Micro Droplet Formation towards Continuous Nanoparticles Synthesis

Abstract

In this paper, micro droplets are generated in a microfluidic focusing contactor and then they move sequentially in a free-flowing mode (no wall contact). For this purpose, two different micro-flow glass devices (hydrophobic and hydrophilic) were used. During the study, the influence of the flow rate of the water phase and the oil phase on the droplet size and size distribution was investigated. Moreover, the influence of the oil phase viscosity on the droplet size was analyzed. It was found that the size and size distribution of the droplets can be controlled simply by the aqueous phase flow rate. Additionally, 2D simulations to determine the droplet size were performed and compared with the experiment.

Continuous, monodisperse silver nanoparticles synthesis using microdroplets as a reactor

“…As there is then also no heat transport issue, only mass transport through diffusion can have impact on the particles size and size distribution. The process of silver nanoparticle formation in microdroplets was conducted in a microreactor, taking into account the results (flow rate conditions) obtained in our previous study [25], in which it the common sense was followed that increasing mixing rate (up to elimination of diffusion) can lead to the formation of monodisperse particles.…”

“…The flow rate of the oil phase was equal to 5 mL/h, and the flow rate of the water phase was equal to 1 mL/h [25].…”

“…In our previse paper [25], optimal conditions for droplet formation were investigated. From this study, essential process conditions for the droplet formation were determined like the phase composition and the flow rate.…”

Microdroplet synthesis of azo compounds with simple microfluidics-based pH control

“…The reagent introduced into the microdroplets diffuses instantaneously throughout, which enables efficient chemical reaction. 7,8 Microdroplet-mediated chemical synthesis has been studied primarily in the eld of organic chemistry. [9][10][11][12] Song et al compared the mixing of reagents during chemical reactions under laminar ow and inside microdroplets.…”

Characterization of Cotton Ball-like Au/ZnO Photocatalyst Synthesized in a Micro-Reactor

“…Nanomaterial synthesis in a micro-reactor with precisely controlled reaction conditions (i.e., minimize heat/mass transfer by instantaneous mixing) has become a versatile approach in modern synthetic chemistry [ 15 , 16 ] and been developed for producing metals (Au, Ag) [ 17 , 18 , 19 , 20 , 21 ], metal oxides (ZnO, TiO 2 , Fe 3 O 4 , SiO 2 ) [ 22 , 23 , 24 , 25 ], chalcogenides (CdSe, PbSe, CuInSe 2 ) [ 26 , 27 , 28 ], and core-shell (Fe 2 O 3 /SiO 2 , CdSe/ZnS) NPs [ 29 , 30 ]. These methods should be amenable to developing an industrially-relevant large-scale synthesis method by arraying many micro-reactors in parallel (hundreds to millions) [ 31 ].…”