Optimising a vortex fluidic device for controlling chemical reactivity and selectivity

Abstract

A vortex fluidic device (VFD) involving a rapidly rotating tube open at one end forms dynamic thin films at high rotational speed for finite sub-millilitre volumes of liquid, with shear within the films depending on the speed and orientation of the tube. Continuous flow operation of the VFD where jet feeds of solutions are directed to the closed end of the tube provide additional tuneable shear from the viscous drag as the liquid whirls along the tube. The versatility of this simple, low cost microfluidic device, which can operate under confined mode or continuous flow is demonstrated in accelerating organic reactions, for model Diels-Alder dimerization of cyclopentadienes, and sequential aldol and Michael addition reactions, in accessing unusual 2,4,6-triarylpyridines. Residence times are controllable for continuous flow processing with the viscous drag dominating the shear for flow rates >0.1 mL/min in a 10 mm diameter tube rotating at >2000 rpm.

Shear induced carboplatin binding within the cavity of a phospholipid mimic for increased anticancer efficacy

“…2B,C). This is despite the short processing time for a finite volume of liquid moving through the VFD under continuous flow three times, being less than three minutes6. Presumably the intense micro-mixing and subsequent shear in the VFD results in the majority of the P4C6 molecules on the solution face of the bilayer (immediately accessible) to bind carboplatin.…”

“…The vesicles were loaded with carboplatin using a recently developed vortex fluidic device (VFD)6 which has a rapidly rotating tube open at one end (Figure S2). The high rotational speed generates shear in the resulting thin films arising from viscous drag, Stewartson/Ekman layers6, and resonance effect8, in tracking towards conditions beyond diffusion control. The constant shear in this microfluidic platform is effective in disassembling self-organized molecular capsules for small molecule inclusion or encapsulation,9101112 as has been established for the related spinning disc processor13.…”

Rapid Vortex Fluidics: Continuous Flow Synthesis of Amides and Local Anesthetic Lidocaine

“…Full workings and schematicso ft he VFD havebeen previouslyreported. [17] chemistry systems. Though notable exceptionse xist, [20][21][22] am ore general solution to these problemsi sw arranted.…”

Microencapsulation of bacterial strains in graphene oxide nano-sheets using vortex fluidics

“…10,16 In the VFD, a rapidly rotating tube generates a thin microuidic lm with rapid micro-mixing of reagents therein, and the mechanoenergy in the lm is effective in increasing reaction rates, and therefore reducing the processing times. 33 Importantly, the VFD can be operated in the conned mode and also continuous ow mode, and it has a diversity of processing capabilities, including in organic synthesis, [33][34][35][36][37] controlled growth of the polymorphs of calcium carbonate, 38 formation of mesoporous silica at room temperature with control over the pore size, 39 compacting single walled carbon nanotube into toroidal structures, 40 exfoliation of graphene and boron nitride, 41 controlled decoration of nanoparticles on 2D nanomaterials, [42][43][44] preparation of functional hybrid bio-nanomaterials, 10,16,45 and the refolding of proteins.…”