Significant effects of sodium acetate, an impurity present in poly(vinyl alcohol) solution on the radiolytic formation of silver nanoparticle

A silver nanoparticle (AgNPs) stabilizer, polyvinyl alcohol (PVA) generally contains a relatively large amount of sodium acetate (NaOAc) as an impurity (up to several weight percentages) as a result of a base-catalyzed hydrolysis of poly(vinyl acetate) (PVAc). In this study, the effects of NaOAc on the radiolytic formation of AgNPs in PVA solutions were studied by using UV/vis spectroscopy. Several AgNPs were prepared by γ-ray irradiation using ⁶⁰Co source at various doses in the presence of various amounts of NaOAc. The UV data of the AgNPs observed at around 410 nm show that more AgNPs are generally produced as the NaOAc concentration in the PVA solution increases. Furthermore, no significant absorption band of the AgNPs was observed when the purified PVA containing a very small amount of NaOAc (less than 3×10^?4 M) was applied with 1×10^?3 M AgNO₃ up to 10 kGy. These results reveal that NaOAc present as an impurity in PVA, plays an important role in the radiolytic formation of AgNPs.