TITLE:
Silver Nanoparticles: Green Route, Stability and Effect of Additives
AUTHORS:
Zaheer Khan, Javed Ijaz Hussain, Sunil Kumar, Athar Adil Hashmi, Maqsood Ahmad Malik
KEYWORDS:
Silver Nanoparticles, Stability, Oxalic Acid, Additives, Ammonia
JOURNAL NAME:
Journal of Biomaterials and Nanobiotechnology,
Vol.2 No.4,
October
13,
2011
ABSTRACT: Colloidal silver nanoparticles were prepared by reducing silver nitrate with oxalic acid in presence of cetyltrimethylammonium bromide (CTAB). The synthesized silver particles show an intense surface plasmon band in the visible region. The work reported in this paper describes the effect of concentration of various additives (NaCl, NaBr, NaNO3, Na2SO4 and NaH2PO4) and ammonia on the growth and stability of Ag-nanoparticles. In all the cases the rate decreases as the [electrolytes] or [ammonia] increases. The nature, polarizability and coordinating ability of the anions play vital roles for nucleus formation and the growth process, which subsequently form different size particles. Transmission electron microscopy, selected areas electron diffraction, and UV-visible spectroscopy have been employed to characterize Ag-nanoparticles. The effect of the following variables on the particle size and size distribution was investigated: the [oxalic acid], [CTAB] and [Ag+].The nanoparticles are stable in NaNO3 and NaH2PO4 solutions; but NaCl, NaBr and Na2SO4 causes their aggregation.