Terrace-like MicroChannel Devices

Three different types of microsystem have been reported for the emulsification of a polymerizable liquid (Figure 18.1), namely the terrace-like microchannel device, the T-junction microchannel device and the flow focusing device (FFD). The emulsification mechanism, which is similar for these three devices, proceeds from the breakup of a liquid thread into droplets when the phase to be dispersed is sheared by the continuous and immiscible phase. 

The terrace-like microchannel device (Figure 18.1a) consists of a main channel in which the continuous phase flows. Several microchannels deliver the dispersed phase at the top and from both sides of the main channel. Then terraces located just below the microchannels allow the break-up of the dispersed phase thread. In T-junction microchannel devices (Figure 18.1b), the phase to be dispersed is delivered through a microchannel perpendicular to a main charmel in which the continuous phase flows. Depending on the flow rates of the continuous and dispersed phases, the break-up is observed at the junction of the two microchannels... 

Figure 18.1 Different microsystems for the emulsification of a liquid monomer (a) terrace-like microchannel device ...

Figure 18.3 Top schematic drawing of the terrace-like microchannel device. From Ref [2], Bottom SEM images of poly (DVB) beads at different magnifications. From Ref [1].

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