Effect of Polyvinylpyrrolidone Molecular Weight on the Synthesis of Silver Nanoparticles using a Polyol Method

Nanoparticles possess a great interest for researchers because of their unique physicochemical properties and their various applications. Polyol synthesis is a kind of synthesis that can produce silver nanoparticles. It has been known that the molecular weight of polyvinylpyrrolidone (PVP) can influence the size and shape of the nanoparticles produced. This research used a polyol synthesis to fabricate silver nanoparticles in which AgNO₃, PVP_{MW= 55,000} and PVP_{MW= 360,000}, ethylene glycol (EG) and natrium bromide (NaBr) were used as precursor, capping agent and additives respectively. The synthesis was carried out at 60 and 100 °C. The silver nanoparticles were characterized using Ultraviolet-visible (UV-Vis) spectrophotometer, Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). The UV-Vis spectrum showed the presence of AgNPs peak between 400-500 nm. The AgNPs synthesized using PVP_MW=55,000 produce a higher absorbance spectrum than PVP_MW=360,000. The TEM image confirmed the size and shape of AgNPs from using PVP_{MW= 55,000} showing sphere and anisotropic shape. This result proved the role of oxidative etching caused by the addition of NaBr which affects the form of AgNPs. In addition, the XRD results showed typical crystalline peaks of AgBr and Ag.