The Experts below are selected from a list of 6153 Experts worldwide ranked by ideXlab platform
Huanting Wang - One of the best experts on this subject based on the ideXlab platform.
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Poly(furfuryl alcohol)-assisted pyrolysis synthesis of Ceramic Nanoparticles for solid oxide fuel cells
Materials Research Bulletin, 2012Co-Authors: Dehua Dong, Jianfeng Yao, Huanting WangAbstract:Abstract A pyrolysis synthesis method was developed to prepare Ceramic Nanoparticles for the fabrication of solid oxide fuel cells. Furfuryl alcohol was used as a polymerizable solvent to dissolve metal nitrates and then polymerized into poly(furfuryl alcohol) (PFA). During the pyrolysis at 600 °C, a mixture of nitrates/PFA was converted into Ceramic Nanoparticles/carbon networks nanocomposite, and the carbon networks act as a barrier to prevent the aggregation of newly formed Nanoparticles during particle crystallization. Dispersible Nanoparticles with particle sizes ranging from 40 nm to 200 nm were obtained after burning off carbon networks in air. As an example, Ce 0.8 Sm 0.2 O 1.9 Nanoparticles were synthesized to prepare solid oxide fuel cells, and the fuel cells achieved maximum power densities of 444.5, 625.5 and 684 mW cm −2 at 500 °C, 550 °C and 600 °C, respectively. Our study shows that the pyrolysis synthesis method described here is promising for the effective synthesis of high quality Ceramic Nanoparticles.
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Combustion synthesis of Ceramic Nanoparticles for solid oxide fuel cells
Asia-Pacific Journal of Chemical Engineering, 2010Co-Authors: Dehua Dong, Huanting WangAbstract:Two combustion synthesis methods involving the use of polyacrylamide hydrogel and humic acids (HAs) as fuels were developed to synthesize Ceramic Nanoparticles for fabrication of solid oxide fuel cells (SOFCs). Using polyacrylamide hydrogel as fuel, highly crystalline NiO/Ce(0.8)Sm(0.2)O(1.9) (SDC) and SDC Nanoparticles were synthesized to make a modified layer and subsequent dense electrolyte film on the anode support. HA was used as complexible fuel to synthesize Sm(0.5)Sr(0.5)CoO(3) Nanoparticles for preparing the SOFC porous cathode. The single SOFCs made from these Nanoparticles exhibited a maximum power density of 740 mW cm(-2) at 650 degrees C operated with H(2)/air as fuel/oxidant, suggesting the synthesized Nanoparticles are of high quality as SOFC materials. (C) 2010 Curtin University of Technology and John Wiley & Sons, Ltd.
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Humic Acids as a Complexible Fuel for Combustion Synthesis of Ceramic Nanoparticles
Journal of the American Ceramic Society, 2007Co-Authors: Wei Zhu, Jianfeng Yao, Huanting Wang, Fei Zhao, Xinyi Zhang, Changrong XiaAbstract:A novel combustion synthesis of Ceramic powder has been developed using humic acids (HA) as the complexible fuel. Synthesis of mixed oxide (Sm0.5Sr0.5CoO3 (SSC)) Ceramic Nanoparticles was chosen to illustrate synthetic procedures. SSC Nanoparticles obtained by combustion of HA-metal complexes exhibited particle sizes of 50-100 nm, and good electrochemical performance as the cathode material for solid oxide fuel cells. The process of using renewable HA as the complexible fuel is of low cost, and thus suitable for sustainable production of various oxide Ceramic materials
Rachman Chaim - One of the best experts on this subject based on the ideXlab platform.
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On the kinetics of liquid-assisted densification during flash sintering of Ceramic Nanoparticles
Scripta Materialia, 2019Co-Authors: Rachman ChaimAbstract:Abstract We analyzed the liquid-assisted densification kinetics of Ceramic Nanoparticles during flash sintering in terms of wetting and melt spreading, from the nanoparticle contacts, affected by the local electric field and capillary forces. Homologous wetting and spreading of the melt from the particle contacts reveal wetting velocities of ~0.3 10−6 m s−1 and ~1 m s−1 induced by the electric field and the capillary forces, respectively. The ultrafast densification kinetics by particle rearrangement is consistent with the enhanced diffusion and calculated wetting velocities. Epitaxial solidification of the melt after particle rearrangement is energetically favorable, and its tendency depends on the melt viscosity.
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on thermal runaway and local endothermic exothermic reactions during flash sintering of Ceramic Nanoparticles
Journal of Materials Science, 2018Co-Authors: Rachman Chaim, Claude EstournesAbstract:Numerical analysis of the heat balance at the flash event during flash sintering of granular Ceramic Nanoparticles was performed assuming continuum solid state as well as simultaneous surface softening/liquid formation and current percolation through the nanoparticle contacts. Assuming inter-particle radiations in the specimen volume, the electric Joule heat generated at the nanoparticle contacts partially lost by radiation from the specimen external surfaces. Considering the thermal effects due to rapid heating rate and free-molecular heat conduction regime, high-temperature gradients between the nanoparticle surfaces and the surrounding gas were developed. The attractive capillary forces, induced by the particle surface softening/liquid at the percolation threshold, lead to rapid rearrangement and densification of the Nanoparticles. The excess Joule heat, already at the flash event, suffices the excess internal heat that is necessary for partial or full melting. Particle surface softening/liquid formation is a transient process, hence followed by crystallization immediate after the nanoparticle rearrangement. Thermal runaway is associated with local surface softening/melting and its solidification.
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On thermal runaway and local endothermic/exothermic reactions during flash sintering of Ceramic Nanoparticles
Journal of Materials Science, 2018Co-Authors: Rachman Chaim, Claude EstournesAbstract:Numerical analysis of the heat balance at the flash event during flash sintering of granular Ceramic Nanoparticles was performed assuming continuum solid state as well as simultaneous surface softening/liquid formation and current percolation through the nanoparticle contacts. Assuming inter-particle radiations in the specimen volume, the electric Joule heat generated at the nanoparticle contacts partially lost by radiation from the specimen external surfaces. Considering the thermal effects due to rapid heating rate and free-molecular heat conduction regime, high-temperature gradients between the nanoparticle surfaces and the surrounding gas were developed. The attractive capillary forces, induced by the particle surface softening/liquid at the percolation threshold, lead to rapid rearrangement and densification of the Nanoparticles. The excess Joule heat, already at the flash event, suffices the excess internal heat that is necessary for partial or full melting. Particle surface softening/liquid formation is a transient process, hence followed by crystallization immediate after the nanoparticle rearrangement. Thermal runaway is associated with local surface softening/melting and its solidification.
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Electric field effects during spark plasma sintering of Ceramic Nanoparticles
Journal of Materials Science, 2013Co-Authors: Rachman ChaimAbstract:The effects of the applied electric field during the spark plasma sintering of Ceramic Nanoparticles were examined at various stages of the process. It was assumed that local intensification of the electric field arises due to the nanoscale structural features. Enhanced surface conductivity is expected in the Nanoparticles during the heating, which otherwise are electrically non-conducting as a bulk. Percolation of the electric current at "optimal" electrical conductivity is obtained by fractal dimension. The defective nanoparticle surfaces experience charging-discharge cycles which lead to local breakdown and to plasma formation due to the ionized surface molecules. High local temperatures which evolved in a nonlinear fashion at the particle surfaces lead to enhanced sintering and densification kinetics, consistent with the flash sintering phenomenon. The contribution of the pondermotive force to the enhancement of the diffusion kinetics is discussed. Temperature windows for enhanced densification kinetics via plastic deformation or plasma-assisted processes are estimated for MgO, Al2O3, and YAG.
Saeed Shakhesi - One of the best experts on this subject based on the ideXlab platform.
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Preparation and characterization of nanoscale ZrB_2/carbon–resol composite for protection against high-temperature corrosion
Journal of Thermal Analysis and Calorimetry, 2015Co-Authors: Zahra Amirsardari, Rouhollah Mehdinavaz Aghdam, Masoud Salavati-niasari, Saeed ShakhesiAbstract:An advanced method combines using ZrB_2 Ceramic Nanoparticles as filler within the carbon fiber–resol type-phenolic resin (C/Ph) composite for the superior ablation properties of thermal protection systems. The oxy-acetylene torch test suggested that ZrB_2 Nanoparticles could effectively protect C/Ph composite from ablation at 2,000 °C for 160 s. The ablation rate decreased when C/Ph composite was filled with 7 mass% of ZrB_2 Ceramic Nanoparticles (Zr/C/Ph) over unfilled composite. In comparison to neat C/Ph composite, the introduction of nanosized ZrB_2 particles embedded in the matrix significantly improved the ablative properties in terms of mass loss and erosion rate. During oxidation and ablation, the interface between carbon matrix and fiber is effectively protected by ZrO_2 due to the reaction of ZrB_2 with the oxygen, and the resultant zirconium oxide may form a film to resist the oxygen at high temperature.
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preparation and characterization of nanoscale zrb2 carbon resol composite for protection against high temperature corrosion
Journal of Thermal Analysis and Calorimetry, 2015Co-Authors: Zahra Amirsardari, Rouhollah Mehdinavaz Aghdam, Masoud Salavatiniasari, Saeed ShakhesiAbstract:An advanced method combines using ZrB2 Ceramic Nanoparticles as filler within the carbon fiber–resol type-phenolic resin (C/Ph) composite for the superior ablation properties of thermal protection systems. The oxy-acetylene torch test suggested that ZrB2 Nanoparticles could effectively protect C/Ph composite from ablation at 2,000 °C for 160 s. The ablation rate decreased when C/Ph composite was filled with 7 mass% of ZrB2 Ceramic Nanoparticles (Zr/C/Ph) over unfilled composite. In comparison to neat C/Ph composite, the introduction of nanosized ZrB2 particles embedded in the matrix significantly improved the ablative properties in terms of mass loss and erosion rate. During oxidation and ablation, the interface between carbon matrix and fiber is effectively protected by ZrO2 due to the reaction of ZrB2 with the oxygen, and the resultant zirconium oxide may form a film to resist the oxygen at high temperature.
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Preparation and characterization of nanoscale ZrB2/carbon–resol composite for protection against high-temperature corrosion
Journal of Thermal Analysis and Calorimetry, 2015Co-Authors: Zahra Amirsardari, Rouhollah Mehdinavaz Aghdam, Masoud Salavati-niasari, Saeed ShakhesiAbstract:An advanced method combines using ZrB2 Ceramic Nanoparticles as filler within the carbon fiber–resol type-phenolic resin (C/Ph) composite for the superior ablation properties of thermal protection systems. The oxy-acetylene torch test suggested that ZrB2 Nanoparticles could effectively protect C/Ph composite from ablation at 2,000 °C for 160 s. The ablation rate decreased when C/Ph composite was filled with 7 mass% of ZrB2 Ceramic Nanoparticles (Zr/C/Ph) over unfilled composite. In comparison to neat C/Ph composite, the introduction of nanosized ZrB2 particles embedded in the matrix significantly improved the ablative properties in terms of mass loss and erosion rate. During oxidation and ablation, the interface between carbon matrix and fiber is effectively protected by ZrO2 due to the reaction of ZrB2 with the oxygen, and the resultant zirconium oxide may form a film to resist the oxygen at high temperature.
Y. Fattahi - One of the best experts on this subject based on the ideXlab platform.
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novel manufacturing process of nanoparticle al composite filler metals of tungsten inert gas welding by accumulative roll bonding
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Mehdi Fattahi, A. R. Dabiri, Shahab Akhavan, Sajjad Amirkhanlou, Noei V Aghaei, Y. FattahiAbstract:Abstract In the present work, accumulative roll bonding (ARB) was used as an effective method for manufacturing nanoparticle/Al composite filler metals of tungsten inert gas (TIG) welding. After welding, the distribution of Ceramic Nanoparticles and mechanical properties of welds were investigated. By applying ARB, Ceramic Nanoparticles were uniformly dispersed in the composite filler metals. Consequently, the welds produced by these filler metals had a uniform dispersion of Ceramic Nanoparticles in their compositions. The test results showed that the yield strength of welds was greatly increased when using the nanoparticle/Al composite filler metals. The improvement in the yield strength was attributed to the coefficient of thermal expansion mismatch and Orowan strengthening mechanisms. Therefore, according to the results presented in this paper, it can be concluded that the nanoparticle/Al composite filler metals can serve as a novel filler metal for TIG welding of aluminum and its alloys.
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Novel manufacturing process of nanoparticle/Al composite filler metals of tungsten inert gas welding by accumulative roll bonding
Materials Science and Engineering A, 2015Co-Authors: Mehdi Fattahi, V. Noei Aghaei, A. R. Dabiri, Shahab Akhavan, Sajjad Amirkhanlou, Y. FattahiAbstract:In the present work, accumulative roll bonding (ARB) was used as an effective method for manufacturing nanoparticle/Al composite filler metals of tungsten inert gas (TIG) welding. After welding, the distribution of Ceramic Nanoparticles and mechanical properties of welds were investigated. By applying ARB, Ceramic Nanoparticles were uniformly dispersed in the composite filler metals. Consequently, the welds produced by these filler metals had a uniform dispersion of Ceramic Nanoparticles in their compositions. The test results showed that the yield strength of welds was greatly increased when using the nanoparticle/Al composite filler metals. The improvement in the yield strength was attributed to the coefficient of thermal expansion mismatch and Orowan strengthening mechanisms. Therefore, according to the results presented in this paper, it can be concluded that the nanoparticle/Al composite filler metals can serve as a novel filler metal for TIG welding of aluminum and its alloys.
Xue Wang - One of the best experts on this subject based on the ideXlab platform.
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rechargeable solid state lithium metal batteries with vertically aligned Ceramic nanoparticle polymer composite electrolyte
Nano Energy, 2019Co-Authors: Xue Wang, Haowei Zhai, Boyu Qie, Qian Cheng, James Borovilas, Changmin Shi, Tianwei Jin, Xiangbiao Liao, Martin DontignyAbstract:Abstract Composite solid electrolytes are attractive as they combine the high ionic conductivity of Ceramic Nanoparticles and the excellent mechanical properties of polymer electrolytes. Vertically aligned Ceramic Nanoparticles in the polymer matrix represent an ideal structure for maximizing ionic conductivity of composite electrolytes. The ice-templating method was used to build rechargeable solid-state lithium metal batteries with a vertically aligned Ceramic/polymer composite electrolyte composed of high ionic conductivity Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and polyethylene oxide (PEO) polymer. The vertical LAGP walls provide continuous channels for fast ionic transport, while the PEO matrix renders the composite electrolyte flexible. This solid-state composite electrolyte has a conductivity of 1.67 × 10−4 S cm−1 at room temperature and 1.11 × 10−3 S cm−1 at 60 °C. LiFePO4 (LFP)/vertically aligned LAGP- PEO/Li full cells were also developed with a high capacity retention of 93.3% after 300 cycles. This study demonstrates the successful application of vertically aligned Ceramic/polymer composite electrolytes for solid-state batteries with high performance.
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Rechargeable solid-state lithium metal batteries with vertically aligned Ceramic nanoparticle/polymer composite electrolyte
Nano Energy, 2019Co-Authors: Xue Wang, Haowei Zhai, Boyu Qie, Qian Cheng, James Borovilas, Changmin Shi, Tianwei Jin, Xiangbiao LiaoAbstract:Abstract Composite solid electrolytes are attractive as they combine the high ionic conductivity of Ceramic Nanoparticles and the excellent mechanical properties of polymer electrolytes. Vertically aligned Ceramic Nanoparticles in the polymer matrix represent an ideal structure for maximizing ionic conductivity of composite electrolytes. The ice-templating method was used to build rechargeable solid-state lithium metal batteries with a vertically aligned Ceramic/polymer composite electrolyte composed of high ionic conductivity Li1.5Al0.5Ge1.5(PO4)3 (LAGP) and polyethylene oxide (PEO) polymer. The vertical LAGP walls provide continuous channels for fast ionic transport, while the PEO matrix renders the composite electrolyte flexible. This solid-state composite electrolyte has a conductivity of 1.67 × 10−4 S cm−1 at room temperature and 1.11 × 10−3 S cm−1 at 60 °C. LiFePO4 (LFP)/vertically aligned LAGP- PEO/Li full cells were also developed with a high capacity retention of 93.3% after 300 cycles. This study demonstrates the successful application of vertically aligned Ceramic/polymer composite electrolytes for solid-state batteries with high performance.