Characterization of AgI nanoparticles synthesized in a spinning disk reactor

The main theme of this research was to characterize silver iodide nanoparticles that were synthesized via a liquid–liquid reaction conducted in a spinning disk reactor (SDR). Silver nitrate and potassium iodide were used as the reactants, and the protecting agent tested was mainly polyvinylpyrrolidone (PVP). The experiment was carried out in a continuous mode by injecting the two streams of AgNO3 and KI solution continuously onto the surface of a spinning disk to generate uniform and small AgI particles. The effects of several operating variables, including the concentration of reactants, the protecting agent concentration, and the disk rotation speed, on the particle size and the product yield were investigated. In addition, the crystal morphology, particle habits, and surface bonding of particles were characterized. Finally, the transition point of the produced AgI nanoparticles changing from α-phase to β/γ-phase was measured and compared with that of the commercial AgI particles of 1 μm mean size. A large decrease in the transition temperature was achieved, i.e., 49.6 °C versus 140.0 °C.

► A mixture of β- and γ-form of AgI nanoparticles was synthesized in a spinning disk reactor.
► The production rate was as high as 23.3 kg/day using PVP as the protection agent.
► Transition temperature of produced AgI nanoparticles to become α-form was greatly reduced to 49.6 °C.