Mass Production of 2D Manifolds of Graphene Oxide by Shear Flow

Abstract

Self-organizing 2D sheets into a 3D structure with a well-defined arrangement and tuned bandgap has garnered significant interest. However, there exist challenges such as scalable and feasible synthetic methods and preservation of 2D properties while preventing re-stacking. Herein, a facile method for the mass production of 2D manifolds of graphene oxide (GO), which are 3D microtubes, while maintaining their 2D properties by applying shear to roll up GO sheets, is reported. The GO mesotubes are formed by shear flow in aluminum-glass parallel plates. Redox reaction plays a vital role during the formation of GO mesotubes by the vorticity alignment during slow shear flow. A high yield of 94% is achieved at an initial pH of 2.2. The maximum d-spacing of the GO sheet in the tube wall is 21 nm, indicating no re-stacking of the graphitic structure. It is demonstrated that the GO mesotubes behaves like a soft gel, rendering them a candidate material for soft robotics, e-skins, and a visible light sensor owing to their reduced optical bandgap.

Simulation of interacting elastic sheets in shear flow: Insights into buckling, sliding, and reassembly of graphene nanosheets in sheared liquids

“…Recently, a mass production method was developed to create graphene oxide (GO) mesotubes for soft robotics and e-skins by placing nanosheet dispersions under linear shear flow conditions. 57 This process resulted in flow-induced self-organization of GO nanosheets into scrolled structures with significantly lower bandgap. These structures demonstrated sensitivity to vibration, temperature, and human artery pulse pressure.…”

“…62,63 While these additional factors are necessary to maintain stable nanosheet morphologies, the emergence of different shapes arises with external forcing, e.g., mixing and shear. 57,58,62 If suitable care is taken in the material preparation and characterization steps (see "Material quality assurance"), the formation of these shapes can be attributed to the mixing or other high shear processes. Indeed the dominance of shear exfoliation on the final shapes has been demonstrated indirectly by previous work on hexagonal boron nitride nanosheets.…”

A Graphene-Based Aerogel Was Prepared as Solid Adsorbent for the Enrichment of Platinum (IV) at Trace Concentration

“…Graphene oxide (GO) has a honeycomb-like six-ring structure and oxygen-containing groups, making it modified easily in the preparation process. It is a precursor to other graphene-based materials including two-dimensional (2D) and three-dimensional (3D) structure [24] [25] [26] [27]. Graphene-based materials as solid extractants have a big potential to be applied in sample pretreatment by functionalizing graphene oxide, due to the intrinsic biocompatibility, enlarged adsorption capacity, increscent specific surface area and the obtained selective specificity.…”