One-dimensional Ni nanostructures were synthesized via a hydrazine reduction route under external magnetic fields. The mixture of de-ionized water and ethanol was used as the reaction solvent and hydrazine hydrate as ...One-dimensional Ni nanostructures were synthesized via a hydrazine reduction route under external magnetic fields. The mixture of de-ionized water and ethanol was used as the reaction solvent and hydrazine hydrate as reducing agents. The morphology and properties of Ni nanostructures were characterized by X-ray diffractometer(XRD), scanning electron microscopy(SEM), and vibrating sample magnetometer(VSM). It was found that the magnetic field strength, concentration of Ni ions,reaction time and temperature as well as p H values played key roles on formation, microstructures and magnetic properties of Ni nanowires. The optimal wires have diameter of ~200 nm and length up to ~200 μm. And their coercivity is ~260 Oe, which is much larger than the commercial Ni powders of 31 Oe. This work presents a simple, low-cost, environment-friendly and large-scale production approach to fabricate one-dimensional magnetic materials. The resulting materials may have potential applications in conductive filters, magnetic sensors and catalytic agents.展开更多
为减少球形Ni/Al填充量并提高Ni/Al填充导电硅橡胶屏蔽效能,选取Ni/C纤维加入到此种导电橡胶中,并从导电性、屏蔽性能方面对其进行评价。实验发现Ni/C纤维的掺杂可以提高导电橡胶的导电性及屏蔽性能。当总颗粒填充量为130 phr时,掺杂纤...为减少球形Ni/Al填充量并提高Ni/Al填充导电硅橡胶屏蔽效能,选取Ni/C纤维加入到此种导电橡胶中,并从导电性、屏蔽性能方面对其进行评价。实验发现Ni/C纤维的掺杂可以提高导电橡胶的导电性及屏蔽性能。当总颗粒填充量为130 phr时,掺杂纤维使导电橡胶的体积电阻率从10^10Ω·cm降至1.4Ω·cm;当总颗粒填充量为240 phr时,在1.0~2.5 GHz的频段内,其屏蔽效能在90 d B以上,而未经过掺杂的仅能超过60 d B。利用面心立方堆垛结构模型计算颗粒间最小距离,结果发现导电橡胶的渗流阈值与颗粒最小间距有较为明显的相关性。展开更多
基金support of the National Basic Research Program of China(No.2006CB300406)Shanghai Science and Technology Grant(No:0752nm015)+2 种基金National Natural Science Foundation of China(No.50730008,20504021)Natural Science Foundation of Shanghai(No.09ZR1414800)Shanghai Applied Materials Collaborative Research Program(No:09520714400)
文摘One-dimensional Ni nanostructures were synthesized via a hydrazine reduction route under external magnetic fields. The mixture of de-ionized water and ethanol was used as the reaction solvent and hydrazine hydrate as reducing agents. The morphology and properties of Ni nanostructures were characterized by X-ray diffractometer(XRD), scanning electron microscopy(SEM), and vibrating sample magnetometer(VSM). It was found that the magnetic field strength, concentration of Ni ions,reaction time and temperature as well as p H values played key roles on formation, microstructures and magnetic properties of Ni nanowires. The optimal wires have diameter of ~200 nm and length up to ~200 μm. And their coercivity is ~260 Oe, which is much larger than the commercial Ni powders of 31 Oe. This work presents a simple, low-cost, environment-friendly and large-scale production approach to fabricate one-dimensional magnetic materials. The resulting materials may have potential applications in conductive filters, magnetic sensors and catalytic agents.
文摘为减少球形Ni/Al填充量并提高Ni/Al填充导电硅橡胶屏蔽效能,选取Ni/C纤维加入到此种导电橡胶中,并从导电性、屏蔽性能方面对其进行评价。实验发现Ni/C纤维的掺杂可以提高导电橡胶的导电性及屏蔽性能。当总颗粒填充量为130 phr时,掺杂纤维使导电橡胶的体积电阻率从10^10Ω·cm降至1.4Ω·cm;当总颗粒填充量为240 phr时,在1.0~2.5 GHz的频段内,其屏蔽效能在90 d B以上,而未经过掺杂的仅能超过60 d B。利用面心立方堆垛结构模型计算颗粒间最小距离,结果发现导电橡胶的渗流阈值与颗粒最小间距有较为明显的相关性。
