Research on chemical modification of nickel coating on diamond particles surface

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.