Encapsulated phase change materials stabilized by modified graphene oxide

The microencapsulation of phase change materials (n-hexadecane) with double-walled shells (polystyrene/graphene oxide) was realized from Pickering emulsion templating. Graphene oxide nanosheets were modified by the polycondensate of diethanolamine and adipic acid, which can well stabilize oil-in-water (O/W) Pickering emulsions. The morphology of the double-walled shell of polymer microspheres was observed by scanning electron microscopy (SEM). The thermal and barrier properties of microcapsules were studied using differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and the flammability test. DSC results indicate that the encapsulation ratio of n-hexadecane is as high as 78%. The encapsulated phase change material has good thermal stability, owing to the existence of graphene oxide on the surface protecting the core material from leakage and evaporation. This double-walled microencapsulation of phase change materials may have potential applications in energy storage and energy saving.