%0 Journal Article
%T Totally Ecofriendly Synthesis of Silver Nanoparticles from Aqueous Dissolutions of Polysaccharides
%A M. A. Garza-Navarro
%A J. A. Aguirre-Rosales
%A E. E. Llanas-V¨¢zquez
%A I. E. Moreno-Cortez
%A A. Torres-Castro
%A V. Gonz¨¢lez-Gonz¨¢lez
%J International Journal of Polymer Science
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/436021
%X In this contribution, a totally ecofriendly synthesis of silver nanoparticles from aqueous dissolution of polysaccharides is reported. The synthesis of nanoparticles was performed using aqueous dissolutions of silver nitrate (AgNO3) and carboxymethyl-cellulose (CMC) as both reducing and stabilization agent and using different AgNO3£¿:£¿CMC weight ratios. Resultant yellowish to reddish dispersions were characterized by means of transmission electron microscopy and their related techniques, such as bright field and Z-contrast imaging and electron diffraction, as well as ultraviolet-visible and infrared spectroscopic techniques. The experimental evidence suggests that the morphology and particle size distribution of the silver nanoparticles depend on the AgNO3£¿:£¿CMC weight ratio. This feature seems to be related to the stabilization given by the CMC matrix, which, according to our experimental findings, is steric in nature. Regarding such experimental evidence, a synthesis mechanism in which CMC acts as stabilizer and reducing agent is proposed. 1. Introduction The synthesis of metal nanostructures has been extensively studied due to their potential applications in technological fields such as electronics, optics, and medicine [1¨C3]. Accordingly, silver nanoparticles (AgNPs) are a promising nanostructured system, due to its potential to be applied as bactericide, fungicide, and antiviral [4¨C6]. Several approaches have been suggested for the synthesis of silver nanoparticles. These approaches propose the preparation of silver nanoparticles into alkaline or acidic media and using toxic reagents, such as sodium borohydride (NaBH4), N, N-dimethylformamide, or hydrazine, as reducing reactants, or ionic surfactants as cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone as stabilization agents [1¨C12]. Nevertheless, these routes generate residues that involved environmental risks. Therefore, in order to minimize the environmental impact of the synthetic processes for the development of nanostructures, green chemistry routes must be adopted. As one can find in the literature, the synthetic methods that evoke green preparation of silver nanoparticles and other metal nanoparticles consider biopolymers such as chitosan, carboxymethyl-chitosan, carboxymethyl-cellulose, or water-soluble starch as both reducing and stabilization agents [11¨C15]. Among these polymers, the polysaccharide carboxymethyl-cellulose (CMC) has emerged as an important stabilization and/or reducing reagent. The CMC is a semisynthetic polysaccharide, derived from the natural polymer
%U http://www.hindawi.com/journals/ijps/2013/436021/