Facile and one-step synthesis of monodisperse silver nanoparticles using gum acacia in aqueous solution

A practical and convenient method for the synthesis of highly stable and small sized silver nanopartides with a narrow distribution from 2 nm to 20 nm is reported. Silver nitrate was used as silver precursor and gum acada was acted as a capping agent as well as a reducing agent. The formation of silver nanoparticles was observed by change of color from light yellow to black green. The silver nanopartides were characterized by high resolution transmission electron microscopy (HRTEM), UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectra. The HRTEM images showed that the as-synthesized silver fine spherical particles were distributed uniformly. The XRD and HRTEM results demonstrated that the obtained metallic particles were single crystalline silver nanoparticles. FT-IR spectra data suggested that the silver nanoparticles were coated with gum acacia. The effects of the reaction time, the reaction temperature, the amount of gum acacia and the silver nitrate on the particle size were investigated. The silver nanoparticles are stable and hence can be found of practical use in medicine such as antimicrobial materials. The preparation process is simple and environmentally-friendly, which may be extended to other noble metal for other technological applications. (C) 2014 Elsevier B.V. All rights reserved.