Tunable electrical properties of polystyrene/gold core-shell structure by in situ metallization of cationic gold complex on selective ion-exchange sites

Gold-coated polystyrene (PS) beads were fabricated by an in situ metallization route involving a cationic-gold complex with a controlled amount of sulfonic acid groups formed on the PS bead surface. The interaction ratio of SO₃^- to [Au(phen)Cl₂]⁺ may be estimated to be 2.4, which means that 2.4 sulfonated groups will interact with one gold cationic ligand based on geometric considerations. A modeling methodology was developed to predict the mechanical deformation, conductivity, and contact surface area of a spherical bead under compression.