Synthesis of silver nanoparticles for use in conductive inks by chemical reduction method

In this study, the chemical reduction method was applied to synthesize silver nanoparticles used to prepare conductive inks. The two variables of polyvinylpyrrolidone (PVP)-stabilized mole in the 0.01–0.03 mol range and hydrazine reducing mole in the 0.1–0.5 mol range, along with constants such as precursor mole (silver nitrate), complexing mole (ethylene diamine) and solvent mole (water), were used. Nine random samples proposed by the Design Expert software were examined and studied. X-ray diffraction (XRD) patterns, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS) were then used to characterize and evaluate the synthesized nanoparticles. According to the results obtained by XRD, FE-SEM and TEM analyses, the sample with 0.025 mol and 0.3 mol PVP had the minimum size of silver nanoparticles, which was around 20 nm, so it was chosen as the optimal sample for further research. The conductive ink was also prepared with the optimal sample of silver nanoparticles in 40% by weight and then characterized and evaluated by applying ultraviolet–visible (UV–Vis), simultaneous thermal analysis (STA), FE-SEM and electrical conductivity analysis. Finally, conductive ink was applied to polyethylene terephthalate (PET) and acrylonitrile butadiene styrene (ABS) substrates. The surface electrical resistance of conductive ink on PET and ABS substrates was then measured at about 6.4 Ω and 2.2 Ω, respectively.