The microscopy image in Figure shows an example of the capsules after the polymerization and TMS-cleavage step. In this typical batch, spherical APCN microcapsules with an outer diameter of 412 ± 23 µm and a shell thickness of 59 ± 14 µm were obtained, when water-swollen. However, the capsule size could vary slightly with each batch. The shell of each capsule had a slightly asymmetric thickness, which is a commonly observed phenomenon for double emulsion microcapsules as the inner phase sinks within the oil phase shell before curing due to gravity, solvent evaporation and the difference in flow speeds between the inner and middle phases. The shell of the capsules is optically transparent, which indicates that no macroscopic phase separation occurred during the synthesis of the APCNs, which would have resulted in turbid materials. As PHEA and PDMS chain segments in the APCNs are not miscible, nanophase separation is expected to occur.