Mixing strategies for zinc oxide nanoparticle synthesis via a polyol process

Abstract

We report on the effect of mixing on the morphology of ultrafine zinc oxide nanoparticles synthesized via a polyol process using zinc acetate and water in a diethylene glycol medium. Three mixing strategies were considered: stirred batch, T-mixer, and impinging free jets. The particle granulometry was accessed using the transmission electron microscopy and x-ray diffraction methods. The nanoparticle size and polydispersity decreased with an increase in the local dissipated energy. In particular, the polyol process conducted in the same chemical environment at 353 K did not lead to the observation of nanoparticles in the stirred batch reactor but resulted in unconventionally small 6-nm particles in the T-mixer and impinging jet configurations. This result is apparently related to the micromixing eddy geometry described by the Kolmogorov length. The hydrodynamic flow patterns and energy dissipation were obtained from computational fluid dynamics simulations, which are essential in the design, optimization, and scale-up of the polyol process.

Metallic Nanoparticles, Toxicity Issues and Applications in Medicine

“…Three mixing strategies such as stirred batch, T-mixer and impinging free jets have been used to study their effect on the particle morphology of ZnO NPs synthesized via a polyol process (Hosni et al 2015). The fascinating benefit of a polyol process is its capacity to produce hydrophilic Fe 2 O 3 NPs of greater magnetization and controllable secondary structures in just a single step (Couto et al 2007).…”

Hydrodynamics of Similar Gases in Vortex Mixers: Effect of Physical Properties on the Onset of Instability

“…As an alternative to impinging type mixers, vortex mixers offer an easier alternative for more general use as the relative momentum of the jets does not play a key role. 10 Usually these mixers are characterized by the jets tangential to the main mixing chamber, which can be prismatic or cylindrical. While prismatic chambers were studied only for liquids as microreactors, 11−13 cylindrical chambers in small diameters (with a jet diameter of 1mm and a chamber diameter of 2−4 mm) were used to manufacture nanoparticles using liquid precursors.…”

Photocatalytic Nanoparticulate ZrxTi1‐xO2 Coatings with Controlled Homogeneity of Elemental Composition

“…In order to overcome this shortcoming, two strategies relevant to the nanoparticles preparation have been adopted: fast mixing and alternatively slow reactions with water vapor, which both explore the total conversion of metal oxide precursors to polyoxometallate nuclei, owing to the point‐like reaction conditions . In general, the fast reagents mixing in a T‐shape injector results in smaller and monodispersed nuclei compare to other methods . An exploration of this micromixing approach has permitted fine size‐selected metal‐oxo‐alkoxy nanoparticles: titanium oxo‐alkoxy (TOA) of 3.2, 3.8 and 5.2 nm size, and zirconium oxo‐alkoxy (ZOA) of 3.6 nm size .…”

“…[28] In general, the fast reagents mixing in a T-shape injector results in smaller and monodispersed nuclei compare to other methods. [29] An exploration of this micromixing approach [30] has permitted fine size-selected metal-oxo-alkoxy nanoparticles: titanium oxoalkoxy (TOA) of 3.2, 3.8 and 5.2 nm size [31,32] and zirconium oxoalkoxy (ZOA) of 3.6 nm size. [33] Recently, the method has been generalized to the binary oxides preparation, which resulted in a controlled nucleation of zirconium-titanium oxo-alkoxy species (ZTOA).…”