Gold nanoparticles formation via gold(III) chloride complex ions reduction with glucose in the batch and in the flow microreactor systems

In these studies, the flow microreactor system was used as a valuable tool for controlled synthesis of gold nanoparticles (AuNPs) with the narrow size distribution. As a method of synthesis, the reduction of gold(III) chloride complex ions using glucose as a reducing agent was carried out. Synthesis was performed in the presence of different amount of PVP (polyvinylpyrrolidone) as a stabilizing agent. The optimal conditions inside the microreactor system (concentrations and the flow rate of components) were established as a results of kinetic measurements in the batch reactor. In these studies the rate constants of AuNPs formation (nucleation and growth) as a function of different reductant concentration as well as temperature were determined using UV–Vis spectrophotometry and Dynamic Light Scattering (DLS) method. Experimentally obtained kinetic data gave us the chance to formulate the rate law of AuNPs formation which further was used to establish synthesis conditions. Applying T-type geometry of microchannels connection, for different reactant and PVP flow rates the injection of PVP at the proper time of AuNPs growth was done. It was found that applied method is promising one for the stabilization and preparation of gold nanoparticles with well-defined shape (spheres) and with narrow size distribution.