Nucleation of Ag nanoparticles in helical microfluidic reactor. Comparison between microwave and conventional heating

The synthesis of silver nanoparticles with small average size and narrow size distribution is a requirement for applications in different fields such as antibacterial or catalysis. Previous studies of nanoparticles synthesis confirm the advantages of combining continuous flow and microwave dielectric heating, given the possibilities that arise regarding the control of residence time and localized volumetric heating. In this paper, we present two experimental set-ups to perform the continuous synthesis of silver nanoparticles using microwave heating (MWH) and conventional heating (CH). Experimental and simulated data confirm a different temperature profile along the reactor, with the case of MWH being more favorable. As a result, the nanoparticles synthesized under MWH presented a synthesis yield of 54% and a narrow particle size distribution (19 ± 4.3 nm). Furthermore, MWH led to reduced wall fouling by deposition of product material and allowed fast cooling of the product stream, preventing further growt...