纳米钴粉的制备及其在乙醇中的分散性能

摘要

The cobalt nanopartjcles were prepared by direct current arc plasma evaporation method and the crystalline structure, chemical composition, morphology, particle size distribution of samples were characteri2ed by X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), vibrating magnetometer (VSM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). On the basis of pH-Zeta measurement of the cobalt nanoparticles, the effect of ultrasonic time and surfactant concentration on dispersing in ethanol were studied. The results indicate that the cobalt nanoparticles prepared by direct current arc plasma evaporation achieves a high purity of 99,923% with a narrow size distribution and spherical shape. Ultrasonic time and dispersant concentration affect the dispersion of cobalt nanoparticles observably. With the increase of ultrasonic time and dispersant concentration, dispersion property increases at first and then decreases after a certain time. The order of dispersant property from strong to weak is PVP, SHMP, TEA, CTAB and STAN-80. The best dispersion condition is proposed as follows: pH value is 7, the concentration of PVP is 2%, the ultrasonic time is 30 min and the ultrasonic power is 560 W.%针对高性能硬质合金的制备基础研究,通过直流电弧等离子体蒸发法制备纳米级钴粉,利用X线衍射(XRD)、X线荧光分析(XRF)、振动磁强计(VSM)、透射电子显微镜(TEM)和相应的选区电子衍射(SAED)等测试手段对样品进行表征.在测定样品粉体于无水乙醇中pH-Zeta电位的基础上,研究超声时间和特定的分散剂及其加入量对分散效果的影响.研究结果表明:直流电弧等离子体蒸发法制备的纳米钴粉为立方晶体结构,纯度(质量分数)达99.923％,粒径分布窄,颗粒呈现球形.随着超声时间和分散剂浓度的增加,纳米钴粉在无水乙醇中的分散效果呈现先增大后减小的趋势;不同分散剂分散效果从优到劣的顺序为:PVP,SHMP,TEA,CTAB和STAN-80.纳米钴粉在无水乙醇中较好分散工艺为:在pH=7的情况下,PVP加入量(质量分数)为2％,超声时间为30 min,超声功率为560W.