Synthesis and electrical resistivity of the monodisperse PMMA/Ag hybrid particles

Abstract Various sizes of poly (methylmethacrylate) (PMMA)/Ag hybrid particles with variable silver contents were prepared to understand the electrical resistivity dependency on the core particle size and shell silver content. In addition, the resistivity of the hybrid particles was compared to that of the simple mixture of PMMA particles and silver nanoparticles. Three different sizes of PMMA core particles (2.17, 4.36, 7.03 μm) were synthesized via dispersion polymerization and silver shell was then plated by the electroless silver plating method using 0.01–0.2 M silver nitrate solution. The characteristics of the PMMA/Ag core/shell hybrid particles were studied by using the field emission scanning electron microscopy (FE-SEM), field emission transmission electron microscopy (FE-TEM), particle size analyzer (PSA), X-ray diffractometer (XRD), thermogravimetric analysis (TGA) and 4-point probe resistivity meter. Based on the FE-SEM and TGA study, each particle size has optimum plating concentration to deposit thick shell with Ag nanoparticles. The lowest electrical resistivity of the hybrid particles with 60 wt% silver was achieved near 10 −3  Ω cm, whereas that of the simple mixture of PMMA particles and silver nanoparticles reached to 10 2  Ω cm, indicating that the resistivity of the hybrid particles was much enhanced compared to that of the simple mixtures. In addition, the percolation threshold of the hybrid particles was observed at 30 wt% silver content, whereas that of the simple mixtures was not. In both cases, the particle size barely affected the electrical resistivity upon silver content. Thus, the electrical resistivity value of the hybrid PMMA/Ag particles was acceptable to use in industrial applications.