an9b01304_si_006.mpg (4.36 MB)

Graphene Nanoscrolls via Electric-Field-Induced Transformation of Water-Submerged Graphene Nanoribbons for Energy Storage, Nanofluidic, and Nanoelectronic Applications

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posted on 13.09.2019 by Mahnaz Islam, Md. Mushfiqur Rahman, Mokter Mahmud Chowdhury, Md. Kawsar Alam
Nanoscroll is a rolled-up sheet of nanoribbon resembling a spiral papyrus-like multilayer structure, having a broad range of applications from gas and energy storage to nanofluidic and nanoelectronic devices. However, the existing methods of fabrication suffer from complex processing, high energy consumption, abundant impurities, and/or hybrid nanostructures, rendering them insufficient to fabricate scalable and high-quality nanoscrolls. Here, we predict that a graphene nanoribbon self-assembles into a nanoscroll under the influence of an external rotating electric field. Using molecular dynamics simulation, we show that electric-field-induced alignment of water dipoles originates rotation in a water-submerged graphene nanoribbon. On the basis of this principle, we propose a setup for nanoscroll formation from water-submerged graphene nanoribbon where 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 nanoscroll. The nanoscroll is found to be energetically more stable than the initial configuration and retains its stability on removal of the external field as well as the aqueous environment. Findings from concentration profiles of the nanoscroll further confirm the stability as well as uniformity of its morphology. The formation mechanism is found to be minimally dependent on the applied field’s strength and frequency. The proposed method can be used to induce self-assembly of any nanoribbon structure independent of its dimensions and chirality and multilayer nanoribbons as well as to form nanotemplate encapsulated core/shell composites. The proposed method would enable large-scale realization of high-quality nanoscrolls from nanoribbons, facilitating fundamental and applied research on nanomaterials.