Electric field induced formation and characterization of nanoscroll from water-submerged graphene nanoribbon

Abstract

In this thesis work, a technique to induce the formation of a nanoscroll from a graphene nanoribbon structure submerged in water using a rotating electric field is proposed. In particular, we use molecular dynamics simulation to show that electric field induced rotation of water dipoles can, in turn, originate rotation of the immersed nanoribbon. The proposed setup is such that one end of the nanoribbon is kept fixed, while the other end orients itself with the rotating electric field and eventually, self-assembles into a more stable nanoscroll configuration. We compute the time evolution of the van der Waals interaction energy of the nanoribbon structure to explain its self-assembly into a nanoscroll. Our results show that the final structure is more stable than the initial configuration and retains its stability on removal of the electric field as well as the aqueous environment. In addition, we characterize the nanoscroll formed using our method by studying concentration profiles along its scrolling directions, which depict the stability and uniformity of its morphology. To study the versatility of our proposed method, we vary the length, width, and chirality of the initial nanoribbon. Further, we study the effect of changing the process conditions such as angular frequency and strength of the applied electric field on the trajectory of the nanoribbon and the resulting scrolls formed. In each case, we use energy and concentration profiles to illustrate the stability and morphology of the nanoscrolls. Our studies reveal that the proposed method can be used to induce the self-assembly of any nanoribbon structure independent of its dimensions and chirality. Moreover, the method is fairly independent of the process conditions and thus can be utilized under any preferred rotating electric fields. Lastly, we show that the proposed method can also be employed to induce the scrolling of multilayer nanoribbons as well as to form nanotemplate encapsulated core/shell composite structures.