The development trend of miniaturization, chipization, integration, and intelligence of new energetic devices has put forward higher requirements for primary explosives, and the toxicity of lead-containing initiating ...The development trend of miniaturization, chipization, integration, and intelligence of new energetic devices has put forward higher requirements for primary explosives, and the toxicity of lead-containing initiating explosives has also caused increasing concerns. Nano copper azide, due to its green and high-energy characteristics, has attracted increasing interest from researchers in recent years. The research progress of Nano copper azide energetic materials is summarized from the design and preparation of composite energetic materials, and the analysis of sensitivity changes. On this basis, the key points to realize its application prospects are discussed: Develop the preparation method of carbon material modification and the combination of processing and forming to prepare new composite materials to make up for their overly sensitive defects, while giving full play to their advantages of high energy density. By comparing the existing research progress of Nano copper azide, we can understand its performance parameters more systematically, and guide the further application of Nano copper azide. .展开更多
In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and mat...In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries （LAGBs）. The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.展开更多
The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support,...The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.展开更多
Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common meth...Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common method. Nano-copper was prepared by reduction in liquid phase. The different project and routine practice for preparing nano-copper were researched. The dispersion problem of nano-copper was investigated by surface treatment and high dispersion. The particles dimension, the dispersion stability and the purity of nano-copper were characterized by TEM and XRD. The conclusion indicates that the methods of the preparation and dispersion can obtain 20nm copper additive with good dispersion property in lubrication oil.展开更多
A simple, multi component, one-pot method has been reported for the synthesis of poly substituted imidazoles in presence of magnetically separable and recyclable spinel nano copper ferrite as heterogeneous catalyst by...A simple, multi component, one-pot method has been reported for the synthesis of poly substituted imidazoles in presence of magnetically separable and recyclable spinel nano copper ferrite as heterogeneous catalyst by the cyclo-condensation of benzil, aromatic aldehyde, ammonium acetate and substituted amines under ultrasonic irradiation. This method of preparation has many advantages compared to those methods which are previously reported in the literature. This methodology offers simple experimental procedure, milder reaction conditions and environmentally benign approach.展开更多
Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were...Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were as follows： the concentration of CuSO4 solution was 0.1 mol·L^-1,NaOH solution 4 mol·L^-1,the dropping rate of the NaOH solution 50 mL·min^-1,the reaction temperature 20℃the pH value of the reaction terminal 13,and the stirring rate 1200 r·min^-1. The chain nano-CuO grains were obtained through the microwave radiation of the Cu（OH）2 nano-fibers.展开更多
Copper nano-particles were prepared by 100 kGy room temperature γ-ray irradiation of CuSO4 aqueous solution added with surfactant and inactive agent.Effects of the surfactants and pH value on particle size and morpho...Copper nano-particles were prepared by 100 kGy room temperature γ-ray irradiation of CuSO4 aqueous solution added with surfactant and inactive agent.Effects of the surfactants and pH value on particle size and morphology of the Cu powder,and the storage stability,were investigated.Structure,morphology,particle size and melting point of the copper nano-particles were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),laser particle size analyzer and differential scanning calorimetry(DSC),respectively.The results show that the Cu nano-particles prepared with PCM as surfactant and N,N-bis-hydroxyethyl dodecyl amide as inactive agent,in pH=4.0-6.5 of the aqueous solution,can be stored in air for 140 days.展开更多
In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different de...In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.展开更多
For the preparation of copper nanoparticles several methods, i.e., thermal reduction, mechanical attrition, chemical reduction metal vapour synthesis, radiation methods, laser ablation and micro emulsion techniques we...For the preparation of copper nanoparticles several methods, i.e., thermal reduction, mechanical attrition, chemical reduction metal vapour synthesis, radiation methods, laser ablation and micro emulsion techniques were developed in the past. Electrolytic deposition is one of the most suitable, simplest and low cost methods which are used for wide range of materials. In the present investigations, efforts were put to produce copper nano powder using electrolytic technique. It could be possible to obtain near nano copper powder of 258 nm size using high cathode current density of 1100 A/m2 in sulphate bath. The specific surface area and shape of the particles were found to be 23.2 m2/g and irregular, respectively.展开更多
Electrochemical-nitrate-reduction-reaction(eNitRR)synthesis of ammonia is an effective way to treat ni-trate wastewater and alleviate the pressure of the Haber-Bosch ammonia production industry.How to develop effectiv...Electrochemical-nitrate-reduction-reaction(eNitRR)synthesis of ammonia is an effective way to treat ni-trate wastewater and alleviate the pressure of the Haber-Bosch ammonia production industry.How to develop effective catalysts to electrochemically reduce nitrate to ammonia and purify sewage under com-plex environmental conditions is the focus of current research.Herein,the dopamine polymerization pro-cess and the[(C_(12)H_(8)N_(2))_(2)Cu]^(2+)complex embedding process were run simultaneously in time and space,and ultrafine Cu nanoparticles(Cu/CN)were effectively loaded on nitrogen-doped carbon after heat treat-ment.Using Cu/CN as the catalyst,the ammonia yield rate and Faradaic efficiency of the electrochemical conversion of NO_(3)^(-)to NH_(3)are highly 8984.0μg h^(−1)mg cat.^(−1)and 95.6%,respectively.Even in the face of complex water environments,such as neutral media,acidic media,coexisting ions,and actual nitrate wastewater,nitrate wastewater can be effectively purified to form high value-added ammonia.The strat-egy of simultaneous embedding increases the exposure rate of Cu sites,and the support of CN is also beneficial to reduce the energy barrier of ^(∗)NO_(3)activation.This study rationally designed catalysts that are beneficial to eNitRR,and considered the situation faced by practical applications during the research stage,reducing the performance gap between laboratory exploration and industrial applications.展开更多
文摘The development trend of miniaturization, chipization, integration, and intelligence of new energetic devices has put forward higher requirements for primary explosives, and the toxicity of lead-containing initiating explosives has also caused increasing concerns. Nano copper azide, due to its green and high-energy characteristics, has attracted increasing interest from researchers in recent years. The research progress of Nano copper azide energetic materials is summarized from the design and preparation of composite energetic materials, and the analysis of sensitivity changes. On this basis, the key points to realize its application prospects are discussed: Develop the preparation method of carbon material modification and the combination of processing and forming to prepare new composite materials to make up for their overly sensitive defects, while giving full play to their advantages of high energy density. By comparing the existing research progress of Nano copper azide, we can understand its performance parameters more systematically, and guide the further application of Nano copper azide. .
基金Project(50975095)supported by the National Natural Science Foundation of ChinaProject(2012ZM0048)supported by the Fundamental Research Funds for the Central Universities,China
文摘In order to investigate a gradient nano/micro-structured surface layer on pure copper produced by severe plasticity roller burnishing （SPRB） and grain refinement mechanism, the microstructure characteristics and material properties of sample at various depths from the topmost surface were investigated by SEM, TEM, XRD, OM etc. The experimental results show that the gradient nano/micro-structure was introduced into the surface layer of over 100μm in thickness. The remarkable increase in hardness near the topmost surface was mainly attributed to the reduced grain size. The equiaxed nano-sized grains were in random orientation and the most of their boundaries were low-angle grain boundaries （LAGBs）. The coarse grains are refined into the few micro-sized grains by dislocation activities;deformation twinning was found to be the primary form for the formation of submicron grains;the formation of nanostructure was dominated by dislocation activities accompanied with rotation of grains in local region.
文摘The nano ZrO2-supported copper-based catalysts for methane combustion were investigated by means of N2 adsorption, TEM, XRD, H2-TPR techniques and the test of methane oxidation. Two kinds of ZrO2 were used as support, one （ZrO2-1） was obtained from the commercial ZrO2 and the other （ZrO2-2） was issued from the thermal decomposition of zirconium nitrate. It was found that the CuO/ZrO2-2 catalyst was more active than CuO/ZrO2-1. N2 adsorption, H2-TPR and XRD measurements showed that larger surface area, better reduction property, presence of tetragonal ZrO2 and higher dispersion of active component for CuO/ZrO2-2 than that of CuO/ZrO2-1. These factors could be the dominating reasons for its higher activity for methane combustion.
文摘Nano-copper used as lubrication oil additive has good tribological property and active self-repairing effect for friction pairs. The reduction in liquid phase for preparing nano-additive is one of the most common method. Nano-copper was prepared by reduction in liquid phase. The different project and routine practice for preparing nano-copper were researched. The dispersion problem of nano-copper was investigated by surface treatment and high dispersion. The particles dimension, the dispersion stability and the purity of nano-copper were characterized by TEM and XRD. The conclusion indicates that the methods of the preparation and dispersion can obtain 20nm copper additive with good dispersion property in lubrication oil.
文摘A simple, multi component, one-pot method has been reported for the synthesis of poly substituted imidazoles in presence of magnetically separable and recyclable spinel nano copper ferrite as heterogeneous catalyst by the cyclo-condensation of benzil, aromatic aldehyde, ammonium acetate and substituted amines under ultrasonic irradiation. This method of preparation has many advantages compared to those methods which are previously reported in the literature. This methodology offers simple experimental procedure, milder reaction conditions and environmentally benign approach.
文摘Cu（OH）2 nano-fibers were prepared by chemical precipitation with CuSO4·5H2O and NaOH as raw materials. The Cu（OH）2 nano-fibers have a diameter of 10-30 nm and a length of 1-6 μm. The reaction conditions were as follows： the concentration of CuSO4 solution was 0.1 mol·L^-1,NaOH solution 4 mol·L^-1,the dropping rate of the NaOH solution 50 mL·min^-1,the reaction temperature 20℃the pH value of the reaction terminal 13,and the stirring rate 1200 r·min^-1. The chain nano-CuO grains were obtained through the microwave radiation of the Cu（OH）2 nano-fibers.
文摘Copper nano-particles were prepared by 100 kGy room temperature γ-ray irradiation of CuSO4 aqueous solution added with surfactant and inactive agent.Effects of the surfactants and pH value on particle size and morphology of the Cu powder,and the storage stability,were investigated.Structure,morphology,particle size and melting point of the copper nano-particles were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),laser particle size analyzer and differential scanning calorimetry(DSC),respectively.The results show that the Cu nano-particles prepared with PCM as surfactant and N,N-bis-hydroxyethyl dodecyl amide as inactive agent,in pH=4.0-6.5 of the aqueous solution,can be stored in air for 140 days.
基金supported by the National Natural Science Foundation of China(Grant Nos.51472250,U1637204,and 51775537)
文摘In order to clarify the influence of methane concentration and deposition time on self-organized nano-multilayers,three serial copper-carbon films have been prepared at various methane concentrations with different deposition times using a facile magnetron sputtering deposition system. The ratios of methane concentration(CH4/Ar+CH4) used in the experiments are 20%, 40%, and 60%, and the deposition times are 5 minutes, 20 minutes, and 40 minutes, respectively.Despite the difference in the growth conditions, self-organizing multilayered copper-carbon films are prepared at different deposition times by changing methane concentration. The film composition and microstructure are investigated by x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), and high-resolution transmission electron microscopy(HRTEM). By comparing the composition and microstructure of three serial films, the optimal growth conditions and compositions for self-organizing nano-multilayers in copper-carbon film are acquired. The results demonstrate that the self-organized nano-multilayered structure prefers to form in two conditions during the deposition process. One is that the methane should be curbed at low concentration for long deposition time,and the other condition is that the methane should be controlled at high concentration for short deposition time. In particular, nano-multilayered structure is self-organized in the copper-carbon film with copper concentration of 10-25 at.%.Furthermore, an interesting microstructure transition phenomenon is observed in copper-carbon films, that is, the nanomultilayered structure is gradually replaced by a nano-composite structure with deposition time and finally covered by amorphous carbon.
文摘For the preparation of copper nanoparticles several methods, i.e., thermal reduction, mechanical attrition, chemical reduction metal vapour synthesis, radiation methods, laser ablation and micro emulsion techniques were developed in the past. Electrolytic deposition is one of the most suitable, simplest and low cost methods which are used for wide range of materials. In the present investigations, efforts were put to produce copper nano powder using electrolytic technique. It could be possible to obtain near nano copper powder of 258 nm size using high cathode current density of 1100 A/m2 in sulphate bath. The specific surface area and shape of the particles were found to be 23.2 m2/g and irregular, respectively.
基金supported by the Zhejiang Province Key Research and Development Project(No.2023C01191)the Construction of the Scientific Research Platform of Yunnan Normal University(No.01100205020503202)+1 种基金the“Union University Innovation Team”of Yunnan Normal University(No.01100205020503209)the“Spring City Plan:the High-level Talent Promotion and Training Project of Kunming(No.2022SCP005)”.
文摘Electrochemical-nitrate-reduction-reaction(eNitRR)synthesis of ammonia is an effective way to treat ni-trate wastewater and alleviate the pressure of the Haber-Bosch ammonia production industry.How to develop effective catalysts to electrochemically reduce nitrate to ammonia and purify sewage under com-plex environmental conditions is the focus of current research.Herein,the dopamine polymerization pro-cess and the[(C_(12)H_(8)N_(2))_(2)Cu]^(2+)complex embedding process were run simultaneously in time and space,and ultrafine Cu nanoparticles(Cu/CN)were effectively loaded on nitrogen-doped carbon after heat treat-ment.Using Cu/CN as the catalyst,the ammonia yield rate and Faradaic efficiency of the electrochemical conversion of NO_(3)^(-)to NH_(3)are highly 8984.0μg h^(−1)mg cat.^(−1)and 95.6%,respectively.Even in the face of complex water environments,such as neutral media,acidic media,coexisting ions,and actual nitrate wastewater,nitrate wastewater can be effectively purified to form high value-added ammonia.The strat-egy of simultaneous embedding increases the exposure rate of Cu sites,and the support of CN is also beneficial to reduce the energy barrier of ^(∗)NO_(3)activation.This study rationally designed catalysts that are beneficial to eNitRR,and considered the situation faced by practical applications during the research stage,reducing the performance gap between laboratory exploration and industrial applications.
