Synthesis of uniform silver nanoparticles by a microwave method in polyethylene glycol with the assistant of polyvinylpyrrolidone

We described a method for the rapid synthesis of uniform silver nanoparticles (NPs) under microwave heating, using poly(ethylene glycol) (PEG) as reducing agent and solvent and poly(vinylpyrrolidinone) (PVP) as capping agent. The transmission electron microscopy (TEM) and UV-Vis extinction spectra were used to characterize the size and uniformity of the silver NPs. At the same reaction temperature, the products with microwave heating were more uniform than that with oil heating. We also investigated the influence of reaction temperature, microwave power, and molar ratio of PVP to AgNO₃. In our experiments, uniform silver NPs with mean diameter of 50 nm were synthesized at 140 °C under 700 W microwave irradiation with PVP/AgNO₃ molar ratio of 5:1.