Porous copper was prepared successfully by physical vacuum dealloying method using the CuZn alloy pre- cursors （Cu30Zn70, Cu40Zn60 and Cu50Zn50 alloys）. The micron porous copper showed a three-dimensional continuous...Porous copper was prepared successfully by physical vacuum dealloying method using the CuZn alloy pre- cursors （Cu30Zn70, Cu40Zn60 and Cu50Zn50 alloys）. The micron porous copper showed a three-dimensional continuous porous structure with 1-5 μm pore size. With the increase of the Zn content in the CuZn alloy, the pore structure of the porous copper was more uniform and ordered. Temperature was the key factor for physical dealloying, and the optimized temperature was 500 ℃ for the CuZn alloy. The pores would fuse and disappear when the temperature was over 500 ℃. Physical vacuum dealloying was an effective preparation method for porous copper, which can be used to prepare other porous metals based on the sublimation and the Kirkendall effect.展开更多
The purpose of this paper is to investigate heat dissipation performance of porous copper with long cylindrical pores fabricated by a unidirectional solidification method. Three samples with porosity of 29.87%, 34.47%...The purpose of this paper is to investigate heat dissipation performance of porous copper with long cylindrical pores fabricated by a unidirectional solidification method. Three samples with porosity of 29.87%, 34.47% and 50.98% were chosen and cut into size of 60 mm （length） × 26 mm （width） × 2 mm （thickness） along the vertical direction of pore axis. Their heat dissipation performance was evaluated by a nonsteady method in air and compared to those of not only bulk copper but also bored coppers with porosity of 30.61% and 32.20%. It is found that the porous copper dissipated heat faster by a forced air convection than that by natural convection from 80 ℃ to room temperature and both porosity and pore size play an important role in the performance for the porous copper. Furthermore, the heat dissipation rate is higher when the forced air was circulated along the specimens than that perpendicular to the specimens for the porous copper. It is revealed that porous copper with bigger porosity and a proper pore size possesses a higher heat dissipation rate. It is concluded that the porous copper with elongated cylindrical pores has larger heat dissipation performance than both the bulk copper and the bored copper, which is attributed to its higher specific surface area. Application of the porous copper for heat dissipation is promising.展开更多
The energy absorption characteristics of the lotus-type porous coppers at the strain rate of 10-3 s-1 to N2400 s 1 were systematically investigated. Depending on the relative density and loading rate, the energy absor...The energy absorption characteristics of the lotus-type porous coppers at the strain rate of 10-3 s-1 to N2400 s 1 were systematically investigated. Depending on the relative density and loading rate, the energy absorption capability of the tested samples varied from -20 to -85 MJ m-1, while the energy absorption efficiency fluctuated around N0.6. An energy absorption efficiency curve based approach was proposed for unambiguous identification of the plateau regime, which gave an extension of -0.50 strain range for the presently investigated porous coppers. With detailed observations of cell wall morphologies at various deformation stages, it was suggested that buckling of cell wails was the dominant mechanism mediat- ing the energy absorption in lotus-type porous coppers.展开更多
In line with recent attention on porous metals having low and medium porosities in the range of 20-50%, this paper studies the effect of porosity on the mechanical properties of sintered copper compacts. Experiments w...In line with recent attention on porous metals having low and medium porosities in the range of 20-50%, this paper studies the effect of porosity on the mechanical properties of sintered copper compacts. Experiments were designed to investigate the effect of porosity, applied stress and sliding velocity on the wear rate of copper compacts, leading to the finding that the effects of both porosity and applied stress of the wear test on the wear rate are approximately similar and higher than that of sliding velocity. The investigation concerning the effect of porosity on compressive strength indicated that the stress-strain curve of high-porosity compact exhibited identifiable ultimate strength points, though low-porosity compact showed distinct stages of elastic plastic behavior.展开更多
Copper porous materials have been manufactured by the method of powder metallurgy.Electrolytic copper powders and atomized copper powders are used as matrix material.Methylcellulose and paraffin are used as porogen.Th...Copper porous materials have been manufactured by the method of powder metallurgy.Electrolytic copper powders and atomized copper powders are used as matrix material.Methylcellulose and paraffin are used as porogen.The influence of porogen type and copper powder morphology on the property of copper porous materials is investigated as well.The results show that copper porous materials with paraffin as porogen have lower porosity and permeability compared with materials using methylcellulose as porogen,due to the different pore-forming mechanisms.The pore forming mechanism of methylcellulose is thermal decomposition,while the pore forming mechanism of paraffin is melting–evaporation.The morphology of copper powders affects the contact state between adjacent powders,which further influence the sintering shrinkage.The porous materials using arborescent copper powders as matrix have lower porosity,smaller pore size and lower permeability,compared with materials with atomized copper powders as matrix.展开更多
The current collector is an indispensable component in potassium-ion hybrid capacitors,which not only provides mechanical support to load electrode materials,but also collects and outputs the current generated.Herein,...The current collector is an indispensable component in potassium-ion hybrid capacitors,which not only provides mechanical support to load electrode materials,but also collects and outputs the current generated.Herein,we investigate the effect of three different current collectors on the electrochemical properties of potassium ion capacitors using carbon black anode as a demonstration.Because of better adhesion and lower charge transfer resistance,the specific capacity of half-cells assembled using three-dimensional(3D)porous copper foil(PCu)and copper as current collector is better than that of Al foil,which stabilizes at 138.2 and 132.8 mAh·g^(-1)after 100 cycles at 0.05 A·g^(-1).The potassium-ion capacitor assembled using PCu exhibits an excellent energy/power density of 86.1 Wh·kg^(-1)and 4000 W·kg^(-1),respectively.This work will boost the rational design and provide an effective strategy to improve the performance of potassium-ion capacitors.展开更多
ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmos...ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmosphere. The electrochemical performance investigation suggests that the harvested ZnO–CuO porous hybrid microspheres illustrate much higher specific capacity and better cycling stability than single ZnO counterparts. A reversible capacity of 585 mAh·g^-1 can be acquired for ZnO–CuO porous hybrid microspheres after cycling 500 times at a current density of 200 mA·g^-1. The porous configuration and the incorporation of CuO are responsible for the enhanced lithium storage properties of ZnO–CuO hybrids.展开更多
Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper w...Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper wick （SCLS-SPC） is proposed to meet the requirements of higher device level heat fluxes and the harsh environments in some applications such as hybrid, fuel cell vehicles and aerospace. Fuzzy logic and proportional-integral-derivative （PID） policies are applied to adjust the electronic temperature within a safe working range. To evaluate the thermal control effect, a mathematical model of a 4-node thermal network and pump are established for predicting the dynamics of the SCLS-SPC. Moreover, the transient response of the 4 nodes and vapor mass flowrate under no control, PID and Fuzzy-PID are numerically investigated and discussed in detail.展开更多
The 2D porous copper（Ⅰ） complex with 1,3-dicyanobenzene （DCB）, [Cu（DCB）2]（PF6）（Me2CO） 1, exhibits channels along axis c, in which one molecule acetone and one anion PF6 per formula unit are included respect...The 2D porous copper（Ⅰ） complex with 1,3-dicyanobenzene （DCB）, [Cu（DCB）2]（PF6）（Me2CO） 1, exhibits channels along axis c, in which one molecule acetone and one anion PF6 per formula unit are included respectively. The reversible incorporation of vip acetone and acetonitrile, as well as the anion exchange from PF6^- to BF4^- or CF3SO3^-, was investigated by thermogravimetric （TG） analysis, ^1H NMR spectra and/or infrared absorption spectroscopy. Additionally, the incorporation of benzene and toluene into complex 1 was also discussed. Complex 1 exhibited size selectivity for vip inclusion or anion exchange.展开更多
Moolooite particles with flaky morphology were synthesized by mixing dilute solutions of copper nitrate and sodium oxalate in the presence of citric acid. Solution p H value, citric acid concentration, and stirring we...Moolooite particles with flaky morphology were synthesized by mixing dilute solutions of copper nitrate and sodium oxalate in the presence of citric acid. Solution p H value, citric acid concentration, and stirring were found to have large effect on the shape of the precipitated particles. Under the stirring, the radial area of flaky moolooite particles was enlarged and extended to become a thinner and larger flake. This is ascribed to growth promotion caused by the selective absorption of citric ligands onto a particular crystalline surface of the moolooite particles. Flaky shape of the moolooite particles tended to become spherical and disappeared completely when decomposed under an Ar atmosphere, leading to the formation of large porous aggregated particles composed of many tiny nanosized copper crystals.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 31370976)the National Basic Research Program of China (Grant No. 2012CB619101)
文摘Porous copper was prepared successfully by physical vacuum dealloying method using the CuZn alloy pre- cursors （Cu30Zn70, Cu40Zn60 and Cu50Zn50 alloys）. The micron porous copper showed a three-dimensional continuous porous structure with 1-5 μm pore size. With the increase of the Zn content in the CuZn alloy, the pore structure of the porous copper was more uniform and ordered. Temperature was the key factor for physical dealloying, and the optimized temperature was 500 ℃ for the CuZn alloy. The pores would fuse and disappear when the temperature was over 500 ℃. Physical vacuum dealloying was an effective preparation method for porous copper, which can be used to prepare other porous metals based on the sublimation and the Kirkendall effect.
基金The financial supports of Cooperative Foundation between Industry,Colleges or Scientific Institutes and Relevant Issuesfrom Guangdong Province(00124720225267058)Natural Science of Foundation from Liaoning Province(No.201102222)Science and Technology Project(No.2010AZ2010)from Jiaxing City
文摘The purpose of this paper is to investigate heat dissipation performance of porous copper with long cylindrical pores fabricated by a unidirectional solidification method. Three samples with porosity of 29.87%, 34.47% and 50.98% were chosen and cut into size of 60 mm （length） × 26 mm （width） × 2 mm （thickness） along the vertical direction of pore axis. Their heat dissipation performance was evaluated by a nonsteady method in air and compared to those of not only bulk copper but also bored coppers with porosity of 30.61% and 32.20%. It is found that the porous copper dissipated heat faster by a forced air convection than that by natural convection from 80 ℃ to room temperature and both porosity and pore size play an important role in the performance for the porous copper. Furthermore, the heat dissipation rate is higher when the forced air was circulated along the specimens than that perpendicular to the specimens for the porous copper. It is revealed that porous copper with bigger porosity and a proper pore size possesses a higher heat dissipation rate. It is concluded that the porous copper with elongated cylindrical pores has larger heat dissipation performance than both the bulk copper and the bored copper, which is attributed to its higher specific surface area. Application of the porous copper for heat dissipation is promising.
基金financial support from the National Natural Science Foundation of China (Grant No. 50904004)
文摘The energy absorption characteristics of the lotus-type porous coppers at the strain rate of 10-3 s-1 to N2400 s 1 were systematically investigated. Depending on the relative density and loading rate, the energy absorption capability of the tested samples varied from -20 to -85 MJ m-1, while the energy absorption efficiency fluctuated around N0.6. An energy absorption efficiency curve based approach was proposed for unambiguous identification of the plateau regime, which gave an extension of -0.50 strain range for the presently investigated porous coppers. With detailed observations of cell wall morphologies at various deformation stages, it was suggested that buckling of cell wails was the dominant mechanism mediat- ing the energy absorption in lotus-type porous coppers.
文摘In line with recent attention on porous metals having low and medium porosities in the range of 20-50%, this paper studies the effect of porosity on the mechanical properties of sintered copper compacts. Experiments were designed to investigate the effect of porosity, applied stress and sliding velocity on the wear rate of copper compacts, leading to the finding that the effects of both porosity and applied stress of the wear test on the wear rate are approximately similar and higher than that of sliding velocity. The investigation concerning the effect of porosity on compressive strength indicated that the stress-strain curve of high-porosity compact exhibited identifiable ultimate strength points, though low-porosity compact showed distinct stages of elastic plastic behavior.
基金Project(2015DFR50580)supported by International S&T Cooperation Program of ChinaProject(51505503)supported by the National Natural Science Foundation of China
文摘Copper porous materials have been manufactured by the method of powder metallurgy.Electrolytic copper powders and atomized copper powders are used as matrix material.Methylcellulose and paraffin are used as porogen.The influence of porogen type and copper powder morphology on the property of copper porous materials is investigated as well.The results show that copper porous materials with paraffin as porogen have lower porosity and permeability compared with materials using methylcellulose as porogen,due to the different pore-forming mechanisms.The pore forming mechanism of methylcellulose is thermal decomposition,while the pore forming mechanism of paraffin is melting–evaporation.The morphology of copper powders affects the contact state between adjacent powders,which further influence the sintering shrinkage.The porous materials using arborescent copper powders as matrix have lower porosity,smaller pore size and lower permeability,compared with materials with atomized copper powders as matrix.
基金financially supported by the National Key Research and Development Program of China(No.2017YFE0198100)the National Natural Science Foundation of China(Nos.52072145 and 51802111)+4 种基金the Research Program on Science and Technology from the Education Department of Jilin Province(Nos.JJKH20220439KJ and JJKH20210450KJ)Jilin Talent Development Funding(No.2021Y027)the Funding of Jilin Province Development and Reform Commission(No.2020C026-2)Special Projects of the Central Government in Guidance of Local Science and Technology Development(No.202002017JC)Funding of JLNU Innovation Program for Graduate Education(No.202016)。
文摘The current collector is an indispensable component in potassium-ion hybrid capacitors,which not only provides mechanical support to load electrode materials,but also collects and outputs the current generated.Herein,we investigate the effect of three different current collectors on the electrochemical properties of potassium ion capacitors using carbon black anode as a demonstration.Because of better adhesion and lower charge transfer resistance,the specific capacity of half-cells assembled using three-dimensional(3D)porous copper foil(PCu)and copper as current collector is better than that of Al foil,which stabilizes at 138.2 and 132.8 mAh·g^(-1)after 100 cycles at 0.05 A·g^(-1).The potassium-ion capacitor assembled using PCu exhibits an excellent energy/power density of 86.1 Wh·kg^(-1)and 4000 W·kg^(-1),respectively.This work will boost the rational design and provide an effective strategy to improve the performance of potassium-ion capacitors.
基金financially supported by the National Key Research Program of China(No.2016YFA0202602)the National Natural Science Foundation of China(Nos.51371154 and 51571167)the Natural Science Foundation of Fujian Province of China(No.2017J05087)
文摘ZnO–CuO porous hybrid microspheres were successfully produced through a facile aging process of zinc citrate solid microspheres in copper sulfate solution combined with the subsequent annealing treatment in air atmosphere. The electrochemical performance investigation suggests that the harvested ZnO–CuO porous hybrid microspheres illustrate much higher specific capacity and better cycling stability than single ZnO counterparts. A reversible capacity of 585 mAh·g^-1 can be acquired for ZnO–CuO porous hybrid microspheres after cycling 500 times at a current density of 200 mA·g^-1. The porous configuration and the incorporation of CuO are responsible for the enhanced lithium storage properties of ZnO–CuO hybrids.
文摘Effective thermal control systems are essential for the reliable working of insulated gate bipolar transistors （IGBTs） in many applications. A novel spray cooling loop system with integrated sintered porous copper wick （SCLS-SPC） is proposed to meet the requirements of higher device level heat fluxes and the harsh environments in some applications such as hybrid, fuel cell vehicles and aerospace. Fuzzy logic and proportional-integral-derivative （PID） policies are applied to adjust the electronic temperature within a safe working range. To evaluate the thermal control effect, a mathematical model of a 4-node thermal network and pump are established for predicting the dynamics of the SCLS-SPC. Moreover, the transient response of the 4 nodes and vapor mass flowrate under no control, PID and Fuzzy-PID are numerically investigated and discussed in detail.
文摘The 2D porous copper（Ⅰ） complex with 1,3-dicyanobenzene （DCB）, [Cu（DCB）2]（PF6）（Me2CO） 1, exhibits channels along axis c, in which one molecule acetone and one anion PF6 per formula unit are included respectively. The reversible incorporation of vip acetone and acetonitrile, as well as the anion exchange from PF6^- to BF4^- or CF3SO3^-, was investigated by thermogravimetric （TG） analysis, ^1H NMR spectra and/or infrared absorption spectroscopy. Additionally, the incorporation of benzene and toluene into complex 1 was also discussed. Complex 1 exhibited size selectivity for vip inclusion or anion exchange.
基金financially supported by the Fundamental Research Funds for the Central Universities of China (FRF-BD-15-004A)
文摘Moolooite particles with flaky morphology were synthesized by mixing dilute solutions of copper nitrate and sodium oxalate in the presence of citric acid. Solution p H value, citric acid concentration, and stirring were found to have large effect on the shape of the precipitated particles. Under the stirring, the radial area of flaky moolooite particles was enlarged and extended to become a thinner and larger flake. This is ascribed to growth promotion caused by the selective absorption of citric ligands onto a particular crystalline surface of the moolooite particles. Flaky shape of the moolooite particles tended to become spherical and disappeared completely when decomposed under an Ar atmosphere, leading to the formation of large porous aggregated particles composed of many tiny nanosized copper crystals.
