Green synthesis of sub 10 nm silver nanoparticles in gram scale using free impinging jet reactor

Abstract

In this paper we report controlled synthesis of sub 10 nm silver nanoparticles at 30 g/day at room temperature condition using a green protocol using a free impinging jet reactor. The focus is on impingement of low velocity liquid jets to ensure process completion in the film. Identical liquid jets of 400-micron diameter with low Weber number (We = 10–40) were impinged at different approach angles (90°–150°) to explore mixing characteristics using iodide-iodate reaction system. The regime showed monotonic improvement in silver nanoparticle mean size and polydispersity with increase in We. The smallest and most uniform (5.2 ± 0.9 nm) particles could be synthesized at We = 40. The study also establishes the horizontal component of jet velocity as a parameter to control mixing and particle size. Under identical reaction condition a free impinging jet reactor outperformed two other continuous reactors viz. a spinning disc reactor and a spinning disc spinning bowl reactor in terms of mean particle size.