Graphene-mediated self-assembly of zeolite-based microcapsules

Porous core-shell microcapsules were obtained by assembling graphene layers on zeolite surfaces during amorphization process. When fused onto the surface, the self-assembled graphene layers played a role as 'isolation bubbles' that prevented the vapor releasing from bulk zeolites. The self-steaming of vapor served as the foaming agent of bringing the porous structure inside zeolites but also created an expansive force to form microcapsules. Due to their porous structures, the as-produced microcapsules showed excellent slow-release characteristics. The release of potassium from the microcapsules reaches equilibrium after 27 days, much slower than that from zeolites (2 days). We believe that the new microcapsules can be used as controlled-release agent for delivery of chemical compounds (e.g., fertilizers) as well as be used as microreactors, micro-devices, sensors, and catalysts. In addition, it is anticipated that the new synthesis route, especially using graphene layers to mediate amorphization, may be extended to other reactions.