Preparation of microporous nickel electrodeposits using a polymer matrix

Nickel-mesh electrodes were embedded into polyHIPE (a generic hollow fiber polymer) by immersion in the precursor emulsion and subsequent entrapment into the solid microporous matrix produced by polymerization and drying. Immersing this Ni/polyHIPE/Ni composite into a nickel electroplating bath and passing direct current through the two electrodes resulted in growing Ni electrodeposits on the cathode and through the polymer cells and pores. When the polymer matrix was subsequently burned off, a granular microporous Ni coating was produced on the cathode. Variation of the electroplating time and current density showed that the structure of the Ni coating is determined by the local distortions of the electric field inside the tortuous microporous body of the insulating polymer.