Method for electroless nickel plating on the surface of CaCO3 powders

Abstract

In this work, electroless nickel plating on the surface of CaCO₃ powders successively modified with stearic acid, oleamide and 3-amino-propyltriethoxysilane in that order was developed. Hydrophobic and hydrophilic coatings were deposited onto the surface of the CaCO₃ powders in that order. On the one hand, the hydrophobic chains coated onto the surface of the modified powders could effectively protect the powders from chemical reaction with acidic solutions (the sensitizing solution and the activating solution). On the other hand, active groups formed on the surface of the hydrophilic coating could adsorb a palladium catalyst for electroless nickel plating. It was observed that Ni–P particles were deposited on the surface of the modified CaCO₃ powders after electroless plating. The size of the particles was less than 100 nm. The mechanical bonds between the modified powders and the plated particles were strong, leading to good adhesion. The saturation magnetization of the plated powders was around 1.5 emu g⁻¹. By changing the type of inorganic powder and plating bath, the established method can potentially be adopted for the plating of metals such as copper, cobalt, and nickel onto different types of powders.