ELECTROCODEPOSITION OF NI-POLYMER COMPOSI TE

Electrocodeposition of Ni and organic polymer has been studied in (1 M Ni2+-H3BO3-5, 10 g/dm(3) polymer) solutions. The mechanism proposed f or the codeposition of Ni End polymer is based on the measurements of polarization curves and potential step-current transients. The polariz ation curves in the Ni-polymer codeposition baths exhibited three dist inct potential regions; hydrogen and Ni+ intermediate adsorptions at n oble potentials, complete covering by deposited polymer at less noble potentials and Ni-polymer codeposition (Ni ion reduction and phase for mation accompanying polymer incorporation in the Ni matrix). The poten tial step experiments revealed that an increase in current transient d uring the current decay due to Ni ion reduction reaction is attributab le to the occurrence of polymer adsorption all over the surface follow ed by the subsequent Ni ion reduction reaction and polymer codepositio n. The Xray diffraction patterns of Ni-polymer codeposits polarized fo r 15 minutes at 10(-3)A/m(2) exhibited three distinct peaks of Ni; (11 1), (200) and (220). The current transient obtained in 1 M Ni2+ with a nd without polymer solutions suggested that the deposition of coagulat ed polymer influences an early stage of Ni ion adsorption, which was c onfirmed as circular traces of undeposited areas in SEM micrographs.