Figure 5.

Interfacial precipitation for enhancing encapsulation efficiency of allura red. Optical microscope images of (a)-(c) jets and (d) droplets of water with 17 wt. % PEG and 1 wt. % calcium chloride in a continuous phase of water with 16 wt. % dextran and 1 wt. % sodium carbonate. Images (a) and (c) are taken at 0.5 cm from the tip of the injection capillary while images (b) and (d) show the same jets as in (a) and (c), respectively, at 2 cm from the tip of the injection capillary. Shaking is only applied to the jet shown in (c) and (d). The calcium ions and the carbonate ions in the dispersed and continuous phases, respectively, react to form a precipitate of calcium carbonate. In (d), the satellite drops form between two larger parent drops since the addition of components for interfacial precipitation modifies the rheological properties of the fluids. Scale bar is 1 mm.