Graphene-Carbon Nanotubes Hybrids for Composite Materials

Abstract

Two different carbon based nanostructures, multiwall carbon nanotubes and multi-layered graphene, were incorporated to carbon epoxy laminated. X-ray diffractometry indicates an average particle size of 22 nm for the multi-layer graphene (MLG) nanostructures. TEM observations revealed a thickness of 10 graphene layers, and a hybrid nanostructure where MWNT interpenetrated the MLG nanostructure. To be able to disperse more efficiently the carbon based nanostructures two different surfactants were employed, i.e. Sodium dodecyl sulfate (SDS) and Polyoxyethylene nonylphenyl ether (IGEPAL CO890). The dispersion of surfactants associated to graphene led to increase on stiffness and strength, for both tensile and bending loads. If on the top of these surfactants/graphene additions, CNTs are added, the improvement is even better. For tensile tests, the average peak stress increase from 542.76 MPa (blank specimen) to 667.51 MPa (CO 890 and graphene/CNT), while for bending the peak stress improved from 369.40 MPa (blank specimen) to 584.15 MPa (CO 890 and graphene/CNT). The association of carbon based nanostructures (graphene and CNT) associated to surfactants seems to be a promising route to improve carbon/epoxy composites.