Fabrication and morphology tuning of graphene oxide nanoscrolls

Abstract

Here we report the synthesis of graphene oxide nanoscrolls (GONS) with tunable dimensions via low and high frequency ultrasound solution processing techniques. GONS can be visualized as a graphene oxide (GO) sheet rolled into a spiral-wound structure and represent an alternative to traditional carbon nano-morphologies. The scrolling process is initiated by the ultrasound treatment which provides the scrolling activation energy for the formation of GONS. The GO and GONS dimensions are observed to be a function of ultrasound frequency, power density, and irradiation time. Ultrasonication increases GO and GONS C-C bonding likely due to in situ thermal reduction at the cavitating bubble-water interface. The GO area and GONS length are governed by two mechanisms; rapid oxygen defect site cleavage and slow cavitation mediated scission. Structural characterization indicates that GONS with tube and cone geometries can be formed with both narrow and wide dimensions in an industrial-scale time window. This work paves the way for GONS implementation for a variety of applications such as adsorptive and capacitive processes.

Reduced graphene oxide enwrapped phosphors for long-term thermally stable phosphor converted white light emitting diodes

“…These rod structures are nothing but rGO sheets that are transformed in to nanoscrolls. This scrolling is a result of the interaction of heavy phosphor particles with rGO sheet during annealing which results in an extremely unfavorable condition for rGO to maintain its planar structure1718. During the annealing of the GO-phosphor composite at high temperatures, along with the removal of functional groups, the phosphor particles are also attached to the rGO sheets.…”

“…This is because, the interaction between phosphor particles and rGO renders the planar structure of the rGO sheets extremely unfavorable19. The bending of the rGO sheets is followed by rolling to form scrolls because of Van der Waals attraction and the π-π stacking effect between rGO layers1718. The formation of the nanoscrolls occurs in two steps.…”

Influence of graphene nanoscrolls on the crystallization behavior and nano‐mechanical properties of polylactic acid

“…3 Formation of GNS from GNPs involves overcoming an energy barrier of about 100 s to 1000s J mol −1 to initiate the GNS formation, after which it self-propagates because of π-π interactions, forming a nanoscroll with an internal diameter of approximately 2 nm. 29 Scrolling was initiated by ultrasonication of the solvent mixture, which provided the energy needed to induce self-propagation of GNPs, and lyophilization enabled a stable scrolled structure. Notably, the GNS prepared in this work was prepared through lyophilization of ice particles using low concentration (0.05 mg mL −1 ) of GNPs.…”

“…This is evident because of the dark layers overlapped on the lighter ones. Scrolling of GNPs is described as a result of self-assembly, which involves ultrasonication of the solvent-intercalated layer of graphene that enabled self-scrolling 4,7,29. As seen inFigure 1E-H, the scrolling of GNPs into GNS exhibits well-defined concentric geometries produced by the fine tuning of GNPs.…”

Architecting Graphene Oxide Rolled‐Up Micromotors: A Simple Paper‐Based Manufacturing Technology

“…These rolled‐up structures mainly assume an Archimedean‐type spiral form resulting from the scroll formation at one corner of a graphene square, for instance. Until now, GO rolled‐up tubes were processed by strong sonication treatments, chemical microexplosion, nanomaterials modification, among others . As a result of such outstanding configuration along with the recognized properties of GO, GO‐based rolled‐up tubes have been explored in myriad of applications such as superlubricity, sensors, supercapacitors, batteries, or catalysis .…”