'Trigger-free' self-healable electromagnetic shielding material assisted by co-doped graphene nanostructures

The repercussions of the miniaturisation and augmentation of modern electronics and telecommunication are the unwanted interferences that come along with it. In the search for a good EMI shield, nanotechnology has come a long way from metal-based EM wave reflector to now lightweight polymeric EM wave absorbers. In this study, we have developed a unique heterostructure by combining the electronic properties of MWNTs, "flower-like" MoS2, magnetic properties of Fe3O4 and graphene oxide (GO) sheets. This resulted in a superior EM shielding performance of - 43.6 dB at 18 GHz with up to 96% absorption of EM waves. Additionally, the effect of two other different type of dopants in rGO@MoS2 namely, dielectric dopant (SiO2) and conducing dopant (Ag) was also studied apart from magnetic dopant (Fe3O4) to establish their effect on final shielding efficiency. It was observed that magnetic dopant exhibited highest absorption performance (96%) followed by dielectric dopant (90%). Since these materials have potential usage in high-end applications, we have attempted to develop a multifunctional material whereby we have modified the polymer matrix to develop a "trigger-free" self-healing polymer with up to 70% recovery of its original mechanical properties and nearly unaltered EMI shielding performance post healing. Such a unique multi-dimensional approach helps to improve the quality and lifetime of high-performance shielding materials which takes care of the fact that polymeric materials are mechanically weak compared to their metal counterparts.