Electroless Ni-Co-P coating of cenospheres using [Ag(NH3)2]+ activator

Electroless Ni-Co-P coating of fly-ash cenosphere particles is demonstrated in the present investigation. The electroless Ni-Co-P coating process is modified by replacing the conventional sensitization and activation steps by only using activation step with [Ag(NH3)(2)](+) activator. The cenosphere particles are characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDX), X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS) during and after the coating process. Relatively uniform coating is obtained under the given coating conditions. The possible mechanism of electroless Ni-Co-P coating of cenosphere particles utilizing [Ag(NH3)(2)](+) activator is suggested. The low density Ni-Co-P-coated cenosphere particles may be utilized for manufacturing conducting polymers for EMI-shielding application and microwave absorbing materials. (C) 2004 Elsevier B.V. All rights reserved.