Shad Siddiqui

Inorganic Nanoparticle Production using a Confined Impinging Jet Reactor

Mixing is a process undertaken to reduce segregation of phases or species concentrations in a system. Chemical reaction occurs at the molecular scale and may be therefore limited by the micro-mixing time scale. Micro-mixing is the final step in turbulent mixing in liquids. Impinging jets offer rapid mixing due to high turbulence and can provide energy dissipation rates as large as 10,000 W/kg. Typically, energy dissipation observed in a stirred tank is 10-12 W/kg. With a high-energy dissipation rate, smaller length and mixing time scale can be reached. As energy dissipation is indicative of the mixing efficiency of the system, it needs to be promoted and quantified. Intense micro-mixing brings about local supersaturation precipitating hard agglomerates of 5-20nm diameter primary magnetite nanoparticles, which agglomerate intensively. Suitable stabilization and sonication strategies of the precipitated particles significantly reduce particle agglomeration, giving 250nm (hard agglomerate) particles.

Shad Siddiqui is doing his PhD in Chemical Engineering under the supervision of Dr. Suzanne Kresta and Dr. Zhenghe Xu.