Silver/Poly(N-Vinyl-2-Pyrrolidone) Nanocomposites Obtained By Electrochemical Synthesis

Silver/poly(N-vinyl-2-pyrrolidone) (Ag/PVP) nanocomposites were obtained by electrochemical reduction of Ag+ at a constant voltage, by in situ synthesis of silver nanoparticles inside a poly(N-vinyl-2-pyrrolidone) matrix, previously crosslinked by gamma-irradiation. Optimal values of synthesis parameters were investigated: the composition of the solution for swelling of PVP hydrogel, implementation time and applied voltage. Ag/PVP nanocomposites were characterized by UV-Visible spectroscopy, and IR spectroscopy. UV-Visible spectroscopy results showed that the reduction of silver ions was more efficient when the more conductive solution for swelling of PVP hydrogel was used, i.e., the solution containing 3.9 mM AgNO3 with 0.1 M KNO3. It was also shown that the concentration of the reduced silver increases with the increase in implementation time and applied voltage, up to values of 4 min and 200 V, respectively. The Ag nanoparticle size was estimated to be 25 nm, by comparison of the experimental results of UV-Vis spectroscopy with the theoretical predictions obtained by the calculations in MiePlot v.3.4 software, having the algorithm based on Mie scattering from a sphere. The results of FTIR spectroscopy have shown that Ag nanoparticles were mainly bonded to PVP by coordination bondages between Ag nanoparticles and N from the pyrrolidone ring of PVP