One-step hybridization of graphene nanoribbons with carbon nanotubes and its strong-yet-ductile thermoplastic polyurethane composites

A hybrid of reduced graphene nanoribbon (GNR) carbon nanotube (CNT) (i.e. R-GNR/CNT hybrid) with unique three-dimensional (3D) nanostructures has been prepared via a facile unzipping and reducing method. Interlocked structures are formed within the nanohybrids where one-dimensional (1D) CNTs act as bridges connecting individual two-dimensional (2D) GNRs, which not only prevent the aggregation of GNRs but also promote the formation of 3D hybrid with cross-linked nanostructure. Thermoplastic polyurethane (TPU) composites with different R-GNR/CNT hybrid loadings have been fabricated via solution casting. With the addition of small amount of R-GNR/CNT hybrids, apart from the largely improved tensile strength and Young's modulus, the toughness of the TPU composites is surprisingly enhanced. Here, the toughening mechanisms are also discussed. Furthermore, the electrical conductivities of the TPU composites are also significantly enhanced in the presence of this 3D R-GNR/CNT nanohybrid due to the formation of conductive pathways within the matrix. (c) 2013 Elsevier Ltd. All rights reserved.