Electroless nickel plating on hollow glass microspheres

Electroless nickel plating on hollow glass microspheres with hypophosphite as a reducing agent in an alkaline bath was studied. Three pretreatment methods were used. The hollow glass spheres via coupling agent solution pretreatment adsorbed more palladium catalytic active centers on their surfaces, hence continuously and uniformly covered microspheres were achieved. The magnetic property of microspheres was improved by adjusting the pH and the concentration of the reducing agent in a certain range. The morphology, composition and structure of deposits were investigated. It was found that the deposits on hollow glass microspheres grew thicker with prolonged plating time. Posttreatment of the coated Ni glass spheres improved the crystalline structure of the plated Ni layer.