Colloidal silver nanoparticles were synthesized by Co-60 ray irradiation of Ag+ in aqueous solution containing polyvinyl alcohol (PVA) as stabilizer and M ethyl alcohol as free radical (OH• ) scavenger. The effect of Ag+ concentration which varied from 1 to 50 mM on the saturated conversion dose (D) of Ag+ into Ag determined by UV-vis spectroscopy and the size of Ag nanoparticles characterized by transmission electron microscopy (TEM) were investigated. The dependence of D (kGy) and average size (d, nm) of Ag nanoparticles on Ag+ concentration was found out to be as: D (kGy) = [Ag+]2 + [Ag+] + (R2 = ) and d(nm) = [Ag+]2 + [Ag+] + (R2 = ) for Ag+ concentration from 1 to 50 mM stabilized by 2% PVA. Results indicated the Ag nanoparticles size to be in the range of 6 - 18 nm. The concentration of PVA ( - ) in the irradiated solution also considerably affected the silver nanoparticles size which decreased with increasing the amount of PVA in the solution. Due to the unique features of the processing procedures, thus Co-60 ray irradiation has been considered as a suitable method for mass production of colloidal silver nanoparticles.
