Self-aligned Graphene Sheets-Polyurethane Nanocomposites

Abstract

Processing graphene and graphene polymer nanocomposites in an aqueous medium has always been a big challenge due to the hydrophobic nature of graphene (or reduced graphene oxide) nanosheets. In this work, a waterborne latex of polyurethane has been used both as the matrix material for embedding the graphene nanosheets and as a unique stabilizer to help produce an up to 5 wt% graphene/PU nanocomposites. The graphene oxide/polyurethane latex aqueous suspension is reduced in-situ using hydrazine, without any trace of aggregation/agglomeration upon completion of the reduction process, which would otherwise have occurred severely were PU not present. A highly aligned nanostructure is produced when graphene content is increased beyond 2 wt%, resulting in a remarkable improvement in electrical and mechanical properties of the nanocomposite. The exceptionally low electrical percolation threshold of 0.078%, as well as 21-fold and 14 fold increases in tensile modulus and strength, respectively, have been attained thanks to the alignment of graphene nanosheets in the polymeric matrix.

Fabrication of 3D honeycomb-like porous polyurethane-functionalized reduced graphene oxide for detection of dopamine

“…Hussain et al, (2015) fabricated a highly sensitive non-enzymatic glucose sensor using 3D graphene-Cu hybrid electrodes. In particular, the 3D-honeycomb-like porous structure of a RGO-PU nanomaterial architectures had the advantages of ease of preparation, high porous surface structure, fast response, ultra-sensitivity, selectivity, stability, good reproducibility and repeatability (Moazzami Gudarzi et al, 2011). The 3D hierarchical nanomaterials offer porous structures made to their adjacent nano-units and large specific surface areas to supply many active sensing sites, which attracts more studies for electrochemical sensor application (Gupta et al, 2015;Xiao et al, 2014).…”