Articles de revues : « Novel Oxides »

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Yamaoka, Mayumi, Mitsuji Yamashita, Manabu Yamada, Michio Fujie, Keita Kiyofuji, Nobuhisa Ozaki, Kazuhide Asai et al. « Synthesis and evaluation of novel phosphasugar anticancer agents ». Pure and Applied Chemistry 84, n^o 1 (27 décembre 2011) : 37–48. http://dx.doi.org/10.1351/pac-con-11-10-09.

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Starting materials of phosphasugars, 1-phenyl-2-phospholene 1-oxides, were prepared from dienes and phenylphosphonous dichloride (dichlorophenylphosphine). Several substituted novel phosphasugars (3- or 4-halo-substituted)-1-phenyl-2-phospholene 1-oxides as well as 1-phenyl-2-phospholane 1-oxides were prepared from 2-phospholenes. The synthesized compounds were evaluated for their antitumor activities against the leukemia cell lines (U937 and K562) by in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. 2,3,4-Tribromo-3-methyl-1-phenylphospholane 1-oxide showed superior antitumor activity against U937 and K562 cell lines in a comparative evaluation with Glivec. The analysis by flow cytometry implied that 2,3-dibromo-3-methyl-1-phenylphospholane 1-oxide induced apoptosis to leukemia cell lines.

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Sivasankaran, S., S. Sankaranarayanan et S. Ramakrishnan. « A Novel Sonochemical Synthesis of Metal Oxides Based Bhasmas ». Materials Science Forum 754 (avril 2013) : 89–97. http://dx.doi.org/10.4028/www.scientific.net/msf.754.89.

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Metal oxides form part of inorganic medicines called Bhasmas, which has been used in a non-allopathic medicine system practiced in India called Ayurveda. Bhasmas may be classified under the nanomedicines of ancient India. The traditional preparation methods involve time consuming and complicated preparation procedures. This paper highlights a novel ultrasound assisted technique called sonochemical synthesis of transition metal oxides in a facile, faster, inherently safer and environmentally benign (green chemistry) way which could be considered to be used for the synthesis of metal oxides such as copper oxide which form part of the copper based Ayurvedic nanomedicine called tamra bhasma, which is copper in its oxide form and used therapeutically as a source of copper. The synthesis procedure outlined here could be considered for the preparation of other types of Bhasmas also.

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Ngai, J. H., K. Ahmadi-Majlan, J. Moghadam, M. Chrysler, D. P. Kumah, C. H. Ahn, F. J. Walker et al. « Electrically Coupling Multifunctional Oxides to Semiconductors : A Route to Novel Material Functionalities ». MRS Advances 1, n^o 4 (2016) : 255–63. http://dx.doi.org/10.1557/adv.2016.101.

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ABSTRACTComplex oxides and semiconductors exhibit distinct yet complementary properties owing to their respective ionic and covalent natures. By electrically coupling oxides to semiconductors within epitaxial heterostructures, enhanced or novel functionalities beyond those of the constituent materials can potentially be realized. Key to electrically coupling oxides to semiconductors is controlling the physical and electronic structure of semiconductor – crystalline oxide heterostructures. Here we discuss how composition of the oxide can be manipulated to control physical and electronic structure in Ba1-xSrxTiO3/ Ge and SrZrxTi1-xO3/Ge heterostructures. In the case of the former we discuss how strain can be engineered through composition to enable the re-orientable ferroelectric polarization to be coupled to carriers in the semiconductor. In the case of the latter we discuss how composition can be exploited to control the band offset at the semiconductor - oxide interface. The ability to control the band offset, i.e. band-gap engineering, provides a pathway to electrically couple crystalline oxides to semiconductors to realize a host of functionalities.

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Hosono, Hideo, Masahiro Yasukawa et Hiroshi Kawazoe. « Novel oxide amorphous semiconductors : transparent conducting amorphous oxides ». Journal of Non-Crystalline Solids 203 (août 1996) : 334–44. http://dx.doi.org/10.1016/0022-3093(96)00367-5.

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Brash, Alan R., William E. Boeglin, Donald F. Stec, Markus Voehler, Claus Schneider et Jin K. Cha. « Isolation and Characterization of Two Geometric Allene Oxide Isomers Synthesized from 9S-Hydroperoxylinoleic Acid by Cytochrome P450 CYP74C3 ». Journal of Biological Chemistry 288, n^o 29 (24 mai 2013) : 20797–806. http://dx.doi.org/10.1074/jbc.m113.482521.

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Specialized cytochromes P450 or catalase-related hemoproteins transform fatty acid hydroperoxides to allene oxides, highly reactive epoxides leading to cyclopentenones and other products. The stereochemistry of the natural allene oxides is incompletely defined, as are the structural features required for their cyclization. We investigated the transformation of 9S-hydroperoxylinoleic acid with the allene oxide synthase CYP74C3, a reported reaction that unexpectedly produces an allene oxide-derived cyclopentenone. Using biphasic reaction conditions at 0 °C, we isolated the initial products and separated two allene oxide isomers by HPLC at −15 °C. One matched previously described allene oxides in its UV spectrum (λmax 236 nm) and NMR spectrum (defining a 9,10-epoxy-octadec-10,12Z-dienoate). The second was a novel stereoisomer (UV λmax 239 nm) with distinctive NMR chemical shifts. Comparison of NOE interactions of the epoxy proton at C9 in the two allene oxides (and the equivalent NOE experiment in 12,13-epoxy allene oxides) allowed assignment at the isomeric C10 epoxy-ene carbon as Z in the new isomer and the E configuration in all previously characterized allene oxides. The novel 10Z isomer spontaneously formed a cis-cyclopentenone at room temperature in hexane. These results explain the origin of the cyclopentenone, provide insights into the mechanisms of allene oxide cyclization, and define the double bond geometry in naturally occurring allene oxides.

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Parihar, Reena, Priya Sharma, Amritpal Singh Chaddha et Narendra Kumar Singh. « Strontium Substituted SmNiO3 : Novel Electrode Materials for Alkaline Water Electrolysis ». Journal of New Materials for Electrochemical Systems 24, n^o 3 (30 septembre 2021) : 201–7. http://dx.doi.org/10.14447/jnmes.v24i3.a08.

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Sr-substituted SmNiO3 perovskite-type oxides have been investigated for their electrocatalytic properties towards oxygen evolution reaction (OER) in alkaline medium. Materials were obtained by using low temperature malic acid sol-gel route. To know the redox behaviour, electrocatalytic activity and thermodynamic parameters of oxides, cyclic voltammetry (CV) and anodic polarization curve (Tafel plot) were recorded in 1 M KOH at 25 ºC. X-ray diffraction (XRD) study indicates the formation of almost pure perovskite phase of the material. A pair of redox peaks was observed (anodic; Epa = 494±12 mV and corresponding cathodic; Epc = 360±4 mV) in the potential region 0.0-0.7 V prior to onset of OER. As observed in the case of La-based perovskite oxides, Sr-substitutions in the SmNiO3 also enhance the electrocatalytic properties of the material. However, Sm-based oxides showed least electrocatalytic activity as compared to La-based oxides. The estimated values of Tafel slope and reaction order indicate that each oxide electrode, except SmNiO3, follows similar mechanistic path towards OER. Standard entropy of activation (DS˚#), standard enthalpy of activation (DH˚#) and standard electrochemical energy of activation (DHel˚#) was determined by recording the anodic polarization curve in 1M KOH at different temperatures.

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Cotell, Catherine M., et Kenneth S. Grabowski. « Novel Materials Applications of Pulsed Laser Deposition ». MRS Bulletin 17, n^o 2 (février 1992) : 44–53. http://dx.doi.org/10.1557/s0883769400040616.

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The successful use of pulsed laser deposition (PLD) to fabricate thin film superconductors has generated interest in using the technique to deposit thin films of other materials. The compositional fidelity between laser target and deposited film and the ability to deposit films in reactive gas environments make the PLD process particularly well suited to the deposition of complex multicomponent materials. Cheung and Sankur recently provided an excellent review of the PLD field, including a table of over 100 elements, inorganic and organic compounds, andsuperlattices that have been laser evaporated. Over 75 of these materials were deposited as thin films.The goal of this article is to provide an introduction to some of the newer applications of PLD for thin film fabrication. Four classes of materials are highlighted: ferroelectrics, bioceramics, ferrites, and tribological materials. Ferroelectric materials are structurally related to the high-temperature superconducting oxides and therefore are a direct extension of the recent superconducting oxide work. Bioceramics are dissimilar in structure and application to both ferroelectrics and superconducting oxides, but they are complex multicomponent oxides and, therefore, benefit from the use of PLD. Ferrites, also complex, multicomponent oxides, represent another exciting, but only lightly explored opportunity for PLD. In contrast, tribological materials are typically neither complex nor multicomponent. Nevertheless, interesting structures and properties have been produced by PLD. A few of the more important ones will be discussed. These different types of materials demonstrate the diversity of capabilities offered by PLD.

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Zhang, Heng, Jack Gromek, Gayanath Fernando et Harris L. Marcus. « Novel nanostructred Pd–Zr oxides ». Materials Science and Engineering : A 366, n^o 2 (février 2004) : 248–53. http://dx.doi.org/10.1016/j.msea.2003.07.004.

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Bai, Shuiquan. « A Research of Selective Catalytic Reduction of NOx with NH3 by Using Novel Catalysts ». Journal of Physics : Conference Series 2539, n^o 1 (1 juillet 2023) : 012058. http://dx.doi.org/10.1088/1742-6596/2539/1/012058.

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Abstract Nitrogen oxides are one of the most important industrial pollutants, which have many harmful effects on the human body and the environment. In this paper, the formation mechanism of nitrogen oxides was studied, and the selective catalytic reduction of nitrogen oxides was carried out by selective catalytic reduction technology. This paper also reviews the low-temperature denitration performance of molecular sieve catalysts, manganese oxide and ceria-based catalysts, and expounds on the influence of catalysts on denitration activity under different active components. It is found that ceria-based catalytic materials have better structural properties and catalytic performance, the methods to improve the performance of ceria-based catalysts are discussed, and the future development of ceria-based catalysts has been prospected.

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Cascos, V., R. Martínez-Coronado, M. T. Fernández-Díaz et J. A. Alonso. « Topotactic Oxidation of Perovskites to Novel SrMo1-xMxO4−δ (M = Fe and Cr) Deficient Scheelite-Type Oxides ». Materials 13, n^o 19 (6 octobre 2020) : 4441. http://dx.doi.org/10.3390/ma13194441.

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New polycrystalline SrMo1−xMxO4−δ (M = Fe and Cr) scheelite oxides have been prepared by topotactical oxidation, by annealing in air at 500 °C, from precursor perovskites with the stoichiometry SrMo1−xMxO3−δ (M = Fe and Cr). An excellent reversibility between the oxidized Sr(Mo,M)O4−δ scheelite and the reduced Sr(Mo,M)O3−δ perovskite phase accounts for the excellent behavior of the latter as anode material in solid-oxide fuel cells. A characterization by X-ray powder diffraction (XRD) and neutron powder diffraction (NPD) has been carried out to determine the crystal structure features. The scheelite oxides are tetragonal, space group I41/a (No. 88). The Rietveld-refinement from NPD data at room temperature shows evidence of oxygen vacancies in the structure, due to the introduction of Fe3+/Cr4+ cations in the tetrahedrally-coordinated B sublattice, where Mo is hexavalent. A thermal analysis of the reduced perovskite (SrMo1−xMxO3−δ) in oxidizing conditions confirms the oxygen stoichiometry obtained by NPD data; the stability range of the doped oxides, below 400–450 °C, is lower than that for the parent SrMoO3 oxide. The presence of a Mo4+/Mo5+ mixed valence in the reduced SrMo1−xMxO3−δ perovskite oxides confers greater instability against oxidation compared with the parent oxide. Finally, an XPS study confirms the surface oxidation states of Mo, Fe, and Cr in the oxidized samples SrMo0.9Fe0.1O4-δ and SrMo0.8Cr0.2O4-δ.

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Long, Nguyet Viet. « INVESTIGATION OF SURFACES OF NOVEL IRON OXIDES WITH GRAIN AND GRAIN BOUNDARY ». Vietnam Journal of Science and Technology 56, n^o 1A (4 mai 2018) : 226. http://dx.doi.org/10.15625/2525-2518/56/1a/12527.

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Hierarchical nano/microscale α-Fe2O3 iron oxide particle system was prepared by an improved and modified polyol method with the use of NaBH4 agent with high heat treatment at 900 °C in air. Here, α-Fe2O3 iron oxide particles with different shapes were analyzed. The morphologies of the surfaces of α-Fe2O3 iron oxide particles show the oxide structures with the different nano/microscale ranges of grain sizes. In this research, we have found that grain and grain boundary growth limits can be determined in α-Fe2O3 iron oxide structure. This leads to the possibility of producing new iron oxide structures with distribution of desirable size grain and grain boundary. With α-Fe2O3 structure obtained, the magnetic properties of the α-Fe2O3 iron oxide system are different from those of previously reported studies. in national and international studies.Keywords: Iron iron oxides, α-Fe2O3, chemical polyol methods, heat treatment.

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Chen, Zheng, Manuel Löber, Anna Rokicińska, Zili Ma, Jianhong Chen, Piotr Kuśtrowski, Hans-Jürgen Meyer, Richard Dronskowski et Adam Slabon. « Increased photocurrent of CuWO4 photoanodes by modification with the oxide carbodiimide Sn2O(NCN) ». Dalton Transactions 49, n^o 11 (2020) : 3450–56. http://dx.doi.org/10.1039/c9dt04752b.

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El-Sayed, I., K. M. H. Hilmy, S. M. El-Kousy, A. Fischer et H. S. Slem. « Synthesis of Novel Trithiocarbonate-S-Oxides ». Phosphorus, Sulfur, and Silicon and the Related Elements 178, n^o 11 (1 novembre 2003) : 2403–13. http://dx.doi.org/10.1080/714040954.

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Liu, Mouxiong, Dongdong Gui, Ping Deng et Hui Zhou. « Asymmetric Henry Reaction of 2-Acylpyridine N-Oxides Catalyzed by a Ni-Aminophenol Sulfonamide Complex : An Unexpected Mononuclear Catalyst ». Molecules 24, n^o 8 (14 avril 2019) : 1471. http://dx.doi.org/10.3390/molecules24081471.

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The asymmetric Henry reaction of 2-acylpyridine N-oxide remains a challenge as N-oxides generally act as competitive catalyst inhibitors or displace activating ligands. A novel variable yield (up to 99%) asymmetric Henry reaction of 2-acypyridine N-oxides catalyzed by a Ni-aminophenol sulfonamide complex with good to excellent enantioselectivity (up to 99%) has been developed. Mechanistic studies suggest that the unique properties of the electron-pairs of N-oxides for complexation with Ni makes the unexpected mononuclear complex, rather than the previously reported dinuclear complex, the active species.

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Lim, Zhi Shiuh, Hariom Jani, T. Venkatesan et A. Ariando. « Skyrmionics in correlated oxides ». MRS Bulletin 46, n^o 11 (novembre 2021) : 1053–62. http://dx.doi.org/10.1557/s43577-021-00227-9.

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AbstractWhile chiral magnets, metal-based magnetic multilayers, or Heusler compounds have been considered as the material workhorses in the field of skyrmionics, oxides are now emerging as promising alternatives, as they host special correlations between the spin–orbital–charge–lattice degrees of freedom and/or coupled ferroic order parameters. These interactions open new possibilities for practically exploiting skyrmionics. In this article, we review the recent advances in the observation and control of topological spin textures in various oxide systems. We start with the discovery of skyrmions and related quasiparticles in bulk and heterostructure ferromagnetic oxides. Next, we emphasize the shortcomings of implementing ferromagnetic textures, which have led to the recent explorations of ferrimagnetic and antiferromagnetic oxide counterparts, with higher Curie temperatures, stray-field immunity, low Gilbert damping, ultrafast magnetic dynamics, and/or absence of skyrmion deflection. Then, we highlight the development of novel pathways to control the stability, motion, and detection of topological textures using electric fields and currents. Finally, we present the outstanding challenges that need to be overcome to achieve all-electrical, nonvolatile, low-power oxide skyrmionic devices. Graphical abstract

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Yan, Shengxue, Shaohua Luo, Liu Yang, Jian Feng, Pengwei Li, Qing Wang, Yahui Zhang et Xin Liu. « Novel P2-type layered medium-entropy ceramics oxide as cathode material for sodium-ion batteries ». Journal of Advanced Ceramics 11, n^o 1 (10 novembre 2021) : 158–71. http://dx.doi.org/10.1007/s40145-021-0524-8.

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AbstractHigh-entropy oxides (HEOs) and medium-entropy oxides (MEOs) are new types of single-phase solid solution materials. MEOs have rarely been reported as positive electrode material for sodium-ion batteries (SIBs). In this study, we first proposed the concept of the application of MEOs in SIBs. P2-type 3-cation oxide Na2/3Ni1/3Mn1/3Fe1/3O2 (NaNMF) and 4-cation oxide Na2/3Ni1/3Mn1/3Fe1/3−xAlxO2 (NaNMFA) were prepared using the solid-state method, rather than the doping technology. In addition, the importance of the concept of entropy stabilization in material performance and battery cycling was demonstrated by testing 3-cation (NaNMF) and 4-cation (NaNMFA) oxides in the same system. Thus, NaNMFA can provide a reversible capacity of about 125.6 mAh·g−1 in the voltage range of 2–4.2 V, and has enhanced cycle stability. The capacity and decay law of the MEO batteries indicate that the configurational entropy (1.28 R (NaNMFA) > 1.10 R (NaNMF)) of the cationic system, is the main factor affecting the structural and cycle stability of the electrode material. This work emphasizes that the rational design of MEOs with novel structures and different electrochemically active elements may be the strategy for exploring high-performance SIB cathode materials in next-generation energy storage devices.

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Kaneko, Kentaro, et Shizuo Fujita. « Novel p-type oxides with corundum structure for gallium oxide electronics ». Journal of Materials Research 37, n^o 3 (19 janvier 2022) : 651–59. http://dx.doi.org/10.1557/s43578-021-00439-4.

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Dick, Gregory J., Justin W. Torpey, Terry J. Beveridge et Bradley M. Tebo. « Direct Identification of a Bacterial Manganese(II) Oxidase, the Multicopper Oxidase MnxG, from Spores of Several Different Marine Bacillus Species ». Applied and Environmental Microbiology 74, n^o 5 (28 décembre 2007) : 1527–34. http://dx.doi.org/10.1128/aem.01240-07.

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ABSTRACT Microorganisms catalyze the formation of naturally occurring Mn oxides, but little is known about the biochemical mechanisms of this important biogeochemical process. We used tandem mass spectrometry to directly analyze the Mn(II)-oxidizing enzyme from marine Bacillus spores, identified as an Mn oxide band with an in-gel activity assay. Nine distinct peptides recovered from the Mn oxide band of two Bacillus species were unique to the multicopper oxidase MnxG, and one peptide was from the small hydrophobic protein MnxF. No other proteins were detected in the Mn oxide band, indicating that MnxG (or a MnxF/G complex) directly catalyzes biogenic Mn oxide formation. The Mn(II) oxidase was partially purified and found to be resistant to many proteases and active even at high concentrations of sodium dodecyl sulfate. Comparative analysis of the genes involved in Mn(II) oxidation from three diverse Bacillus species revealed a complement of conserved Cu-binding regions not present in well-characterized multicopper oxidases. Our results provide the first direct identification of a bacterial enzyme that catalyzes Mn(II) oxidation and suggest that MnxG catalyzes two sequential one-electron oxidations from Mn(II) to Mn(III) and from Mn(III) to Mn(IV), a novel type of reaction for a multicopper oxidase.

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Zhang, Mao Lin, et Long Feng Li. « A Novel Route to Prepare ZnO-SnO₂ Nanocomposite with High Photocatalytic Activity ». Advanced Materials Research 197-198 (février 2011) : 1038–41. http://dx.doi.org/10.4028/www.scientific.net/amr.197-198.1038.

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A nanometer coupled oxide ZnO-SnO2 was prepared by the fractional homogeneous co-precipitation route using urea as the latent precipitant under boiling reflux condition. The samples prepared from different initial concentrations of urea or at different calcination temperatures were characterized by X-ray diffration (XRD) or transmission electron microscopy (TEM). It was found that the coupled oxides ZnO-SnO2 mainly consist of nanosized ZnO and SnO2, the calcination temperature had obvious effect on the phase composition and the crystal size of the samples obtained, and the precipitant concentration also had obvious effect on the oxide particles size and the production rate of ZnO. Moreover, their photocatalytic activity was investigated for the liquids-phase photocatalytic degradation of methyl orange (MO) in water under UV light irradiation.The coupled oxides showed better photocatalytic activity for the degradation of MO than the pure ZnO or SnO2.

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Wu, Lei, Kai Luo, Ling Zhang, Kai Wei et Wen-Chao Yang. « Latent Radical Cleavage of α-Allenylic C–O Bonds : Potassium Persulfate Mediated Thiolation of Allenylphosphine Oxides ». Synthesis 50, n^o 15 (19 avril 2018) : 2990–98. http://dx.doi.org/10.1055/s-0037-1609835.

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A novel potassium persulfate (K2S2O8) mediated thiolation of allenylphosphine oxides with diaryl sulfides is disclosed. Mechanistic studies indicate that K2S2O8 homolyzes the diaryl sulfide to produce a thiyl radical (PhS•), which is followed by C–O bond cleavage of the allenylphosphine oxide under metal-free conditions, affording novel S,P-bifunctionalized butadienes in moderate to excellent yields.

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Shirzadi, A. A., et E. R. Wallach. « Novel Method for Diffusion Bonding Superalloys and Aluminium Alloys (USA Patent 6,669,534 B2, European Patent Pending) ». Materials Science Forum 502 (décembre 2005) : 431–36. http://dx.doi.org/10.4028/www.scientific.net/msf.502.431.

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A novel method for diffusion bonding metallic alloys with stable surface oxide films (e.g. nickel and cobalt base superalloys and aluminium alloys) has been developed. The stable oxides on the faying surfaces of these alloys are replaced, prior to the bonding process, with a very thin metallic layer and/or less stable oxides, using a proprietary non-chemical oxide removal method based on the use of gallium. This new method is very rapid and neither requires the use of any sophisticated equipment nor is a costly process. Bonding is then readily achieved by either solid-state or transient-liquid-phase (TLP) diffusion bonding. Using this method, bonds in nickelbase and cobalt-base superalloys with “virtually invisible” bond interfaces and bonds in aluminium alloys with strengths as high as those of the parent alloys can be produced.

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Černý, Radovan, et Pascal Schouwink. « Borohydride - Oxide Isomorphism in Design of Energy Storage Materials ». Acta Crystallographica Section A Foundations and Advances 70, a1 (5 août 2014) : C944. http://dx.doi.org/10.1107/s205327331409055x.

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An increasing number of novel single, double and triple cation borohydrides has been structurally characterized in the last few years as hydrogen storage materials and solid state electrolytes for battery applications [1,2]. It is interesting to note that the majority of these novel metal borohydrides resemble structures of various metal oxides. This is not altogether surprising considering the fact that [BH4]-and O2-anions are isoelectronic. The particularity of the borohydride-oxide analogy is the double negative charge of O2-vs. the simply charged borohydride [BH4]-, this providing a superior structural flexibility in oxides with respect to mixed valence compounds. Though somewhat handicapped by its lower charge regarding this issue, the borohydride anion obtains its versatility as a building block due to being a non-spherical anion with a tetrahedral shape as opposed to the oxide, which is approximately spherical. This commonly results in a lower symmetry of the borohydride when compared to the related oxide, the prototype very often showing a close packing of a readily polarisable soft oxide anion. We will show by means of in-situ synchrotron X-ray powder diffraction and ab initio calculations in the solid state that structural distortions in metal borohydrides compared to oxide prototypes have their origin in close hydridic di-hydrogen contacts of repulsive nature. These contacts may be suggested as a tool to tailor the crystal symmetry in complex metal hydrides in the future. Nearly twice as big as the oxide, the borohydride anion allows for connectivities of the coordination polyhedra rarely observed among the oxides such as tetrahedral edge sharing. We will show how the borohydride-oxide isomorphism, and cationic heterovalent substitution allow the prediction and design of novel borohydrides with high hydrogen content or high cation mobility.

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Kang, Ju Hwan, Aeran Song, Yu Jung Park, Jung Hwa Seo, Bright Walker et Kwun-Bum Chung. « Tungsten-Doped Zinc Oxide and Indium–Zinc Oxide Films as High-Performance Electron-Transport Layers in N–I–P Perovskite Solar Cells ». Polymers 12, n^o 4 (26 mars 2020) : 737. http://dx.doi.org/10.3390/polym12040737.

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Perovskite solar cells (PSCs) have attracted tremendous research attention due to their potential as a next-generation photovoltaic cell. Transition metal oxides in N–I–P structures have been widely used as electron-transporting materials but the need for a high-temperature sintering step is incompatible with flexible substrate materials and perovskite materials which cannot withstand elevated temperatures. In this work, novel metal oxides prepared by sputtering deposition were investigated as electron-transport layers in planar PSCs with the N–I–P structure. The incorporation of tungsten in the oxide layer led to a power conversion efficiency (PCE) increase from 8.23% to 16.05% due to the enhanced electron transfer and reduced back-recombination. Scanning electron microscope (SEM) images reveal that relatively large grain sizes in the perovskite phase with small grain boundaries were formed when the perovskite was deposited on tungsten-doped films. This study demonstrates that novel metal oxides can be used as in perovskite devices as electron transfer layers to improve the efficiency.

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Vertegel, A. A., S. V. Kalinin, N. N. Oleynikov, Yu G. Metlin et Yu D. Tretyakov. « Cryosol method : A novel powder processing technique based on ion-exchange phenomena ». Journal of Materials Research 13, n^o 4 (avril 1998) : 901–4. http://dx.doi.org/10.1557/jmr.1998.0122.

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A novel technique has been suggested for synthesis of highly dispersed oxide powders. The method is based on the treatment of aqueous solution of a multivalent metal nitrate (or chloride) by anion-exchange resin in the OH− form. The presented technique yields a stable colloid solution of the corresponding hydroxide with concentration up to 1 M. The subsequent freeze-drying and thermal dehydration results in very fine powder of metal oxide. The individual and multicomponent oxides obtained by the cryosol method were shown to possess unusual properties due to their high dispersity and chemical homogeneity.

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Muruganantham, Rasu, Jeng-Shin Lu et Wei-Ren Liu. « Spinel rGO Wrapped CoV2O4 Nanocomposite as a Novel Anode Material for Sodium-Ion Batteries ». Polymers 12, n^o 3 (3 mars 2020) : 555. http://dx.doi.org/10.3390/polym12030555.

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Binary mixed transition-based metal oxides have some of the most potential as anode materials for rechargeable advanced battery systems due to their high theoretical capacity and tremendous electrochemical performance. Nonetheless, binary metal oxides still endure low electronic conductivity and huge volume expansion during the charge/discharge processes. In this study, we synthesized a reduced graphene oxide (rGO)-wrapped CoV2O4 material as the anode for sodium ion batteries. The X-ray diffraction analyses revealed pure-phased CoV2O4 (CVO) rGO-wrapped CoV2O4 (CVO/rGO) nanoparticles. The capacity retention of the CVO/rGO composite anode demonstrated 81.6% at the current density of 200 mA/g for more than 1000 cycles, which was better than that of the bare one of only 73.5% retention. The as-synthesized CVO/rGO exhibited remarkable cyclic stability and rate capability. The reaction mechanism of the CoV2O4 anode with sodium ions was firstly studied in terms of cyclic voltammetry (CV) and ex situ XRD analyses. These results articulated the manner of utilizing the graphene oxide-coated spinel-based novel anode-CoV2O4 as a potential anode for sodium ion batteries.

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Ide, E., S. Angata, Akio Hirose et 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 (avril 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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Du Yong-Ping, Liu Hui-Mei et Wan Xian-Gang. « Novel properties of 5d transition metal oxides ». Acta Physica Sinica 64, n^o 18 (2015) : 187201. http://dx.doi.org/10.7498/aps.64.187201.

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Dong, Z. W., S. P. Pai, R. Ramesh, T. Venkatesan, Mark Johnson, Z. Y. Chen, A. Cavanaugh et al. « Novel high-Tc transistors with manganite oxides ». Journal of Applied Physics 83, n^o 11 (juin 1998) : 6780–82. http://dx.doi.org/10.1063/1.367764.

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Zhang, Heng, Jack Gromek, Matthew Augustine, Gayanath Fernando, R. Samuel Boorse et Harris L. Marcus. « Study of novel nanostructured Pd–Mn oxides ». Physica B : Condensed Matter 344, n^o 1-4 (février 2004) : 278–83. http://dx.doi.org/10.1016/j.physb.2003.08.131.

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Nikitina, L. E., V. A. Startseva, V. V. Plemenkov, S. A. Dieva, O. A. Lodochnikova et I. A. Litvinov. « Novel S-containing lactones from monoterpene oxides ». Chemistry of Natural Compounds 43, n^o 3 (mai 2007) : 263–67. http://dx.doi.org/10.1007/s10600-007-0101-6.

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Sampathkumaran, E. V., P. L. Paulose, V. Nagarajan, N. Nambudripad, A. K. Grover, S. K. Dhar, R. Nagarajan et R. Vijayaraghavan. « Investigation of novel highT c superconducting oxides ». Pramana 29, n^o 3 (septembre 1987) : L327—L333. http://dx.doi.org/10.1007/bf02845740.

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Szabó, Anna, et István Hermecz. « Novel Intramolecular Rearrangement of Tertiary PropargylamineN-Oxides ». Journal of Organic Chemistry 66, n^o 21 (octobre 2001) : 7219–22. http://dx.doi.org/10.1021/jo0104779.

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Gruber, Nadia, Lidia L. Piehl, Emilio Rubin de Celis, Jimena E. Díaz, María B. García, Pierluigi Stipa et Liliana R. Orelli. « Amidinoquinoxaline N-oxides as novel spin traps ». RSC Advances 5, n^o 4 (2015) : 2724–31. http://dx.doi.org/10.1039/c4ra14335c.

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A series of nitrones were synthesized and tested as novel spin traps. The adducts generated by CH₃ addition showed remarkably persistent signals. Their EPR features and kinetics were rationalised by DFT and MP2 calculations.

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Lion, S. S., et W. L. Worrell. « Electrical properties of novel mixed-conducting oxides ». Applied Physics A Solids and Surfaces 49, n^o 1 (juillet 1989) : 25–31. http://dx.doi.org/10.1007/bf00615461.

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Prosandeev, Sergey, Dawei Wang, Wei Ren, Jorge Íñiguez et Laurent Bellaiche. « Novel Nanoscale Twinned Phases in Perovskite Oxides ». Advanced Functional Materials 23, n^o 2 (24 août 2012) : 234–40. http://dx.doi.org/10.1002/adfm.201201467.

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Takikawa, Hiroshi, Shogo Sato, Ryota Seki et Keisuke Suzuki. « Oxidative Ring Opening of Benzocyclobutenone Oximes : Novel Access to Stable Nitrile Oxides ». Chemistry Letters 46, n^o 7 (5 juillet 2017) : 998–1000. http://dx.doi.org/10.1246/cl.170328.

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Qiu, Guohong, Kai Jiang, Meng Ma, Dihua Wang, Xianbo Jin et George Z. Chen. « Roles of Cationic and Elemental Calcium in the Electro-Reduction of Solid Metal Oxides in Molten Calcium Chloride ». Zeitschrift für Naturforschung A 62, n^o 5-6 (1 juin 2007) : 292–302. http://dx.doi.org/10.1515/zna-2007-5-610.

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Previous work, mainly from this research group, is re-visited on electrochemical reduction of solid metal oxides, in the form of compacted powder, in molten CaCl2, aiming at further understanding of the roles of cationic and elemental calcium. The discussion focuses on six aspects: 1.) debate on two mechanisms proposed in the literature, i. e. electro-metallothermic reduction and electro-reduction (or electro-deoxidation), for the electrolytic removal of oxygen from solid metals or metal oxides in molten CaCl2; 2.) novel metallic cavity working electrodes for electrochemical investigations of compacted metal oxide powders in high temperature molten salts assisted by a quartz sealed Ag/AgCl reference electrode (650 ºC- 950 ºC); 3.) influence of elemental calcium on the background current observed during electrolysis of solid metal oxides in molten CaCl2; 4.) electrochemical insertion/ inclusion of cationic calcium into solid metal oxides; 5.) typical features of cyclic voltammetry and chronoamperometry (potentiostatic electrolysis) of metal oxide powders in molten CaCl2; and 6.) some kinetic considerations on the electrolytic removal of oxygen.

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Ting, D. Z. Y., Erik S. Daniel et T. C. Mcgill. « Interface Roughness Effects in Ultra-Thin Tunneling Oxides ». VLSI Design 8, n^o 1-4 (1 janvier 1998) : 47–51. http://dx.doi.org/10.1155/1998/23567.

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Advanced MOSFET for ULSI and novel silicon-based devices require the use of ultrathin tunneling oxides where non-uniformity is often present. We report on our theoretical study of how tunneling properties of ultra-thin oxides are affected by roughness at the silicon/oxide interface. The effect of rough interfacial topography is accounted for by using the Planar Supercell Stack Method (PSSM) which can accurately and efficiently compute scattering properties of 3D supercell structures. Our results indicate that while interface roughness effects can be substantial in the direct tunneling regime, they are less important in the Fowler-Nordheim regime.

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Shen, Ming Li, Sheng Long Zhu, Li Xin et Fu Hui Wang. « Hot Corrosion Behavior of a Novel Enamel-Based Thermal Barrier Coating ». Materials Science Forum 654-656 (juin 2010) : 1944–47. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.1944.

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A novel thermal barrier coating comprised two layers: sputtered bond coat and enamel-zirconia composite top layer. The hot corrosion tests were carried out at 900 °C for 100 h. The salt used in the tests was 25wt% NaCl + 75wt% Na2SO4. Mass loss and spalltion of oxide scales of uncoated K444 specimens was obvious. For the coated specimens, no oxide scale spallation and no weight loss were observed. The TGO formed on the coated specimens was thin layer of mixture oxides of Al, Ti and Cr, while thick multi-layered oxide scales formed on the uncoated specimens. Besides, deep internal oxidation zone was observed on the uncoated specimens. The coatings after hot corrosion tests contained t-ZrO2 and NaAlSi3O8, while the oxide scales formed on the uncoated K444 were TiO2, Cr2O3, NiCr2O4 and Na2Cr2Ti6O16.

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Gao, Yuan, Si-Yan Gong, Baixiao Chen, Wen-Hao Xing, Yan-Fei Fei, Zhong-Ting Hu et Zhiyan Pan. « Progress in Metal-Organic Framework Catalysts for Selective Catalytic Reduction of NOx : A Mini-Review ». Atmosphere 13, n^o 5 (13 mai 2022) : 793. http://dx.doi.org/10.3390/atmos13050793.

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Nitrogen oxides released from the combustion of fossil fuels are one of the main air pollutants. Selective catalytic reduction technology is the most widely used nitrogen oxide removal technology in the industry. With the development of nanomaterials science, more and more novel nanomaterials are being used as catalysts for the selective reduction of nitrogen oxides. In recent years, metal-organic frameworks (MOFs), with large specific surface areas and abundant acid and metal sites, have been extensively studied in the selective catalytic reduction of nitrogen oxides. This review summarizes recent progress in monometallic MOFs, bimetallic MOFs, and MOF-derived catalysts for the selective catalytic reduction of nitrogen oxides and compares the reaction mechanisms of different catalysts. This article also suggests the advantages and disadvantages of MOF-based catalysts compared with traditional catalysts and points out promising research directions in this field.

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You, Caihong, Toshiki Miyazaki, Eiichi Ishida, Masahiro Ashizuka, Chikara Ohtsuki et Masao Tanihara. « Apatite Deposition on Organic-Inorganic Hybrids Synthesized from Poly(Vinyl Alcohol) and Various Metal Oxides ». Key Engineering Materials 284-286 (avril 2005) : 469–72. http://dx.doi.org/10.4028/www.scientific.net/kem.284-286.469.

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Organic polymers with ability of apatite formation in body environment are expected as novel bone substitutes having not only bone-bonding ability, i.e. bioactivity, but also mechanical performance analogous to natural bone. Several metal oxides have been found to be effective for the apatite deposition in body environment. In addition, release of calcium ions from the materials significantly enhances it. In this study, we attempted to synthesize bioactive organic-inorganic hybrids from Poly(vinyl alcohol) (PVA) by incorporation of various metal oxides and calcium salt. Silica and molybdenum oxides were selected as metal oxides. Ability of apatite formation on the hybrids was examined in vitro using simulated body fluid (SBF, Kokubo solution). Apatite deposition were observed to occur on the surfaces of PVA/silica and PVA/molybdenum oxide hybrids in SBF, when their compositions were appropriately controlled.

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Li, Xiu Ping, Rong Xiang Zhao et Chu Jia Li. « Preparation and Photocatalyst of Ce/Zn Composite Oxide ». Advanced Materials Research 873 (décembre 2013) : 441–44. http://dx.doi.org/10.4028/www.scientific.net/amr.873.441.

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With abscibe acid as combustion agent, Zn (NO3)27H2O and Ce (NO3)36H2O as raw material, the CeO2-ZnO composite oxide was synthesized by an novel combustion method. The experiment investaged the effect of molar ratio of combustion agents, Zn and Ce on composite oxides. The samples were characterized by XRD, SEM, IR, UV. The molar ratio of Ce, Zn and combustion agents is different, the composite oxides possess various morphology and properities. The photocatalytic experiment of composite oxide showed that under the optimal photocatalytic condition Methylene blue solution is completely degradated to need 240 min and under the optimal decoloring condition Methylene blue solution is completely decolorized to need 180 min.

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Oprea, Madalina, et Denis Mihaela Panaitescu. « Nanocellulose Hybrids with Metal Oxides Nanoparticles for Biomedical Applications ». Molecules 25, n^o 18 (4 septembre 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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Argyropoulos, Nicolaos G., John K. Gallos, Ze-Ying Zhang et Gus J. Palenik. « Benzo-as-triazine tri-N-oxide ; a novel cycloaddition product from reactions of benzofurazan N-oxides with nitrile oxides ». Journal of the Chemical Society, Chemical Communications, n^o 15 (1989) : 986. http://dx.doi.org/10.1039/c39890000986.

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Zhuang, Ting Ting, Jia Hui Xu, Jia Rong Xia, Yi Cao, Shi Lu Zhou, Ying Wang, Yuan Chun et Jian Hua Zhu. « New Development in Nanoporous Composites : Novel Functional Materials for Capturing Nitrosamines in Airstreams ». Journal of Nanomaterials 2006 (2006) : 1–9. http://dx.doi.org/10.1155/jnm/2006/54909.

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The latest progresses of the series of research on the trapper of nitrosamines are reported in this paper, involving the attempts to elevate the selective adsorption of zeolites through enhancing adsorbent-adsorbate interaction, in order to prepare the new functional nanoporous materials with high efficiency to eliminate the carcinogenic pollutants in environment and to protect public health. Incorporation of metal oxide such as copper oxide in NaY accelerated adsorption of volatile nitrosamines and anthracene, and moreover, coating zirconia onto the zeolite could dramatically suppress the release of nitrogen oxides in the decomposition ofN-nitrosopyrrolidine (NPYR) during temperature-programmed surface reaction (TPSR) process.

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Moura, Hipassia M., et Miriam M. Unterlass. « Biogenic Metal Oxides ». Biomimetics 5, n^o 2 (23 juin 2020) : 29. http://dx.doi.org/10.3390/biomimetics5020029.

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Biogenic metal oxides (MxOy) feature structures as highly functional and unique as the organisms generating them. They have caught the attention of scientists for the development of novel materials by biomimicry. In order to understand how biogenic MxOy could inspire novel technologies, we have reviewed examples of all biogenic MxOy, as well as the current state of understanding of the interactions between the inorganic MxOy and the biological matter they originate from and are connected to. In this review, we first summarize the origins of the precursors that living nature converts into MxOy. From the point-of-view of our materials chemists, we present an overview of the biogenesis of silica, iron and manganese oxides, as the only reported biogenic MxOy to date. These MxOy are found across all five kingdoms (bacteria, protoctista, fungi, plants and animals). We discuss the key molecules involved in the biosynthesis of MxOy, the functionality of the MxOy structures, and the techniques by which the biogenic MxOy can be studied. We close by outlining the biomimetic approaches inspired by biogenic MxOy materials and their challenges, and we point at promising directions for future organic-inorganic materials and their synthesis.

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Cooper, Valentino R., Brian K. Voas, Craig A. Bridges, James R. Morris et Scott P. Beckman. « First principles materials design of novel functional oxides ». Journal of Advanced Dielectrics 06, n^o 02 (juin 2016) : 1650011. http://dx.doi.org/10.1142/s2010135x16500119.

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We review our efforts to develop and implement robust computational approaches for exploring phase stability to facilitate the prediction-to-synthesis process of novel functional oxides. These efforts focus on a synergy between (i) electronic structure calculations for properties predictions, (ii) phenomenological/empirical methods for examining phase stability as related to both phase segregation and temperature-dependent transitions and (iii) experimental validation through synthesis and characterization. We illustrate this philosophy by examining an inaugural study that seeks to discover novel functional oxides with high piezoelectric responses. Our results show progress towards developing a framework through which solid solutions can be studied to predict materials with enhanced properties that can be synthesized and remain active under device relevant conditions.

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Li, Zhaoyi, Jie Zhang, Chengtun Qu, Ying Tang et Michal Slaný. « Synthesis of Mg-Al Hydrotalcite Clay with High Adsorption Capacity ». Materials 14, n^o 23 (26 novembre 2021) : 7231. http://dx.doi.org/10.3390/ma14237231.

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A novel Mg-Al metal oxide has been successfully synthesized by the calcination of hierarchical porous Mg-Al hydrotalcite clay obtained by using filter paper as a template under hydrothermal conditions. Various characterizations of the obtained nanoscale oxide particles verified the uniform dispersion of Mg-Al metal oxides on the filter paper fiber, which had a size of 2–20 nm and a highest specific surface area (SSA) of 178.84 m2/g. Structural characterization revealed that the as-prepared Mg-Al metal oxides preserved the tubular morphology of the filter paper fibers. Further experiments showed that the as-synthesized Mg-Al metal oxides, present at concentrations of 0.3 g/L, could efficiently remove sulfonated lignite from oilfield wastewater (initial concentration of 200 mg/L) in a neutral environment (pH = 7) at a temperature of 298 K. An investigation of the reaction kinetics found that the adsorption process of sulfonated lignite (SL) on biomorphic Mg-Al metal oxides fits a Langmuir adsorption model and pseudo-second-order rate equation. Thermodynamic calculations propose that the adsorption of sulfonated lignite was spontaneous, endothermic, and a thermodynamically feasible process.

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Lorenz, Michael. « Pulsed laser deposition of functional oxides - towards a transparent electronics ». Acta Crystallographica Section A Foundations and Advances 70, a1 (5 août 2014) : C1412. http://dx.doi.org/10.1107/s2053273314085878.

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Metal oxides, in particular with transition metals, show strong electronic correlations which determine a huge variety of electronic properties, together with other functionalities. For example, ZnO and Ga2O3 as wide-bandgap semiconductors have a high application potential as transparent functional layers in future oxide electronics [1-2]. Other oxides of current interest are ferrimagnetic spinels of the type MFe2O4 (M=Zn,Co,Ni), see K. Brachwitz et al. Appl. Phys. Lett. 102, 172104 (2013), or highly correlated iridate films, see M. Jenderka et al. Phys. Rev. B 88, 045111 (2013). Furthermore, combinations of ferroelectric and magnetic oxides in multiferroic composites and multilayers show promising magnetoelectric coupling. For the exploratory growth of the above mentioned novel oxides into nm-thin films, pulsed laser deposition (PLD) appears as the method of choice because of its extremely high flexibility in terms of material and growth conditions, high growth rate and excellent structural properties [3]. This talk highlights recent developments of new functional oxides using unique large-area PLD processes running for more than two decades in the lab of the author [3].

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Dlamini, Caroline Lomalungelo, Lueta-Ann De Kock, Kebede Keterew Kefeni, Bhekie Brilliance Mamba et Titus Alfred Makudali Msagati. « Novel hybrid metal loaded chelating resins for removal of toxic metals from acid mine drainage ». Water Science and Technology 81, n^o 12 (12 juin 2020) : 2568–84. http://dx.doi.org/10.2166/wst.2020.285.

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Abstract Iron (Fe), zirconium (Zr) and titanium (Ti) oxides nanoparticles were each embedded onto a weak acid chelating resin for support using the precipitation method to generate three hybrid adsorbents of hydrated Fe oxide (HFO-P), hydrated Zr oxide (HZO-P) and hydrated Ti oxide (HTO-P). This paper reports on the characterization, performance and potential of these generated nanoadsorbents in the removal of toxic metal ions from acid mine drainage (AMD). The optimum contact time, adsorbent dose and pH for aluminium (Al) (III) adsorption were established using the batch equilibrium technique. The metal levels were measured using inductively coupled plasma-optical emission spectrometry. The scanning electron microscopy–energy dispersive X-ray spectroscopy results confirmed the presence of the metal oxides within the hybrid resin beads. HFO-P, HZO-P and HTO-P adsorbed Al(III) rapidly from synthetic water with maximum adsorption capacities of 54.04, 58.36 and 40.10 mg/g, respectively, at initial pH 1.80 ± 0.02. The adsorption of Al(III) is of the second-order in nature (R2 > 0.98). The nanosorbents removed ten selected metals from environmental AMD and the metal removal efficiency was in the order HTO-P > HZO-P > HFO-P. All three hybrid nanosorbents can be used to remove metals from AMD; the choice would be dependent on the pH of the water to be treated.

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