FORMATION AND CHARACTERISATION OF A STABLE AQUEOUS DISPERSION OF SILVER NANOPARTICLES IN AQUEOUS AND MICELLAR MEDIA. A KINETIC STUDY

The kinetics and mechanism of the formation of silver nanoparticles by reduction with arabinose are studied spectrophotometrically in aqueous and micellar media at different temperatures. The reaction was carried out under pseudo-first-order condition by taking the [arabinose] >10-fold the [Ag+]. The rate of reaction increases with increasing in the [OH-]. A mechanism of the reaction between silver ion and arabinose was proposed and the rate equation derived from the mechanism was consistent with experimental rate. Cetyltrimethylammoniuom bromide (CTAB) as capping agent stabilised the formed silver sol. The formation of silver nanoparticles by this method gave an easy and viable strategy for the obtained silver sols with well controlled shape and size. Enthalpy and entropy of activation were calculated. The particle size of silver sols is characterised by transmission electron microscopic (TEM), physicochemical and spectroscopic methods.