A novel super-hydrophobic stearic acid(STA)film with a water contact angle of 166° was prepared by chemical adsorption on aluminum wafer coated with polyethyleneimine(PEI)film. The micro-tribological behavior of ...A novel super-hydrophobic stearic acid(STA)film with a water contact angle of 166° was prepared by chemical adsorption on aluminum wafer coated with polyethyleneimine(PEI)film. The micro-tribological behavior of the super-hydrophobic STA monolayer was compared with that of the polished and PEI-coated Al surfaces.The effect of relative humidity on the adhesion and friction was investigated as well.It was found that the STA monolayer showed decreased friction,while the adhesive force was greatly decreased by increasing the surface roughness of the Al wafer to reduce the contact area between the atomic force microscope(AFM)tip and the sample surface to be tested.Thus the friction and adhesion of the Al wafer was effectively decreased by generating the STA monolayer, which indicated that it could be feasible and rational to prepare a surface with good adhesion resistance and lubricity by properly controlling the surface morphology and the chemical composition.Both the adhesion and friction decreased as the relative humidity was lowered from 65% to 10%,though the decrease extent became insignificant for the STA monolayer.展开更多
By using a new method, ^60Co γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanop...By using a new method, ^60Co γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM), respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation (10 kGy) is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation (10 kGy) are mainly in small cubic shape and the size uniformity of these particles is good.展开更多
High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of...High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ~1.4 mol ? L^(-1) and0.031~0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ~18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .展开更多
Amidst <span><span><span style="font-family:;" "="">the </span></span></span><span><span><span style="font-family:;" "="&...Amidst <span><span><span style="font-family:;" "="">the </span></span></span><span><span><span style="font-family:;" "="">COVID-19 pandemic, environmental problems such as ener<span>gy crisis, global warming, and contamination from pathogenic mi</span>cro-organisms <span>are still prevailed and strongly demanded progress in high</span></span></span></span><span><span><span style="font-family:;" "="">-</span></span></span><span><span><span style="font-family:;" "="">performance</span></span></span><span><span><span style="font-family:;" "=""> energy storing and anti-microbial materials. The nanocomposites are materials <span>that have earned large interest owing to their promising applications for</span> countering global issues related to sustainable energy and</span></span></span><span><span><span style="font-family:;" "=""> a</span></span></span><span><span><span style="font-family:;" "=""> flourishing environ<span>ment. Here, polypyrrole </span></span></span></span><span><span><span style="font-family:;" "="">coated</span></span></span><span><span><span style="font-family:;" "=""> hybrid nanocomposites of multi-walled</span></span></span><span><span><span style="font-family:;" "=""> carbon nanotube and cadmium sulfide quantum dots named MCP were synthe<span>sized using facile and low-cost <i>in-situ</i> oxidative polymerization method.</span> Cha<span>racterization techniques confirmed the synthesis. Electrochemical studies</span> showed that the nanocomposite <span>1-MCP<i> </i></span>showed an impressively higher super capacitance behavior in comparison to f-MWCNT, 7-MCP and 5-MCP. The improved performance of the nanocomposites was attributed mainly to the good conductivity of carbon nanotubes and polypyrrole, high surface area, and stability of the carbon nanotubes and the high electrocatalytic activity of the cadmium sulfide quantum dots. Owing to the synergistic effect of MWCNT, <span>CdS, and PPy the synthesized ternary nanocomposite also inhibited the</span> growth and multiplication of tested bacteria such as <i>S. aureus</i>, and <i>E. coli</i> completely within 24 h. On the whole, the assimilated nanocomposite MCP opens promising aspects for the development of upcoming energy storage devices and as<span style="color:red;"> </span></span></span></span><span><span><span style="font-family:;" "="">an </span></span></span><span><span><span style="font-family:;" "="">antibacterial agent.</span></span></span>展开更多
A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the simila...A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the similar capability and structure of lotus leaves. the super-hydrophobic surface shows static contact angle as high as 173° and tilt angle as low as 2.5° for 6.5 μL water droplet.展开更多
基金The project supported by the National Natural Science Foundation of China (50375151,50323007,10225209)the Chinese Academy of Sciences (KJCX-SW-L2)
文摘A novel super-hydrophobic stearic acid(STA)film with a water contact angle of 166° was prepared by chemical adsorption on aluminum wafer coated with polyethyleneimine(PEI)film. The micro-tribological behavior of the super-hydrophobic STA monolayer was compared with that of the polished and PEI-coated Al surfaces.The effect of relative humidity on the adhesion and friction was investigated as well.It was found that the STA monolayer showed decreased friction,while the adhesive force was greatly decreased by increasing the surface roughness of the Al wafer to reduce the contact area between the atomic force microscope(AFM)tip and the sample surface to be tested.Thus the friction and adhesion of the Al wafer was effectively decreased by generating the STA monolayer, which indicated that it could be feasible and rational to prepare a surface with good adhesion resistance and lubricity by properly controlling the surface morphology and the chemical composition.Both the adhesion and friction decreased as the relative humidity was lowered from 65% to 10%,though the decrease extent became insignificant for the STA monolayer.
基金This work was supported by the Natural Science Foundation of Henan Province under grant No. 0611023900.
文摘By using a new method, ^60Co γ-ray irradiation, Fe3O4 magnetic nano-particles were successfully synthesized at room temperature under ambient pressure. The structure, morphology and magnetic properties of these nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM), respectively. The radiation formation mechanism was also discussed. The results show that the absorbed dose can greatly influence the structure, morphology and magnetic properties of the products. XRD and TEM studies show that the product prepared by γ-ray irradiation (10 kGy) is pure FesO4 phase and the mean diameter of these nano-particles is about 21 nm. The Fe3O4 nano-particles synthesized by γ-ray irradiation (10 kGy) are mainly in small cubic shape and the size uniformity of these particles is good.
文摘High purity Y_2O_3 nano-powders was synthesized directly from solution ofindustrial YCl_3 by method of oxalate precipitation through super-micro-reactors made by complexnon-ionic surfactant. The purity and diameter of Y_2O_3 particles were controlled by such processingparameters as concentration of YCl_3 and oxalic acid and complex non-ionic surfactant etc. TEMphotomicrographs show that Y_2O_3 particles are spherical in shape, with an average diameter of lessthan 30 nm. Test results certify that the purity and particle diameter as well as the dispersion ofY_2O_3 nano-powder depend on the concentrations of YCl_3, oxalic acid and complex non-ionicsurfactant. The optimum ranges of the concentrations for YCl_3 and complex non-ionic surfactant whenthe diameter of Y_2O_3 particles is smaller than 100 nm are 0.43 ~1.4 mol ? L^(-1) and0.031~0.112 mol·L^(-1) respectively, while the mass fraction range of oxalic acid is 10% ~18% .The purity of Y_2O_3 nano-powder tested by ICP-AES analysis is 99.99% .
文摘Amidst <span><span><span style="font-family:;" "="">the </span></span></span><span><span><span style="font-family:;" "="">COVID-19 pandemic, environmental problems such as ener<span>gy crisis, global warming, and contamination from pathogenic mi</span>cro-organisms <span>are still prevailed and strongly demanded progress in high</span></span></span></span><span><span><span style="font-family:;" "="">-</span></span></span><span><span><span style="font-family:;" "="">performance</span></span></span><span><span><span style="font-family:;" "=""> energy storing and anti-microbial materials. The nanocomposites are materials <span>that have earned large interest owing to their promising applications for</span> countering global issues related to sustainable energy and</span></span></span><span><span><span style="font-family:;" "=""> a</span></span></span><span><span><span style="font-family:;" "=""> flourishing environ<span>ment. Here, polypyrrole </span></span></span></span><span><span><span style="font-family:;" "="">coated</span></span></span><span><span><span style="font-family:;" "=""> hybrid nanocomposites of multi-walled</span></span></span><span><span><span style="font-family:;" "=""> carbon nanotube and cadmium sulfide quantum dots named MCP were synthe<span>sized using facile and low-cost <i>in-situ</i> oxidative polymerization method.</span> Cha<span>racterization techniques confirmed the synthesis. Electrochemical studies</span> showed that the nanocomposite <span>1-MCP<i> </i></span>showed an impressively higher super capacitance behavior in comparison to f-MWCNT, 7-MCP and 5-MCP. The improved performance of the nanocomposites was attributed mainly to the good conductivity of carbon nanotubes and polypyrrole, high surface area, and stability of the carbon nanotubes and the high electrocatalytic activity of the cadmium sulfide quantum dots. Owing to the synergistic effect of MWCNT, <span>CdS, and PPy the synthesized ternary nanocomposite also inhibited the</span> growth and multiplication of tested bacteria such as <i>S. aureus</i>, and <i>E. coli</i> completely within 24 h. On the whole, the assimilated nanocomposite MCP opens promising aspects for the development of upcoming energy storage devices and as<span style="color:red;"> </span></span></span></span><span><span><span style="font-family:;" "="">an </span></span></span><span><span><span style="font-family:;" "="">antibacterial agent.</span></span></span>
文摘A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the similar capability and structure of lotus leaves. the super-hydrophobic surface shows static contact angle as high as 173° and tilt angle as low as 2.5° for 6.5 μL water droplet.