Electromagnetic Interference Shielding of a Sequential Dual-Curing Thiol-Epoxy System Reinforced with GNPs with High Shape Memory.

Abstract

Modern electronics face several challenges during operation, such as interference of disruptive electromagnetic signals and high temperatures within a limited space. Both electromagnetic interference (EMI) and thermal management could be tackled simultaneously by employing smart efficient materials with high thermal and electrical conductivity. A dual-curing epoxy system, a new subset of adaptable materials, could potentially solve those challenges, with the proper selection of the reinforcement. Moreover, its manufacturing and synthesis process, which involves a sequential curing stage, constitute an attractive, selective, and fast methodology. The thiol-epoxy chemistry allows the synthesis of an epoxy system with high shape-memory capabilities while retaining optimal mechanical properties. Herein, dual-curing epoxy systems reinforced with graphene nanoplatelets (GNPs) are manufactured. The influence of the GNPs content is evaluated, which greatly increases upon loading while retaining a high shape-memory fixation and recovery rates (near 99%). A maximum EMI shielding efficiency of 24 dB is achieved for the higher GNPs content, which is endowed by the high electrical conductivity of the system. Moreover, a modelization of the near-field and far-field EMI shielding is reported, which agrees with experimental observation. This report shows the potential and multifunctional nature of dual-curing epoxy composites for EMI shielding and shape-memory-related application.