The phase separation within the shell was confirmed by differential scanning calorimetry (DSC) of the APCN microcapsules, which revealed two glass transition temperatures, at -123 °C, corresponding to PDMS, and 4 °C, corresponding to PHEA (Figure ). Thermogravimetric analysis under a nitrogen atmosphere indicated a mass loss with an onset at 150 °C and mass loss of 7% until 265 °C, after which the main mass loss proceeded over a relatively large temperature range up to 470 °C (Figure ). The observed two-step mass loss corresponds most likely to the PHEA and PDMS chain segments of the APCN. Moreover, when PtNPs were present in the microcapsules, the mass loss in TGA experiments extended to above 550 °C. Attenuated total reflection Fourier-transform infra-red (ATR FT-IR) spectra of dried APCN microcapsules show no evidence of the absorption bands at 1637 and 837 cm -1 (Figure ), indicating that the TMS group was cleaved off and that PHEA chain segments formed.