and Mohamed M. Chehimi. "Citric-Acid-Assisted Preparation of Biochar Loaded with Copper/Nickel Bimetallic Nanoparticles for Dye Degradation." Colloids and Interfaces 6, no. 2 (March 22, 2022): 18. http://dx.doi.org/10.3390/colloids6020018.

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Immobilization of nanocatalysts on biochar is receiving unprecedented interest among material and catalysis scientists due to its simplicity, versatility, and high efficiency. Herein, we propose a new direct approach to obtain bimetallic copper/nickel nanoparticles loaded on olive stone biochar. The bimetallic-coated biochar and the reference materials, namely bare biochar, copper rich-loaded biochar, and nickel-loaded biochar, were prepared by pyrolysis from olive pit powder particles impregnated first with citric acid (CA) and then with copper and nickel nitrates at 400 °C under nitrogen flow. We employed citric acid in the process in order to examine its effect on the structural and textural properties of biochar supporting the metallic nanoparticles. Surprisingly, citric acid induced the formation of agglomerated or even raspberry-shaped bimetallic copper/nickel nanoparticles. Large 450–500 nm agglomerates of ~80 nm bimetallic CuNi NPs were noted for B-CA@CuNi. Interestingly, for biochar material prepared with initial Cu/Ni = 10 molar ratio (B-CA@CuNi10/1), the bimetallic NPs formed unusual nanoraspberries (174 ± 8 nm in size), which were agglomerates of individual 10–20 nm CuNi10/1 nanoparticles. The B-CA@CuNi and reference materials were characterized by Raman spectroscopy, scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and magnetometry. The B-CA@CuNi and B-CA@Ni materials could be efficiently attracted with a magnet but not B-CA@CuNi10/1 due to the low nickel loading. B-CA@CuNi was tested as a catalyst for the degradation of methyl orange (MO). Discoloration was noted within 10 min, much faster than a similar material prepared in the absence of CA. B-CA@CuNi could be recycled at least 3 times while still exhibiting the same fast catalytic discoloration performance. This paper stresses the important role of citric acid in shaping bimetallic nanoparticles loaded in situ on biochar during the slow pyrolysis process and in enabling faster catalytic discoloration of organic dye solution.

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Asmat-Campos, D., D. Delfin-Narciso, L. Juárez-Cortijo, and R. Nazario-Naveda. "Influence of the volume of ascorbic acid in the synthesis of copper nanoparticles mediated by chemical pathway and its stability over time." IOP Conference Series: Earth and Environmental Science 897, no. 1 (November 1, 2021): 012010. http://dx.doi.org/10.1088/1755-1315/897/1/012010.

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Abstract In the present investigation, the effect of ascorbic acid volume in the synthesis of copper nanoparticles (Cu NPs) mediated by chemical route and their stability over time was evaluated. For the synthesis, copper sulfate pentahydrate CuSO4 (5H2O) was used as a precursor agent and ascorbic acid (AA) as a reducing agent. Cu NPs was characterized by the following techniques: UV-Visible spectrophotometry to evaluate structural changes that are evidenced in the absorbance peak and atomic absorption spectrophotometry to define nanoparticulate concentrations material in the precipitated and supernatant phases generated. On the methodology it was possible to observe a controlled formation based on the increase in the volume of ascorbic acid in the presence of sodium hydroxide, noticing a production of Cu nanostructures with a tendency to oxidation over time. The UV-visible results showed characteristic surface plasmon resonance peaks of metallic copper for the colloid containing 1.2 mL of A.A; as well as a specific copper concentration of 0.14 ppm in the supernatant and 1519.1 ppm in the precipitate. It is also evidenced that the solution exhibits a rapid reaction on exposure to air by shifting the absorbance peak to 386 nm. In addition, it does not present notable photosensitivity with respect to exposure to sunlight.

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Khomenko, I., O. Kosyk, and N. Taran. "The influence of cadmium and essential nanometals on the physiological And biochemical parameters of lettuce plants." Bulletin of Taras Shevchenko National University of Kyiv. Series: Biology 75, no. 1 (2018): 37–45. http://dx.doi.org/10.17721/1728_2748.2018.75.37-45.

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Due to the aim the effect of pre-sowing treatment with a nonionic colloidal solution of the mix of copper, zinc, manganese and iron nanoparticles, cadmium ions and their combined action on the physiological and biochemical indices: the content of lipid peroxidation products and balance of photosynthetic pigments in green Lolo and red Lolo Ross varieties of Lactuca sativa L. was investigated. Spectrophotometric methods of investigating the content of peroxides, thiobarbiturate-active products (with use of the modified Kumar and Knowles method), as well as the content of the main photosynthetic pigments (chlorophyll a, b, a/b ratio, and the carotenoid content) with the Wintermans, de Mots calculations application were used. Due to the results, a decrease in the content of peroxides and growth of malonic dialdehyde was observed for most treatment variants of Lolo. The opposite tendency was observed for the Ross variety (the initial growth of these parameters under the nanoparticles influence decreased to the control during the fourteen-day exposure). The decrease of chlorophyll content was observed In the Lolo variety under the essential metal nanoparticles influence, in contrast to the action of cadmium.For the Ross variety, a significant reduction of both chlorophyll and carotenoid contents in all treatment types during exposure was calculated.The a/b-index for Lolo plants has significantly increased in variants of cadmium influence, for Ross plants the divergence of the influence of all treatment variants has been marked. As a result, the treatment with a mixture of essential nanometals showed additive stress-loading functions. It was observed in a growth of the level of lipid peroxidation products and the reduction of the photosynthetic pigment biomarkers in both varieties during the 0,1 mM cadmium exposure. The Lolo Ross variety showed a higher variability of results under different treatment, compared to the Lolo variety.

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Bokshits, Yu V., G. P. Shevchenko, A. N. Ponyavina, and S. K. Rakhmanov. "Formation of Silver and Copper Nanoparticles upon the Reduction of Their Poorly Soluble Precursors in Aqueous Solution." Colloid Journal 66, no. 5 (September 2004): 517–22. http://dx.doi.org/10.1023/b:coll.0000043830.66390.72.

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Liu, Zhi Ming, Xue Feng Wang, and Wen Jian Wu. "Biomimetic Films of BLMs Based on Conductive Hybrid Films of Au NPs and Cellulose." Applied Mechanics and Materials 461 (November 2013): 373–80. http://dx.doi.org/10.4028/www.scientific.net/amm.461.373.

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A new type of biomimetic films of bilayer lipid membrane (BLM) supported by conductive hybrid film of Au nanoparticles (Au NPs) and cellulose is developed. The facile preparation method of the conductive hybrid films and the relevant micro conducting mechanism under electrochemical redox environment are revealed. The regenerated cellulose film is prepared from the cellulose/N-methylmorpholine N-oxide monohydrate solution. After the cellulose film is regenerated by deionized water, Au NPs in the colloid react with the newborn cellulose film. Rectangular pieces of dry hybrid films with one ends clamped with copper foil are used as electrodes. The lipid solution of phospholipid and cholesterol with a ratio of 3:1 is brushed onto the surface of dry hybrid films. There are only reducing currents in the cyclic voltammetry responses of biomimetic films under the aqueous electrolyte solution of 0.1 mol/L KCl, 1 mmol/L K3[Fe (CN)6] and 1 mmol/L K4[Fe (CN)6]. It means that the anions of [Fe (CN)6]4- are almost impossible to be oxidized into [Fe (CN)6]3- by the positively charged surfaces of Au NPs under voltages below 0.3 V.

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Huang, Shuai, Yunhe Wang, Si Shen, Yuting Tang, Ancan Yu, Bonan Kang, S. Ravi P. Silva, and Geyu Lu. "Enhancing the performance of polymer solar cells using solution-processed copper doped nickel oxide nanoparticles as hole transport layer." Journal of Colloid and Interface Science 535 (February 2019): 308–17. http://dx.doi.org/10.1016/j.jcis.2018.10.013.

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Yulia, Pysmenna, Panyuta Olha, and Taran Natalia. "The effect of pre-sowing seed treatment with nonionic colloidal solutions of silver and copper metal nanoparticles on growth and water-retaining ability of winter wheat seedlings." Chornomorski Botanical Journal 14, no. 1 (May 30, 2018): 26–31. http://dx.doi.org/10.14255/2308-9628/18.141/2.

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Ясная, Мария Анатольевна, Андрей Владимирович Блинов, Алексей Борисович Голик, Давид Гурамиевич Маглакелидзе, Алексей Алексеевич Гвозденко, Александр Александрович Кравцов, and Анастасия Александровна Блинова. "INFLUENCE OF THE POLYETHYLENE GLYCOL MOLECULAR MASS ON THERMAL TRANSITIONS OF NANOSIZED COPPER OXIDE." Physical and Chemical Aspects of the Study of Clusters, Nanostructures and Nanomaterials, no. 13 (December 23, 2021): 937–46. http://dx.doi.org/10.26456/pcascnn/2021.13.937.

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В данной работе получены образцы наноразмерного оксида меди, стабилизированного полиэтиленгликолем различных марок с молекулярными массами от 200 до 6000 Да. Методом рентгеновской дифрактометрии исследована кристаллическая структура полученных образцов наноразмерного оксида меди. В результате рентгенофазового анализа установлено, что структура образцов представляет собой моноклинную кристаллическую решетку, с пространственной группой C2/ c. Методом фотонно-корреляционной спектроскопии изучено влияние молекулярной массы полимера на размер наночастиц. Анализ результатов исследования показал наличие во всех образцах наноразмерного оксида меди (II), стабилизированного полиэтиленгликолем с различной молекулярной массой, одной фракции частиц, распределение которых по размеру носит мономодальный характер. Установлено, что молекулярная масса полиэтиленгликоля оказывает, влияние на размер частиц CuO в коллоидных растворах, при этом фазовый состав и размеры кристаллитов остаются неизменными. Средний гидродинамический радиус частиц CuO в полученных образцах составляет порядка 140 ± 40 нм. Наименьшие значения гидродинамического радиуса 70 ± 15 нм наблюдаются в образце наноразмерного оксида меди, стабилизированного полиэтиленгликолем с молярной массой 6000 Дa. Методом синхронного термического анализа исследовано влияние стабилизатора с различными молекулярными массами на фазовые переходы образцов при термической обработке. В результате термического анализа установлено, что оптимальной температурой прокаливания порошков наноразмерного CuO является 500°C. In this work, samples of nanosized copper oxide stabilized with polyethylene glycol of various grades with molecular weights from 200 to 6000 Da were obtained. The crystal structure of the samples was investigated by X-ray diffractometry. As a result of the XRD analysis, it was found that the samples have a monoclinic crystal lattice with space group C2 / c . The effect of the molecular weight of the polymer on the size of nanoparticles was studied by the photon correlation spectroscopy method. Analysis of the results showed the presence of one fraction of particles in all samples, the size distribution was monomodal. It was found that the molecular weight of polyethylene glycol has an effect on the CuO particle size in colloidal solutions, while the phase composition and crystallite size remain unchanged. The average hydrodynamic radius of CuO particles in the obtained samples was about 140 ± 40 nm. The smallest hydrodynamic radius of 70 ± 15 nm was observed in a sample of nanosized copper oxide stabilized with polyethylene glycol with a molecular weight of 6000 Da. The effect of stabilizers with different molecular weights on the phase transitions of samples during heat treatment was investigated by the synchronous thermal analysis. As a result of thermal analysis, it was found that the optimum temperature for calcining nanosized CuO powders was 500 °C.

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Mikhlin, Yuri, Sergey Vorobyev, Svetlana Saikova, Yevgeny Tomashevich, Olga Fetisova, Svetlana Kozlova, and Sergey Zharkov. "Preparation and characterization of colloidal copper xanthate nanoparticles." New Journal of Chemistry 40, no. 4 (2016): 3059–65. http://dx.doi.org/10.1039/c6nj00098c.

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Akhtar, Masood, Yousef Alghamdi, Javeed Akhtar, Zabeada Aslam, Neerish Revaprasadu, and Mohammad Azad Malik. "Phase controlled synthesis of copper sulfide nanoparticles by colloidal and non-colloidal methods." Materials Chemistry and Physics 180 (September 2016): 404–12. http://dx.doi.org/10.1016/j.matchemphys.2016.06.024.

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Al-Johani, Basma, Amna N. Khan, Zahra M. Alamshany, Munazza Gull, Elham S. Azam, Samia A. Kosa, and M. Tahir Soomro. "Synthesis, Electrochemical and Antimicrobial Activity of Colloidal Copper Nanoparticles." Biosciences, Biotechnology Research Asia 14, no. 4 (December 25, 2017): 1259–68. http://dx.doi.org/10.13005/bbra/2568.

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ABSTRACT: The colloidal dispersion of copper nanoparticles (CuNPs), prepared by reducing Cu2+ ions using ascorbic acid, was characterized and used for electrochemical and antimicrobial activity investigations. By depositing CuNPs onto the glassy carbon electrode (GCE) surface the CuNPs/GCE was constructed, which was used to study electrochemical behavior of CuNPs and to carry out direct electrochemical detection of trichloroacetic acid (TCA) and 2-chlorophenol (2-CP) in neutral medium. Excellent electrocatalytic ability of CuNPs, assessed by cyclic voltammetry (CV), for the reduction of TCA and 2-CP was detected. The electrochemical impedance analysis (EIS) of the GCE and CuNPs modified GCE evidenced higher charge transfer activity across the modified electrode surface. The antibacterial activity tests of as-synthesized CuNPs on the selected pathogenic strains of pathogenic strains of Salmonella group B (7.9±0.912), Klebsiella pneumonia (8.33±1.561), Escherichia Coli (15.65±1.612), Enterococcus faecalis (5.4±0.612), Staphylococcus aureus (12.6±1.531) and yeast Candida albicans (11.4.3±1.512), respectively, were performed. The results indicated that the use of CuNPs can be pursued as an alternative strategy (to antibiotics) for averting infections by controlling bacterial adhesion and bacterial bio-film formation against microbial infections.

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Saito, Genki, Sou Hosokai, Masakatsu Tsubota, and Tomohiro Akiyama. "Synthesis of copper/copper oxide nanoparticles by solution plasma." Journal of Applied Physics 110, no. 2 (July 15, 2011): 023302. http://dx.doi.org/10.1063/1.3610496.

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Lin, Yiliang, Yang Liu, Jan Genzer, and Michael D. Dickey. "Shape-transformable liquid metal nanoparticles in aqueous solution." Chemical Science 8, no. 5 (2017): 3832–37. http://dx.doi.org/10.1039/c7sc00057j.

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Maksimović, Vesna, Milovan Stoiljković, Vladimir Pavkov, Jovan Ciganović, and Ivana Cvijović‐Alagić. "Arc Plasma Deposition of TiO2 Nanoparticles from Colloidal Solution." Metallurgical and Materials Engineering 26, no. 4 (December 31, 2020): 341–48. http://dx.doi.org/10.30544/587.

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Surface modifications of metallic biomaterials can in great merit, improve the properties of the hard-tissue implants and in that way contribute to the success of the surgical implantation process. Coating deposition stands out as one of the many surface-modifying techniques that can be used to improve implant surface properties and, in turn, induce successful osseointegration. Deposition of the TiO2 layer on the surface of the metallic implants has a great potential to enhance not only their osseointegration ability but also their biocompatibility and corrosion resistance. In the present study, the possibility of successful deposition of the TiO2 layer on the surface of commercially pure titanium (CP-Ti), as the most commonly used metallic implant material, by spraying the colloidal nanoparticles aqueous solution in the electric discharge plasma at atmospheric pressure was investigated. To characterize the colloidal TiO2 nanoparticle solution, used for the coating deposition process, transmission electron microscopy (TEM) was utilized, while scanning electron microscopy (SEM) and optical profilometry were used to investigate the deposited surface layer morphology and quality. Estimation of the deposited film quality and texture was used to confirm that the arc plasma deposition technique can be successfully used as an advanced and easy-to-apply method for coating the metallic implant material surface with the bioactive TiO2 layer which favors the osseointegration process through the improvement of the implant surface properties. The TiO2 coating was successfully deposited using the arc plasma deposition technique and covered the entire surface of the CP-Ti substrate without any signs of coating cracking or detachment.

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Jin, Yizheng, Jianpu Wang, Baoquan Sun, James C. Blakesley, and Neil C. Greenham. "Solution-Processed Ultraviolet Photodetectors Based on Colloidal ZnO Nanoparticles." Nano Letters 8, no. 6 (June 2008): 1649–53. http://dx.doi.org/10.1021/nl0803702.

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Sadovnikov, S. I., Yu V. Kuznetsova, and A. A. Rempel. "Synthesis of a stable colloidal solution of PbS nanoparticles." Inorganic Materials 50, no. 10 (August 23, 2014): 969–75. http://dx.doi.org/10.1134/s0020168514100148.

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Ago, Hiroki, Satoshi Ohshima, Kunio Uchida, Toshiki Komatsu, and Motoo Yumura. "Carbon nanotube synthesis using colloidal solution of metal nanoparticles." Physica B: Condensed Matter 323, no. 1-4 (October 2002): 306–7. http://dx.doi.org/10.1016/s0921-4526(02)01032-3.

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Adams, Sarah M., Salvatore Campione, Filippo Capolino, and Regina Ragan. "Directing Cluster Formation of Au Nanoparticles from Colloidal Solution." Langmuir 29, no. 13 (March 22, 2013): 4242–51. http://dx.doi.org/10.1021/la3051719.

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Park, Yoonsu, Hyeri Kang, Wooseok Jeong, Hyungbin Son, and Don-Hyung Ha. "Electrophoretic Deposition of Aged and Charge Controlled Colloidal Copper Sulfide Nanoparticles." Nanomaterials 11, no. 1 (January 8, 2021): 133. http://dx.doi.org/10.3390/nano11010133.

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Colloidal nanoparticles (NPs) have been recently spotlighted as building blocks for various nanostructured devices. Their collective properties have been exhibited by arranging them on a substrate to form assembled NPs. In particular, electrophoretic deposition (EPD) is an emerging fabrication method for such nanostructured films. To maximize the benefits of this method, further studies are required to fully elucidate the key parameters that influence the NP deposition. Herein, two key parameters are examined, namely: (i) the aging of colloidal NPs and (ii) the charge formation by surface ligands. The aging of Cu2-xS NPs changes the charge states, thus leading to different NP deposition behaviors. The SEM images of NP films, dynamic light scattering, and zeta potential results demonstrated that the charge control and restoration of interparticle interactions for aged NPs were achieved via simple ligand engineering. The charge control of colloidal NPs was found to be more dominant than the influence of aging, which can alter the surface charges of the NPs. The present results thus reveal that the charge formation on the colloidal NPs, which depends on the surface ligands, is an important controllable parameter in EPD.

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

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