Polymer/graphene oxide composite microcapsules with greatly improved barrier properties

Microcapsules with a polystyrene/graphene oxide composite shell were prepared by Pickering emulsion templating. Graphene oxide was modified using [2-(methacryloxy)ethyl]trimethylammonium chloride (METAC) or decyltrimethylammonium chloride (DTAC) to stabilize oil-in-water (O/W) Pickering emulsions. Scanning electron microscopy (SEM) was used to observe the morphology of the microcapsules. Thermal gravimetric analysis (TGA) was utilized to investigate the barrier property of the microcapsules. The activation energy of evaporation of the encapsulated material (n-hexadecane) is enhanced from 32.2 kJ mol−1 to 46.2 kJ mol−1, and even 60.9 kJ mol−1 because of the restriction of the polymer/graphene oxide composite shells. These microcapsules with greatly enhanced barrier properties may be potential candidates in encapsulating gas- or moisture-sensitive substances and volatile materials, especially for long-term storage or application.