A novel method to produce Pd nanoparticle ink for ink-jet printing technology

A novel method for the preparation of ink-jet printing ink with palladium (Pd) nanoparticles reduced by styrene (St) oligomers is presented in this study. The noble metal nanoparticles reduced and stabilized by styrene oligomer showed their well dispersion in the organic solvent without surfactant and reductant in the mixture. These Pd nanoparticles can be used as activator for electroless metal deposition. The deposition rate of St/Pd nanoparticles system was higher than that of conventional Sn/Pd colloids. It is an indication that the catalytic activity of St/Pd is better than Sn/Pd colloids. The ink based on St/Pd colloids was successfully ink-jet printed onto a flexible substrate. The formed metallic palladium patterns were subjected to electroless nickel plating, yielding well-defined nickel lines at low temperature. The properties of Pd nanoparticle ink and kinetics of electroless nickel deposition (EN) were characterized by transmission electron microscopy (TEM), quartz crystal microbalance (QCM), four-point probe, mixed potential theory (MPT) and scanning electron microscopy (SEM), respectively.