Metal-organic frameworks mediated interface engineering of polymer nanocomposites for enhanced dielectric constant and low dielectric loss

Interface modulation is a key issue for the incorporation of inorganic nanofillers into polymeric matrixes, especially in the applications of dielectric materials. Metal-organic frameworks (MOFs) with special organic and inorganic characteristics represent enormous potential in the interface engineering of polymer-based nanocomposites with desirable dielectric performance. Herein, we report a novel strategy to synthesize graphene oxide nanosheets with UiO-66-NH2 MOF decoration (G@M) using an in-situ and ex-situ method, which are utilized as the nanofillers in the super-engineering polymeric matrix namely polyarylene ether nitrile (PEN). In-situ MOF decoration improves the compatibility between graphene oxide and PEN matrix, and the resulting G@M/PEN nanocomposite shows an enhanced dielectric constant of 7.94 and an ultra-low dielectric loss of 0.014 (1000 Hz) at a low filling content (4 wt%) with outstanding tensile strength (106 MPa) and high glass transition temperature (208°C). Besides, owing to the in-situ interface tailoring, the G@M/PEN nanocomposite exhibits a much higher energy storage capability, about 107% higher than that of conventional graphene oxide-incorporated nanocomposite. This research provides new insight into the interface design of polymer-based nanocomposites for dielectric applications.