Assembly of Silver Nanoparticles in Pearl-Necklace-Like Nanostructure Using a Polyelectrolyte

Pearl-necklace-like Ag nanostructures are prepared with microwave irradiation in a one-step process using polymethacrylic acid (PMAA) as a reducing agent, and AgNO3 as a silver precursor without other chemical agent in a 6.5≤pH≤8.0 aqueous solution. Derjaguin- Landau-Verwey-Overbeek theory is used to calculate the stability of Ag particles in the aqueous medium. The calculated results are fairly consistent with the experimental results. The formation mechanism of pearl-necklace-like silver nanostructures is suggested as three steps: immobilization of Ag+ ions with the PMAA template, reduction of Ag+ ions with PMAA under microwave irradiation, anisotropic self-assembly of silver particles capped by the negatively charged PMAA with electrostatic interactions and Van der Waals forces.