Highly Conductive and Transparent Reduced Graphene Oxide Nanoscale Films via Thermal Conversion of Polymer-Encapsulated Graphene Oxide Sheets

Abstract

Despite noteworthy progress in the fabrication of large-area graphene sheetlike nanomaterials, the vapor-based processing still requires sophisticated equipment and a multistage handling of the material. An alternative approach to manufacturing functional graphene-based films includes the employment of graphene oxide (GO) micrometer-scale sheets as precursors. However, search for a scalable manufacturing technique for the production of high-quality GO nanoscale films with high uniformity and high electrical conductivity is still continuing. Here we show that conventional dip-coating technique can offer fabrication of high quality mono- and bilayered films made of GO sheets. The method is based on our recent discovery that encapsulating individual GO sheets in a nanometer thick molecular brush copolymer layer allows for the nearly perfect formation of the GO layers via dip coating from water. By thermal reduction the bilayers (cemented by a carbon-forming polymer linker) are converted into highly conductive and transparent reduced GO films with a high conductivity up to 10 S/cm and optical transparency on the level of 90%. The value is the highest electrical conductivity reported for thermally reduced nanoscale GO films and is close to the conductivity of indium tin oxide currently in use for transparent electronic devices, thus making these layers intriguing candidates for replacement of ITO films.

Plasma Enabled Conformal and Damage Free Encapsulation of Fragile Molecular Matter: from Surface‐Supported to On‐Device Nanostructures

“…Widespread use of atomically thin materials such as graphene, transition metal dichalcogenides, and several other classes of fragile nanoscale matter in electronic, opto‐ and magnetoelectronic, biomedical, and many other nanodevices necessitates atomically conformal encapsulation layers . Ideally, any sort of damage should be avoided during the fabrication.…”

Concentration Gradient‐Based Soft Robotics: Hydrogels Out of Water

“…[ 20 ] Despite being soluble in water, this graphene material has very few defects, it is not oxidized (as evidenced by its characterization, see Figure S1, Supporting Information) and it gives low resistivity values (5.40 ± 0.07 Ω ⬜), i.e., much lower than those observed for graphene oxide (4.11–6.67 MΩ ⬜) [ 21 ] or reduced graphene oxide (500–1100 Ω ⬜). [ 22 ]…”

“…[20] Despite being soluble in water, this graphene material has very few defects, it is not oxidized (as evidenced by its characterization, see Figure S1, Supporting Information) and it gives low resistivity values (5.40 ± 0.07 Ω ⬜), i.e., much lower than those observed for graphene oxide (4.11-6.67 MΩ ⬜) [21] or reduced graphene oxide (500-1100 Ω ⬜). [22] The initial CN and CNG compositions are 50.50 ± 0.74% (by weight, wt%) of water. Both materials can swell in an external aqueous medium, and the quantity of water contained in them can reach a maximum of 99.65 ± 0.07% and 99.33 ± 0.04%, respectively.…”

Adhesion and Stability of Nanocellulose Coatings on Flat Polymer Films and Textiles

“…These two types of functional groups provide a combination of strong hydrogen bonds and covalent cross-linking. The covalent cross-linking mechanism involves the opening of epoxy rings and the formation of covalent bonds between epoxy groups of P(GMA-OEGMA) [ 54 ]. Reactivity of cellulosic -OH with epoxy-groups is not high enough to provide substantial effect for the cross-linking involving nanocellulose [ 55 ].…”