Microwave polyol process for metal nanophases

The microwave-assisted polyol process was investigated for the synthesis of several nanophase metals under different conditions in the temperature range of 100 to 200 °C. Nanophase Ag metal particle synthesis using ethylene glycol (EG) was carried out at 100 and 150 °C in the presence of polyvinyl pyrrolidone (PVP), dodecyl amine (DDA), oleic acid (OA) or trioctylphosphine (TOP) to determine whether particle size and shape can be controlled. The Ag particle size was changed with different capping agents. The use of PVP led to well defined Ag nanoparticles in the range of about 30-50 nm. Morphologically well defined nanophase metals of Fe, Co and Ni were produced in the presence of both PVP and DDA, while the use of just PVP or PVP and TOP did not yield such particles. The results presented here show that a variety of well defined nanophase metals can be produced by using the microwave-polyol process and optimizing the metal capping agents.