Nanosized SnO2 particles which are uniformly distributed are prepared through sol-gel process using anhydrous SnCl4 and iso-PrOH. By comgaring the results of XRD patterns with the JCPDS standard card of SnO2 and ahaly...Nanosized SnO2 particles which are uniformly distributed are prepared through sol-gel process using anhydrous SnCl4 and iso-PrOH. By comgaring the results of XRD patterns with the JCPDS standard card of SnO2 and ahalysing the TEM images of the product, we can prove that we got the narrow distributed SnO2 particles. The mean diameter of the particles is about 20 nm even sintered at 700℃ for 2 hours.展开更多
A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDO...A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.展开更多
The capture,regeneration,and conversion of CO_(2) from ambient air and flue gas streams are critical aspects of mitigating global warming.Solid sorbents for CO_(2) absorption are very promising as they have high mass ...The capture,regeneration,and conversion of CO_(2) from ambient air and flue gas streams are critical aspects of mitigating global warming.Solid sorbents for CO_(2) absorption are very promising as they have high mass transfer areas without energy input and reduce emissions and minimize corrosion as compared to liquid sorbents.However,precisely tunable solid CO_(2) sorbents are difficult to produce.Here,we demonstrate the high-throughput production of hydrogel-based CO_(2)-absorbing particles via liquid jetting.By wrapping a liquid jet consisting of an aqueous solution of cross-linkable branched polyethylenimine(PEI)with a layer of suspension containing hydrophobic silica nanoparticles,monodisperse droplets with a silica nanoparticle coating layer was formed in the air.A stable Pickering emulsion containing PEI droplets was obtained after these ejected droplets were collected in a heated oil bath.The droplets turn into mm-sized particles after thermal curing in the bath.The diameter,PEI content,and silica content of the particles were systematically varied,and their CO_(2) absorption was measured as a function of time.Steam regeneration of the particles enabled cyclic testing,revealing a CO_(2) absorption capacity of 6.5±0.5 mol kg^(−1)solid PEI in pure CO_(2) environments and 0.7±0.3 mol kg^(−1)solid PEI for direct air capture.Several thousands of particles were produced per second at a rate of around 0.5 kg per hour,with a single nozzle.This process can be further scaled by parallelization.The complete toolbox for the design,fabrication,testing,and regeneration of functional hydrogel particles provides a powerful route toward novel solid sorbents for regenerative CO_(2) capture.展开更多
SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surfa...SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surface chemistry of these nano particles were characterized by transmission electron microscope,X-ray diffractometer and X-ray photoelectron spectroscope respectively.It was observed that Pd-doping had little effect on the grain sizes of the obtained SnO2 nano particles during the hydrothermal route.During thermal annealing,Pd-doping could restrain the growth of grain sizes below 500℃ while the grain growth was promoted when the temperature increased to above 700℃.XPS results revealed that Pd existed in three chemical states in the as-synthesized sample as Pd^0,Pd^2＋ and Pd^4＋,respectively.Pd^4＋ was the main state which was responsible for improving the gas-sensing property.The optimal Pd-doping concentration for better gas-sensing property and thermal stability was 2.0%-2.5% （mole fraction）.展开更多
To clarify the effect of SnO2 particle size on the arc erosion behavior of AgSnO2 contact material, Ag?4%SnO2 (mass fraction) contact materials with different sizes of SnO2 particles were fabricated by powder metallur...To clarify the effect of SnO2 particle size on the arc erosion behavior of AgSnO2 contact material, Ag?4%SnO2 (mass fraction) contact materials with different sizes of SnO2 particles were fabricated by powder metallurgy. The microstructure of Ag?4%SnO2 contact materials was characterized, and the relative density, hardness and electrical conductivity were measured. The arc erosion of Ag?4%SnO2 contact materials was tested, the arc duration and mass loss before and after arc erosion were determined, the surface morphologies and compositions of Ag?4%SnO2 contact materials after arc erosion were characterized, and the arc erosion mechanism of AgSnO2 contact materials was discussed. The results show that fine SnO2 particle is beneficial for the improvement of the relative density and hardness, but decreases the electrical conductivity. With the decrease of SnO2 particle size, Ag?4%SnO2contact material presents shorter arc duration, less mass loss, larger erosion area and shallower arc erosion pits.展开更多
文摘Nanosized SnO2 particles which are uniformly distributed are prepared through sol-gel process using anhydrous SnCl4 and iso-PrOH. By comgaring the results of XRD patterns with the JCPDS standard card of SnO2 and ahalysing the TEM images of the product, we can prove that we got the narrow distributed SnO2 particles. The mean diameter of the particles is about 20 nm even sintered at 700℃ for 2 hours.
基金the National Research Foundation of Korea(Nos.2018R1A5A7023490 and 2022R1A2C1003003)。
文摘A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.
基金supported by the European Regional Development Fund(CONTROL,EFRO#00943).
文摘The capture,regeneration,and conversion of CO_(2) from ambient air and flue gas streams are critical aspects of mitigating global warming.Solid sorbents for CO_(2) absorption are very promising as they have high mass transfer areas without energy input and reduce emissions and minimize corrosion as compared to liquid sorbents.However,precisely tunable solid CO_(2) sorbents are difficult to produce.Here,we demonstrate the high-throughput production of hydrogel-based CO_(2)-absorbing particles via liquid jetting.By wrapping a liquid jet consisting of an aqueous solution of cross-linkable branched polyethylenimine(PEI)with a layer of suspension containing hydrophobic silica nanoparticles,monodisperse droplets with a silica nanoparticle coating layer was formed in the air.A stable Pickering emulsion containing PEI droplets was obtained after these ejected droplets were collected in a heated oil bath.The droplets turn into mm-sized particles after thermal curing in the bath.The diameter,PEI content,and silica content of the particles were systematically varied,and their CO_(2) absorption was measured as a function of time.Steam regeneration of the particles enabled cyclic testing,revealing a CO_(2) absorption capacity of 6.5±0.5 mol kg^(−1)solid PEI in pure CO_(2) environments and 0.7±0.3 mol kg^(−1)solid PEI for direct air capture.Several thousands of particles were produced per second at a rate of around 0.5 kg per hour,with a single nozzle.This process can be further scaled by parallelization.The complete toolbox for the design,fabrication,testing,and regeneration of functional hydrogel particles provides a powerful route toward novel solid sorbents for regenerative CO_(2) capture.
基金Projects(60806032,20975107) supported by the National Natural Science Foundation of ChinaProject(2009R10064) supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of Education Ministry,China+2 种基金 Project(2009R10064) supported by "Qianjiang Talent Program"Projects(2009A610058,2009A610030) supported by the Ningbo Natural Science Foundation,ChinaProject supported by K.C.WONG Magna Fund in Ningbo University,China
文摘SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surface chemistry of these nano particles were characterized by transmission electron microscope,X-ray diffractometer and X-ray photoelectron spectroscope respectively.It was observed that Pd-doping had little effect on the grain sizes of the obtained SnO2 nano particles during the hydrothermal route.During thermal annealing,Pd-doping could restrain the growth of grain sizes below 500℃ while the grain growth was promoted when the temperature increased to above 700℃.XPS results revealed that Pd existed in three chemical states in the as-synthesized sample as Pd^0,Pd^2＋ and Pd^4＋,respectively.Pd^4＋ was the main state which was responsible for improving the gas-sensing property.The optimal Pd-doping concentration for better gas-sensing property and thermal stability was 2.0%-2.5% （mole fraction）.
基金Project(51274163)supported by the National Natural Science Foundation of ChinaProject(13JS076)supported by the Key Laboratory Research Program of Shaanxi Province,China+1 种基金Project(2012KCT-25)supported by the Pivot Innovation Team of Shaanxi Electrical Materials and Infiltration Technique,ChinaProject(2011HBSZS009)supported by the Special Foundation of Key Disciplines,China
文摘To clarify the effect of SnO2 particle size on the arc erosion behavior of AgSnO2 contact material, Ag?4%SnO2 (mass fraction) contact materials with different sizes of SnO2 particles were fabricated by powder metallurgy. The microstructure of Ag?4%SnO2 contact materials was characterized, and the relative density, hardness and electrical conductivity were measured. The arc erosion of Ag?4%SnO2 contact materials was tested, the arc duration and mass loss before and after arc erosion were determined, the surface morphologies and compositions of Ag?4%SnO2 contact materials after arc erosion were characterized, and the arc erosion mechanism of AgSnO2 contact materials was discussed. The results show that fine SnO2 particle is beneficial for the improvement of the relative density and hardness, but decreases the electrical conductivity. With the decrease of SnO2 particle size, Ag?4%SnO2contact material presents shorter arc duration, less mass loss, larger erosion area and shallower arc erosion pits.
