Chemical reaction and mixing inside a coalesced droplet after a head-on collision

Abstract

the rate of chemical reaction and the profile of a coalesced droplet, which is a significant reference in droplet-based microfluidic systems for biochemical applications.

Magnetically-Actuated Mixing and Merging of Acid-Base Micro-Droplets on Open Surfaces: Preliminary Study

“…The mixing time of the reactive droplets is 7 to 12 times lower than the non-reactive droplets. Similar trend had been reported by Yeh et al [ 22 ]. Their mixing time of the non-reactive droplet was 100 times lower than their reactive droplets.…”

“…In terms of our current results, the characterizations of the chemical reaction of these magnetically actuated acid-base droplets would be useful. As mentioned in Section 1 , Yeh et al [ 22 ] passively merged and mixed phenolphthalein and 0.1 M NaOH micro-droplets. They studied the chemical reaction at the interface of the mixed droplet using a high speed camera.…”

“…The variation of the volume of the acid and base droplets would produce different profiles of the “neck curvature” during the merging of the droplet [ 22 ]. Ultimately we would like to record the “finger formation” as reported by several articles that studied the hydrodynamics instabilities of those reactions [ 21 , 22 , 24 , 25 ]. In addition, the concentration of the acid-base solutions should be titrated from 1.0 M down to a micro-M. By doing that, we could study the influence of these lower concentrated droplets to the measured peak temperature.…”

“…In that particular work, they credited it to the released heat from the exothermic reaction. Another group i.e., Yeh et al [ 22 ] studied the kinematics of the mixing and merging of phenolphthalein and 0.1 M NaOH micro-droplets. The passive mixing was implemented using different wettability gradient on top of a glass surface.…”

Development of a millimetrically scaled biodiesel transesterification device that relies on droplet-based co-axial fluidics

“…In recent years, microfluidic devices have been developed for biodiesel transesterification to include capillary reactors 11 12 and microreactors 13 14 15 16 . However, a droplet-based microfluidic system with a large surface-to-volume ratio is more suitable for biodiesel transesterification because it can increase the chemical reaction rate by increasing the material interface between reagents 17 18 . Regarding recent two-phase immiscible reagent system reaction reaseach 19 20 , it has been shown that mass transfer across the boundary between two immiscible liquids in a microchannel is enhanced significantly by internal circulation in the segmented liquid 21 22 .…”