金刚石颗粒表面镍镀层化学改性研究

Research on chemical modification of nickel coating on diamond particles surface

为消除金刚线生产过程中分散剂对工艺的负面影响,探索新的金刚线镀镍工艺。首先,使用H_(2)O_(2)对镀镍金刚石颗粒表面进行羟基化;然后,将其同二甲基十八烷基[3-(三甲氧基硅)丙基]氯化铵进行反应,制备表面带正电的金刚石颗粒;最后,对金刚线的制备工艺进行优化。研究结果表明:反应后金刚石颗粒的表面电位从−7.50 mV转变至14.10 mV以上,最高可达30.68 mV。其最佳制备条件为原砂与H_(2)O_(2)的质量比为2∶1,处理时间为1 h;金刚石颗粒与季铵盐的质量比为1∶2,处理时间为4 h。在电镀过程中,经表面化学修饰的金刚石颗粒能够在没有分散剂的条件下,均匀地向阴极迁移,其上砂量增多20%以上。

A new nickel plating process for diamond wire is explored to eliminate the negative impact of dispersants on the production process of diamond wires.The surface of of Ni-plated diamond particles was first hydroxylated with hydrogen peroxide,and then reacted with dimethyloctadecyl[3-trimethoxysilylpropyl]ammonium chloride to prepare positively charged diamond particles.Finally,the preparing process of diamond wires were optimized.Results show that the surface potential of diamond particles increases from−7.50 mV to 14.10 mV or above after reaction,up to 30.68 mV.The best preparing conditions are as follows:The mass ratio of raw sand to hydrogen peroxide is 2 to 1,with treating time of 1 h;The mass ratio of diamond particles to quaternary ammonium salts is 1 to 2,with treating time of 4 h.In the electroplating process,the diamond particles with chemically modified surface would uniformly migrate towards the cathode without dispersants,the sanding capacity of which could be increased by 20%or more.