Properties of Ag/PVP Hydrogel Nanocomposite Synthesized In Situ by Gamma Irradiation

Metal nanoparticles embedded in crosslinking polymer matrices i.e. hydrogels are novel class of materials which have attracted great attention due to applications in catalysis, photonics, optic, pharmaceutics and biomedicine. This work describes novel, simple and facile radiolytic synthesis of silver nanoparticles (AgNPs) within the poly(N-vinyl-2-pyrrolidone) (PVP) hydrogel. The hydrogel matrix was previously obtained by gamma irradiation induced crosslinking, while the in situ reduction of \(\mathrm{Ag}^{+}\) ions was performed using strongly reducing species formed under the radiolysis of water. Absorption spectrum of Ag/PVP hydrogel shows the presence of surface plasmon band with maxima at 400 nm, which confirms formation of AgNPs (diameter less than 10 nm). Swelling properties of synthesized hydrogels, neat PVP and Ag/PVP nanocomposite, were investigated in the SBF (simulated body fluid) solution at \(37^{\circ}\mathrm{C}\). Obtained results show that Ag/PVP hydrogel nanocomposite has higher equilibrium swelling compared with neat PVP hydrogel. Moreover, kinetics parameters were calculated from the swelling curves. The fluid transport mechanism is non-Fickian for both PVP and Ag/PVP hydrogels, meaning that both diffusion and polymer relaxation control the fluid transport.