Artículos de revistas: "ZrO2 incorporation"

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Salinas, Daniela, Sichem Guerrero, Cristian H. Campos, Tatiana M. Bustamante y Gina Pecchi. "The Effect of the ZrO2 Loading in SiO2@ZrO2-CaO Catalysts for Transesterification Reaction". Materials 13, n.º 1 (4 de enero de 2020): 221. http://dx.doi.org/10.3390/ma13010221.

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The effect of the ZrO2 loading was studied on spherical SiO2@ZrO2-CaO structures synthetized by a simple route that combines the Stöber and sol-gel methods. The texture of these materials was determined using SBET by N2 adsorption, where the increment in SiO2 spheres’ surface areas was reached with the incorporation of ZrO2. Combined the characterization techniques of using different alcoholic dissolutions of zirconium (VI) butoxide 0.04 M, 0.06 M, and 0.08 M, we obtained SiO2@ZrO2 materials with 5.7, 20.2, and 25.2 wt % of Zr. Transmission electron microscopy (TEM) analysis also uncovered the shape and reproducibility of the SiO2 spheres. The presence of Zr and Ca in the core–shell was also determined by TEM. X-ray diffraction (XRD) profiles showed that the c-ZrO2 phase changed in to m-ZrO2 by incorporating calcium, which was confirmed by Raman spectroscopy. The purity of the SiO2 spheres, as well as the presence of Zr and Ca in the core–shell, was assessed by the Fourier transform infrared (FTIR) method. CO2 temperature programmed desorption (TPD-CO2) measurements confirmed the increment in the amount of the basic sites and strength of these basic sites due to calcium incorporation. The catalyst reuse in FAME production from canola oil transesterification allowed confirmation that these calcium core@shell catalysts turn out to be actives and stables for this reaction.

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2

Hassan, S. F. "Mg-ZrO2 Nanocomposite: Relative Effect of Reinforcement Incorporation Technique". Archives of Metallurgy and Materials 61, n.º 3 (1 de septiembre de 2016): 1521–28. http://dx.doi.org/10.1515/amm-2016-0249.

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Abstract In this study, ingot metallurgy and powder metallurgy processes were used to incorporate 0.2 and 0.7 vol% of nano-size ZrO2 particles reinforcement to develop magnesium nanocomposite. Both of the processing methods led to reasonably fair reinforcement distribution, substantial grain refinement and minimum porosity in the nanocomposites. Strengthening effect of nano-ZrO2 reinforcement in the magnesium matrix was greater when incorporated using the ingot metallurgy process. The matrix ductility and resistance to fracture were significantly improved due to the presence of nano-ZrO2 reinforcement when incorporated using the powder metallurgy process. Tensile fracture surfaces revealed that the less-ductile cleavage fracture mechanism of hexagonal close packed magnesium matrix has changed to more ductile mode due to the presence of nano-ZrO2 particles in all the processed nanocomposites.

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Abu El-Fadl, A., Amna M. Eltokhey, A. A. Abu-Sehly y Amina A. Abozeed. "Stabilization of tetragonal phase of nanostructured Fe_x/ZrO₂ system (0 ≤ x ≤ 25) prepared by modified sol-gel method". Physica Scripta 97, n.º 2 (24 de enero de 2022): 025706. http://dx.doi.org/10.1088/1402-4896/ac4864.

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Abstract In the present study, Fex/ZrO2 (0 ≤ x ≤ 25) nanoparticles were synthesized by a facile modified Sol-Gel method. Stabilization of the tetragonal phase of ZrO2 is studied as a function of both the Fe incorporation ratios and thermal treatment. The Fe incorporation ratios are tested up to the extreme just before FeO and Fe2O3 phases are formed separately. The prepared Fex/ZrO2 nanoparticles XRD analysis depicts the formation of zirconium oxide at different Fe ratios in the nanoscale with an excellent degree of crystallinity in the tetragonal phase. The effect of thermal treatment on stabilizing the tetragonal phase of Fex/ZrO2 nanoparticles is extensively studied. The phase transition to the monoclinic phase is determined as function of Fe incorporation ratios and annealing temperatures. The optical absorbance spectra showed that the optical band gap decreased with increasing Fe ratios without the formation of doping bands which confirms the formation of Fex/ZrO2 single matrix.

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4

Sripada, Suresh, M. Chandrashekhar Reddy, T. Sreekanth, Rajesh Siripuram y K. Venkateshwarlu. "Influence of Nano Filler (ZrO<sub>2</sub>) on Optical and Thermal Studies of Potassium Doped Polyethylene Oxide Solid Polymer Electrolytes". Materials Science Forum 1048 (4 de enero de 2022): 101–9. http://dx.doi.org/10.4028/www.scientific.net/msf.1048.101.

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Solid polymer electrolyte films made with potassium doped Polyethylene oxide using ZrO2 as nanofiller (70PEO-30KBF4-x ZrO2 where x = 1, 2.5, 5, 7.5, & 10 wt% ) were prepared by solution casting technique. Optical and thermal properties of polymer electrolyte films were studied by using Optical absorption and DSC techniques. From Optical absorption spectra, it is observed that fundamental absorption edge is shifted towards the higher wavelength side (range 259- 297 nm) with increase of nano filler (ZrO2) concentration (1-10 wt %). Optical band gap for all electronic transitions (p=1/2, 2, 2/3 and 1/3) are found to be increased as incorporation of nano filler (ZrO2) which confirms the structural rearrangements takes place in polymer electrolyte films. Optical band gap for indirect allowed transitions (p=1/2) are found to be in the range of 1.93-3.34eV. Decrease in Urbach energy (4.8eV- 1.4eV) is associated with decrease in defect formation in host polymeric matrix (PEO-KBF4) as a result of embedded nano filler (ZrO2). DSC spectra analysis of polymer electrolytes has showed melting temperatures in the range 63.63-73.71°C and highest crystallinity is found to be 85 % (10 wt % ZrO2). Enthalpy values are elevated with increase in nanofiller composition (ZrO2) in the present polymer electrolyte films.Keywords: PEO based polymer electrolytes, Solid polymer electrolytes, Optical and Thermal studies.

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5

Xiong, Chao, Jin Xiao, Yu Zhao, Yuxin Wang, See Leng Tay y Weilong Xu. "Properties of Ni–ZrO2 nanocomposite coatings by electroplating". International Journal of Modern Physics B 33, n.º 01n03 (30 de enero de 2019): 1940024. http://dx.doi.org/10.1142/s0217979219400241.

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The microstructure, microhardness and wear property of electroplated Ni–ZrO2 nanocomposite coatings with different ZrO2 concentration were analyzed using SEM, microhardness and wear tests. It was found that in the composite coatings, incorporation of ZrO2 particles improves the mechanical property of Ni coatings and the effect of ZrO2 nanoparticles concentration on the surface morphology, microstructure and mechanical property of electroplated coatings was discussed. The mechanical properties of Ni–ZrO2 coatings reach the optimum value when the ZrO2 concentration is 10 g/L.

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6

Zhang, Ying, Ai Chen, Cheng Liu, Hai Rong Wang y Ze Song Li. "Effect of Nano Zirconia on Microstructure and Electrochemical Behavior of Aluminium-Zinc Sacrificial Anodes". Key Engineering Materials 519 (julio de 2012): 41–44. http://dx.doi.org/10.4028/www.scientific.net/kem.519.41.

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In this study, nano ZrO2 powders were incorporated into Al-5 wt% Zn sacrificial anode and the effect of ZrO2 contents (wt% =0.1, 0.2) on microstructures and electrochemical properties were investigated. The results show that the addition of nano ZrO2 was effective on improving metallurgical and electrochemical properties. With the increase of ZrO2 content, the dendritic structure is fined gradually and the corrosion current density values is also increased. The incorporation of ZrO2 also can result in a moderate efficiency value. When the ZrO2 content in the alloy was 0.2 wt%, the optimal microstructure, electrochemical properties and as high as 70% the efficiency value was obtained.

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7

Yin, Guo Xiang, Yong Li, Jun Hong Chen y Xin Kui Gao. "The Wear Mechanism Comparison between MgO-Based Chrome-Free Brick and MgO-Cr₂O₃ Brick in the Lower Part of RH Vacuum Degasser". Advanced Materials Research 476-478 (febrero de 2012): 1991–96. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.1991.

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The damage and improvement mechanism of rebonded MgO-Cr2O3 brick and MgO-ZrO2 brick used in the lower part of RH vacuum degasser were studied. The results show that the main damage of rebonded MgO-Cr2O3 brick is structure spalling because of the penetration of slag. MgO-ZrO2 brick has characteristics of high direct-bonding degree, small air permeability and making the viscosity of penetrated slag increased by means of ZrO2 absorbing CaO in slag to form CaZrO3 or ZrO2 solid solution, which make the degree of slag penetration decrease and improve the structure spalling resistance. MgO-ZrO2 brick has the defect of poor thermal shock resistance in use, the incorporation of MgO-rich spinel into MgO-ZrO2 brick significantly improved both thermal shock resistance and hot modulus of rupture because of the formation of eutectoid structure of grain-refining spinel and zirconia, which also improved structure spalling resistance because air permeability was decreased to 5% of MgO-ZrO2 brick

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8

Yu, Lei, Hui Liu, Kai Liang, Zhen Di Zang, Jia Cheng Shi, Yi Ru Shen, Qi Tian y Xu Hong Wang. "Isothermal Oxidation Resistance of Zr₃[Al(Si)]₄C₆-Based Composite Ceramics at 1000-1300°C in Air". Solid State Phenomena 281 (agosto de 2018): 444–49. http://dx.doi.org/10.4028/www.scientific.net/ssp.281.444.

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The isothermal oxidation behavior of Zr3[Al(Si)]4C6-ZrB2-ZrC composite ceramics at 1000-1300 °C in air has been investigated. The oxidation kinetics of the composites and generally follows a parabolic law. At the same oxidation temperature and time, the weight gain per unit surface area, oxidation rate constant and oxide thickness of the composites are higher than those of monolithic Zr3[Al(Si)]4C6 ceramic. With the incorporation of ZrB2 and ZrC, the oxidation resistance of the composites becomes poor. The surfaces of the oxide layer have a loose and porous structure, consisting of mainly ZrO2 and little mullite, and there are no dense oxide films preventing the inward diffusion of oxygen element effectively.

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9

Zhou, Kai, Faqin Xie, Xiangqing Wu y Shaoqing Wang. "Fabrication of High Temperature Oxidation Resistance Nanocomposite Coatings on PEO Treated TC21 Alloy". Materials 13, n.º 1 (18 de diciembre de 2019): 11. http://dx.doi.org/10.3390/ma13010011.

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The effects of ZrO2 nanoparticles in a NaAlO2 electrolyte on the thickness, morphology, composition, structure, and high temperature oxidation resistance of plasma electrolytic oxidation (PEO) coatings on a TC21 titanium alloy were investigated. The coating thickness increased with increasing concentration of ZrO2 nanoparticles in the electrolyte, accompanied by a decrease in the porosity of the coating surface. The PEO coatings formed in the ZrO2 nanoparticle-free electrolyte were composed of Al2TiO5. ZrTiO4, m-ZrO2, and t-ZrO2 were detected in the PEO coatings produced by the electrolyte that contained ZrO2 nanoparticles, which indicated that the deposition mechanism of the nanoparticles was partly reactive incorporation. The high temperature oxidation resistance of the TC21 titanium alloy at 650 °C and 750 °C was improved by 3–5 times after PEO treatment. The oxidation mechanism involved oxygen diffusing inward to form an oxide layer at the interface of the PEO coating and substrate.

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10

Kadi, Mohammad W. y R. M. Mohamed. "Enhanced Photocatalytic Activity of ZrO2-SiO2Nanoparticles by Platinum Doping". International Journal of Photoenergy 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/812097.

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ZrO2-SiO2mixed oxides were prepared via the sol-gel method. Photo-assisted deposition was utilized for doping the prepared mixed oxide with 0.1, 0.2, 0.3, and 0.4 wt% of Pt. XRD spectra showed that doping did not result in the incorporation of Pt within the crystal structure of the material. UV-reflectance spectrometry showed that the band gap of ZrO2-SiO2decreased from 3.04 eV to 2.48 eV with 0.4 wt% Pt doping. The results show a specific surface area increase of 20%. Enhanced photocatalysis of Pt/ZrO2-SiO2was successfully tested on photo degradation of cyanide under illumination of visible light. 100% conversion was achieved within 20 min with 0.3 wt% of Pt doped ZrO2-SiO2.

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11

Li, Ning, Hong Xu, Xinhui Li, Weizeng Chen, Lijuan Zheng y Lirong Lu. "Tribological Properties and Corrosion Resistance of Porous Structure Ni-Mo/ZrO2 Alloys". Coatings 10, n.º 8 (7 de agosto de 2020): 767. http://dx.doi.org/10.3390/coatings10080767.

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Ni-Mo-ZrO2 composite coatings were produced by pulse electrodeposition technique from alkaline electrolytes containing dispersed ZrO2 nanopowder. The structure, microhardness, corrosion properties and tribological properties of Ni-Mo-ZrO2 composites with different content of molybdenum and ZrO2 have also been examined. Structural characterization was performed using X-ray diffraction (XRD) and a scanning electron microscope (SEM). It was found that an increase in molybdate concentration in the electrolyte affects the microstructure, microhardness, corrosion properties and tribological properties of the amount of co-deposited ZrO2 nanoparticles. The incorporation of ZrO2 nanoparticles into the Ni-Mo alloy matrix positively affects the microhardness and also slightly improves the corrosion properties of Ni-Mo alloy coatings. In addition, both the coefficient of friction and the salt-water lubrication sliding wear rate of Ni-Mo-ZrO2 coatings decreased with increasing the ZrO2 content. Wear test and corrosion resistance test results indicated that the intermetallic composite had an excellent wear-resistance and corrosion resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases Ni-Mo and polarization effect of ZrO2 nanoparticles.

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12

Xue, Yu Jun, Chen Shen, Ji Shun Li y Yi Liu. "Oxidation and Wear Resistance of Ni-Y₂O₃-ZrO₂ Nanocomposite Coating Prepared by Ultrasonic Electrodeposition". Key Engineering Materials 455 (diciembre de 2010): 427–30. http://dx.doi.org/10.4028/www.scientific.net/kem.455.427.

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Ni-Y2O3-ZrO2 nanocomposite coating was prepared by co-deposition of nickel, Yttrium oxide (Y2O3) and zirconium oxide (ZrO2) nanoparticles using ultrasonic electrodeopsition. The surface morphology and composition of coatings were ananlyzed by an environmental scanning electron microscope (ESEM) and energy dispersive spectrometer(EDS). The high temperature oxidation, microhardness and wear resistance of the coatings were investigated. It is found that both the incorporation of nanoparticles and the use of ultrasonic could refine Ni crystal grains and improve properties of the coatings. The Ni-Y2O3-ZrO2 nanocomposite coating prepared with ultrasonic exhibits finer grains, higher microhardness and better oxidation and wear resistance.

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13

Al-Fatesh, Ahmed Sadeq, Yasir Arafat, Ahmed Aidid Ibrahim, Samsudeen Olajide Kasim, Abdulrahman Alharthi, Anis Hamza Fakeeha, Ahmed Elhag Abasaeed, Giuseppe Bonura y Francesco Frusteri. "Catalytic Behaviour of Ce-Doped Ni Systems Supported on Stabilized Zirconia under Dry Reforming Conditions". Catalysts 9, n.º 5 (22 de mayo de 2019): 473. http://dx.doi.org/10.3390/catal9050473.

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Ni supported on bare and modified ZrO2 samples were synthesized using the incipient wet impregnation method. The t-ZrO2 phase was stabilized by incorporation of La2O3 into ZrO2. Moreover, the influence of CeO2-doping on the physico-chemical and catalytic properties under CO2 reforming conditions was probed. The characterization data of the investigated catalysts were obtained by using XRD, CO2/H2-TPD, BET, TPR, TPO, TGA, XPS and TEM characterization techniques. In the pristine Ni/Zr catalyst, the t-ZrO2 phase transformed into the monoclinic phase. However, upon support modification by La2O3, significant effects on the physicochemical properties were observed due to the monoclinic-to-tetragonal ZrO2 phase transformation also affecting the catalytic activity. As a result, superior activity on the La2O3 modified Ni/Zr catalyst was achieved, while no relevant change in the surface properties and activity of the catalysts was detected after doping by CeO2. The peculiar behavior of the Ni/La-ZrO2 sample was related to higher dispersion of the active phase, with a more pronounced stabilization of the t-ZrO2 phase.

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14

Verma, Akrati, Reena Dwivedi, R. Prasad y K. S. Bartwal. "Microwave-Assisted Synthesis of Mixed Metal-Oxide Nanoparticles". Journal of Nanoparticles 2013 (20 de marzo de 2013): 1–11. http://dx.doi.org/10.1155/2013/737831.

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Nanoparticles of mixed metal oxides, ZrO2, ZrTiO4, and ZrV2O7 were prepared by microwave-assisted citrate sol-gel and solution combustion method. The prepared nanoparticles were characterized for their structural details using XRD and TEM techniques. The broadening of Raman bands is ascribed to local compositional fluctuations or local positional disordering produced due to random distribution of Zr4+ and Ti4+between equivalent sites. The XPS spectra confirm the incorporation of Ti in ZrO2 and suggest Zr as well as Ti in +4 oxidation state. Gelation and fast combustion seem to be the reason for smaller particle sizes. ZrV2O7 nanocrystalline material was synthesized by microwave- assisted solution combustion method. Low angle powder XRD measurements confirm the mesoporous nature of the prepared material. The effect of calcination temperature on the phase transformation of the materials has been investigated. Among tetragonal, monoclinic, and cubic phases, the monoclinic phase is predominant at higher calcinations temperature. The XPS confirms the incorporation of V2O5 in ZrO2 and suggests that Zr and V are in the same oxidation state (+4). The average particle sizes for ZrO2, ZrTiO4, and ZrV2O7 were found to be in the ranges of 5–10 nm, 2–5 nm, and 10–50 nm, respectively.

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Manriquez, M. E., M. Picquart, X. Bokhimi, T. López, P. Quintana y J. M. Coronado. "X-Ray Diffraction, and Raman Scattering Study of Nanostructured ZrO2-TiO2 Oxides Prepared by Sol–Gel". Journal of Nanoscience and Nanotechnology 8, n.º 12 (1 de diciembre de 2008): 6623–29. http://dx.doi.org/10.1166/jnn.2008.18436.

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In the present work, we study the phase composition of ZrO2-TiO2 system by means of XRD and Raman spectroscopy, using also TG-ATD, and N2 adsorption isotherms as complementary characterization techniques. TiO2-ZrO2 samples of selected compositions (0, 10, 90, 50 and 100% in weight of TiO2) were prepared by sol–gel method and annealed at three different temperatures (400, 600 and 800 °C). Structural characterization reveals that only the pure oxides are crystalline at 400 °C: TiO2 as anatasa with a minor brookite component, and ZrO2 as a mixture of tetragonal (majority) and monoclinic phases. Following the 600 °C calcination, the TiO2-ZrO2 50–50% sample forms the ZrTiO4 mixed oxide, although this materials remains partly amorphous. In contrast, samples with higher and lower TiO2 content form solid solutions with, respectively, anatasa and tetragonal ZrO2 structures. Zirconium incorporation into the TiO2 lattice leads to the expansion of the unit cell parameters, and it stabilizes the anatase phase, hindering its transformation into rutile. Similarly, dissolving titanium atoms into the ZrO2 structure delays the transformation from the tetragonal to the monoclinic polymorph.

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Li, Jianhua. "Microstructure and Piezoelectric Properties of Lead Zirconate Titanate Nanocomposites Reinforced with In-Situ Formed ZrO2 Nanoparticles". Materials 15, n.º 4 (14 de febrero de 2022): 1389. http://dx.doi.org/10.3390/ma15041389.

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Lead zirconate titanate (PZT)-based ceramics are used in numerous advanced applications, including sensors, displays, actuators, resonators, chips; however, the poor mechanical characteristics of these materials severely limits their utility in composite materials. To address this issue, we herein fabricate transgranular type PZT ceramic nanocomposites by a novel method. Thermodynamically metastable single perovskite-type Pb0.99(Zr0.52+xTi0.48)0.98Nb0.02O3+1.96x powders are prepared from a citrate precursor before both monoclinic and tetragonal ZrO2 nanoparticles ranging from 20 to 80 nm are precipitated in situ at a sintering temperature of 1260 °C. The effects of ZrO2 content on the microstructure, dielectric, and piezoelectric properties are investigated and the mechanism, by which ZrO2 toughened PZT is analyzed in detail. The ZrO2 nanoparticles underwent a tetragonal to monoclinic phase transition upon cooling. The fracture mode changed from intergranular to transgranular with increasing ZrO2 content. The incorporation of ZrO2 nanoparticles improved the mechanical and piezoelectric properties. The optimized piezoelectric properties (εT33/ε0 = 1398, tan δ = 0.024 d33 = 354 pC N−1, kp = 0.66 Qm = 78) are obtained when x = 0.02. Tc initially increased and subsequently decreased with increasing ZrO2 content. The highest Tc = (387 °C) and lowest εT33/ε0 was obtained at x = 0.01.

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Gjorgievska, Elizabeta, John W. Nicholson, Dragana Gabrić, Zeynep Asli Guclu, Ivana Miletić y Nichola J. Coleman. "Assessment of the Impact of the Addition of Nanoparticles on the Properties of Glass–Ionomer Cements". Materials 13, n.º 2 (8 de enero de 2020): 276. http://dx.doi.org/10.3390/ma13020276.

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The aim of the study was to evaluate the effects of incorporation of Al2O3, ZrO2 and TiO2 nanoparticles into glass–ionomer cements (GICs). Two different GICs were used in the study. Four groups were prepared for each material: the control group (without nanoparticles) and three groups modified by the incorporation of nanoparticles at 2, 5 or 10 wt %, respectively. Cements were mixed and placed in moulds (4 mm × 6 mm); after setting, the samples were stored in saline (one day and one week). Compressive strengths were measured and the morphology of the fractured surfaces was analyzed by scanning electron microscopy. The elements released into the storage solutions were determined by Inductively coupled plasma-optical emission spectrometry (ICP-OES). Addition of nanoparticles was found to alter the appearance of cements as examined by scanning electron microscopy. Compressive strength increased with the addition of ZrO2 and especially TiO2 nanoparticles, whereas the addition of Al2O3 nanoparticles generally weakened the cements. The ion release profile of the modified cements was the same in all cases. The addition of Al2O3, ZrO2 and TiO2 nanoparticles into GICs is beneficial, since it leads to reduction of the microscopic voids in the set cement. Of these, the use of ZrO2 and TiO2 nanoparticles also led to increased compressive strength. Nanoparticles did not release detectable levels of ions (Al, Zr or Ti), which makes them suitable for clinical use.

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Silva, V. B., V. S. Silva, L. M. Madeira, Suzana Pereira Nunes y A. Mendes. "An Impedance Study on the sPEEK/ZrO₂ Membranes for Direct Methanol Fuel Cell Applications". Materials Science Forum 587-588 (junio de 2008): 926–30. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.926.

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Electrochemical impedance experiments were carried out in order to study the influence of the ZrO2 inorganic incorporation on the proton conductivity of sulfonated poly(ether ether ketone) (sPEEK) membranes. The impedance data was fitted to an extension of Randles’ circuit, within the inorganic content and temperature ranges considered. The model fits quite well for ZrO2 loads up to 10 wt.%. Such a model allows for characterizing the diffusion phenomena (Warburg) of the membrane electrode assembly (MEA), membrane and electrodes resistances, capacitive and inductive behavior. Proton conductivity was obtained from the impedance spectra and it was observed that it increases with temperature and decreases with the inorganic content. As a general trend, the Warburg parameter decreases slightly with the temperature, except for the 5 wt. % ZrO2 membrane that suffers a more pronounced influence. The Warburg parameter also decreases with the ZrO2 content.

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Abdel Hamid, Z., A. Y. El-Etre y M. Fareed. "Performance of Ni–Cu–ZrO2 nanocomposite coatings fabricated by electrodeposition technique". Anti-Corrosion Methods and Materials 64, n.º 3 (2 de mayo de 2017): 315–25. http://dx.doi.org/10.1108/acmm-05-2016-1672.

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Purpose The purpose of this study is to investigate the effect of the incorporated zirconia (ZrO2) nanoparticles on the performance of the deposited layer Ni–Cu alloy on steel sheet. Design/methodology/approach The aim was to produce Ni–Cu–ZrO2 nanocomposite coatings by electrodeposition technique and estimate the influence of ZrO2 nanoparticles on the performance of Ni–Cu alloy. The surface morphologies and chemical compositions of the deposited layers were assessed using scanning electron microscopy and energy-dispersive X-ray analysis, respectively. Nanoindentation was used as a well-advanced technique for measuring microhardness and Young’s modulus values of different coatings. The corrosion resistance in 3.5 per cent NaCl solution of electrodeposited films has been investigated. Findings The main conclusion is that the surface morphologies of Ni–Cu–ZrO2 nanocomposite coatings were fine granular compared with Ni–Cu alloy. The corrosion behavior illustrated that the incorporation of ZrO2 nanoparticles with Ni–Cu film improved the corrosion resistance. Significant improvement was also demonstrated in the hardness of nanocomposite coatings. Social implications The optimized industrial use of steel-coated Ni–Cu alloy with super properties. Consequently, a social benefit can be associated with the reduction in the corrosion rate and increases the microhardness and Young’s modulus. Originality/value The results presented in this work are an insight into understanding the incorporation of ceramic reinforcement with metal or alloy films (matrix) on carbon steel using the electrodeposition technique. The development of corrosion resistance of Ni–Cu alloys has been considered as a promising behavior. In this work, a consistent assessment of the results achieved on laboratory scale has been conducted.

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Nejatian, T., A. Johnson y R. Van Noort. "Reinforcement of Denture Base Resin". Advances in Science and Technology 49 (octubre de 2006): 124–29. http://dx.doi.org/10.4028/www.scientific.net/ast.49.124.

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The fracture resistance of polymethyl methacrylate (PMMA) the most popular denture base materials, is not satisfactory. The aim of this study is to improve the mechanical properties of PMMA by adding filler particles. Different inorganic filler particles including micronised glass flakes, acryl silane micronised, glass flakes 350nm, TiO2 and ZrO2 with different ratios by weight were incorporated into heat-cure plain PMMA and processed with optimal condition [2.5:1 Powder/ monomer ratio, conventional packing method and water bath curing for 2 hours at 95°C] to produce 12mm diameter and 2mm thick discs. Plain PMMA without additives was prepared as a test control. Three types of mechanical tests, biaxial flexure, microindentation fracture toughness and Vickers hardness were carried out on the samples. It was found that incorporating the particles did not improve the biaxial flexural strength of the resin. However, TiO2, ZrO2 and micronised glass flakes increased the fracture toughness of the resin. The hardness of PMMA was improved by the incorporation of all the particles.

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Prymak, Oleg, Lida E. Vagiaki, Ales Buyakov, Sergei Kulkov, Matthias Epple y Maria Chatzinikolaidou. "Porous Zirconia/Magnesia Ceramics Support Osteogenic Potential In Vitro". Materials 14, n.º 4 (23 de febrero de 2021): 1049. http://dx.doi.org/10.3390/ma14041049.

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Porous zirconia (ZrO2), magnesia (MgO) and zirconia/magnesia (ZrO2/MgO) ceramics were synthesised by sintering and designated as ZrO2(100), ZrO2(75)MgO(25), ZrO2(50)MgO(50), ZrO2(25)MgO(75), MgO(100) based on their composition. The ceramic samples were characterised by means of scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic absorption spectrometry to explore the incorporation of Mg atoms into the zirconia lattice. The resulting porosity of the samples was calculated based on the composition and density. The final porosity of the cylinder-shaped ceramic samples ranged between 30 and 37%. The mechanical analysis exhibited that the Young modulus increased and the microstress decreased with increasing magnesia amount, with values ranging from 175 GPa for zirconia to 301 GPa for magnesia. The adhesion, viability, proliferation and osteogenic activity of MC3T3-E1 pre-osteoblastic cells cultured on the zirconia/magnesia ceramics was found to increase, with the magnesia-containing ceramics exhibiting higher values of calcium mineralisation. The results from the mechanical analysis, the ALP activity, the calcium and collagen production demonstrate that the zirconia/magnesia ceramics possess robust osteoinductive capacity, therefore holding great potential for bone tissue engineering.

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Algailani, Hiba M., Adel K. Mahmoud y Hanaa A. Al-Kaisy. "Fabrication of Ni-ZrO2 Nanocomposite Coating by Electroless Deposition Technique". Engineering and Technology Journal 38, n.º 5A (25 de mayo de 2020): 649–55. http://dx.doi.org/10.30684/etj.v38i5a.491.

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This work aims preparation of Ni-based nanocomposite coating by electroless deposition method onto stainless steel (316L) substrate, the present work will compare the effects of incorporation of ZrO2 nanoparticles at different percentages (1.25 wt %, 2.25 wt %, and 4.25 wt %) Ni-based electroless deposition coating of the bath nanocomposite on the phase structure, microhardness, and corrosion resistance is studied. Where the structure and chemical composition of nanocomposite coatings were studied by using (X-ray), (SEM) and (EDS). of Ni - ZrO2 nanocomposite coating exhibits much-increased microhardness and remarkably improved corrosion resistance.

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Barroso-Bogeat, Adrián, Iván Daza Raposo, Ginesa Blanco y José María Pintado. "Tuning the Integration Rate of Ce(Ln)O2 Nanoclusters into Nanoparticulated ZrO2 Supports: When the Cation Size Matters". Materials 13, n.º 12 (23 de junio de 2020): 2818. http://dx.doi.org/10.3390/ma13122818.

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Three nanostructured catalysts with low total rare earth elements (REEs) content (i.e., 15 mol.%) were prepared by depositing CeO2 or Ln3+-doped CeO2 (Ln3+ = Y3+ or La3+; Ln/Ce = 0.15) on the surface of ZrO2 nanoparticles, as nanometre-thick, fluorite-type clusters. These samples were subjected to successive reduction treatments at increasing temperatures, from 500 to 900 °C. A characterisation study by XPS was performed to clarify the diffusion process of cerium into the bulk of ZrO2 crystallites upon reduction to yield CexZr1−xO2−δ surface phases, and the influence of the incorporation of non-reducible trivalent REE cations, with sizes smaller (Y3+) and larger (La3+) than Ce4+ and Ce3+. For all nanocatalysts, a reduction treatment at a minimum temperature of 900 °C was required to accomplish a significant cerium diffusion. Notwithstanding, the size of the dopant noticeably affected the extent of this diffusion process. As compared to the undoped ZrO2-CeO2 sample, Y3+ incorporation slightly hindered the cerium diffusion, while the opposite effect was found for the La3+-doped nanocatalyst. Furthermore, such differences in cerium diffusion led to changes in the surface and nanostructural features of the oxides, which were tentatively correlated with the redox response of the thermally aged samples.

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24

Tikhani, Farimah, Behzad Shirkavand Hadavand, Hamed Fakharizadeh Bafghi, Maryam Jouyandeh, Henri Vahabi, Krzyszof Formela, Hossein Hosseini et al. "Polyurethane/Silane-Functionalized ZrO2 Nanocomposite Powder Coatings: Thermal Degradation Kinetics". Coatings 10, n.º 4 (21 de abril de 2020): 413. http://dx.doi.org/10.3390/coatings10040413.

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A polyurethane (PU)-based powder coating reinforced with vinyltrimethoxysilane (VTMS)-functionalized ZrO2 nanoparticles (V-ZrO2) for thermal stability was developed. Chemical structure, microstructure and thermal degradation kinetics of the prepared coatings were investigated. The peak of aliphatic C–H vibrating bond in the Fourier transform infrared (FTIR) spectrum of V-ZrO2 was a signature of VTMS attachment. Scanning electron microscopy (SEM) images reveled that, by increase of V-ZrO2 content from 0.1 to 0.3 wt.% and then 0.5 wt.%, some agglomerations of nanoparticles are formed in the PU matrix. Thermogravimetric analysis (TGA) of the PU/V-ZrO2 powder coatings was performed at different heating rates nonisothermally to capture alteration of activation energy (Ea) of degradation of PU/V-ZrO2 powder coatings as a function of partial mass loss by using Friedman, Kissinger–Akahira-Sunose (KAS), Ozawa–Wall–Flynn (FWO) and modified Coats–Redfern isoconversional approaches. It was observed that by addition of 1 wt.% V-ZrO2 to PU resin the early state degradation temperature at 5% weight loss increased about 65 °C, suggesting a physical barrier effect limiting the volatility of free radicals and decomposition products. Incorporation of 5 wt.% ZrO2 led to about 16% and 10% increase in Ea and LnA of blank PU, respectively, which was indicative of higher thermal resistance of nanocomposite powder coatings against thermal degradation. There was also obvious agreement between model outputs and experimental data. The results reveal that nanocomposite coating shows superior thermal properties compared to neat PU powder coatings, and the presence of nano ZrO2 in sufficient amount causes retardation of the thermal decomposition process.

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Linh, Nguyen Thi Dieu, Khuc Duong Huy, Nguyen Thi Kim Dung, Ngo Xuan Luong, Thai Hoang y Do Quang Tham. "Fabrication and characterization of PMMA/ZrO₂ nanocomposite 3D printing filaments". Vietnam Journal of Chemistry 61, n.º 4 (19 de julio de 2023): 461–69. http://dx.doi.org/10.1002/vjch.202200185.

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AbstractThe 3D printing PMMA/ZrO2 filaments with a diameter of 1.75 ± 0.05 mm were fabricated by using a single‐screw extruder at temperatures of four heating zones of 190, 200, 210, and 210°C. Testing samples were prepared from the extruded filaments by using a fusion deposition modeling 3D printer and a Haake MiniJet piston injection molding machine. Fourier transform infrared spectroscopy, mechanical properties, field emission scanning electron microscopy (FESEM), differential scanning calorimetry, and thermogravimetric analysis of the filaments were investigated. It was suggested the formation of physical and molecular interactions between surface hydroxyl groups of ZrO2 nanoparticles and C‐O‐C groups of PMMA in the PMMA/ZrO2 filaments. FESEM images of the filaments indicated the good dispersion of ZrO2 nanoparticles in the PMMA matrix, nevertheless, there was still the formation of clusters of ZrO2 nanoparticles in the nanocomposite filaments. The incorporation of nano ZrO2 increased the thermal properties, bending, and tensile moduli of PMMA. The mechanical properties of the 3D‐printed samples were lower than those of the molded samples. However, the bending strength of the 3D‐printed samples was much higher than 50 MPa, bending modulus was much higher than 1800 MPa, as required for acrylic bone cement (in ISO 5833:2002).

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26

Shaalan, Nagih M., Mohamed Rashad, Osama Saber, Adil Alshoaibi y Chawki Awada. "A Comprehensive Photocatalysis Study of Promising Zirconia/Laser-Induced Graphene Nanocomposite for Wastewater Treatment-Based Methylene Blue Pollution". Separations 9, n.º 8 (22 de julio de 2022): 185. http://dx.doi.org/10.3390/separations9080185.

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In this paper, the photocatalytic effect of zirconia/laser-induced graphene on the degradation of methylene blue was comprehensively studied. The average particle size measured by HRTEM is 6 nm for both ZrO2 and ZrO2/G10 samples, which explains the high-quality TEM imaging of isolated squared sections of cubic particles. The weight percentages of Zr, O, and C elements using EDX were 72.16, 18.56, and 9.28, respectively. These results confirm the formation of binary composites. Moreover, Raman scattering exhibited that the spectrum of pure ZrO2 was difficult to be detected due to the high luminescence. However, ZrO2 vibration modes were detected for ZrO2-graphene nanocomposites at 1012, 615, 246, and 150 cm−1. A shift of the D- and G-bands of graphene were observed, where D-peak and G-peak were observed at 1370 and 1575 cm−1 for ZrO2/5G and, 1361 and 1565 cm−1 for ZrO2/10G, respectively. The shift is ascribed to the incorporation of graphene into the surface of the oxide material. Compared to ZrO2, the newly fabricated ZrO2-graphene nanocomposites have the advantage of increased photocatalytic effects. An adsorbent concentration of 5 and 10 mg·L−1 at room temperature over 240 min was observed to be suitable experimental conditions. The kinetic results indicate that the practical results obtained are well expressed by the first-order kinetic model at different concentrations. In addition, the results showed that the addition of graphene led to a significant degradation process increase. The results also showed the significant effect of the investigated ZrO2-graphene nanocomposites on the decomposition of methylene blue cation. The decomposition of cationic pollutants showed a synergistic effect of the ZrO2-graphene nanocomposites on wastewater treatment.

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27

Yong, Jiahui, Hongzhan Li, Zhengxian Li, Yongnan Chen, Yifei Wang y Juanjuan Geng. "Effect of (NH4)2ZrF6, Voltage and Treating Time on Corrosion Resistance of Micro-Arc Oxidation Coatings Applied on ZK61M Magnesium Alloys". Materials 14, n.º 23 (3 de diciembre de 2021): 7410. http://dx.doi.org/10.3390/ma14237410.

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The effects of (NH4)2ZrF6 concentration, voltage and treating time on the corrosion resistance of ZK61M magnesium alloy micro-arc oxidation coatings were studied by orthogonal experiments. The SEM result shows that the surface roughness and porosity of MAO coatings increased with (NH4)2ZrF6 concentration, voltage and treating time as a whole, except the porosity decreased with treating time. EDS, XRD and XPS analysis show that (NH4)2ZrF6 was successfully incorporated into coatings by reactive incorporation, coatings are dominantly composed of ZrO2, MgO, MgF2 and amorphous phase Mg phosphate. Potentiodynamic polarization was used to evaluate the corrosion property of coatings. When the concentration of (NH4)2ZrF6 is 6 g/L, the voltage is 450 V, and the treating time is 15 min, the coating exhibits the best corrosion resistance which corrosion current density is four magnitudes lower than substrate attributed to the incorporation of ZrO2 and the deposition of MgF2 in the micropores.

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28

Sedmale, Gaida M., I. Sperberga, A. Hmelov, U. Sedmalis y A. Actins. "Phase Formation and Structure of Mullite-Alumina-Zirconia and Spinel-Enstatite Ceramics Developed from Synthetic and Mineral Raw Materials". Materials Science Forum 575-578 (abril de 2008): 953–58. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.953.

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New dense and porous ceramics are developed using two formulation approaches. These are ceramics with remarkable content of mullite, corundum and ZrO2 - tetragonal and monoclinic in crystalline phase and porous (average size of pores up to 150-350μm) spinel-enstatite/forsterite ceramics. To promote the phase development by high-temperature synthesis of these ceramics the mineral raw materials – illite clay and illite clay together with dolomite are used. Bulk density for mullite (corundum) – zirconia ceramics is increased by equal addition of illite clay (8.2 wt.%) as well as ZrO2 and especially ZrO2 +Y2O3 to starting mullite mixtures. Contrary the addition of different kind and amount of illite clay together with dolomite trends to formation of spinel – enstatite (forsterite) ceramics and decrease the bulk density to the value up to 0.35 g/cm3. The XRD results indicate that ZrO2 monoclinic/tetragonal incorporation in mullite (corundum) structure realizes through the liquid phase. Development of the spinel MgAl2O4 and enstatite MgSiO3 crystalline phases along with the sufficient amount of glassy phase in microstructure and even distributed pores are proper for spinel-enstatite (forsterite) ceramic samples.

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29

Basak, Sayandip, M. Helen Santhi y Caroline Ponraj. "Performance of Concrete with Waste Tyre and Nano ZrO2". Advanced Science Letters 24, n.º 8 (1 de agosto de 2018): 5737–41. http://dx.doi.org/10.1166/asl.2018.12188.

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This paper presents the compressive strength of concrete which consists of 5% replacement of coarse aggregate with rubber aggregate, 25% replacement of cement with fly ash (Class C) and an additional amount of 0.2% of ZrO2 nanoparticles. The ZrO2 nanoparticles were synthesized using gel combustion technique where zirconium oxynitrate was used as the precursor and citric acid as the fuel in the molar ratio of 1:1.5 respectively. The synthesized ZrO2 nano particles were characterized using X-ray diffraction and the average crystallite size was found as 9.7 nm. Three types of mixes were taken into consideration; control mix (M40), rubber modified concrete mix and nano-rubber modified mix. The Scanning Electron Microscope imaging was done to study the morphology of the mixes. With the percentage of rubber aggregate replacement mentioned above there was found to be a considerable decrease in the compressive strength but on incorporation of nano ZrO2 along with rubber aggregate it was found out that there was an increase in compressive strength which even surpassed the strength of conventional concrete.

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30

Kundana, N., M. Venkatapathy, V. Neeraja, Chandra Sekhar Espenti, Venkata Ramana Jeedi y V. Madhusudhana Reddy. "Effect of Zr-Nanofiller on Structural and Thermal Properties of PVDF-co-HFP Porous Polymer Electrolyte Membranes Doped with Mg2+ Ions". Asian Journal of Chemistry 35, n.º 1 (27 de diciembre de 2022): 99–108. http://dx.doi.org/10.14233/ajchem.2023.26893.

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New poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP)/ZrO2-based nanocomposite porous polymer membranes were prepared with doping of magnesium ions using THF as solvent. These membranes were prepared using the solvent casting technique. The optimal nanofiller (0, 2, 4, 6, 8 and 10% Zr nanopowder) was incorporated into the PVDF-co-HFP/MgTf3/ZrO2 and the incorporation of the nanofiller results in an increase in the porosity of the prepared membranes. The structural, morphological and thermal properties of the nanocomposite porous polymer membranes were also investigated. The structural investigation and the identification of functional groups were accomplished using FTIR technique. X-ray diffraction (XRD) analysis was performed to ascertain the phase of polymer membranes and the phase change that happens upon interaction with nanofiller and Mg2+ ions. Assessment of the nanocomposite porous polymer membrane's morphology and porous structure was performed using a scanning electron microscope (SEM). DSC analysis was used to evaluate the thermal behaviour of the nanocomposite porous membranes. The electrical and dielectric studies confirmed the structural reformation of the polymer electrolyte materials. It was found that 8% nanofiller is the best conducting composition for maximum ionic conductivity, dielectric constant and Mg2+ ion mobility. The incorporation of ZrO2 nanofiller predominantly increases the number of free ions and mobility of the charge carriers in the composite polymer electrolyte systems.

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Cho, M. H., D. W. Moon, S. A. Park, Y. S. Rho, Y. K. Kim, K. Jeong, C. H. Chang, J. H. Gu, J. H. Lee y S. Y. Choi. "Enhanced thermal stability of high-dielectric Gd2O3 films using ZrO2 incorporation". Applied Physics Letters 84, n.º 5 (2 de febrero de 2004): 678–80. http://dx.doi.org/10.1063/1.1644047.

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32

Gu, Y. W., A. U. J. Yap, P. Cheang y K. A. Khor. "Effects of incorporation of HA/ZrO2 into glass ionomer cement (GIC)". Biomaterials 26, n.º 7 (marzo de 2005): 713–20. http://dx.doi.org/10.1016/j.biomaterials.2004.03.019.

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33

Cho, Byeong-Ok, Sandy X. Lao y Jane P. Chang. "Origin and effect of impurity incorporation in plasma-enhanced ZrO2 deposition". Journal of Applied Physics 93, n.º 11 (junio de 2003): 9345–51. http://dx.doi.org/10.1063/1.1572193.

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34

Camposeco, Roberto, Viridiana Maturano-Rojas y Rodolfo Zanella. "Highly Efficient Au/ZnO−ZrO2 Catalysts for CO Oxidation at Low Temperature". Catalysts 13, n.º 3 (15 de marzo de 2023): 590. http://dx.doi.org/10.3390/catal13030590.

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A series of gold catalysts on ZnO−ZrO2 featuring nominal ZnO loads of 3, 5, and 10 wt. % were synthesized by the sol–gel method using Zn(NO3)2 and zirconium (IV) propoxide aqueous solutions. In addition, gold catalysts with nominal loads between 1 and 3 wt. % were produced by the method of deposition-precipitation with urea, and their performance in the CO oxidation reaction at low temperature was evaluated. HRTEM outcomes revealed high gold dispersion on the 3Au/5ZnO−ZrO2 catalyst with Zn/Zr atomic ratio of (5/95) and 3 wt. % of gold, which showed the highest CO conversion at low temperature (−5 °C) under air treatment when the CO oxidation was carried out with a space velocity of ~46,000 h−1. The incorporation of ZnO to ZrO2 provoked high dispersion of the gold nanoparticles on the support and close size distribution; moreover, the presence of Au1+ and Zr3+ species was increased by the Zr−O−Zn interaction, which was stronger than in the single Au/ZrO2 and Au/ZnO catalysts. DRIFT/GC−MS confirmed that the Au1+/Au0 ratio and formation of carbonate species played an important role in determining the CO conversion; likewise, the 3Au/5ZnO–ZrO2 catalyst was stable at 10 °C for 24 h.

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35

Samad, Ubair Abdus, Mohammad Asif Alam, Hany S. Abdo, Arafat Anis y Saeed M. Al-Zahrani. "Synergistic Effect of Nanoparticles: Enhanced Mechanical and Corrosion Protection Properties of Epoxy Coatings Incorporated with SiO2 and ZrO2". Polymers 15, n.º 14 (20 de julio de 2023): 3100. http://dx.doi.org/10.3390/polym15143100.

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This research paper presents the fabrication of epoxy coatings along with the hybrid combination of SiO2 and ZrO2. The epoxy resin is incorporated with SiO2 as the primary pigment and ZrO2 as the synergist pigment. The study delves into the adhesion, barrier, and anti-corrosion properties of these coatings, enriched with silica and zirconium nanoparticles, and investigates their impact on the final properties of the epoxy coating. The epoxy resin, a Diglycidyl ether bisphenol-A (DGEBA) type, is cured with a polyamidoamine adduct-based curing agent. To evaluate the protective performance of silica SiO2 and zirconia ZrO2 nanoparticles in epoxy coatings, the coated samples were tested in a 3.5% NaCl solution. The experimental results clearly demonstrate a remarkable improvement in the ultimate tensile strength (UTS), yield strength (YS), and Elastic Modulus. In comparison to using SiO2 separately, the incorporation of both ZrO2 and SiO2 resulted in a substantial increase of 43.5% in UTS, 74.2% in YS, and 8.2% in Elastic Modulus. The corrosion test results revealed that the combination of DGEBA, SiO2, and ZrO2 significantly enhanced the anti-corrosion efficiency of the organic coatings. Both these pigments exhibited superior anti-corrosion effects and mechanical properties compared to conventional epoxy coatings, leading to a substantial increase in the anti-corrosion efficiency of the developed coating. This research focuses the potential of SiO2 and ZrO2 in hybrid combination for applications, where mechanical, corrosion and higher adhesion to the substrates are of prime importance.

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36

Novakovic, Jelica, M. Delagrammatikas, P. Vassiliou y C. T. Dervos. "Electroless Ni-P Composites with ZrO₂: Preparation, Characterization, Thermal Treatment". Defect and Diffusion Forum 297-301 (abril de 2010): 899–905. http://dx.doi.org/10.4028/www.scientific.net/ddf.297-301.899.

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The study of composite electroless Ni-P coatings is pursued in order to obtain coatings on a metal substrate with advanced properties i.e. with high wear and corrosion resistance for particular engineering uses. Composite NiP-ZrO2 layers were prepared by simultaneous electroless co-deposition of Ni-P and ZrO2 on steel, from a reducing solution in which ZrO2 particles were kept in suspension by stirring. The particles load in the bath was 0, 0.5, 1.0, 2.0 and 5.0 g/l. The deposits of 30 m in thickness, were characterized for structure, morphology and hardness by scanning electron microscopy and microanalysis as well as X-ray diffraction. It was found that the maximum ZrO2 particle incorporation attained was 7-10% of Zr. Vickers microhardness was measured for the plain deposit and found to be 720 HV and for the maximum zirconia content of 10%, 820 HV. After a vacuum heat treatment for 10 min, the microhardness of the composite is found to be 1500 HV. The electrochemical linear polarization measurements in a corrosive NaCl 3.5% solution shows at 2.0 g/l bath load favourable conditions for the formation of a defects free composite deposit could be created.

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37

Muftah, Amal A., Shobha A. Waghmode y Sharda R. Gadale. "Synthesis of Zirconia Doped Molybdenum Oxide as Efficient Catalysts for Ultrasound Assisted Synthesis of Substituted Pyrazoles". Asian Journal of Chemistry 33, n.º 9 (2021): 2007–14. http://dx.doi.org/10.14233/ajchem.2021.23260.

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To explore green methodology for the synthesis of mixed oxide, its catalytic activity and temperature stability of series of ZrO2/MoO3 and ZrO2 were prepared by sol-gel method and characterized by XRD, FT-IR, X-ray photoelectron spectroscopy (XPS), temperature programmed Desorption (TPD), Raman spectroscopy and transmission electron microscopes (TEM). These mixed oxides were showed high stability with nanocrystalline nature. Due to highly acidic nature of the catalysts, ultra sound assisted synthesis of substituted pyrazoles was carried out successfully with high yield. The reaction was carried out in solvent free medium, which showed green approach and energy saving reaction. Condensation of dibenzoyl methane and hydrazine to form substituted pyrazoles with 97.7% yield. The acid strength and acid amount of synthesized catalysts were determined by temperature programmed desoprtion (TPD), incorporation of zirconia into the molybdenum, network has changed its surface acid properties due to the Zr2+ and Mo6+ ions. After addition of ZrO2 on MoO3, it showed weak and strong acid sites.

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38

Checa, Manuel, Vicente Montes, Jesús Hidalgo-Carrillo, Alberto Marinas y Francisco Urbano. "Influence of Boron, Tungsten and Molybdenum Modifiers on Zirconia Based Pt Catalyst for Glycerol Valorization". Nanomaterials 9, n.º 4 (2 de abril de 2019): 509. http://dx.doi.org/10.3390/nano9040509.

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The influence of boron, tungsten and molybdenum modifiers on zirconia-based Pt catalyst was studied for glycerol valorization. Zirconia modified supports were prepared by impregnation of ZrO2 with either boric, silicontungstic or phosphomolybdic acids to obtain supports with enhanced Brönsted acidic properties. The modified supports were subsequently impregnated with chloroplatinic acid to obtain Pt-based catalysts. Pt incorporation resulted in the increase in Lewis acidity of the solids, being more significant for the Pt//W/ZrO2 catalyst. Reduced Pt catalysts were tested for the liquid-phase glycerol hydrogenolysis, observing a synergistic effect between catalyst acid sites and metal function that proved to be crucial in glycerol hydrogenolysis. The Pt//W/ZrO2 catalyst was the most active catalyst in this reaction, being the only leading to 1,3-PDO (45% sel., 160 °C) while Pt//Mo/ZrO2 is the best option for 1,2-PDO (49% sel., 180 °C). Reusability studies carried out for Pt//W/ZrO2 showed that catalytic activity dropped after the first use, remaining constant for the second and subsequent ones. Selectivity to reaction products also changes during reuses. Therefore, the selectivity to 1,2 PDO increases in the first reuse in detriment to the selectivity to n-propanol whereas the selectivity to 1,3-PDO remains constant along the uses. This behavior could be associated to the lixiviation of W species and/or catalyst fouling during reaction runs.

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39

Chang, Hung-Chih, Cheng-Ming Lin, Chih-Hsiung Huang y C. W. Liu. "Hysteresis reduction by fluorine incorporation into high permittivity tetragonal ZrO2 on Ge". Applied Physics Letters 104, n.º 3 (20 de enero de 2014): 032902. http://dx.doi.org/10.1063/1.4862481.

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40

Yori, J. C., C. L. Pieck y J. M. Parera. "n-Butane isomerization on Pt/WO3–ZrO2: effect of the Pt incorporation". Applied Catalysis A: General 181, n.º 1 (mayo de 1999): 5–14. http://dx.doi.org/10.1016/s0926-860x(98)00362-7.

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41

SUTHANTHIRARAJ, S. AUSTIN, R. KUMAR y B. JOSEPH PAUL. "IMPACT OF ZrO2 NANOPARTICLES ON IONIC TRANSPORT AND ELECTROCHEMICAL PROPERTIES OF NANOCOMPOSITE GEL POLYMER ELECTROLYTE: PPG (4000)–AgCF3SO3:ZrO2". International Journal of Nanoscience 10, n.º 01n02 (febrero de 2011): 241–46. http://dx.doi.org/10.1142/s0219581x11007855.

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The phenomenon of enhancement of ionic transport and electrochemical behavior of a new poly (propylene glycol) (PPG 4000)–silver triflate ( AgCF3SO3 ) as a result of incorporation of varying concentrations of ZrO 2 nanoparticles have been investigated. The significant conformal changes and the strength of interactions along with chain enlargement of polymer matrix have been analyzed by means of FT-IR and DSC studies as well. From the ac impedance measurements, it is clear that the addition of filler particles favors an increase in the conductivity by more than two orders of magnitude and that the typical sample PPG4– AgCF3SO3 :10 wt% ZrO 2 exhibits a maximum conductivity of 2.9 × 10-3 Scm-1 along with the cationic transference number of 0.49 at room temperature.

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42

Yaacob, Nurshahnawal, Pei Sean Goh, Ahmad Fauzi Ismail, Noor Aina Mohd Nazri, Be Cheer Ng, Muhammad Nizam Zainal Abidin y Lukka Thuyavan Yogarathinam. "ZrO2-TiO2 Incorporated PVDF Dual-Layer Hollow Fiber Membrane for Oily Wastewater Treatment: Effect of Air Gap". Membranes 10, n.º 6 (16 de junio de 2020): 124. http://dx.doi.org/10.3390/membranes10060124.

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Dual-layer hollow fiber (DLHF) nanocomposite membrane prepared by co-extrusion technique allows a uniform distribution of nanoparticles within the membrane outer layer to enhance the membrane performance. The effects of spinning parameters especially the air gap on the physico-chemical properties of ZrO2-TiO2 nanoparticles incorporated PVDF DLHF membranes for oily wastewater treatment have been investigated in this study. The zeta potential of the nanoparticles was measured to be around –16.5 mV. FESEM–EDX verified the uniform distribution of Ti, Zr, and O elements throughout the nanoparticle sample and the TEM images showed an average nanoparticles grain size of ~12 nm. Meanwhile, the size distribution intensity was around 716 nm. A lower air gap was found to suppress the macrovoid growth which resulted in the formation of thin outer layer incorporated with nanoparticles. The improvement in the separation performance of PVDF DLHF membranes embedded with ZrO2-TiO2 nanoparticles by about 5.7% in comparison to the neat membrane disclosed that the incorporation of ZrO2-TiO2 nanoparticles make them potentially useful for oily wastewater treatment.

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43

Wang, Xue Tao, Xu Bin, Shu Juan Kang y Cheng Rui Qu. "The Activity and Characterization of Pd/Ce_0.5Zr_0.5O₂ Catalyst for the Reduction of NO". Advanced Materials Research 800 (septiembre de 2013): 93–97. http://dx.doi.org/10.4028/www.scientific.net/amr.800.93.

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Pd catalysts and Ce0.5Zr0.5O2 mixed oxides (CZ) was prepared by co-precipitation technique and their physicochemical properties were characterized by specific surface area measurements (BET), scanning electron microscope (SEM), and X-ray diffraction (XRD) techniques. CeO2-ZrO2 solid solutions supported with Pd are investigated as catalysts for reduction of NO. The research presented in this paper is focused on the intrinsic structure of CeO2-ZrO2 solid solution and catalytic behavior of NO over Pd/Ce0.5Zr0.5O2 mixed oxides catalyst. The incorporation of ZrO2 into the CeO2 framework strongly promotes the reduction of Ce4+ in the bulk of the support. The surface area of Ce0.5Zr0.5O2 was 32 m2/g after calcination in air at 1000 °C for 5 h. XRD results revealed the existence of Zr-rich phase in CZ sample. The experimental results show that the best Pd/Ce0.5Zr0.5O2 catalyst yielded 97.75% NO conversion at typical reaction temperatures (280-320 C) and the high gas hourly space velocity of 15,000 h1. The effect of the calcination temperature was also investigated, and the optimal calcination temperature was 400-500 C.

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44

Zapién, Alberto Hernández, Juan Manuel Hernández Enríquez, Ricardo García Alamilla, Guillermo Sandoval Robles, Ulises Páramo García y Luz Arcelia García Serrano. "Influence of Molybdenum Content and MoOxy-Species on the Textural and Structural ZrO2Properties". Advances in Materials Science and Engineering 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/432031.

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The present work proposes to study the incorporation of molybdenum into the zirconium oxide precursor (Zr(OH)4), in order to analyze its possible repercussions on the textural and structural zirconia properties (ZrO2). For this, the Zr(OH)4was synthesized by the sol-gel method and modified with 5, 10, and 15 wt% of molybdenum into the stabilized oxide. The synthesized materials were dried at 120°C for 24 h and then were calcined at 600°C for 3 h. The characterization of the solids was carried out by thermal analysis, X-ray diffraction, nitrogen physisorption, infrared spectroscopy, and scanning electron microscopy. The thermal analyses results showed that the change from the amorphous to the crystalline phase of ZrO2is shifted to higher temperatures due to the presence of molybdenum content. Tetragonal phase was identified for all synthesized materials, showing a decrease in crystallinity as a function of the metal content. The textural properties were improved due to the incorporation of molybdenum into the ZrO2structure, developing specific surface areas which are above up to four times the area of pure ZrO2. The synthesized materials presented spherical morphology with particle sizes less than 1 µm, with a change of this morphology for high metal contents (15 wt%) being observed.

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Miranda, Maicon Oliveira, Francisca Pereira de Araújo, Josy Anteveli Osajima y Edson Cavalcanti Silva Filho. "Incorporation of Zirconium Oxide on the Surface of Palygorskite Clay for Photodegradation of Industrial Dye". Materials Science Forum 869 (agosto de 2016): 768–72. http://dx.doi.org/10.4028/www.scientific.net/msf.869.768.

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The palygorskite or attapulgite is a mineral clay of fibrous habits, a phyllosilicate 2:1, presented by the formula Mg5[Si8O20](OH)2(OH2)4.4H2O. Taking advantage of this natural resource available in the State of Piauí, this research aims at incorporating the zirconium oxide to the surface of this clay, through the sol-gel method, in order to evaluate the photoactivity of the composite. The material was characterized by the X-ray diffractometry (XRD), indicating the presence of the zirconium oxide, with the emergence of peaks in 30.8° and 60.9°. It was observed the incorporation of zirconium on the clay by transmission electron microscopy (TEM) and verified the fibrous habit and the presence of ZrO2 on the surface of the clay with 1.35% of incorporated zirconium and 127.4 m2 g-1. The rate of degradation of the Remazol Blue dye was 93.5% when using the composite.

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Park, S. A., Y. S. Roh, Y. K. Kim, J. H. Baeck, M. Noh, K. Jeong, M. H. Cho et al. "Effect of ZrO2 incorporation into high dielectric Gd2O3 film grown on Si(111)". Journal of Applied Physics 98, n.º 2 (15 de julio de 2005): 024906. http://dx.doi.org/10.1063/1.1990263.

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Sedelnikova, Mariya B., Alexander D. Kashin, Pavel V. Uvarkin, Alexey I. Tolmachev, Yurii P. Sharkeev, Anna V. Ugodchikova, Nikita A. Luginin y Olga V. Bakina. "Porous Biocoatings Based on Diatomite with Incorporated ZrO2 Particles for Biodegradable Magnesium Implants". Journal of Functional Biomaterials 14, n.º 5 (24 de abril de 2023): 241. http://dx.doi.org/10.3390/jfb14050241.

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In the present work, the surface of a biodegradable Mg alloy was modified to create porous diatomite biocoatings using the method of micro-arc oxidation. The coatings were applied at process voltages in the range of 350–500 V. We have studied the influence of the addition of ZrO2 microparticles on the structure and properties of diatomite-based protective coatings for Mg implants. The structure and properties of the resulting coatings were examined using a number of research methods. It was found that the coatings have a porous structure and contain ZrO2 particles. The coatings were mostly characterized by pores less than 1 μm in size. However, as the voltage of the MAO process increases, the number of larger pores (5–10 μm in size) also increases. However, the porosity of the coatings varied insignificantly and amounted to 5 ± 1%. It has been revealed that the incorporation of ZrO2 particles substantially affects the properties of diatomite-based coatings. The adhesive strength of the coatings has increased by approximately 30%, and the corrosion resistance has increased by two orders of magnitude compared to the coatings without zirconia particles.

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Wei, Yong Gang, Xing Zhu, Kong Zhai Li, Ya Ne Zheng y Hua Wang. "Reaction Characteristics of Ce-Based Oxygen Carrier for Two-Step Production Syngas and Hydrogen through Methane Conversion and Water Splitting". Advanced Materials Research 641-642 (enero de 2013): 123–27. http://dx.doi.org/10.4028/www.scientific.net/amr.641-642.123.

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The two-step steam methane reforming for production syngas and hydrogen was investigated by using Ce-based oxygen carriers (CeO2, CeO2-ZrO2，CeO2-Fe2O3) which were prepared by co-precipitation method and characterized by means of X-ray diffractometer and Raman spectroscopy. CH4 temperature programmed and isothermal reactions were adopted to test syngas production reactivity, and redox properties were evaluated by a successive redox cycle. The results showed that the incorporation of ZrO2 into CeO2 was found to be an effective approach for enhancing the reducibility of CeO2 in methane conversion reaction and redox performance, and the addition of Fe2O3 into CeO2 could obviously increase the amount of reactive oxygen species in CeO2-Fe2O3 and the yields of syngas and hydrogen reached maximum in the 3rd cycle, but the redox stability of CeO2-Fe2O3 needs to be enhanced.

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Sabbar, Huda M., Zulkiflle Leman, Shazarel B. Shamsudin, Suraya Mohd Tahir, Che N. Aiza Jaafar, Mohamed A. Azmah Hanim, Zahari N. Ismsrrubie y Sami Al-Alimi. "AA7075-ZrO2 Nanocomposites Produced by the Consecutive Solid-State Process: A Review of Characterisation and Potential Applications". Metals 11, n.º 5 (15 de mayo de 2021): 805. http://dx.doi.org/10.3390/met11050805.

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Solid-state recycling is a direct conversion method for producing metal chips, whereas the materials are plastically deformed into the final product without melting, offering lower energy consumption and metal waste. This technique was reported for fabricating aluminium-zirconium oxide (Al-ZrO2) composite and it was widely used to avoid metal chips bounding at high temperatures during the extrusion process. Aluminium alloy (AA7075) is known for its high yield strength of more than 500 MPa under optimum ageing conditions. However, AA7075 can be further reinforced by zirconium oxide nanoparticles when needed for high-performance applications. Hot extrusion is used to obtain better mechanical properties of composite materials. The equal channel angular pressing (ECAP), a severe plastic deformation technique, was recently used to produce bulk and light recycled metal chips, such as porosity-free and ultra-fine-grained aluminium nanocomposites (ANCs). Heat treatments (HT) and ECAP post hot extrusion are mostly incorporated to improve tribological and mechanical properties and aluminium nanocomposite bonding efficiency. In this review, ANCs’ fabrication by the hot extrusion technique and the effects of ZrO2 nanoparticle are duly summarised and discussed. Furthermore, this review emphasises the importance of using HT and ECAP techniques to acquire better metal alloy incorporation, such as AA7075-ZrO2. Interestingly, owing to the lightweight properties and superior performance of AA7075-ZrO2, it was reported to be suitable for fabricating many drones’ parts, military equipment, and some other promising applications.

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Biswas, Bhabatosh, Biplab Hazra, Nillohit Mukherjee y Arijit Sinha. "Nanomechanical behaviour of ZrO2 dispersed sisal-based polymeric composites". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 235, n.º 8 (27 de mayo de 2021): 1841–49. http://dx.doi.org/10.1177/14644207211016015.

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Alkali-treated sisal fibre-incorporated silanized ZrO2 dispersed unsaturated polyester composites were fabricated with a filler loading of 5, 15, 25, 35, 45 wt%, respectively. The mechanical characterization of the composites was suitably executed at the sub-micron scale using the nanoindentation technique. Various mechanical properties were derived from the standard nanoindentation measurements namely, nanohardness, reduced modulus, recovery index, residual depth, wear rate and indentation creep, respectively. A marked improvement in the mechanical properties of the unsaturated polyester matrix due to the incorporation of the fillers (sisal and/or ZrO2) was observed through indentation-derived parameters namely, nanohardness (∼186%), reduced modulus (∼175%), recovery index (∼62%), wear rate (∼63%) and indentation creep (∼33%), respectively. A simulated dynamic mechanical analysis was performed using the sinus mode of the nanoindentation technique. A similar enhancement in the dynamic mechanical properties of the matrix was further observed through dynamic mechanical analysis as storage modulus (∼71%), loss modulus (∼60%), loss factor (∼150%) and specific damping coefficient (∼200%), respectively.

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