Toughing epoxy nanocomposites with graphene-encapsulated liquid metal framework

Abstract

Multifunctional epoxy nanocomposites have long been pursued as the crucial component of future aerial vehicles, while their practical implementation is unfortunately restricted by the poor toughness and incapability of chemical activity derived from highly cross-linked networks. Here, inspired by “brittle–ductile” laminated architecture, a stress-induced graphene-encapsulated liquid metal framework was developed to enhance the fracture toughness of multifunctional epoxy nanocomposites and their electromagnetic interference shielding, outdoor deicing and crosslinking behaviors were discussed. The resulting “brittle-ductile” laminated structure enables effective crack deflection and unique fracture surface; the plane strain fracture toughness (KIC) of epoxy nanocomposites is 2.34 times higher than that of pure epoxy resin. Moreover, the reinforced epoxy nanocomposites exhibited high electromagnetic interference shielding effectiveness of 48.24 dB at X-band, about 20 times greater than that of the pure epoxy (∼2.4 dB), and its efficient solar de-icing capability enable spontaneously melting surface ice/frost within 3 min. The dimensionless Cure Index (CI) was used for qualitative analysis of epoxy crosslinking in the presence of graphene-encapsulated liquid metal framework performed by nonisothermal differential scanning calorimetry (DSC). This work shows for the first time to the best of our knowledge graphene encapsulated liquid metal framework as reinforced fillers in epoxy nanocomposite achieve a unification of high toughness, electromagnetic shielding capabilities, and solar deicing properties. Present work thus provides an alternative of constructing high-toughness multifunctional epoxy nanocomposites for aerial vehicles application.