The VFD can operate under so call c

The VFD can operate under so call continuous ow modewhere jet feeds deliver liquid to the base of the rapidly rotatingtube leading to intense shearing and micromixing in theresulting dynamic thin lm, with the lm thickness primarilygoverned by the rotational speed, ow rate and tilt angle, q ofthe tube. Controlling the delivery of a drop of liquid onto thehemispherical bottom of the VFD tube sets the level of shearingand when the liquid exits the hemisphere, a helical wave isformed, which is likely to provide additional shearing due to theviscous drag of the liquid against the rotating tube. The intenseshear that is created at the base of the tube is also present in thethin lm, which arises from the Stewartson/Ekman layers.18Also noteworthy, is that the intense shear can result in a changeof the surface tension of the thin lm, which can facilitate highmass transfer of gases into and out of the liquid.19The VFD is a versatile processing platform in materialschemistry, for example, in exfoliating graphene and h-BN,20coating algal cells with graphene and a magnetic polymer,21controlling the pore size of mesoporous silica22 and decoratinggraphene with palladium nano-particles.23 In the context of thepresent study, the VFD is effective in enhancing the dimerization of cyclopentadienes, the direct base catalysed synthesis of2,4,6-triarylpyridines from aromatic aldehydes and ketones in asingle pass,7 the stereospecic synthesis of calixarenes derivedfrom resorcinol or pyrogallol and aldehydes,24 and roomtemperature conversion of sunower oil to biodiesel,25 all undercontinuous ow conditions. The work herein focuses onfurthering fundamental organic chemistry, with an aim ofunderstanding the remarkable outcome of the above reactionscarried out using the device.