Artículos de revistas: "Alkaline nanoparticles"

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Dutka, R. M. "Peculiarities of Ag metallic nanoparticles formation in alkaline and alkaline-earth tetraborate glasses". Functional materials 22, n.º 2 (30 de junio de 2015): 155–61. http://dx.doi.org/10.15407/fm22.02.155.

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Sánchez M., J. F., H. A. Ritacco y M. D. Sánchez. "FORMATION OF PALLADIUM NANOPARTICLES BY THE POLYOL METHOD:INFLUENCE OF ALKALINE CONDITIONS". Anales AFA 33, n.º 4 (15 de enero de 2023): 103–11. http://dx.doi.org/10.31527/analesafa.2022.33.4.103.

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The effect of sodium hydroxide (NaOH) on the size of palladium (Pd) nanoparticles obtained by the simple polyol route was studied. Nanoparticles were synthesized at room temperature using palladium(II) chloride (PdCl2) and NaOH dissolved in ethylene glycol (EG) as reduction reaction promoters. No protective agents or stabilizers were used. We monitored the reaction kinetics and the growth of the nanoparticles by UV-vis spectroscopy and their crystallinity by powder X-ray diffraction (XRD) as a function of NaOH concentration. Crystallite size was evaluated from the diffraction pattern. We found that nanoparticle growth is strongly influenced by the NaOH: Pd molar ratio. Crystallite sizes from 2 to 24 nm were obtained for molar ratios ranging from 1 to 33. At lower concentrations of NaOH, the nucleation and growth process of the nanoparticles were found to be controlled by the reduction of the Pd ion precursors.At higher concentrations, the intermediate reduction of Pd-Cl-OH species determines the nanoparticle growth rate resulting in the formation of the smallest final-size nanoparticles.

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Sutthavas, Pichaporn, Matthias Schumacher, Kai Zheng, Pamela Habibović, Aldo Roberto Boccaccini y Sabine van Rijt. "Zn-Loaded and Calcium Phosphate-Coated Degradable Silica Nanoparticles Can Effectively Promote Osteogenesis in Human Mesenchymal Stem Cells". Nanomaterials 12, n.º 17 (24 de agosto de 2022): 2918. http://dx.doi.org/10.3390/nano12172918.

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Nanoparticles such as mesoporous bioactive glasses (MBGs) and mesoporous silica nanoparticles (MSN) are promising for use in bone regeneration applications due to their inherent bioactivity. Doping silica nanoparticles with bioinorganic ions could further enhance their biological performance. For example, zinc (Zn) is often used as an additive because it plays an important role in bone formation and development. Local delivery and dose control are important aspects of its therapeutic application. In this work, we investigated how Zn incorporation in MSN and MBG nanoparticles impacts their ability to promote human mesenchymal stem cell (hMSC) osteogenesis and mineralization in vitro. Zn ions were incorporated in three different ways; within the matrix, on the surface or in the mesopores. The nanoparticles were further coated with a calcium phosphate (CaP) layer to allow pH-responsive delivery of the ions. We demonstrate that the Zn incorporation amount and ion release profile affect the nanoparticle’s ability to stimulate osteogenesis in hMSCs. Specifically, we show that the nanoparticles that contain rapid Zn release profiles and a degradable silica matrix were most effective in inducing hMSC differentiation. Moreover, cells cultured in the presence of nanoparticle-containing media resulted in the highest induction of alkaline phosphate (ALP) activity, followed by culturing hMSC on nanoparticles immobilized on the surface as films. Exposure to nanoparticle-conditioned media did not increase ALP activity in hMSCs. In summary, Zn incorporation mode and nanoparticle application play an important role in determining the bioactivity of ion-doped silica nanoparticles.

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Lee, Jae Hoon, Tae Min Kim, In-Gyu Choi y Joon Weon Choi. "Phenolic Hydroxyl Groups in the Lignin Polymer Affect the Formation of Lignin Nanoparticles". Nanomaterials 11, n.º 7 (9 de julio de 2021): 1790. http://dx.doi.org/10.3390/nano11071790.

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Alkaline soda lignin (AL) was sequentially fractionated into six fractions of different molecular size by means of solvent extraction and their phenolic hydroxyl groups were chemoselectively methylated to determine their effect on nanoparticle formation of lignin polymers. The effect of the lignin structure on the physical properties of nanoparticles was also clarified in this study. Nanoparticles were obtained from neat alkaline soda lignin (ALNP), solvent-extracted fractions (FALNPs, i.d. 414–1214 nm), and methylated lignins (MALNPs, i.d. 516–721 nm) via the nanoprecipitation method. Specifically, the size properties of MALNPs showed a high negative correlation (R2 = 0.95) with the phenolic hydroxyl group amount. This indicates that the phenolic hydroxyl groups in lignin could be influenced on the nucleation or condensation during the nanoprecipitation process. Lignin nanoparticles exhibited high colloidal stability, and most of them also showed good in vitro cell viability. This study presents a possible way to control nanoparticle size by blocking specific functional groups and decreasing the interaction between hydroxyl groups of lignin.

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Qiu, Lang, Hengbo Yin, Aili Wang, Lingqin Shen y Wei Tao. "Oxidation of 1,2-Propanediol to Carboxylic Acid Over Hydroxyapatite Nanorod-Supported Metallic Cu0 Nanoparticles". Journal of Nanoscience and Nanotechnology 20, n.º 3 (1 de marzo de 2020): 1723–31. http://dx.doi.org/10.1166/jnn.2020.16985.

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Hydroxyapatite nanorod-supported metallic Cu0 nanoparticle catalysts (Cux/HAP) were prepared by the wetness chemical reduction method. The metallic Cu0 nanoparticles were well dispersed on the surfaces of the HAP nanorods. The alkaline HAP nanorods inhibited the crystal growth of the metallic Cu0 nanoparticles. The HAP nanorods also retarded the oxidation of the metallic Cu0 nanoparticles. The Cux/HAP catalyst exhibited a higher catalytic activity for the oxidation of 1,2-propanediol with gaseous oxygen to lactic, acetic, and formic acids with the total selectivity of 70.3% even at a lower reaction temperature of 140 °C. The total selectivity of lactic, acetic, and formic acids reached 93.1% at a mild reaction temperature of 180 °C. However, the sole monometallic Cu0 nanoparticles or HAP nanorods had no catalytic activity for the oxidation of 1,2-propanediol. The metallic Cu0 nanoparticles and alkaline HAP nanorods in the Cux/HAP catalyst synergistically catalyzed the oxidation of 1,2-propanediol to carboxylic acid.

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Anish, M., Ignatius Raja, K. Rahul, J. Jayaprabakar, Nivin Joy y P. Bency. "The Experimental Investigation of Heat Transfer Properties and Pressure Drop of a Corrugated Plate Heat Exchanger Using a Chemically Synthesised Zinc Oxide/Alkaline Water Nano Fluid". Journal of Nanofluids 12, n.º 2 (1 de marzo de 2023): 405–17. http://dx.doi.org/10.1166/jon.2023.1931.

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An experiment is performed to study the effects of chemically synthesized Zinc Oxide-Alkaline/water nanofluid on the pressure drop and heat convection properties of a corrugated plate heat exchanger. Nanofluids are chemically synthesised ZnO nanoparticles with diameters ranging from 200 nm to 99% purity. The weight and Reynolds number of these particles are studied to define the heat transfer properties of the finished products. The heat transfer characteristics of chemically produced ZnO are examined as a work of weight percentage and Reynolds number. In addition, the effect of adding nanoparticles to alkaline water on heat transfer coefficient is studied. The effect of increasing the nanoparticle weight concentrations and Reynolds number on the heat transfer characteristics of chemically produced ZnO-Alkaline/Water nano fluid is investigated. The results show that increasing the weight concentration of nanofluid in the corrugated plate heat exchanger enhances the heat transfer properties. At 0.2%, 0.6%, and 1.0% weight fractions of nanoparticles, the highest argumentation of the nanofluid heat transfer rate is approximately 8.6%, 16.7%, and 29.4%, respectively.

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Ikeda, Shoichiro, Akinari Nobumoto, Hideo Ono, Shinji Ono, Shinji Kawasaki y Mohamad Rusop. "Hydrophilic Carbon Nano-Particles; Preparation and Applications". Advanced Materials Research 1109 (junio de 2015): 232–37. http://dx.doi.org/10.4028/www.scientific.net/amr.1109.232.

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The hydrophilic carbon nanoparticles have been produced from synthetic graphite blocks by the electrochemical oxidation method in pure water. The resulting electrolyzed solution contains colloidal carbon nanoparticles (mean diameter is ca. 400 nm) and shows the pH value of around 2.5. The colloidal state of the solution is maintained more than a several years. After evaporation of water from the solution, carbon powders are obtained, which show a high solubility to water, namely the powder is hydrophilic. The electrolyzed solution containing carbon nanoparticles directly used as the electrical conductivity enhancer for the restoring the deteriorated lead-acid batteries by electrochemical method. The hydrophilic carbon nanoparticles were used as the environmental friendly solid-lubricant for the mechanical cutting coolants. In the case of aqueous coolants, the oily substances are used in the emulsion state in usual. By using the hydrophilic carbon nanoparticle suspension, no surfactants and no oily substances are required to maintain the suspension state. However, the cutting coolants are used in the pH values of alkaline state near 10, so the hydrophilic carbon nanoparticle solution has been neutralized by alkaline substances such as alkanolamines. In the case of oily cutting fluids for heavy duties, carbon mamo-particle powders are used after neutralized by basic barium dinonylnaphthalenesulfonate. The aqueous solutions of hydrophilic carbon nanoparticles exhibit the ability of sanitization effects to the cutting fluids and prolong the life times of them.

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Patil Machindra Balwant y Bhangale Pallavi Ravindra. "Greenery method for Synthesis of some alkali and alkaline earth metallic nanoparticles and its antibacterial screening activity". World Journal of Advanced Research and Reviews 16, n.º 3 (30 de diciembre de 2022): 494–504. http://dx.doi.org/10.30574/wjarr.2022.16.3.1356.

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In the presence study of science and technology has greater significance for the development of nanoparticles and its physicochemical properties. Alkali and alkaline earth metalic nanoparticle has synthesized by using various plant extract and metalic solution. However, biogenic reduction of metal precursors to produce corresponding metalic nanoparticle is eco-friendly, low cost, free of chemical contaminants for medical and biological applications. The synthesized Metallic nanoparticle is found to be more susceptible towards the bacterial strains.

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Chen, Qiu Ling, Wan Lin, Qiu Ling Chen y Shuang Bao Wang. "Study on the Effect of Fe₃O₄ Nanoparticle Dopants on the Properties of Magneto Optical Glasses". Advanced Materials Research 213 (febrero de 2011): 330–33. http://dx.doi.org/10.4028/www.scientific.net/amr.213.330.

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Fe3O4 nanoparticles doped magnetic-optical PbO-Bi2O3-B2O3 glasses were prepared and studied and the effects of Fe3O4 nanoparticle on the properties of magnetic-optical glass were analyzed. It is found that the doping of Fe3O4 nanoparticles into glasses increased the Verdet constant of magneto optical glass without evident degradation in glass transmittance. The formation of Fe3O4 nanoparticles was obtained through coprecipitation of Fe(II) and Fe(III) in alkaline media. The structure and properties of doped glasses were studied by X-ray diffraction (XRD), scanning electric microscope (SEM), UV-VIS spectray analysis and Faraday rotation test etc.

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Quinson, Jonathan, Søren Bredmose Simonsen, Luise Theil Kuhn y Matthias Arenz. "Commercial Spirits for Surfactant-Free Syntheses of Electro-Active Platinum Nanoparticles". Sustainable Chemistry 2, n.º 1 (4 de enero de 2021): 1–7. http://dx.doi.org/10.3390/suschem2010001.

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The Co4CatTM process is a simple, surfactant-free method to produce colloidal dispersions of precious metal nanoparticles in alkaline mono-alcohols. The synthesis is performed in low-boiling-point solvents and is relevant for industrial production. The robustness of the process is demonstrated by using three different commercial spirits as solvents to obtain Pt nanoparticles. The results demonstrate that careful control of the solvent purity is not needed to achieve the synthesis of stable 2 nm platinum nanoparticle colloids readily active electrocatalysts for energy conversion reactions like the methanol oxidation.

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Wang, Yan, Ying Yan, Xinfa Liu y Changbei Ma. "An Exonuclease I-Aided Turn-Off Fluorescent Strategy for Alkaline Phosphatase Assay Based on Terminal Protection and Copper Nanoparticles". Biosensors 11, n.º 5 (29 de abril de 2021): 139. http://dx.doi.org/10.3390/bios11050139.

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As an important DNA 3′-phosphatase, alkaline phosphatase can repair damaged DNA caused by replication and recombination. It is essential to measure the level of alkaline phosphatase to indicate some potential diseases, such as cancer, related to alkaline phosphatase. Here, we designed a simple and fast method to detect alkaline phosphatase quantitively. When alkaline phosphatase is present, the resulting poly T-DNA with a 3′-hydroxyl end was cleaved by exonuclease I, prohibiting the formation of fluorescent copper nanoparticles. However, the fluorescent copper nanoparticles can be monitored with the absence of alkaline phosphatase. Hence, we can detect alkaline phosphatase with this turn-off strategy. The proposed method is able to quantify the concentration of alkaline phosphatase with the LOD of 0.0098 U/L. Furthermore, we utilized this method to measure the effects of inhibitor Na3VO4 on alkaline phosphatase. In addition, it was successfully applied to quantify the level of alkaline phosphatase in human serum. The proposed strategy is sensitive, selective, cost effective, and timesaving, having a great potential to detect alkaline phosphatase quantitatively in clinical diagnosis.

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12

Chen, Xian, Dengfeng Peng y Feng Wang. "Tuning NaYF4 Nanoparticles through Alkaline Earth Doping". Nanomaterials 3, n.º 4 (24 de octubre de 2013): 583–91. http://dx.doi.org/10.3390/nano3040583.

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13

Jafary, Fariba, Jaleh Varshosaz, Mojtaba Panjehpour y Parichehr Yaghmaei. "Immobilization of alkaline phosphatase using chitosan nanoparticles". Russian Journal of Applied Chemistry 88, n.º 5 (mayo de 2015): 891–97. http://dx.doi.org/10.1134/s1070427215050262.

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14

Cuevas, R., N. Durán, M. C. Diez, G. R. Tortella y O. Rubilar. "Extracellular Biosynthesis of Copper and Copper Oxide Nanoparticles byStereum hirsutum, a Native White-Rot Fungus from Chilean Forests". Journal of Nanomaterials 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/789089.

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The white-rot fungusStereum hirsutumwas studied to evaluate its applicability for use in the biosynthesis of copper/copper oxide nanoparticles under different pH conditions and in the presence of three different copper salts (CuCl2, CuSO4, and Cu(NO3)2). The nanoparticle formation was evaluated by UV-visible spectroscopy, electron microscopy (TEM), X-ray diffraction analysis (XRD), and Fourier transforms infrared spectroscopy (FTIR). The nanoparticles biosynthesis in presence of all copper salts demonstrated higher formation with 5 mM CuCl2under alkaline conditions. TEM analysis confirmed that the nanoparticles were mainly spherical (5 to 20 nm). The presence of amine groups attached to nanoparticles was confirmed by FTIR, which suggests that extracellular protein of fungus is responsible for the formation of the nanoparticles. Therefore, the white-rot fungusS. hirsutumwas found to exhibit potential for use in the synthesis of copper/copper oxide nanoparticles.

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Carissimi, Guzmán, A. Abel Lozano-Pérez, Mercedes G. Montalbán, Salvador D. Aznar-Cervantes, José Luis Cenis y Gloria Víllora. "Revealing the Influence of the Degumming Process in the Properties of Silk Fibroin Nanoparticles". Polymers 11, n.º 12 (9 de diciembre de 2019): 2045. http://dx.doi.org/10.3390/polym11122045.

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Several studies have stated that the process used for sericin removal, or degumming, from silk cocoons has a strong impact in the silk fibroin integrity and consequently in their mechanical or biochemical properties after processing it into several biomaterials (e.g. fibers, films or scaffolds) but still, there is a lack of information of the impact on the features of silk nanoparticles. In this work, silk cocoons were degummed following four standard methods: autoclaving, short alkaline (Na2CO3) boiling, long alkaline (Na2CO3) boiling and ultrasounds. The resultant silk fibroin fibers were dissolved in the ionic liquid 1-ethyl-3-methylimidazolium acetate and used for nanoparticle synthesis by rapid desolvation in polar organic solvents. The relative efficiencies of the degumming processes and the integrity of the resulting fibroin fibers obtained were analyzed by mass loss, optical microscopy, thermogravimetric analysis, infrared spectroscopy and SDS-PAGE. Particle sizes and morphology were analyzed by Dynamic Light Scattering and Field Emission Scanning Electronic Microscopy. The results showed that the different treatments had a remarkable impact on the integrity of the silk fibroin chains, as confirmed by gel electrophoresis, which can be correlated with particle mean size and size distribution changes. The smallest nanoparticles (156 ± 3 nm) and the most negative Z potential (−30.2 ± 1.8 mV) were obtained with the combination of long treatment (2 h) of boiling in alkaline solution (Na2CO3 0.02 eq/L). The study confirms that parameters of the process, such as composition of the solution and time of the degumming step, must be controlled in order to reach an optimum reproducibility of the nanoparticle production.

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Guerra-Balcázar, M., J. Torres-González, I. Terol-Villalobos, J. Morales-Hernández y F. Castañeda. "Glassy Carbon Electrode-Supported Au Nanoparticles for the Glucose Electrooxidation: On the Role of Crystallographic Orientation". Journal of Nanomaterials 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/387581.

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Glucose electrooxidation in alkaline solution was examined using glassy carbon electrodes modified with Au nanoparticles. Au nanoparticles were prepared following the two-phase protocol and characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, X-ray diffraction spectroscopy (XRD), and cyclic voltammetry (CV). It was found that, under the study conditions, it is possible to obtain nanoparticles between 1 and 5 nm; also it was found that the crystallographic orientation is strongly influenced by the ratio metal/thiol and to a lesser extent by the synthesis temperature. The voltammetric response for the electrocatalytic oxidation of glucose at carbon Au nanoparticle-modified electrode shows an increasing activity with nanoparticles size. Electroactivity and possibly selectivity are found to be nanoparticles' crystallographic orientation dependent. Classical electrochemical analysis shows that glucose electrooxidation is a diffusion-controlled process followed by a homogenous reaction.

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Pourali, Parastoo, Oldřich Benada, Miroslav Pátek, Eva Neuhöferová, Volha Dzmitruk y Veronika Benson. "Response of Biological Gold Nanoparticles to Different pH Values: Is It Possible to Prepare Both Negatively and Positively Charged Nanoparticles?" Applied Sciences 11, n.º 23 (6 de diciembre de 2021): 11559. http://dx.doi.org/10.3390/app112311559.

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The mycelium-free supernatant (MFS) of a five-day-old culture medium of Fusarium oxysporum was used to synthesize gold nanoparticles (AuNPs). The experimental design of the study was to answer the question: can this production process of AuNPs be controllable like classical chemical or physical approaches? The process of producing AuNPs from 1 mM tetrachloroauric (III) acid trihydrate in MFS was monitored visually by color change at different pH values and quantified spectroscopically. The produced AuNPs were analyzed by transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The presence of capping agents was confirmed by Fourier transform infrared spectroscopy (FTIR). Two AuNP samples with acidic and alkaline pH were selected and adjusted with the pH gradient and analyzed. Finally, the size and zeta potential of all samples were determined. The results confirmed the presence of the proteins as capping agents on the surface of the AuNPs and confirmed the production of AuNPs at all pH values. All AuNP samples exhibited negative zeta potential, and this potential was higher at natural to alkaline pH values. The size distribution analysis showed that the size of AuNPs produced at alkaline pH was smaller than that at acidic pH. Since all samples had negative charge, we suspect that there were other molecules besides proteins that acted as capping agents on the surface of the AuNPs. We conclude that although the biological method of nanoparticle production is safe, green, and inexpensive, the ability to manipulate the nanoparticles to obtain both positive and negative charges is limited, curtailing their application in the medical field.

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Papagiannis, Ioannis, Mauro S. Innocente y Evangelos I. Gkanas. "Synthesis and Characterisation of Iron Oxide Nanoparticles with Tunable Sizes by Hydrothermal Method". Materials Science Forum 1053 (17 de febrero de 2022): 176–81. http://dx.doi.org/10.4028/p-0so8ha.

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The present study investigates the effect of different reaction times on the crystallinity, surface morphology and size of iron oxide nanoparticles. In this synthetic system, aqueous iron (III) nitrate (Fe (NO3)3·9H2O) nonahydrate, provided the iron source and triethylamine was the precipitant and alkaline agent. The as-synthesised iron oxide nanoparticles were characterised by X-ray diffraction (XRD), Rietveld analysis, Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Prolonged reaction times indicated the change on nanoparticle shape from elongated nanorods to finally distorted nanocubes. Analysis on the crystallinity of the iron oxide nanoparticles suggest that the samples mainly consist of two phases, which are Goethite (α-FeOOH) and Hematite (α-Fe2O3) respectively.

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Eggermont, Sam G. F., Rafael Prato, Xochitl Dominguez-Benetton y Jan Fransaer. "Oxidation-assisted alkaline precipitation of nanoparticles using gas-diffusion electrodes". Reaction Chemistry & Engineering 6, n.º 6 (2021): 1031–41. http://dx.doi.org/10.1039/d0re00463d.

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By benchmarking gas-diffusion electrocrystallization against alkaline precipitation for the synthesis of (hydr)oxide nanoparticles, oxidation-assisted precipitation of magnetite nanoparticles was demonstrated.

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Marć, Maciej, Andrzej Drzewiński, Wiktor W. Wolak, Lidia Najder-Kozdrowska y Mirosław R. Dudek. "Filtration of Nanoparticle Agglomerates in Aqueous Colloidal Suspensions Exposed to an External Radio-Frequency Magnetic Field". Nanomaterials 11, n.º 7 (1 de julio de 2021): 1737. http://dx.doi.org/10.3390/nano11071737.

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The study investigated the phenomenon of the fast aggregation of single-domain magnetic iron oxide nanoparticles in stable aqueous colloidal suspensions due to the presence of a radio-frequency (RF) magnetic field. Single-domain nanoparticles have specific magnetic properties, especially the unique property of absorbing the energy of such a field and releasing it in the form of heat. The localized heating causes the colloid to become unstable, leading to faster agglomeration of nanoparticles and, consequently, to rapid sedimentation. It has been shown that the destabilization of a stable magnetic nanoparticle colloid by the RF magnetic field can be used for the controlled filtration of larger agglomerates of the colloid solution. Two particular cases of stable colloidal suspensions were considered: a suspension of the bare nanoparticles in an alkaline solution and the silica-stabilized nanoparticles in a neutral solution. The obtained results are important primarily for biomedical applications and wastewater treatment.

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Rák, Zs y D. W. Brenner. "Negative Surface Energies of Nickel Ferrite Nanoparticles under Hydrothermal Conditions". Journal of Nanomaterials 2019 (7 de octubre de 2019): 1–6. http://dx.doi.org/10.1155/2019/5268415.

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The formation of nickel ferrite (NiFe2O4) nanoparticles under hydrothermal conditions has been modeled using a method that combines results of first-principle calculations, elements of aqueous thermochemistry, and experimental free energies of formation. The calculations predict negative formation energies for the (111) surfaces and positive free energies for the formation of bulk nickel ferrite. Based on classical nucleation theory, the combination of the negative surface and positive bulk energies yields thermodynamically stable nickel ferrite nanoparticles with sizes between 30 and 150 nm in the temperature range of 300 to 400 K under alkaline conditions. The surface and bulk energetics as well as the stability of the nickel ferrite nanoparticle as a function of temperature and pH are discussed.

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Kim, Yu-Jin, Jaeyoung Lee, Gwang-Bum Im, Jihun Song, Jiwoo Song, Jiyong Chung, Taekyung Yu y Suk Ho Bhang. "Dual Ion Releasing Nanoparticles for Modulating Osteogenic Cellular Microenvironment of Human Mesenchymal Stem Cells". Materials 14, n.º 2 (15 de enero de 2021): 412. http://dx.doi.org/10.3390/ma14020412.

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In this study we developed a dual therapeutic metal ion-releasing nanoparticle for advanced osteogenic differentiation of stem cells. In order to enhance the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and induce angiogenesis, zinc (Zn) and iron (Fe) were synthesized together into a nanoparticle with a pH-sensitive degradation property. Zn and Fe were loaded within the nanoparticles to promote early osteogenic gene expression and to induce angiogenic paracrine factor secretion for hMSCs. In vitro studies revealed that treating an optimized concentration of our zinc-based iron oxide nanoparticles to hMSCs delivered Zn and Fe ion in a controlled release manner and supported osteogenic gene expression (RUNX2 and alkaline phosphatase) with improved vascular endothelial growth factor secretion. Simultaneous intracellular release of Zn and Fe ions through the endocytosis of the nanoparticles further modulated the mild reactive oxygen species generation level in hMSCs without cytotoxicity and thus improved the osteogenic capacity of the stem cells. Current results suggest that our dual ion releasing nanoparticles might provide a promising platform for future biomedical applications.

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Oliveira, João Pedro Jenson de, Marta Bonet San Emeterio, Acelino Cardoso de Sá, Leonardo Lataro Paim y Manel del Valle. "Methanol, Ethanol, and Glycerol Oxidation by Graphite-Epoxy Composite Electrodes with Graphene-Anchored Nickel Oxyhydroxide Nanoparticles". Proceedings 42, n.º 1 (14 de noviembre de 2019): 5. http://dx.doi.org/10.3390/ecsa-6-06544.

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In this work, a graphite-epoxy electrode with cyclic voltammetry electrodeposited reduced graphene oxide and nickel oxyhydroxide nanoparticles was prepared by decomposition in NaOH alkaline solution of cyclic voltammetry electrodeposited nickel hexacyanoferrate. FE-SEM studies were performed to confirm the NiOOH nanoparticle; the average size of the NiOOH nanoparticles was 61 ± 16 nm and EDX was applied to analyze chemical composition. To verify the performance of the prepared electrode, it was used in the electrooxidation of alcohols in alkaline medium by cyclic voltammetry. By performing different calibration experiments of methanol, ethanol, and glycerol, it was possible to extract some information about the electrode in the presence of alcohols. The LOD for methanol, ethanol, and glycerol were 2.16 mM, 2.73 mM and 0.09 mM, respectively, with sensitivity values of 1.32 µA mM−1, 1.80 µA mM−1 and 24.60 µA mM−1, respectively. Multivariate inspection of the data using Principal Component Analysis (performed with the ClustVis online tool) demonstrated the potential ability to discriminate between the different alcohols, whereas the explained variance with the first two components was as high as 89.7%.

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Sushko, Peter V., Keith McKenna, D. Muñoz Ramo, A. L. Shluger, Andreas Sternig, Slavica Stankic, Markus Müller y Oliver Diwald. "(Invited) Photoluminescence Properties of Alkaline-Earth Oxide Nanoparticles". ECS Transactions 28, n.º 3 (17 de diciembre de 2019): 67–80. http://dx.doi.org/10.1149/1.3367212.

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Zaccheo, Brian A. y Richard M. Crooks. "Stabilization of Alkaline Phosphatase with Au@Ag2O Nanoparticles". Langmuir 27, n.º 18 (20 de septiembre de 2011): 11591–96. http://dx.doi.org/10.1021/la202405t.

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Cole, Kevin M., Sagar Prabhudev, Gianluigi A. Botton, Donald W. Kirk y Steven J. Thorpe. "Amorphous Ni-Based Nanoparticles for Alkaline Oxygen Evolution". ACS Applied Nano Materials 3, n.º 10 (7 de octubre de 2020): 10522–30. http://dx.doi.org/10.1021/acsanm.0c02501.

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Jiang, Hui y Xuemei Wang. "Alkaline Phosphatase-Responsive Anodic Electrochemiluminescence of CdSe Nanoparticles". Analytical Chemistry 84, n.º 16 (30 de julio de 2012): 6986–93. http://dx.doi.org/10.1021/ac300983t.

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Saravanan, Nagalingam, Geok Bee Teh, Samuel Yong Peen Yap y Kar Mun Cheong. "Simple synthesis of ZnS nanoparticles in alkaline medium". Journal of Materials Science: Materials in Electronics 19, n.º 12 (29 de diciembre de 2007): 1206–8. http://dx.doi.org/10.1007/s10854-007-9529-5.

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Boopathi, Sidhureddy, Shanmugam Senthilkumar y Kanala Lakshminarasimha Phani. "Facile and One Pot Synthesis of Gold Nanoparticles Using Tetraphenylborate and Polyvinylpyrrolidone for Selective Colorimetric Detection of Mercury Ions in Aqueous Medium". Journal of Analytical Methods in Chemistry 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/348965.

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In this work, we reported for the first time, a facile and one step synthesis of gold nanoparticles from HAuCl4, employing tetraphenylborate as the reducing agent. The synthesis is not only facile but also yields “dumb-bell-shaped”particles. This shape appears to arise from a possible emulsion of the products of oxidation/decomposition of tetraphenylborate by HAuCl4, surrounding the particle. The size and shape of the AuNPs were characterized by Transmission electron microscopy (TEM) and UV-visible Spectroscopy. Interestingly, the addition of polyvinylpyrrolidone (PVP) during the synthesis was found to enhance the stability of the nanoparticle dispersion. The particles synthesized under these conditions assume “spherical” shape with the appearance of only transverse surface plasmon resonance band. The highlight of the observations is that the gold nanoparticles synthesized using tetraphenylborate as reducing agent and PVP as stabilizer are highly stable in alkaline medium, in contrast to the synthesis wherein borohydride is used as reducing agent. The AuNPs synthesized using tetraphenylborate and PVP show their mercury sensing behavior only in the alkaline medium. The color of the nanoparticle dispersion undergoes distinct color change from pink to blue with the addition of mercury ions. They also show dramatic selectivity to mercury ions in presence of other interfering ions, Pb2+, Zn2+and Ca2+.

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Zhu, Chunxiao, Hugh Daigle y Steven L. Bryant. "Paramagnetic nanoparticles as nuclear magnetic resonance contrast agents in sandstone: Importance of nanofluid-rock interactions". Interpretation 4, n.º 2 (1 de mayo de 2016): SF55—SF65. http://dx.doi.org/10.1190/int-2015-0137.1.

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Nuclear magnetic resonance has been applied in well logging to investigate pore size distribution with high resolution and accuracy based on the relaxation time distribution. However, due to the heterogeneity of natural rock, pore surface relaxivity, which links relaxation time and pore size, varies within the pore system. To analyze and alter pore surface relaxivity, we saturated Boise sandstone cores with positively charged zirconia nanoparticle dispersions in which nanoparticles can be adsorbed onto the sandstone pore wall, while negatively charged zirconia nanoparticles dispersions were used as a control group to provide the baseline of nanoparticle retention due to nonelectrostatic attraction. We have performed core flushing with deionized water, pure acid, and alkali with different pH values; compared properties of zirconia nanoparticles before and after exposure to Boise sandstone; analyzed the portion of zirconia nanoparticles retained in the rock; altered pore surface relaxivity; and linked the adsorbed nanoparticle concentration on the pore surface to the modified surface relaxivity. Our work has indicated that after two pore volumes of core flooding, there was approximately 1% of negatively charged nanoparticles trapped in the Boise sandstone core, whereas approximately 8%–11% of positively charged nanoparticles was retained in the Boise sandstone cores. Our results indicated that besides van der Waals attraction, electrostatic attraction was the driving force for retention of nanoparticles with a positive surface charge in sandstone cores. The attachment of nanoparticles onto sandstone surfaces changed the mineral surface relaxivity. Exposure to acidic or strong alkaline conditions increased the Boise sandstone surface relaxivity. After contact with Boise sandstone, the nanoparticles themselves exhibited increased relaxivity due to interactions between nanoparticles dispersion and mineral surface under different pH conditions.

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31

Song, Yang, Sandra Casale, Antoine Miche, David Montero, Christel Laberty-Robert y David Portehault. "Converting silicon nanoparticles into nickel iron silicide nanocrystals within molten salts for water oxidation electrocatalysis". Journal of Materials Chemistry A 10, n.º 3 (2022): 1350–58. http://dx.doi.org/10.1039/d1ta08097k.

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Silicon nanoparticles are converted into multimetallic silicide nanoparticles by using molten salts as liquid reaction media under dynamic vacuum. They deliver highly efficient electrocatalysts for alkaline water oxidation.

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32

Tientong, Jeerapan, Stephanie Garcia, Casey R. Thurber y Teresa D. Golden. "Synthesis of Nickel and Nickel Hydroxide Nanopowders by Simplified Chemical Reduction". Journal of Nanotechnology 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/193162.

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Nickel nanopowders were synthesized by a chemical reduction of nickel ions with hydrazine hydrate at pH ~12.5. Sonication of the solutions created a temperature of 54–65°C to activate the reduction reaction of nickel nanoparticles. The solution pH affected the composition of the resulting nanoparticles. Nickel hydroxide nanoparticles were formed from an alkaline solution (pH~10) of nickel-hydrazine complexed by dropwise titration. X-ray diffraction of the powder and the analysis of the resulting Williamson-Hall plots revealed that the particle size of the powders ranged from 12 to 14 nm. Addition of polyvinylpyrrolidone into the synthesis decreased the nickel nanoparticle size to approximately 7 nm. Dynamic light scattering and scanning electron microscopy confirmed that the particles were in the nanometer range. The structure of the synthesized nickel and nickel hydroxide nanoparticles was identified by X-ray diffraction and Fourier transform infrared spectroscopy.

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33

Ye, Yuanfeng y Xiaohong Hu. "A pH-Sensitive Injectable Nanoparticle Composite Hydrogel for Anticancer Drug Delivery". Journal of Nanomaterials 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/9816461.

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According to previous reports, low pH-triggered nanoparticles were considered to be excellent carriers for anticancer drug delivery, for the reason that they could trigger encapsulated drug release at mild acid environment of tumor. Herein, an acid-sensitiveβ-cyclodextrin derivative, namely, acetalated-β-cyclodextrin (Ac-β-CD), was synthesized by acetonation and fabricated to nanoparticles through single oil-in-water (o/w) emulsion technique. At the same time, camptothecin (CPT), a hydrophobic anticancer drug, was encapsulated into Ac-β-CD nanoparticles in the process of nanoparticle fabrication. Formed nanoparticles exhibited nearly spherical structure with diameter of209±40 nm. The drug release behavior of nanoparticles displayed pH dependent changes due to hydrolysis of Ac-β-CD. In order to overcome the disadvantages of nanoparticle and broaden its application, injectable hydrogels with Ac-β-CD nanoparticles were designed and prepared by simple mixture of nanoparticles solution and graphene oxide (GO) solution in this work. The injectable property was confirmed by short gelation time and good mobility of two precursors. Hydrogels were characterized by dynamic mechanical test and SEM, which also reflected some structural features. Moreover, all hydrogels underwent a reversible sol-gel transition in alkaline environment. Finally, the results ofin vitrodrug release profile indicated that hydrogel could control drug release or bind drug inside depending on the pH value of released medium.

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34

Pushankina, Polina, Mikhail Baryshev y Iliya Petriev. "Synthesis and Study of Palladium Mono- and Bimetallic (with Ag and Pt) Nanoparticles in Catalytic and Membrane Hydrogen Processes". Nanomaterials 12, n.º 23 (24 de noviembre de 2022): 4178. http://dx.doi.org/10.3390/nano12234178.

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A controlled strategy for the electrochemical synthesis of mono- and bimetallic nanoparticles with a unique and complex morphology has been developed. The investigation of the effect of changing the surfactant concentration and current density regulating the medium pH has revealed the fundamental patterns of nanoparticle growth. The developed method has allowed to synthesis of nanoparticles with a controlled pentabranched structure for the monometallic palladium as well as for favorable combinations of metals—Pd-Ag and Pd-Pt. The obtained nanoparticles were investigated in alkaline methanol oxidation. The results demonstrated quite high catalytic activity up to 83.51 mA cm−2 and long-term stability, which are caused by the increase in electrochemically active surface area by increasing the active center’s number. This was made possible due to the creation of unusual nanoparticle morphology, namely the presence of high-energy high-index facets. The developed nanoparticles were also studied as a modifying coating for hydrogen-permeable membranes in the processes of hydrogen transport. The membranes coated with the nanoparticles demonstrated sufficiently high hydrogen flux up to 11.33 mmol s−1 m−2 and high H2/N2 selectivity up to 2254. Such results can be explained by the obvious acceleration of surface processes through the application of the developed nanoparticles. The novel synthesis strategy can potentially be extended to other metal nanoparticle systems. Thus it can be an effective way to solve relevant problems of design of controlled synthetic methods allowing the nanoparticle morphology tuning according to the required functional properties.

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35

Park, Jun-Woo y Jeongsuk Seo. "Ultrafine TaOx/CB Oxygen Reduction Electrocatalyst Operating in Both Acidic and Alkaline Media". Catalysts 12, n.º 1 (29 de diciembre de 2021): 35. http://dx.doi.org/10.3390/catal12010035.

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The high activity of non-platinum electrocatalysts for oxygen reduction reaction (ORR) in alkaline media is necessary for applications in energy conversion devices such as fuel cells and metal-air batteries. Herein, we present the electrocatalytic activity of TaOx/carbon black (CB) nanoparticles for the ORR in an alkaline atmosphere as well as in an acidic electrolyte. Ultrafine TaOx nanoparticles 1–2 nm in size and uniformly dispersed on CB supports were prepared by potentiostatic electrodeposition in a nonaqueous electrolyte and subsequent annealing treatment in an H2 flow. The TaOx/CB nanoparticles largely catalyzed the ORR with an onset potential of 1.03 VRHE in an O2-saturated 0.1 M KOH solution comparable to that of a commercial Pt/CB catalyst. ORR activity was also observed in 0.1 M H2SO4 solution. According to the rotating ring disk electrode measurement results, the oxide nanoparticles partly produced H2O2 during the ORR in 0.1 M KOH, and the ORR process was dominated by both the two- and four-electron reductions of oxygen in a diffusion-limited potential region. The Tafel slope of −120 mV dec−1 in low and high current densities revealed the surface stability of the oxide nanoparticles during the ORR. Therefore, these results demonstrated that the TaOx/CB nanoparticles were electroactive for the ORR in both acidic and alkaline electrolytes.

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36

Ďorďovič, Vladimír, Mariusz Uchman, Mehedi Reza, Janne Ruokolainen, Alexander Zhigunov, Olexandr I. Ivankov y Pavel Matějíček. "Cation-sensitive compartmentalization in metallacarborane containing polymer nanoparticles". RSC Advances 6, n.º 12 (2016): 9884–92. http://dx.doi.org/10.1039/c5ra27588a.

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37

Farhadyar, Nazanin y Mirabdullah Seyed Sadjadi. "Synthesis and Characterization of the Gold-SiO₂ Core-Shell Nanoparticle on the X-Nanozeoliate Used for Immobilization of the Alkaline Protease Enzyme". Defect and Diffusion Forum 326-328 (abril de 2012): 93–98. http://dx.doi.org/10.4028/www.scientific.net/ddf.326-328.93.

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Immobilized enzymes enhance process robustness, allow longer duration of activity of enzymes, and re-use of the same enzymes in multiple cycles. Enzymes can be operated in the liquid form or immobilized on various supports. In this work, we prepared gold nanoparticle core-shell structure by assembling of the gold nanoparticles on the surface of amine-functionalized x-type zeolite and then used them for immobilization of the alkaline protease. Characterization of these assembled systems were carried out by UVvisible, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX). Biocatalytic activity of the alkaline protease in this bioconjugate system was examined and showed an increase in comparing with the free enzyme in solution.

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38

Garcia, Amanda G., Pietro P. Lopes, Janaina F. Gomes, Cleiton Pires, Eduardo B. Ferreira, Rubens G. M. Lucena, Luiz H. S. Gasparotto y Germano Tremiliosi-Filho. "Eco-friendly synthesis of bimetallic AuAg nanoparticles". New J. Chem. 38, n.º 7 (2014): 2865–73. http://dx.doi.org/10.1039/c4nj00041b.

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39

Xu, Ming Li y Guo Tao Yang. "Electrooxidation for Methanol on Pd Nanoparticles Modified Electrodes in Alkaline Medium". Advanced Materials Research 535-537 (junio de 2012): 431–35. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.431.

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In this paper, Palladium nanoparticles were electrodeposited on the surface of glassy carbon electrodes by more circles cyclic voltammetry method and Palladium nanoparticles modified electrode (Pd/GCE) was obtained. Morphology and crystal structure of nanoparticles were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The performance and electrochemical process of catalytic oxidation methanol were measured and analyzed by cyclic voltammetry (CV), chronoamperometric curves (i-t) and alternating current impedance spectra (AC impedance) in KOH solution. The results showed that catalytic activity of Pd nanoparticles modified electrode for methanol was over 30 times higher than that of the plate Pd electrode, and catalytic performance was good. In addition, the catalytic oxidation was mainly diffusion-controlled process.

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40

Khan, Muhammad, Rozina Khattak, Abbas Khan, Qiuling Chen, Jan Nisar, Zahoor Iqbal, Abdur Rashid et al. "Synthesis and Characterizations of PdNi Carbon Supported Nanomaterials: Studies of Electrocatalytic Activity for Oxygen Reduction in Alkaline Medium". Molecules 26, n.º 11 (5 de junio de 2021): 3440. http://dx.doi.org/10.3390/molecules26113440.

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Electrocatalytic materials offer numerous benefits due to their wide range of applications. In this study, a polyol technique was used to synthesize PdNi nanoparticles (NPs) with different percent atomic compositions (Pd = 50 to 90%) to explore their catalytic efficiency. The produced nanoparticles were characterized using X-ray diffraction (XRD) and electrochemical investigations. According to XRD measurements, the synthesized NPs were crystalline in nature, with crystallite sizes of about 2 nm. The electrochemical properties of the synthesized NPs were studied in alkaline solution through a rotating ring-disk electrode (RRDE) technique of cyclic voltammetry. The PdNi nanoparticles supported on carbon (PdNi/C) were used as electrocatalysts and their activity and stability were compared with the homemade Pd/C and Pt/C. In alkaline solution, PdNi/C electrocatalysts showed improved oxygen reduction catalytic activity over benchmark Pd/C and Pt/C electrocatalysts in all composition ratios. Furthermore, stability experiments revealed that PdNi 50:50 is more stable in alkaline solution than pure Pd and other PdNi compositions.

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41

Lubambo, Adriana Freire, Ney Mattoso, Lucy Ono, Gisele Gomes da Luz, Bruno Gavinho, Andressa Amado Martin, Maria Rita Sierakowski y Cyro Ketzer Saul. "In Situ Synthesis of AZO-Np in Guar Gum/PVOH Composite Fiber Mats for Potential Bactericidal Release". Polymers 14, n.º 22 (17 de noviembre de 2022): 4983. http://dx.doi.org/10.3390/polym14224983.

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Since the number of antibiotic-resistant bacterial infections is growing and cases are getting worse every year, the search for new alternative bactericidal wound dressing treatments is becoming crucial. Within this context, the use of polysaccharides from plants and seeds in innovative biopolymer technologies is of key importance. In this work, bio-nano-composite guar gum/polyvinyl alcohol (PVOH) membranes loaded with aluminum-doped zinc oxide nanoparticles were produced via electrospinning. Citric acid was added to the mixture to increase spinnability. However, depending on the pH, zinc oxide nanoparticles are partially dissociated, decreasing their bactericidal efficiency. Thus, a second successful alkaline thermo-chemical regrowth step was added to the process to treat the obtained fibers. This alkaline thermo-chemical treatment reconstituted both the nanoparticles and their bactericidal properties. The Staphylococcus aureus antibacterial assay results show that the membranes obtained after the alkaline thermo-chemical treatment presented a 57% increase in growth inhibition.

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42

Yang, Wenqian, Junjun Luo, Min Qi y Minghui Yang. "Detection of alkaline phosphatase activity and inhibition with fluorescent hydroxyapatite nanoparticles". Analytical Methods 11, n.º 17 (2019): 2272–76. http://dx.doi.org/10.1039/c9ay00176j.

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43

Vigil, Julian A., Timothy N. Lambert y Benjamin T. Christensen. "Cobalt phosphide-based nanoparticles as bifunctional electrocatalysts for alkaline water splitting". Journal of Materials Chemistry A 4, n.º 20 (2016): 7549–54. http://dx.doi.org/10.1039/c6ta00637j.

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44

Jiang, Fang, Hai Tao Lin, Jun Sheng Li, Ji Wei Huang, Xin Xia Yue, Xin Long Ling y Wen Jie Mao. "Preparation of Nano-Silver Artemisia Argyi and Anti-Bacterial Finishing to Silk Fabric". Advanced Materials Research 175-176 (enero de 2011): 707–11. http://dx.doi.org/10.4028/www.scientific.net/amr.175-176.707.

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The hydroxyl in polysaccharide and flavones that extracted from Artemisia argyi can absorb onto the surface of silver nanoparticles and prevent aggregation from nanoparticles. The stable nano-silver solution was got. The preparation of Nano-silver Artemisia Argyi by Artemisia Argyi extract in alkaline and acidic environment was investigated, and the antibacterial property of fabric finished by the nano-silver Artemisia Argyi was analyzed. The experimental results show that the silver nanoparticles prepared in alkaline environment has small size with the minimum 12nm and uniform dispersion. The fabric finished by Nano-silver Artemisia Argyi exhibited strong antibacterial activity against E.coli and S.aureus, the sterilized rate was over 99.9%. The fabric has excellent antibacterial washability too.

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45

Chakrapani, Kalapu y Srinivasan Sampath. "The morphology dependent electrocatalytic activity of Ir nanostructures towards oxygen reduction". Phys. Chem. Chem. Phys. 16, n.º 31 (2014): 16815–23. http://dx.doi.org/10.1039/c4cp01882f.

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46

Usman, Mohammad Rofik, Atiek Rostika Noviyanti y Diana Rakhmawaty Eddy. "Photocatalytic Degradation of Diazinon Using Titanium Oxide Synthesized by Alkaline Solvent". Indonesian Journal of Chemistry 17, n.º 1 (1 de abril de 2017): 22. http://dx.doi.org/10.22146/ijc.23548.

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Photoactivity of titanium dioxide (TiO2) can be improved by turning it into nanoparticles. Synthesis of TiO2 nanoparticles can be done by using hydrothermal method. Hydrothermal method is influenced by types of precursor, hydrothermal conditions, including time, temperature, type and concentration of reactants. The purpose of this study is to obtain a hydrothermal condition which produces crystals of TiO2 nanoparticles with high quality. The material used was titanium tetrachloride (TiCl4) as initial precursors and for the type of reactants was used aqudestilate, aquabidestilate, ethanol, t-butanol, sodium hydroxide (NaOH) and potassium hydroxide (KOH). The resulting diffractogram showed the crystal structure of TiO2 nanoparticles with anatase and rutile. Based on calculations using the scherrer equation, TiO2 crystal obtained had a crystal size below 50 nm in both anatase and rutile. The percentage of rutile and anatase composition was obtained by using rietveld method with the help of rietica software. Morphology of TiO2 anatase showed particles with shape of cubic, while rutile was flower-shaped.

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47

Yang, Yao, Yin Xiong, Megan E. Holtz, Xinran Feng, Rui Zeng, Gary Chen, Francis J. DiSalvo, David A. Muller y Héctor D. Abruña. "Octahedral spinel electrocatalysts for alkaline fuel cells". Proceedings of the National Academy of Sciences 116, n.º 49 (14 de noviembre de 2019): 24425–32. http://dx.doi.org/10.1073/pnas.1906570116.

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Designing high-performance nonprecious electrocatalysts to replace Pt for the oxygen reduction reaction (ORR) has been a key challenge for advancing fuel cell technologies. Here, we report a systematic study of 15 different AB2O4/C spinel nanoparticles with well-controlled octahedral morphology. The 3 most active ORR electrocatalysts were MnCo2O4/C, CoMn2O4/C, and CoFe2O4/C. CoMn2O4/C exhibited a half-wave potential of 0.89 V in 1 M KOH, equal to the benchmark activity of Pt/C, which was ascribed to charge transfer between Co and Mn, as evidenced by X-ray absorption spectroscopy. Scanning transmission electron microscopy (STEM) provided atomic-scale, spatially resolved images, and high-energy-resolution electron-loss near-edge structure (ELNES) enabled fingerprinting the local chemical environment around the active sites. The most active MnCo2O4/C was shown to have a unique Co-Mn core–shell structure. ELNES spectra indicate that the Co in the core is predominantly Co2.7+ while in the shell, it is mainly Co2+. Broader Mn ELNES spectra indicate less-ordered nearest oxygen neighbors. Co in the shell occupies mainly tetrahedral sites, which are likely candidates as the active sites for the ORR. Such microscopic-level investigation probes the heterogeneous electronic structure at the single-nanoparticle level, and may provide a more rational basis for the design of electrocatalysts for alkaline fuel cells.

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48

Jadali, Salma, Mohammad Ali Kamyabi, José Solla-Gullón y Enrique Herrero. "Effect of Pd on the Electrocatalytic Activity of Pt towards Oxidation of Ethanol in Alkaline Solutions". Applied Sciences 11, n.º 3 (1 de febrero de 2021): 1315. http://dx.doi.org/10.3390/app11031315.

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The understanding of electrocatalytic activity and poisoning resistance properties of Pt and Pd nanoparticles, recognized as the best electrocatalysts for the ethanol oxidation reaction, is an essential step for the commercialization of direct ethanol fuel cells (DEFCs). In this paper, mono and bimetallic Pt and Pd nanoparticles with different atomic ratios have been synthesized to study their electrocatalytic properties for an ethanol oxidation reaction in alkaline solutions. The different nanoparticles were physiochemically characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical characterization was performed by cyclic voltammetry and chronoamperometry measurements. The electrochemical measurements indicate that Pt nanoparticles have much higher electrocatalytic activity for ethanol oxidation than Pd nanoparticles. The studies with bimetallic PtPd nanoparticles showed a significant impact of their composition on the ethanol oxidation. Thus, the highest electrocatalytic activity and poisoning resistance properties were obtained for Pt3Pd2 nanoparticles. Moreover, this study demonstrates that the poisoning of the catalyst surface through ethanol oxidation is related to the prevalence of the acetaldehyde–acetate route and the polymerization of acetaldehyde through aldol condensation in the alkaline media.

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49

Rao, Honghong, Huiyi Huang, Xinyuan Zhang, Xin Xue, Mingyue Luo, Haixia Liu y Zhonghua Xue. "A simple thermometer-based photothermometric assay for alkaline phosphatase activity based on target-induced nanoprobe generation". New Journal of Chemistry 44, n.º 41 (2020): 17753–60. http://dx.doi.org/10.1039/d0nj03920a.

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50

Singh, Jitendra Pal, Weon Cheol Lim, Sung Ok Won, Jonghan Song y Keun Hwa Chae. "Synthesis and Characterization of Some Alkaline-Earth-Oxide Nanoparticles". Journal of the Korean Physical Society 72, n.º 8 (abril de 2018): 890–99. http://dx.doi.org/10.3938/jkps.72.890.

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