Peripherally decorated binary microcapsules containing two liquids

In this work, similar to 1.4 mu m dibutylphthalate (DBP) filled urea-formaldehyde (UF) microcapsules were used as Pickering stabilizers to create larger similar to 140 mu m microcapsules containing a second liquid phase, dicyclopentadiene (DCPD). The binary microcapsules were made by encapsulating the dispersed DCPD liquid (stabilized with the UF(DBP) microcapsules in water) via an isocyanate-alcohol interfacial polymerization reaction. Fluorescent optical microscopy and scanning electron microscopy (SEM) showed that the resulting microcapsules have a central liquid core decorated at its periphery with a layer of microcapsules containing the second liquid. The presence of both the encapsulated liquids within a single capsule structure was demonstrated by differential scanning calorimetry (DSC). DSC data analysis indicated a DBP volume fraction of 8.8%. This value was validated by the calculated theoretical fraction on the basis of the observed architecture and capsule dimensions.