Title: Synthesis of metallic and bimetallic nanoparticles in millifluidic continuous reactor
Metallic nanoparticles find extensive applications in several fields ranging from medicine where they are used as drug delivery vehicles or antibacterial agents to chemical process systems where they are utilized as catalysts. The spectrum of applications can be enhanced if two or more metals are synthesised as bimetallic nanoparticles or as alloys. There have been several reports on the synthesis of nanoparticles in both batch and microfluidic scale. Though batch scale synthesis is widely studied, multiple parameter control and the ensuing low throughput makes it undesirable for scale up. Thus, the scale-out technique in a continuous reactor system is a preferable choice for industrial production of nanoparticles. Also, significant attention has been given to the development of different microfluidic reactors that are generally difficult to fabricate and also have low production rates. Hence, research on synthesis in “easy to fabricate” millifluidic reactors with high production rates is very essential. Our research objective is to effectively synthesize metallic and bimetallic nanoparticles in millifluidic reactors. An illustrative comparison of the synthesis of silver nanoparticles in spiral and straight millifluidic reactor systems has been performed. Reactant ratio has been found to play a major role in the shape control of such nanoparticles. Also, the synthesis of copper-silver bimetallic nanoparticles in a batch reactor system and their long term stability has been studied. Sequence of precursor addition has been found to play a major role in the shape and morphology of such nanoparticles. Based on the parameter studies, synthesis of these bimetallic nanoparticles in the millifluidic channels will be explored in future. Probable mechanisms for the interesting observations will be investigated. Finally, large scale synthesis of both metallic and bimetallic nanoparticles will be carried out and guidelines for this will be suggested.