Generation of Droplets in Double T‐Shaped Microchannels with Necked Structures

Abstract

Microfluidic droplets are widely applied in various fields such as biomedicine, aerospace, energy utilization, and chemical engineering due to their advantages of large specific surface area, uniform size, stability, and easy control. The double T‐shaped microchannel has the characteristics of rapid preparation of microdroplets with controllable size and good uniformity. Through 3D numerical simulation, the influence of the constriction structure of the microchannel on the formation of droplets was studied qualitatively and quantitatively. Compared with ordinary double T‐shaped microchannels, the microchannels with a necked structure generate smaller droplets in diameter and faster generation frequency. Among the three structures of rectangular necking, inverted trapezoidal necking, and trapezoidal necking, the microchannel with the latter structure has the best performance, can produce monodisperse droplets of uniform size, and the period is stable.

Numerical Analysis of Droplet Impacting on an Immiscible Liquid via Three-Phase Field Method

“…Microdroplets, the scale-down analytical platforms, are commonly used in the fields of analytical chemistry [ 1 ], biology [ 2 ], material synthesis [ 3 ], and so on. Understanding the impacting mechanism between a liquid-in-air droplet and an immiscible aqueous solution is important and helpful for lots of applications, such as biofabrication through inkjet printing [ 4 , 5 ] and droplet encapsulation [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ] for drug delivery [ 14 , 15 ], PCR reaction [ 16 , 17 ], and preparation of Janus droplets [ 18 ] or double-emulsions [ 19 , 20 ]. When the oil droplet impacts with another immiscible aqueous solution, it will transiently knock a crater on the surface of the aqueous solution and lead to the floating, bouncing, jetting, or splashing of the solution [ 21 , 22 , 23 ].…”

Comparative study on the mechanical and thermal properties of polycarbonate composites reinforced by KH570/SA/SDBS modified wollastonite fibers

“…[36,37] For example, Xu et al [38] used four kinds of surfactants (i.e., KH-570, KH-550, Zinc stearate, and Sodium stearate) to modify the Wo fibers and found that KH-570 modified sample possessed the maximum contact angle and activation index. Zhang [39] compared the effects of surface modification of Wo with KH-570 and titanate coupling agent JN-114 and demonstrated better interface integration between KH-570-fillers and PP matrix through SEM images. Stearic acid was used by Salas-Papayanopolos et al as a modifier for the PP-Wo system.…”

Simulation of Droplet Formation in T‐Inlet Microchannels with Different Junction Angle

“…The generation process of microdroplets in the T-inlet microchannel device is jointly affected by multiple parameters, among which the fluid property parameters include flow rate ratio, interfacial tension, internal wettability of the microchannel [24,25], etc. The geometrical parameters include the angle between the two phases of the T-junction microchannel, aspect ratio of the inlet, width ratio of different entry channels [26][27][28][29], etc. In experimental studies, researchers often change the flow rate ratio by altering the two-phase fluid flow rate, the wettability inside the microchannel by attaching a chemical coating to the surface of the microchannel, and use of chemical active agents to vary the interfacial tension of the two-phase fluid.…”