Eur. Phys. J. E (2007) 22: 51-59
https://doi.org/10.1140/epje/e2007-00008-y

Regular Articles

Preparation and properties of nano-sized Ag and Ag₂S particles in biopolymer matrix

¹ Institut of Nuclear Sciences “Vinča", P.O. Box 522, 11001, Belgrade, Serbia
² Department of Chemistry Lash-Miller Chemical Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
³ Department of Chemistry, University of Toronto at Mississauga, Mississauga, Ontario, L5L 1C6, Canada

^* e-mail: djokovic@vin.bg.ac.yu
^** e-mail: tradhakr@utm.utoronto.ca

Received: 31 October 2006
Published online: 21 February 2007

Abstract

Silver (Ag) and silver sulfide (Ag₂S) nanoparticles were synthesized in a sago starch matrix. The resulting nanocomposites were investigated using structural, optical and thermal methods. XRD spectra of the nanocomposites confirmed the presence of nanostructured silver (cubic phase) and silver sulfide (monoclinic phase) in the matrix. TEM micrographs showed that the nanoparticles are mostly spherical in shape. Analyzes of the optical properties of the silver nanocomposite aqueous dispersions/solutions of various concentrations were carried out. The results and the theoretical considerations suggested that at high concentrations there is a release of silver nanoparticles from the composite in the water environment. Further dilution produces homogeneous solution in which silver nanoparticles are capped with starch macromolecules. TGA analysis revealed reduced thermal stability of the nanocomposites with respect to pure starch matrix.