Preparation of silver nanocomposites stabilized by an amphiphilic block copolymer under ultrasonic irradiation

Silver nanoparticles were synthesized by using amphiphilic block copolymer Polyacrylonitrile-block-poly(ethylene glycol)-blcok-Polyacrylonitrile (PAN-b-PEG-b-PAN, PEA) based on the flexibility of the copolymer chains and the complex effect of –CN in the polyacrylonitrile with Ag+ ion and Ag under ultrasonic irradiation. The product was characterized by X-ray Diffraction (XRD), Fourier Transfer Infrared Spectrometer (FTIR), Transmission Electron Microscope (TEM), UV–Vis spectrum and Thermal Gravity Analysis (TGA). The results revealed that the size and size distribution of the resulting silver nanoparticles prepared basing on the copolymer were strongly dependent on the initial concentration of the silver ion solution and the irradiation conditions. Low initial silver ion concentration allowed for yielding silver nanoparticles with a small size and the size of the silver nanoparticles increased with increasing of silver ion concentration. The silver crystal was polycrystalline with a cubic structure, as confirmed by XRD. This work provides a simple route for the in situ synthesis of Ag nanoparticles.