%0 Journal Article
%T Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver
%A A. Hebeish
%A M. H. El-Rafie
%A M. A. El-Sheikh
%A Mehrez E. El-Naggar
%J Journal of Nanotechnology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/201057
%X Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM), particle size analyzer (PS), Polydispersity index (PdI), Zeta potential (ZP), XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20£¿nm with spherical shape and high concentration of AgNPs (30000£¿ppm). The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs). 1. Introduction A nanoscale metal is defined as a metal that has a structure in the nanometer size range, usually ranging from 1 to 100£¿nm. Of these metal nanoparticles, silver nanoparticles (AgNPs) have been by far the most important both from scientific and practical points of view by virtue of their potential use in industrial and other applications [1]. Intensive research has been focused on AgNPs due to their unique optical electronic, [2, 3] catalytic, [4¨C6], and antimicrobial [7¨C9] properties which are greatly different from bulk substances. Such properties strongly depend on size and shape of AgNPs as well as on their interactions with the stabilizing agent and the surrounding media in addition to the manner of their preparation. Thus, the controllable synthesis of the nanocrystals is a key challenge to achieve their better applied characteristics [10]. AgNPs have been synthesized using various methods. The physicochemical methods (e.g., ultrasound, templates, and milling process [11¨C13]), as well as ¡°green¡± synthesis using microorganisms, enzymes, plants, or plant extracts [14¨C16] are equally effective, but sometimes they
%U http://www.hindawi.com/journals/jnt/2013/201057/