Journal articles on the topic 'Metal Oxides Nanoparticles'
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1
Frolov, Georgiy Aleksandrovich, Irina Aleksandrovna Lundovskikh, Marina Robertovna Shabalina, Mikhail Borisovich Tarasov, Ivan Petrovich Pogorelskiy, Konstantin Igorevich Gurin, and Aleksandr Viktorovich Mironin. "Morphofunctional changes in Bacillus cereus cells under the influence of nanoparticles of metals and metal oxides." Disinfection affairs, no. 4 (December 2020): 5–18. http://dx.doi.org/10.35411/2076-457x-2020-4-5-18.
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The results are presented of the comparative study of the presence of characteristic features of disorders of the microstructural organization of the test strain B. cereus ATCC 10702 cells by stable nanoparticles of silver, gold, platinum, zinc oxide and titanium dioxide with loss of cell viability during their interaction with nanoparticles in an aqueous medium using methods of bacteriology and electron microscopy. General size-dependent features of the effect of nanoparticles on B. cereus ATCC 10702 cells and differences associated with both the adsorption of metal oxide and noble metal nanoparticles on the surface of bacteria and the loss of viability of bacterial cells with different levels of their destruction, reaching 67-70 % in the case of nanoparticles noble metals, were found. The chemistry of the effects of silver, gold, platinum and zinc and titanium oxides nanoparticles on the test microbe B. cereus ATCC 10702 is considered. The assumption is made that the main feature of the interaction of nanodispersed structures based on noble metals and metal oxides is not associated with an increase in the specific contact surface of the dispersed phase, but with a significant increase in the specific surface energy, which leads to the modification of the multilayer hydrated water shells surrounding nanoparticles. The measured zeta (ζ-)-potential of metal and metal oxides nanoparticles characterizes the total effect formed on the diffusion-mobile boundary of the nanoparticle; its value is a quantitative characteristic of the equilibrium energy state of dispersed systems acting as biocatalysts of intracellular enzymes and causing hydrolysis of the polymer structures of cytoplasmic membranes and cell membranes and ultimately the death of microbial cells. The obtained experimental data can be used in creation effective antimicrobial compositions.
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Merah, Abdelali, Abdenabi Abidi, Hana Merad, Noureddine Gherraf, Mostepha Iezid, and Abdelghani Djahoudi. "Comparative Study of the Bacteriological Activity of Zinc Oxide and Copper Oxide Nanoparticles." Acta Scientifica Naturalis 6, no. 1 (March 1, 2019): 63–72. http://dx.doi.org/10.2478/asn-2019-0009.
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Abstract Interest in nanomaterials, especially metal oxides, in the fight against resistant and constantly changing bacterial strains, is more and more expressed. Their very high reactivity, resulting from their large surface area, promoted them to the rank of potential successors of antibiotics. Our work consisted of the synthesis of zinc oxide (ZnO) and copper oxide (CuO) in the nanoparticle state and the study of their bactericidal effect on various Gram-negative and Gram-positive bacterial strains. The nanoparticles of metal oxides have been synthesized by sol-gel method. Qualitative analysis and characterization by UV / Visible and infrared spectrophotometry and X-ray diffraction confirmed that the synthetic products are crystalline. The application of the Scherrer equation allows to determine the size of the two metal oxides, namely: 76.94 nm for ZnO and 24.86 nm for CuO. The bactericidal effect of ZnO and CuO nanoparticles was tested on Gram-positive bacteria (Staphylococcus aureus, Staphylococcus hominis, Staphylococcus haemolyticus, Enterococcus facials) and Gram-negative bacteria (Escherichia coli, Schigella, Klepsiella pneumoniae and Pseudomonas aeruginosa). The results indicate that the tested metal oxides nanoparticles have an effect that varies depending on bacterial species. Indeed, Gram-positive bacteria show greater sensitivity to ZnO nanoparticles whereas Gram-negative bacteria are more sensitive to CuO nanoparticles.
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Ide, E., S. Angata, Akio Hirose, and Kojiro F. Kobayashi. "Bonding of Various Metals Using Ag Metallo-Organic Nanoparticles-A Novel Bonding Process Using Ag Metallo-Organic Nanoparticles-." Materials Science Forum 512 (April 2006): 383–88. http://dx.doi.org/10.4028/www.scientific.net/msf.512.383.
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We propose a novel bonding process using Ag metallo-organic nanoparticles, of which the average particle size is around 11 nm. In this paper, Al, Ti, Ni, Cu, Ag and Au disc joints were made using the Ag metallo-organic nanoparticles in order to investigate the bondability of the various metals. These joints are evaluated based on measurement of the shear strength, and the observation of the fracture surfaces and the cross-sectional microstructures. The shear strength of the various metal joints increased in the following order: Al, Ti, Ni, Cu, Ag and Au. This corresponds to the order of the standard-free energy value of the oxide formation for each metal. In particular, while the strengths of the Cu, Ag and Au joints, in which the oxides can be reduced by carbon, were the same level, those of the Al and Ti joints, of which the oxides were more stable than carbon oxides, were extremely low. This result suggests that the carbon atoms or organic elements generated by the decomposition of the organic shell of the Ag metallo-organic nanoparticles may play a role in deoxidizing the oxide film on the metal surface. This can promote chemical bonding between the Ag nanoparticles and metals at low temperatures.
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Mehtab, Amir, Jahangeer Ahmed, Saad M. Alshehri, Yuanbing Mao, and Tokeer Ahmad. "Rare earth doped metal oxide nanoparticles for photocatalysis: a perspective." Nanotechnology 33, no. 14 (January 12, 2022): 142001. http://dx.doi.org/10.1088/1361-6528/ac43e7.
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Abstract Metal oxides are well-known materials that have been considered as the prominent photocatalysts. Photocatalysis is a promising way to address the environmental issues which are caused by fossil fuel the combustion and industrial pollutants. Lot of efforts such as doping of metal oxides with metals, non-metals have been made to enhance their photocatalytic activity. More specifically, in this review we have discussed detailed synthesis procedures of rare earth doped metal oxides performed in the past decades. The advantage of doping metal oxides with rare earth metals is that they readily combine with functional groups due to the 4f vacant orbitals. Moreover, doping rare earth metals causes absorbance shift to the visible region of the electromagnetic spectrum which results to show prominent photocatalysis in this region. The effect of rare earth doping on different parameters of metal oxides such as band gap and charge carrier recombination rate has been made in great details. In perspective section, we have given a brief description about how researchers can improve the photocatalytic efficiencies of different metal oxides in coming future. The strategies and outcomes outlined in this review are expected to stimulate the search for a whole new set of rare earth doped metal oxides for efficient photocatalytic applications.
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Ali Esmail Al-Snafi, Hussein Ali Hussein Al-Sa'idy, and Hussein Kamil Hamid. "The utilization of plant extracts/biomaterials for the green synthesis of nanoparticles, their biological activity and mode of action." Open Access Research Journal of Biology and Pharmacy 6, no. 1 (September 30, 2022): 017–46. http://dx.doi.org/10.53022/oarjbp.2022.6.1.0063.
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Nanotechnology is one of the modern approaches that has found access to the medicinal as well as pharmaceutical uses where the nanoparticles of the nobel as well as other metals nanoparticles and their oxides have been reported to exploite various biological activities particularly antimicrobial besides antineoplastic activities. In addition, metal/metal oxides nanoparticles have also been proposed to have diagnostic applications in radioscanning of neoplastic diseases besides pharmaceutical application in neoplastic drugs delivery. Green/eco-friendly synthesis of these nanoparticles using biomaterials is considered as an innovatory approach for their production through which attaining economically beneficial along with drastic polluting methods avoidance advantages. In this context, plants extracts are increasingly finding the way for their production. In this survey, the green chemical synthesis approaches of nanoparticals of different metals and their oxides, their medical uses and biological activities, particularly antimicrobial mechanism of silver nanoparticles, as well as antineoplastic activity are discussed. The outcomes of this survey encourage us to conclude the feasibility of investment in the investigations in this approach.
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Oprea, Madalina, and Denis Mihaela Panaitescu. "Nanocellulose Hybrids with Metal Oxides Nanoparticles for Biomedical Applications." Molecules 25, no. 18 (September 4, 2020): 4045. http://dx.doi.org/10.3390/molecules25184045.
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Cellulose is one of the most affordable, sustainable and renewable resources, and has attracted much attention especially in the form of nanocellulose. Bacterial cellulose, cellulose nanocrystals or nanofibers may serve as a polymer support to enhance the effectiveness of metal nanoparticles. The resultant hybrids are valuable materials for biomedical applications due to the novel optical, electronic, magnetic and antibacterial properties. In the present review, the preparation methods, properties and application of nanocellulose hybrids with different metal oxides nanoparticles such as zinc oxide, titanium dioxide, copper oxide, magnesium oxide or magnetite are thoroughly discussed. Nanocellulose-metal oxides antibacterial formulations are preferred to antibiotics due to the lack of microbial resistance, which is the main cause for the antibiotics failure to cure infections. Metal oxide nanoparticles may be separately synthesized and added to nanocellulose (ex situ processes) or they can be synthesized using nanocellulose as a template (in situ processes). In the latter case, the precursor is trapped inside the nanocellulose network and then reduced to the metal oxide. The influence of the synthesis methods and conditions on the thermal and mechanical properties, along with the bactericidal and cytotoxicity responses of nanocellulose-metal oxides hybrids were mainly analyzed in this review. The current status of research in the field and future perspectives were also signaled.
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Daigle, Jean-Christophe, and Jerome P. Claverie. "A Simple Method for Forming Hybrid Core-Shell Nanoparticles Suspended in Water." Journal of Nanomaterials 2008 (2008): 1–8. http://dx.doi.org/10.1155/2008/609184.
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Core-shell hybrid nanoparticles, where the core is an inorganic nanoparticle and the shell an organic polymer, are prepared by a two-step method. Inorganic nanoparticles are first dispersed in water using poly(acrylic acid) (PAA) prepared by reversible addition fragmentation chain transfer (RAFT) polymerization as dispersant. Then, the resulting dispersion is engaged in a radical emulsion polymerization process whereby a hydrophobic organic monomer (styrene and butyl acrylate) is polymerized to form the shell of the hybrid nanoparticle. This method is extremely versatile, allowing the preparation of a variety of nanocomposites with metal oxides (alumina, rutile, anatase, barium titanate, zirconia, copper oxide), metals (Mo, Zn), and even inorganic nitrides (Si3N4).
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Hayashi, Yamato, Masahiro Inoue, Ichitito Narita, Katsuaki Suganuma, and Hirotsugu Takizawa. "Eco-Fabrication of Metal Nanoparticle Related Materials by Home Electric Appliances." Materials Science Forum 620-622 (April 2009): 185–88. http://dx.doi.org/10.4028/www.scientific.net/msf.620-622.185.
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Applications of various noble metal nanoparticles were investigated for newly, ecology and economy home electric appliances (microwave, ultrasonic) used system. Noble metal oxides have merit in metal particles fabrication, as one of these example example, there are decomposed by only heating in air. That is, noble metal oxide don't use strong reduction atmosphere. This reduction is ecologically clean, because many noble metal oxides are not toxic and during decomposition O2 is evolved. We have reduced noble metal oxides by microwave and ultrasound, and tried to fabricate noble metal nanoparticles, and investigated various processing. These energy are widely used by home electric appliances. By choosing suitable process and conditions, it is reasonable to expect that home electric appliances ecology and economy fabrications can be extended to obtain simply various noble metal nanoparticles related materials.
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Thwala, M. M., A. Afantitis, A. G. Papadiamantis, A. Tsoumanis, G. Melagraki, L. N. Dlamini, C. N. M. Ouma, et al. "Using the Isalos platform to develop a (Q)SAR model that predicts metal oxide toxicity utilizing facet-based electronic, image analysis-based, and periodic table derived properties as descriptors." Structural Chemistry 33, no. 2 (December 23, 2021): 527–38. http://dx.doi.org/10.1007/s11224-021-01869-w.
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AbstractEngineered nanoparticles (NPs) are being studied for their potential to harm humans and the environment. Biological activity, toxicity, physicochemical properties, fate, and transport of NPs must all be evaluated and/or predicted. In this work, we explored the influence of metal oxide nanoparticle facets on their toxicity towards bronchial epithelial (BEAS-2B), Murine myeloid (RAW 264.7), and E. coli cell lines. To estimate the toxicity of metal oxide nanoparticles grown to a low facet index, a quantitative structure–activity relationship ((Q)SAR) approach was used. The novel model employs theoretical (density functional theory calculations) and experimental studies (transmission electron microscopy images from which several particle descriptors are extracted and toxicity data extracted from the literature) to investigate the properties of faceted metal oxides, which are then utilized to construct a toxicity model. The classification mode of the k-nearest neighbour algorithm (EnaloskNN, Enalos Chem/Nanoinformatics) was used to create the presented model for metal oxide cytotoxicity. Four descriptors were identified as significant: core size, chemical potential, enthalpy of formation, and electronegativity count of metal oxides. The relationship between these descriptors and metal oxide facets is discussed to provide insights into the relative toxicities of the nanoparticle. The model and the underpinning dataset are freely available on the NanoSolveIT project cloud platform and the NanoPharos database, respectively.
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Kim, Gil Pyo, Seung Bum Yoon, Young Soo Jung, Jae Hoon Ahn, Sung Hyeon Baeck, Alan Kleiman-Schwarsctein, and Eric W. Mc Farland. "Fabrication of Nanoparticles Supported on Metal Oxides by PS-PVP Block Copolymer Encapsulation Method." Solid State Phenomena 119 (January 2007): 17–20. http://dx.doi.org/10.4028/www.scientific.net/ssp.119.17.
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Nanoparticles (Au, Pt, Ru) supported on metal oxides (TiO2, Heteropoly Acid) were prepared by PS-PVP block copolymer encapsulation method. It was confirmed by XPS analysis that the oxidation state of metal is 0 after calcination, which indicates the complete removal of polymer. Synthesized catalysts were characterized by TEM, SEM-EDS, and UV-VIS spectroscopy and it was observed that synthesis and calcination conditions, and the interaction between nanoparticle and metal oxide affected significantly the particle size of metal on the surface of metal oxide. When two different metal precursors were diffused into the core of inversed micelles, nano alloy could be synthesized and the composition of nano alloy was controlled by varying the ratio between the two metal precursors.
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Xu, Veena Wenqing, Mohammed Zahedul Islam Nizami, Iris Xiaoxue Yin, Ollie Yiru Yu, Christie Ying Kei Lung, and Chun Hung Chu. "Application of Copper Nanoparticles in Dentistry." Nanomaterials 12, no. 5 (February 27, 2022): 805. http://dx.doi.org/10.3390/nano12050805.
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Nanoparticles based on metal and metallic oxides have become a novel trend for dental applications. Metal nanoparticles are commonly used in dentistry for their exclusive shape-dependent properties, including their variable nano-sizes and forms, unique distribution, and large surface-area-to-volume ratio. These properties enhance the bio-physio-chemical functionalization, antimicrobial activity, and biocompatibility of the nanoparticles. Copper is an earth-abundant inexpensive metal, and its nanoparticle synthesis is cost effective. Copper nanoparticles readily intermix and bind with other metals, ceramics, and polymers, and they exhibit physiochemical stability in the compounds. Hence, copper nanoparticles are among the commonly used metal nanoparticles in dentistry. Copper nanoparticles have been used to enhance the physical and chemical properties of various dental materials, such as dental amalgam, restorative cements, adhesives, resins, endodontic-irrigation solutions, obturation materials, dental implants, and orthodontic archwires and brackets. The objective of this review is to provide an overview of copper nanoparticles and their applications in dentistry.
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Davis, Nithya, Usha Rajalakshmi P, and Sakthivel T. "Mixed Metal Oxide Mesoporous Nanoparticles For Environmental Remediation." Kongunadu Research Journal 6, no. 2 (December 30, 2019): 61–65. http://dx.doi.org/10.26524/krj303.
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Mesoporous mixed metal oxides (SnO2(x) -TiO2 (1-x) , x= 0.75,0.50 and 0.25) were synthesized by evaporation induced self assembly using cationic surfactant, Cetyl Trimethyl Ammonium Bromide (CTAB) as the structure directing agent. The small angle X-ray diffraction pattern of mesoporous SnO2 and SnO2-TiO2 mixed metal oxides revealed the presence of well defined mesostructure in the metal oxides. The mixed metal oxide system has crystallized in orthorhombic structure, resembling the host lattice. Mesopore channels were collapsed upon calcinations at 550°C. The optical absorption of the SnO2 has been extended into the visibleregion upon incorporation of “Ti”. A remarkable enhancement of the photocatalytic degradation efficiency (60% ) of (SnO2(0.5) -TiO2 (0.5) was observed against aqueous solution of methylene blue dye.
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Mohamed, HudaElslam, Unal Camdali, Atilla Biyikoglu, and Metin Aktas. "Enhancing the Performance of a Vapour Compression Refrigerator System Using R134a with a CuO/CeO2 Nano-refrigerant." Strojniški vestnik - Journal of Mechanical Engineering 68, no. 6 (June 22, 2022): 395–410. http://dx.doi.org/10.5545/sv-jme.2021.7454.
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Most studies report that dispersing nanoparticles into refrigerants and lubricating oils leads to performance improvements in refrigeration systems, due to improvements in the thermal physics properties of a pure refrigerant, which leads to reduced energy consumption. Using nanoparticles in a refrigeration system is associated with many difficulties, such as the cost of preparing and obtaining a stable and homogeneous mixture with less agglomeration and sedimentation. Most current studies focus on the use of metals, metal oxides, and a hybrid of oxides as nanoparticles in refrigeration systems. In this research, nanoparticles were prepared in an inexpensive and easy way as a single oxide and as a mixture consisting of copper and cerium oxides. The results of nanoparticle preparation using X-ray diffraction and scanning electron microscopy prove that the particles of the samples were spherical in shape, with suitable average diameters ranging from 78.95 nm, 79.9 nm, 44.15 nm and 63.3 nm for copper oxide, cerium oxide, the first mixture, and the second mixture, respectively. Cerium oxide has not been used in a refrigeration system; this study preferred the implementation of a theoretical study using Ansys Fluent software to verify the possibility of improving the performance of the refrigeration system. The results confirmed that copper oxide enhanced the coefficient of performance of the refrigeration system by 25 %, and cerium oxide succeeded in improving the performance of the. system by a lesser value. The mixture containing a higher percentage of copper oxide yielded better results.
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Girardet, Thomas, Pierre Venturini, Hervé Martinez, Jean-Charles Dupin, Franck Cleymand, and Solenne Fleutot. "Spinel Magnetic Iron Oxide Nanoparticles: Properties, Synthesis and Washing Methods." Applied Sciences 12, no. 16 (August 13, 2022): 8127. http://dx.doi.org/10.3390/app12168127.
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Nanoparticles have experienced increasing interest over the past three decades owing to the development of new synthesis methods and the adaptation of analysis tools with spatial resolutions below one micrometer. Among the different types of nanoparticles developed in recent years (metals, metal oxides, silica, polymers, etc.), significant scientific interest has developed around iron oxide nanoparticles. This review will focus on these magnetic iron oxide nanoparticles. We will first discuss the magnetic properties of iron oxide nanoparticles, then the different methods of synthesis and washing. Finally, we will discuss some functionalization strategies of iron oxide nanoparticles which are developed within our research team.
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Gudkov, Sergey V., Dmitriy E. Burmistrov, Veronika V. Smirnova, Anastasia A. Semenova, and Andrey B. Lisitsyn. "A Mini Review of Antibacterial Properties of Al2O3 Nanoparticles." Nanomaterials 12, no. 15 (July 30, 2022): 2635. http://dx.doi.org/10.3390/nano12152635.
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Bacterial antibiotic resistance is one of the most serious modern biomedical problems that prioritizes the search for new agents to combat bacterial pathogens. It is known that nanoparticles of many metals and metal oxides can have an antibacterial effect. However, the antibacterial efficacy of aluminum oxide nanoparticles has been studied little compared to the well-known antimicrobial properties of nanoparticles of oxides of metals such as zinc, silver, iron, and copper. In this review, we have focused on the experimental studies accumulated to date demonstrating the antibacterial effect of aluminum oxide nanoparticles. The review discusses the main ways of synthesis and modification of these nanoparticles, provides the proposed mechanisms of their antibacterial action against gram-positive and gram-negative bacteria, and also compares the antibacterial efficacy depending on morphological characteristics. We have also partially considered the activity of aluminum oxide nanoparticles against water microalgae and fungi. In general, a more detailed study of the antibacterial properties of aluminum oxide nanoparticles is of great interest due to their low toxicity to eukaryotic cells.
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Lee, Jin Ah, Won Jun Lee, Joonwon Lim, and Sang Ouk Kim. "N-Dopant-Mediated Growth of Metal Oxide Nanoparticles on Carbon Nanotubes." Nanomaterials 11, no. 8 (July 22, 2021): 1882. http://dx.doi.org/10.3390/nano11081882.
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Metal oxide nanoparticles supported on heteroatom-doped graphitic surfaces have been pursued for several decades for a wide spectrum of applications. Despite extensive research on functional metal oxide nanoparticle/doped carbon nanomaterial hybrids, the role of the heteroatom dopant in the hybridization process of doped carbon nanomaterials has been overlooked. Here, the direct growth of MnOx and RuOx nanoparticles in nitrogen (N)-doped sites of carbon nanotubes (NCNTs) is presented. The quaternary nitrogen (NQ) sites of CNTs actively participate in the nucleation and growth of the metal nanoparticles. The evenly distributed NQ nucleation sites mediate the generation of uniformly dispersed <10 nm diameter MnOx and RuOx nanoparticles, directly decorated on NCNT surfaces. The electrochemical performance of the resultant hybridized materials was evaluated using cyclic voltammetry. This novel hybridization method using the dopant-mediated nucleation and growth of metal oxides suggests ways that heteroatom dopants can be utilized to optimize the structure, interface and corresponding properties of graphitic carbon-based hybrid materials.
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Nakamura, Ryusuke, Hideo Nakajima, and Hirotaro Mori. "Shrinkage of Hollow Nanoparticles of Oxides of Cu and Ni at High Temperatures." Defect and Diffusion Forum 289-292 (April 2009): 673–78. http://dx.doi.org/10.4028/www.scientific.net/ddf.289-292.673.
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The structural stability of hollow Cu2O and NiO nanoparticles, which were obtained via oxidation of Cu and Ni nanoparticles in air, was studied by transmission electron microscopy (TEM). Hollow Cu2O and NiO were observed to have shrunk at 473 and 623 K in annealing under 5.0×10-5 Pa, respectively, where the reduction reactions from oxides to metals started. As a result of shrinking associated with reduction, hollow oxides turned into solid metal nanoparticles after annealing at higher temperatures for a long time. In addition, hollow oxides shrunk and collapsed through high-temperature oxidation. It was found that shrinking of hollow oxides during oxidation occurs at temperature where the diffusion coefficients of slower diffusing species reach around 10-22 m2s-1. It seems that the hollow oxide nanoparticles tend to shrink and collapse at high temperatures because the hollow structures are energetically unstable.
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Diaz, Carlos, Maria Luisa Valenzuela, and Miguel Á. Laguna-Bercero. "Solid-State Preparation of Metal and Metal Oxides Nanostructures and Their Application in Environmental Remediation." International Journal of Molecular Sciences 23, no. 3 (January 20, 2022): 1093. http://dx.doi.org/10.3390/ijms23031093.
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Nanomaterials have attracted much attention over the last decades due to their very different properties compared to those of bulk equivalents, such as a large surface-to-volume ratio, the size-dependent optical, physical, and magnetic properties. A number of solution fabrication methods have been developed for the synthesis of metal and metal oxides nanoparticles, but few solid-state methods have been reported. The application of nanostructured materials to electronic solid-state devices or to high-temperature technology requires, however, adequate solid-state methods for obtaining nanostructured materials. In this review, we discuss some of the main current methods of obtaining nanomaterials in solid state, and also we summarize the obtaining of nanomaterials using a new general method in solid state. This new solid-state method to prepare metals and metallic oxides nanostructures start with the preparation of the macromolecular complexes chitosan·Xn and PS-co-4-PVP·MXn as precursors (X = anion accompanying the cationic metal, n = is the subscript, which indicates the number of anions in the formula of the metal salt and PS-co-4-PVP = poly(styrene-co-4-vinylpyridine)). Then, the solid-state pyrolysis under air and at 800 °C affords nanoparticles of M°, MxOy depending on the nature of the metal. Metallic nanoparticles are obtained for noble metals such as Au, while the respective metal oxide is obtained for transition, representative, and lanthanide metals. Size and morphology depend on the nature of the polymer as well as on the spacing of the metals within the polymeric chain. Noticeably in the case of TiO2, anatase or rutile phases can be tuned by the nature of the Ti salts coordinated in the macromolecular polymer. A mechanism for the formation of nanoparticles is outlined on the basis of TG/DSC data. Some applications such as photocatalytic degradation of methylene by different metal oxides obtained by the presented solid-state method are also described. A brief review of the main solid-state methods to prepare nanoparticles is also outlined in the introduction. Some challenges to further development of these materials and methods are finally discussed.
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Nakajima, Hideo, and Ryusuke Nakamura. "Fabrication of Hollow Nano Particles of Metallic Oxides through Oxidation Process." Materials Science Forum 638-642 (January 2010): 67–72. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.67.
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The formation mechanisms of hollow metal oxide through the oxidation of several metal nanoparticles have been studied by transmission electron microscopy. For Zn, Al, Cu, Ni and Fe nanoparticles, hollow oxide nanoparticles were obtained as a result of vacancy aggregation in the oxidation processes. The formation of the hollow morphology is attributed to the faster outward diffusion of metal ions through the oxide layer in the oxidation processes. Further changes in morphology during the annealing of hollow Cu, Ni and Fe oxides at higher temperatures in air were examined.
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R. Aarathy, A., M. S. Gopika, and S. Savitha Pillai. "Recent Insights into the Potential of Magnetic Metal Nanostructures as Magnetic Hyperthermia Agents." Sensor Letters 18, no. 12 (December 1, 2020): 861–80. http://dx.doi.org/10.1166/sl.2020.4297.
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The advancements in magnetic nanoparticle mediated hyperthermia give so many optimistic and fruitful results that make it a promising and complementary approach for the existing treatment modalities of cancer. This thermotherapy is gaining wide acceptance among the medical community compared to the conventional treatment methods. The former provides a local heat generation in the malignant tumor cells and remains non-invasive to the adjacent healthy cells. The increased heating efficiency of magnetic nanoparticles and the control of local therapeutic temperature are the main challenges of hyperthermia. Superparamagnetic Iron Oxide nanoparticles have been intensively studied and dominating in magnetic hyperthermia. Recently many researchers successfully demonstrated high heating efficiency and biocompatibility of a wide variety of magnetic metal nanoparticles and proposed as the most promising alternative for traditional iron oxides, which opens up a new avenue for magnetic metal nanoparticles in magnetic hyperthermia. The review presents the recent advancements that occurred in the field of metal nanoparticle mediated magnetic hyperthermia. The theory underlying heat generation, synthesis methods, biofunctionalization, Specific Absorption Rate studies, challenges and future perspectives of magnetic metal nanoparticles are presented. This will inspire more in-depth research and advance practical applications of metal nanoparticles in magnetic hyperthermia.
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Kumar, Dr K. Vinoth, and C. UDAYASOORIAN C.UDAYASOORIAN. "Toxicity Potential of Different Metal Oxides Nanoparticles on Germination of Maize Plant." Global Journal For Research Analysis 3, no. 1 (June 15, 2012): 116–18. http://dx.doi.org/10.15373/22778160/january2014/61.
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Singh, Anupama, BLR Madhavi, and M. N. Nithin Sagar. "An overview of green synthesis mediated metal nanoparticles preparation and its scale up opportunities." Journal of Drug Delivery and Therapeutics 11, no. 6 (November 15, 2021): 304–14. http://dx.doi.org/10.22270/jddt.v11i6.5082.
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Nanoparticles in different field of science have a wide range of utility. They come in different forms. Among these, metal nanoparticles (MNP) have become an emerging tool for diagnostic as well as for therapeutic purposes. Metal nanoparticles are nano-sized particles made up of inorganic metals or their metal oxides. Various methods are available for the preparation/production of metal nanoparticles. In addition to the existing physical and chemical methods, green synthesis is an area that has drawn the attention of researchers in the decade and continues to be a potential area of research. The following review introduces about metal nanoparticles and discusses in details about the plant extract mediated metal nanoparticles synthesis, the principle of metal nanoparticle formation, various process parameters that are important for its synthesis, characterization of metal nanoparticles and the scope for commercialization are elaborated. Metal nanoparticles at research, employing plant extract mediated green synthesis have been extensively reviewed. This review tries to bring into light the feasibility of commercializing the green synthesis by using plant extracts.
Keywords: Green synthesis; Plant extract; One-step synthesis; Characterization; Process parameters; Scale-up
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Kim, Nari, Calvin C. H. Cheng, and M. Cynthia Goh. "Universal aqueous synthesis of ultra-small polymer-templated nanoparticles: synthesis optimization methodology for counterion-collapsed poly(acrylic acid)." Canadian Journal of Chemistry 96, no. 1 (January 2018): 44–50. http://dx.doi.org/10.1139/cjc-2017-0444.
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A long polyelectrolyte chain collapses into a nano-sized particle upon the addition of counterions under appropriate solution conditions. This phenomenon forms the basis for a simple universal method for aqueous synthesis of ultra-small (<10 nm) metal, metal oxide, and other types of nanoparticles in the following manner: the counterion-collapsed polyelectrolyte chains are made stable by crosslinking, effectively trapping the counterions, which are subsequently chemically modified, to form metal nanoparticles via reduction or metal oxides nanoparticles via oxidation, within the collapsed polymer nanoparticle. This highly versatile platform methodology can be applied to almost any polyelectrolyte–counterion pair, making possible the rapid development of syntheses of different nanoparticles within the same chemical environment. Using poly(acrylic acid) as a model system, a methodology for the optimization of conditions for the polyelectrolyte collapse by various mono- and multi-valent metal cations is developed. The optimal counterion concentration did not correlate with ionic strength and metal ion valency and was highly variable from system to system. By monitoring the polyelectrolyte conformation using viscosity and turbidity measurements, the appropriate metal ion concentration for each nanoparticle system was determined.
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Walsh, Dominic, Yi Yeoun Kim, and Carolina Neudeck. "Synthesis of a Range of Functional Oxide and Sulphide Nanoparticles by Biopolymer Stabilization and Enzymatic Treatment." Advanced Materials Research 123-125 (August 2010): 783–86. http://dx.doi.org/10.4028/www.scientific.net/amr.123-125.783.
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Nanoparticles of the metal oxides magnetite (Fe3O4), cobalt oxide (Co3O4), manganese oxide (Mn3O4) and the metal sulfides CuS, Cu1.96S, Ag2S and CdS were prepared using the biopolymer dextran as a stablising agent. The corresponding enzyme dextranase could then used remove the biopolymer coat to give nanoparticles stabilized by a remnant oligomer. A green and aqueous general route to functional nanoparticles is described.
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Ometto, Felipe Berto, Valdecir Antonio Paganin, Peter Hammer, and Edson Antonio Ticianelli. "Effects of Metal–Support Interaction in the Electrocatalysis of the Hydrogen Evolution Reaction of the Metal-Decorated Titanium Dioxide Supported Carbon." Catalysts 13, no. 1 (December 23, 2022): 22. http://dx.doi.org/10.3390/catal13010022.
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It has been found that the electrocatalytic properties of metallic nanoparticles supported on transition metal oxides are affected by the existing strong metal–support interaction (SMSI). Herein, the effects of SMSI on the electrocatalysis of the hydrogen evolution reaction (HER) were investigated in acid electrolyte by using Pt and Ag nanoparticles supported on carbon and titanium oxide (TiO2). High-resolution transmission electron microscopy (HR–TEM) images showed that Pt and Ag nanoparticles present a spherical shape at the TiO2 support and an average size distribution of around 4.5 nm. The X-ray photoelectron spectroscopy (XPS) results for Pt/TiO2/C and Ag/TiO2/C evidenced higher amounts of surface oxides in the metallic particles, when compared to the materials supported on carbon. Consistently, electrode polarization and electrochemical impedance results revealed that both metal–TiO2 and metal–C-supported catalysts were more active in catalyzing the HER than the corresponding carbon-supported materials, with Pt presenting better results. These differences in the HER activities were related to the electronic effects of the TiO2/C substrate on the Pt and Ag metals, introduced by strong metal-support (SMSI) in the metal–TiO2/C catalysts.
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Rabinovich, G. Yu, and N. A. Lyubimova. "Biosynthesis of metal nanoparticles and metal oxidesand their use as components of fertilizers and preparations for plant growing (literature review)." Agricultural Science Euro-North-East 22, no. 5 (October 27, 2021): 627–40. http://dx.doi.org/10.30766/2072-9081.2021.22.5.627-640.
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A promising direction in agriculture is the use of metal nanoparticles as nanofertilizers, which can increase the yield of agricultural crops and, at the same time, minimize the frequency of fertilization due to the long-term release of nutrients. One of the environmentally safest and cheapest methods of synthesizing metal nanoparticles is biosynthesis using plant extracts. During the redox reaction, proteins, carbohydrates, organic acids, phenols and other metabolites are able to transfer electrons to metal cations, restoring their charge to zero on the nanometer scale. This article, based on publications on the issue under study by authors from the United States of America, Europe and the Middle East, China and India, describes the biosynthesis of nanoparticles of zinc oxide, copper and copper oxide, iron and iron oxide, as well as manganese and manganese oxide using the formation of plant extracts, and data on the use of these metals and their oxides as nanofertilizers and preparations for plant growing are presented. It has been shown that the use of metal nanoparticles and their oxides as fertilizers is more effective than conventional compounds used as fertilizers. This is probably due to the fact that it is easier for nanoparticles to penetrate through the plant membrane, as well as to pass into a form accessible to plants in comparison with conventional analogs. The positive effect of the influence of nanoparticles on plants is expressed in the elongation of the roots and shoots of model plants and an increase in the biomass of seedlings. In addition, the amount of chlorophyll in the leaves increases, and some biochemical processes also change, for example, the amount of antioxidant enzymes increases, which makes it possible to increase the stress resistance of plants.
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Staroń, Anita, Olga Długosz, Jolanta Pulit-Prociak, and Marcin Banach. "Analysis of the Exposure of Organisms to the Action of Nanomaterials." Materials 13, no. 2 (January 12, 2020): 349. http://dx.doi.org/10.3390/ma13020349.
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The rapid development of the production of materials containing metal nanoparticles and metal oxides is a potential risk to the environment. The degree of exposure of organisms to nanoparticles increases from year to year, and its effects are not fully known. This is due to the fact that the range of nanoparticle interactions on cells, tissues and the environment requires careful analysis. It is necessary to develop methods for testing the properties of nanomaterials and the mechanisms of their impact on individual cells as well as on entire organisms. The particular need to raise public awareness of the main sources of exposure to nanoparticles should also be highlighted. This paper presents the main sources and possible routes of exposure to metal nanoparticles and metal oxides. Key elements of research on the impact of nanoparticles on organisms, that is, in vitro tests, in vivo tests and methods of detection of nanoparticles in organisms, are presented.
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Yadav, S., N. Rani, and K. Saini. "A review on transition metal oxides based nanocomposites, their synthesis techniques, different morphologies and potential applications." IOP Conference Series: Materials Science and Engineering 1225, no. 1 (February 1, 2022): 012004. http://dx.doi.org/10.1088/1757-899x/1225/1/012004.
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Abstract In the field of nanotechnology and nanoscience, transition metal oxides based nanocomposites (TMONCs) are promising for various application uses such as Supercapacitors, Sensors, Bactericidal properties, Photocatalytic Degradation, Solar Cells etc. Modification of transition metal oxide nanoparticles (TMONPs) to TMONCs by doping/mixing of another transition metal and metal oxide, carbon based nanoparticles, conducting polymers etc. to achieve enhanced surface area, increasing surface activities or number of active surface sites, reducing electron-hole recombination, increasing charge transfer processes etc. have been reported in literature. These improved properties are the possible reason for the enhancement in its practical applications efficiencies. This review summarizes recent development on transition metal oxides based nanocomposites for different potential applications. Also synthesis methods of transition metal oxide based nanocomposites have obtained an increasing attractions to achieve cost effectiveness and environment friendly routes of synthesis with high rate of production, high yield of product and also less toxic waste production. Transition metal oxides nanocomposites have been fabricated by various methods such as Microwave assisted synthesis technique, Sol-Gel method, Biosynthesis method, Co-precipitation process, Simple Chemical method etc. Different morphologies of transition metal oxides based nanocomposites have been summarized in this review article. Herein, this paper discuss about several reported synthesis techniques, various characterization techniques used for structural and surface properties identifications, different morphologies and various potential applications of transition metal oxide based nanocomposites.
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Mizoshiri, Mizue, and Kyohei Yoshidomi. "Cu Patterning Using Femtosecond Laser Reductive Sintering of CuO Nanoparticles under Inert Gas Injection." Materials 14, no. 12 (June 14, 2021): 3285. http://dx.doi.org/10.3390/ma14123285.
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In this paper, we report the effect of inert gas injection on Cu patterning generated by femtosecond laser reductive sintering of CuO nanoparticles (NPs). Femtosecond laser reductive sintering for metal patterning has been restricted to metal and metal-oxide composite materials. By irradiating CuO-nanoparticle paste with femtosecond laser pulses under inert gas injection, we intended to reduce the generation of metal oxides in the formed patterns. In an experimental evaluation, the X-ray diffraction peaks corresponding to copper oxides, such as CuO and Cu2O, were much smaller under N2 and Ar gas injections than under air injection. Increasing the injection rates of both gases increased the reduction degree of the X-ray diffraction peaks of the CuO NPs, but excessively high injection rates (≥100 mL/min) significantly decreased the surface density of the patterns. These results qualitatively agreed with the ratio of sintered/melted area. The femtosecond laser reductive sintering under inert gas injection achieved a vacuum-free direct writing of metal patterns.
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Shabatina, Tatyana I., Olga I. Vernaya, and Mikhail Y. Melnikov. "Hybrid Nanosystems of Antibiotics with Metal Nanoparticles—Novel Antibacterial Agents." Molecules 28, no. 4 (February 7, 2023): 1603. http://dx.doi.org/10.3390/molecules28041603.
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The appearance and increasing number of microorganisms resistant to the action of antibiotics is one of the global problems of the 21st century. Already, the duration of therapeutic treatment and mortality from infectious diseases caused by pathogenic microorganisms have increased significantly over the last few decades. Nanoscale inorganic materials (metals and metal oxides) with antimicrobial potential are a promising solution to this problem. Here we discuss possible mechanisms of pathogenic microorganisms’ resistance to antibiotics, proposed mechanisms of action of inorganic nanoparticles on bacterial cells, and the possibilities and benefits of their combined use with antibacterial drugs. The prospects of using metal and metal oxide nanoparticles as carriers in targeted delivery systems for antibacterial compositions are also discussed.
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Iacob, Mihail, Carmen Racles, Codrin Tugui, George Stiubianu, Adrian Bele, Liviu Sacarescu, Daniel Timpu, and Maria Cazacu. "From iron coordination compounds to metal oxide nanoparticles." Beilstein Journal of Nanotechnology 7 (December 28, 2016): 2074–87. http://dx.doi.org/10.3762/bjnano.7.198.
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Various types, shapes and sizes of iron oxide nanoparticles were obtained depending on the nature of the precursor, preparation method and reaction conditions. The mixed valence trinuclear iron acetate, [Fe2 IIIFeIIO(CH3COO)6(H2O)3]·2H2O (FeAc1), μ3-oxo trinuclear iron(III) acetate, [Fe3O(CH3COO)6(H2O)3]NO3∙4H2O (FeAc2), iron furoate, [Fe3O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeF), iron chromium furoate, FeCr2O(C4H3OCOO)6(CH3OH)3]NO3∙2CH3OH (FeCrF), and an iron complex with an original macromolecular ligand (FePAZ) were used as precursors for the corresponding oxide nanoparticles. Five series of nanoparticle samples were prepared employing either a classical thermal pathway (i.e., thermal decomposition in solution, solvothermal method, dry thermal decomposition/calcination) or using a nonconventional energy source (i.e., microwave or ultrasonic treatment) to convert precursors into iron oxides. The resulting materials were structurally characterized by wide-angle X-ray diffraction and Fourier transform infrared, Raman, energy-dispersive X-ray, and X-ray fluorescence spectroscopies, as well as thermogravimetric analysis. The morphology was characterized by transmission electron microscopy, atomic force microscopy and dynamic light scattering. The parameters were varied within each route to fine tune the size and shape of the formed nanoparticles.
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Wang, Dongyue, Yuhang Meng, Aidong Tang, and Huaming Yang. "Dehydroxylation of Kaolinite Tunes Metal Oxide–Nanoclay Interactions for Enhancing Antibacterial Activity." Minerals 12, no. 9 (August 29, 2022): 1097. http://dx.doi.org/10.3390/min12091097.
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Engineered nanoparticle–support interaction is an effective strategy for tuning the structures and performance of engineered nanoparticles. Here, we show that tuning the dehydroxylation of kaolinite nanoclay as the support could induce zinc oxide–kaolinite interactions. We used free energy theory, electron microscopy, and X-ray photoemission spectroscopy to identify interaction strengths between metal oxides and the underlying nanoclay induced by dehydroxylation. Desirable exposure of nanoparticle sites and the geometrical and crystal structure were obtained by tuning the interface interactions between ZnO nanoparticles and nanoclay. The surface free energy of zinc oxide–nanoclay results in different interfacial interactions, and the properties of the surface free energy electron-donating (γ−) and electron-accepting (γ+) parameters have significant effects on the electron acceptor. This could, in turn, promote stronger interactions between zinc oxide and the kaolinite surface, which produce more active (0001) Zn-polar surfaces with promoting zinc oxide nanoparticles growing along the <0001> direction. Reactive oxygen species, leached zinc ions, and electron transfer can modulate the antibacterial activities of the samples as a function of interface free energy. This further demonstrates the interfacial interactions induced by dehydroxylation. This work has new application potential in biomedicine and materials science.
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Iswandi, Iswandi, Dwi Puryanti, and Elvaswer Elvaswer. "Remediation of Heavy Metals in the Leachate of the Final Waste Processing Site Using Magnetite Nanoparticles." Eduvest - Journal Of Universal Studies 2, no. 5 (May 20, 2022): 930–37. http://dx.doi.org/10.36418/edv.v2i5.438.
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Nanoparticles are iron oxides that are used in various fields of life, one of which is to absorb heavy metals. In this study, magnetite (Fe3O4) nanoparticles were synthesized using the correspirate method and magnetite nanoparticle templates with PEG-6000. Synthesis of magnetite nanoparticles was carried out to obtain magnetite nanoparticles to be used to remediate heavy metals Cu, Ni and Mn in waste leachate. The susceptibility analysis of the leachate sample type showed that the type of magnetic material. The calculation results from the XRD diffractogram obtained that the crystal size of Fe3O4 nanoparticles is 56.35 nm. By varying the mass of 0.4 grams of Fe3O4, 0.8 grams of Fe3O4 and coating Fe3O4 using PEG 6000, it is known that the reduction in the concentration of heavy metal Cu is 7.71%, 23.09% and 42.31%, respectively. The percentage reduction in the concentration of heavy metal Ni was 6.29%, 9.45% and 7.09%, respectively.The percentage reduction in the concentration of heavy metal Mn was 25.369%, 19.98% and 4.05%, respectively. This indicates that Fe3O4 and PEG-6000 nanoparticles are able to reduce the concentration of heavy metals in waste leachate contained in the leachate sample
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Li, Zhe Fei, Jian Xie, Lia Stanciu, and Yang Ren. "Nanostructured Graphenes and Metal Oxides for Fuel Cell and Battery Applications." Advanced Materials Research 705 (June 2013): 126–31. http://dx.doi.org/10.4028/www.scientific.net/amr.705.126.
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Graphene/spacer nanoparticle composites were prepared by reducing graphene oxide with hydrazine in the presence of different contents of polyaniline nanoparticles. In-situ cryo-TEM image of GO-spacer solution shows that spacer nanoparticles are anchored on GO sheets. During the reduction, as-adsorbed spacer nanoparticles were sandwiched between layers of graphene. These spacer nanoparticles act as spacers to create gaps between neighboring graphene sheets, resulting in higher surface area. Graphene/spacer nanocomposites exhibited highest specific surface area of 1500 m2/g. Utilizing this composite material, a supercapacitor with specific capacitance of 267 F/g at a current density of 0.1 A/g was achieved.
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Długosz, Olga, Krzysztof Szostak, Anita Staroń, Jolanta Pulit-Prociak, and Marcin Banach. "Methods for Reducing the Toxicity of Metal and Metal Oxide NPs as Biomedicine." Materials 13, no. 2 (January 8, 2020): 279. http://dx.doi.org/10.3390/ma13020279.
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The rapid development of medicine has forced equally rapid progress in the field of pharmaceuticals. In connection with the expensive and time-consuming process of finding new drugs, great emphasis is put on the design and use of metal and metal oxides nanoparticles in nanomedicine. The main focus is on comprehensive presentation of both physicochemical properties and the possibilities of using, in particular, silver (Ag) and gold (Au) nanoparticles, as well as zinc oxide (ZnO) and titanium oxide (TiO2) nanoparticles as drug carriers and in the treatment of cancer. An important element of this subject is the possibility of occurrence of toxic effects of these nanoparticles. For this reason, possible mechanisms of toxic actions are presented, as well as methods used to reduce their toxicity to ensure the safety of drug carriers based on these nanostructures.
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Hayashi, Yamato, Hirotsugu Takizawa, Yoshitaka Saijo, Tohru Sekino, Katsuaki Suganuma, and Koichi Niihara. "Various Applications of Silver Nano-Particles by Ultrasonic Eco-Fabrication." Materials Science Forum 486-487 (June 2005): 530–33. http://dx.doi.org/10.4028/www.scientific.net/msf.486-487.530.
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Applications of silver nano-sized metal particles were investigated for a new, ecologically friendly and economical liquid-solid (silver oxide-alcohol) system. Silver metal oxides as starting materials have merits in metal particles fabrication because these materials are decomposed only by heating in air. That is, noble metal oxide does not use thestrong reduction atmosphere. This reduction is ecologically clean because many noble metal oxides are not toxic, and because O2 is evolved during decomposition. We reduced silver metal oxides by ultrasound and fabricated silver nano metal nanoparticles at room temperature, and various applications were investigated. By choosing a suitable process and conditions, it is reasonable to expect that ultrasonic eco-fabrications can be extended to obtain various silver nano-particles containing materials.
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Nallusamy, S., and A. Manoj Babu. "X-Ray Differaction and FESEM Analysis for Mixture of Hybrid Nanoparticles in Heat Transfer Applications." Journal of Nano Research 37 (December 2015): 58–67. http://dx.doi.org/10.4028/www.scientific.net/jnanor.37.58.
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Heat transfer development has encouraged researcher in recent decades to develop concepts and technologies promoted by manufactures of ultra compact, miniaturized the heat transfer application. In thermal engineering lots of particle are being used for heat transfer application astonishing potential of hybrid nanoparticles. Amalgamation of hybrid nanoparticles has increasing interest in heat transfer enhancement. In this research mixture of hybrid nanoparticle was prepared using Aluminum Oxide (Al2O3) and Copper (Cu) in different proportion in order to increase thermal conductivity. Two tests of X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) analysis were carried out. The heat transfer development was found in the hybrid nanoparticles mixed with water and tested in shell and tube heat exchanger and found that the enhancement is more with nanofluid when compared to water alone. Hybrid nanoparticles form immediate precipitate when it was used in any mechanical applications and it characterised by an improvement of base particles like nanoparticles of metals, metal oxides and carbides.
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Acosta-Torres, Laura S., Luz M. López-Marín, R. Elvira Núñez-Anita, Genoveva Hernández-Padrón, and Victor M. Castaño. "Biocompatible Metal-Oxide Nanoparticles: Nanotechnology Improvement of Conventional Prosthetic Acrylic Resins." Journal of Nanomaterials 2011 (2011): 1–8. http://dx.doi.org/10.1155/2011/941561.
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Nowadays, most products for dental restoration are produced from acrylic resins based on heat-cured Poly(Methyl MethAcrylate) (PMMA). The addition of metal nanoparticles to organic materials is known to increase the surface hydrophobicity and to reduce adherence to biomolecules. This paper describes the use of nanostructured materials, TiO2and Fe2O3, for simultaneously coloring and/or improving the antimicrobial properties of PMMA resins. Nanoparticles of metal oxides were included during suspension polymerization to produce hybrid metal oxides-alginate-containing PMMA. Metal oxide nanoparticles were characterized by dynamic light scattering, and X-ray diffraction. Physicochemical characterization of synthesized resins was assessed by a combination of spectroscopy, scanning electron microscopy, viscometry, porosity, and mechanical tests. Adherence ofCandida albicanscells and cellular compatibility assays were performed to explore biocompatibility and microbial adhesion of standard and novel materials. Our results show that introduction of biocompatible metal nanoparticles is a suitable means for the improvement of conventional acrylic dental resins.
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Navarrete, Eric, and Eduard Llobet. "Synthesis of p-n Heterojunctions via Aerosol Assisted Chemical Vapor Deposition to Enhance the Gas Sensing Properties of Tungsten Trioxide Nanowires: A Mini-Review." Journal of Nanoscience and Nanotechnology 21, no. 4 (April 1, 2021): 2462–71. http://dx.doi.org/10.1166/jnn.2021.19105.
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Here we discuss the aerosol-assisted synthesis of p–n heterojunction metal oxides and we report their gas sensing properties via a short review of the latest results achieved. In particular, we show that the decoration of one-dimensional tungsten oxide (n-type) with nanoparticles of different p-type oxides from transition metals such as Ni, Co or Ir enables achieving a chemical and electronic sensitization of the resulting hybrid metal oxide materials. This leads to remarkable differences in responsiveness to gases, showing that, to some extent, a selective detection of some major pollutant gases (NO2, H2S or NH3) would be possible. Results are critically reviewed, shortcomings are identified and future research directions are given.
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Barbillon, Grégory. "Latest Novelties on Plasmonic and Non-Plasmonic Nanomaterials for SERS Sensing." Nanomaterials 10, no. 6 (June 19, 2020): 1200. http://dx.doi.org/10.3390/nano10061200.
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An explosion in the production of substrates for surface enhanced Raman scattering (SERS) has occurred using novel designs of plasmonic nanostructures (e.g., nanoparticle self-assembly), new plasmonic materials such as bimetallic nanomaterials (e.g., Au/Ag) and hybrid nanomaterials (e.g., metal/semiconductor), and new non-plasmonic nanomaterials. The novel plasmonic nanomaterials can enable a better charge transfer or a better confinement of the electric field inducing a SERS enhancement by adjusting, for instance, the size, shape, spatial organization, nanoparticle self-assembly, and nature of nanomaterials. The new non-plasmonic nanomaterials can favor a better charge transfer caused by atom defects, thus inducing a SERS enhancement. In last two years (2019–2020), great insights in the fields of design of plasmonic nanosystems based on the nanoparticle self-assembly and new plasmonic and non-plasmonic nanomaterials were realized. This mini-review is focused on the nanoparticle self-assembly, bimetallic nanoparticles, nanomaterials based on metal-zinc oxide, and other nanomaterials based on metal oxides and metal oxide-metal for SERS sensing.
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Zegan, Georgeta, Daniela Anistoroaei, Loredana Golovcencu, Eduard Radu Cernei, Cristina Gena Dascalu, and Elena Mihaela Carausu. "Physicochemical Properties of Advanced Nanostructured Materials for Dental Microimplant Coatings." Revista de Chimie 68, no. 9 (October 15, 2017): 2052–54. http://dx.doi.org/10.37358/rc.17.9.5820.
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An important aspect of orthodontic microimplants is represented by biocompatibility and avoidance of infection development at living tissue surrounding it. Therefore, nanotechnology has the ability to improve this issue by coating microimplants with metal oxides type nanomaterials possessing antimicrobial effect. Some features of advanced nanostructured materials used as implant coatings, such as composition, structure, specific surface area, porosity, shape and size are factors that make them suitable as antimicrobial agents. The present work deals with the structural and morphological studies of ZnO and TiO2 nanoparticles used to combat oral diseases. Coating microimplants with nanosized titanium oxide (TiO2) and zinc oxide (ZnO) may improve conditions for osseointegration in accordance with preventing oral infection. These metal oxides nanopowders were synthesized using sol-gel method. Structural and morphological investigation were carried out by XRD and FTIR spectra, SEM-EDX and TEM images respectively. XRD and FTIR analyses confirmed metal oxides crystallization and metal oxide bonds. SEM-EDX and TEM features confirmed elemental composition of these nanoparticles and their textural characteristics such as shape, size, porosity and agglomeration degree.
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Астафьева, Л. Г., В. К. Пустовалов, and В. Фритче. "Анализ оптических свойств однородных металлических, окисных наночастиц и двухслойных наночастиц с металлическим ядром и окисной оболочкой с целью эффективного поглощения солнечной радиации." Журнал технической физики 126, no. 3 (2019): 374. http://dx.doi.org/10.21883/os.2019.03.47381.88-18.
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AbstractProblems related to using nanoparticles for absorption of solar radiation and photothermal nanotechnologies are now being actively studied. The efficiency of using nanoparticles as photothermal agents for solar energy is determined by their spectral optical properties. We performed computer simulation of optical properties of homogeneous metal (nickel, titanium, and molybdenum) nanoparticles and their oxides, along with nanoparticles consisting of a metal core and an oxide shell, with radii in the range from 50 to 100 nm in the spectral interval between 200 and 2500 nm. The influence of nanoparticle radius, the type of metal and its oxide on spectral coefficients of efficiency absorption ( K _abs) and scattering ( K _sca) of radiation by nanoparticles is investigated. The type of nanoparticles suitable for absorption of solar radiation was chosen based on a comparative analysis of the wavelength dependences of absorption efficiency coefficients K _abs, intensity of solar radiation I _ S , and parameter P _1 = K _abs/ K _sca. Spherical double–layer nanoparticles consisting of nickel or titanium core and oxide shells with a radius of 75 or 100 nm can be used in the spectral interval from 200 to 2500 nm for efficient absorption of solar radiation. These results are a substantial contribution to the investigation of optical properties of nanoparticles that can be used in systems of thermal energy.
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Sunil, Dhanya. "Recennt Advances on Chitosan-Metal Oxide Nanoparticles and their Biological Application." Materials Science Forum 754 (April 2013): 99–108. http://dx.doi.org/10.4028/www.scientific.net/msf.754.99.
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There is a growing interest in the use of green resources for nanoparticle (NP) synthesis. Natural polymer, Chitosan (CH) has been employed as templates for the preparation of metal oxide NPs. They modify the surface characteristics of the nanometal oxides generated. In the presence of template CH, the spatial separation of the particles, enable the synthesis of highly crystalline, mono-dispersed particles of < 100 nm. The properties of metal oxides can be improved by combining with CH and the product can be employed for different applications. CH along with metal oxide NPs has recently been utilized as a stabilizing agent due to its excellent film-forming ability, mechanical strength, biocompatibility, non-toxicity, high permeability towards water, susceptibility to chemical modification and cost-effectiveness. Metal oxide NPs-CH based hybrid composites have attracted much interest for the development of desired biosensors, MRI agents, buffers, antibacterial agents etc.
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Memarzadeh, K., M. Vargas, Jie Huang, J. Fan, and R. P. Allaker. "Nano Metallic-Oxides as Antimicrobials for Implant Coatings." Key Engineering Materials 493-494 (October 2011): 489–94. http://dx.doi.org/10.4028/www.scientific.net/kem.493-494.489.
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The use of metallic nanoparticles in the field of orthopaedics as antimicrobial components of coatings is receiving particular attention. An innovative approach has been developed whereby various metal/metal oxide nanoparticles are used to prevent infection occurring on the surface of prostheses. In this study nano metallic oxides (zinc oxide - ZnO and tungsten oxide - WO3) were used. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of each nanoparticulate were determined against four species of bacteria (Staphylococcus aureus, Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa). Subsequently the nanoparticles were prepared in a suspension of ethanol and sprayed onto the surface of glass using electrohydrodynamic deposition. Quantitative assessments as regards the antimicrobial properties of these coated samples were carried out. Comparisons of the antibacterial properties demonstrated that 2500 µg/ml or above of the oxides were required to kill the species of bacteria tested. WO3 was the most effective oxide tested in suspension using growth inhibition tests. However, coated samples demonstrated that ZnO was more bactericidal than WO3 under these conditions.
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Seeta Rama Raju, G., Leah Benton, E. Pavitra, and Jae Su Yu. "Multifunctional nanoparticles: recent progress in cancer therapeutics." Chemical Communications 51, no. 68 (2015): 13248–59. http://dx.doi.org/10.1039/c5cc04643b.
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In recent times, several biocompatible nanomaterials with different morphologies and compositions, such as metals, metal oxides, and polymers, have been employed as multi-functional biomaterials to target cancer cells.
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Abdelrahman, Meram S., Sahar H. Nassar, Hamada Mashaly, Safia Mahmoud, Dalia Maamoun, Mohamed El-Sakhawy, Tawfik A. Khattab, and Samir Kamel. "Studies of Polylactic Acid and Metal Oxide Nanoparticles-Based Composites for Multifunctional Textile Prints." Coatings 10, no. 1 (January 9, 2020): 58. http://dx.doi.org/10.3390/coatings10010058.
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A novel approach toward the production of multifunctional printed technical textiles is reported. Three different metal oxides nanoparticles including titanium dioxide, magnesium oxide, and zinc oxide were prepared and characterized. Both natural wool and synthetic acrylic fibers were pretreated with the prepared metal oxide nanoparticles followed by printing using polylactic acid based paste containing acid or basic dyestuffs. Another route was applied via post-treatment of the targeted fabrics with the metal oxide nanoparticles after running the printing process. The color strength (K/S) and colorfastness properties of pretreated and post-treated printed fabrics were evaluated and compared with untreated printed fabrics. The presence of nanoparticles on a fabric surface during the coating process was found to significantly increase the color strength value of the coated textile substrates. The increased K/S value depended mainly on the nature and concentration of the applied metal oxide, as well as the nature of colorant and fabric. In addition, the applied metal oxide nanoparticles imparted the printed fabrics with good antibacterial activity, high ultraviolet protection, photocatalytic self-cleaning, and improved colorfastness properties. Those results suggest that the applied metal oxide-based nanoparticles could introduce ideal multifunctional prints for garments.
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Rani, N., and K. Saini. "Biogenic Metal and Metal Oxides Nanoparticles as Anticancer Agent: A Review." IOP Conference Series: Materials Science and Engineering 1225, no. 1 (February 1, 2022): 012043. http://dx.doi.org/10.1088/1757-899x/1225/1/012043.
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Abstract Herein this review we have summarized a number of cytotoxic studies which have been done using various biosynthesized metal nanoparticles (MNPs) and metal oxide nanoparticles (MONPs) on different cancer cell lines. Plants can serve as a good candidate to provide natural surfactants for the green approach in the preparation of nanoparticles. Numerous bio-molecules are present in the plants. Also, numerous plant extract-based MNPs and MONPs have been synthesized and used in several fields of applications particularly in biomedicine. This property can be attributed because of their low cost, biocompatibility and favourable to the environment. In the past few years, the utilisation of these biogenic nanoparticles has in-creased tremendously particularly in cancer therapy. These biogenic nanoparticles considered as an excellent tool for cancer diagnosis and drug delivery at the tumour site preferentially. By utilising the unique properties of nanoparticles and antioxidant and antitumor nature of plants, these biosynthesised nanoparticles selectively destroy the tumour cells and do not harm the normal healthy cells. In this review, we have compiled the most significant results obtained by the biosynthesized MNPs and MONPs like silver (Ag), gold (Au), Fe2O3/Fe3O4, ZnO, and CuO respectively.
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Motshekga, Sarah C., Sreejarani K. Pillai, Suprakas Sinha Ray, Kalala Jalama, and Rui W. M. Krause. "Recent Trends in the Microwave-Assisted Synthesis of Metal Oxide Nanoparticles Supported on Carbon Nanotubes and Their Applications." Journal of Nanomaterials 2012 (2012): 1–15. http://dx.doi.org/10.1155/2012/691503.
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The study of coating carbon nanotubes with metal/oxides nanoparticles is now becoming a promising and challenging area of research. To optimize the use of carbon nanotubes in various applications, it is necessary to attach functional groups or other nanostructures to their surface. The combination of the distinctive properties of carbon nanotubes and metal/oxides is expected to be applied in field emission displays, nanoelectronic devices, novel catalysts, and polymer or ceramic reinforcement. The synthesis of these composites is still largely based on conventional techniques, such as wet impregnation followed by chemical reduction of the metal nanoparticle precursors. These techniques based on thermal heating can be time consuming and often lack control of particle size and morphology. Hence, there is interest in microwave technology recently, where using microwaves represents an alternative way of power input into chemical reactions through dielectric heating. This paper covers the synthesis and applications of carbon-nanotube-coated metal/oxides nanoparticles prepared by a microwave-assisted method. The reviewed studies show that the microwave-assisted synthesis of the composites allows processes to be completed within a shorter reaction time with uniform and well-dispersed nanoparticle formation.
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Khine, Ei Ei, and George Kaptay. "Identification of Nano-Metal Oxides That Can Be Synthesized by Precipitation-Calcination Method Reacting Their Chloride Solutions with NaOH Solution and Their Application for Carbon Dioxide Capture from Air—A Thermodynamic Analysis." Materials 16, no. 2 (January 12, 2023): 776. http://dx.doi.org/10.3390/ma16020776.
Full textAbstract:
Several metal oxide nanoparticles (NPs) were already obtained by mixing NaOH solution with chloride solution of the corresponding metal to form metal hydroxide or oxide precipitates and wash—dry—calcine the latter. However, the complete list of metal oxide NPs is missing with which this technology works well. The aim of this study was to fill this knowledge gap and to provide a full list of possible metals for which this technology probably works well. Our methodology was chemical thermodynamics, analyzing solubilities of metal chlorides, metal oxides and metal hydroxides in water and also standard molar Gibbs energy changes accompanying the following: (i) the reaction between metal chlorides and NaOH; (ii) the dissociation reaction of metal hydroxides into metal oxide and water vapor and (iii) the reaction between metal oxides and gaseous carbon dioxide to form metal carbonates. The major result of this paper is that the following metal-oxide NPs can be produced by the above technology from the corresponding metal chlorides: Al2O3, BeO, CaO, CdO, CoO, CuO, FeO, Fe2O3, In2O3, La2O3, MgO, MnO, Nd2O3, NiO, Pr2O3, Sb2O3, Sm2O3, SnO, Y2O3 and ZnO. From the analysis of the literature, the following nine nano-oxides have been already obtained experimentally with this technology: CaO, CdO, Co3O4, CuO, Fe2O3, NiO, MgO, SnO2 and ZnO (note: Co3O4 and SnO2 were obtained under oxidizing conditions during calcination in air). Thus, it is predicted here that the following nano-oxides can be potentially synthesized with this technology in the future: Al2O3, BeO, In2O3, La2O3, MnO, Nd2O3, Pr2O3, Sb2O3, Sm2O3 and Y2O3. The secondary result is that among the above 20 nano-oxides, the following five nano-oxides are able to capture carbon dioxide from air at least down to 42 ppm residual CO2-content, i.e., decreasing the current level of 420 ppm of CO2 in the Earth’s atmosphere at least tenfold: CaO, MnO, MgO, CdO, CoO. The tertiary result is that by mixing the AuCl3 solution with NaOH solution, Au nano-particles will precipitate without forming Au-oxide NPs. The results are significant for the synthesis of metal nano-oxide particles and for capturing carbon dioxide from air.
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Kuzmin, Alexei, Andris Anspoks, Aleksandr Kalinko, and Janis Timoshenko. "Simulation based approach to structure relaxation in oxides nanomaterials." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C747. http://dx.doi.org/10.1107/s2053273314092523.
Full textAbstract:
Physical properties of nanoparticles depend strongly on their structure, therefore an understanding of atomic structure relaxation at nanoscale is very important for properties tuning but is a challenging task. Upon crystallite size reduction below about 10 nm, the unit-cell volume expansion is observed in most nanooxides, opposite to metal nanoparticles. The detailed understanding of this phenomenon requires joint use of modern experimental and theoretical methods. In this study we will illustrate how the nanostructure problem can be addressed using classical molecular dynamics [1] and reverse Monte Carlo [2] simulation methods, employed to the analysis of synchrotron radiation x-ray absorption spectra. The two simulation based approaches allow us to obtain structural models which account for the nanoparticle size, thermal disorder and high-order correlation effects. Two examples of their use will be discussed in details: (i) the role of nickel vacancies in nickel oxide nanoparticles/thin films and (ii) the effect of transition metal type on tungstate nanoparticles.