Multifunctional Composites Based on Nanocarbons

This talk starts with a review of the different strategies to incorporate nanocarbons (CNTs, graphene) inpolymer matrices and their relative merit in terms of mechanical reinforcement, improvement inelectrical/thermal conductivity and emergence of other functional properties, such as sensingcapabilities [1] [2]. Three types of nanocomposites are discussed: the first type corresponds tocomposites where the nanocarbon is used as a filler added to a polymer matrix, the second consists ofhierarchical composites with macroscopic fibres and nanocarbon in a polymer, typically thermosettingmatrix; the third type are nanocarbon-based macroscopic fibres which can be processed to formstandard fibre reinforced polymer (FRP) composites (Figure 1). We then show examples ofexperimental results of low volume fractions nanocomposites with a high level of reinforcement and asignificant increase in thermal conductivity. The effects of the nanofiller on the matrix are particularlynoticeable in the low volume fraction regime; in this work we use by Raman spectroscopy to study thestress-transfer between nanocarbons and the matrix, and the possible residual strains in the compositesdue to mismatch in coefficients of thermal expansion. The stiffening of the polymer through reducedmobility and its increase in thermal stability are analysed by standard DMA and related to resultsobtained using a state-of-the-art nanoindentation DMA system.References [1] J J Vilatela and D Eder, "Nanocarbon composites and hybrids in sustainability: a review," Chem. Sus. Chem.,vol. In press, 2012.[2] R Guzman de Villoria, N Yamamoto, A Miravete, and B Wardle, "Multi-physics damage sensing in nano-engineered structural composites ," vol. 22, p. 185502, 2011.[3] E Logakis et al., "Low electrical percolation threshold in poly(ethylene terephthalate)/multi-walled carbonnanotube nanocomposites," European Polymer Journal, vol. 46, pp. 928 936, 2010.[4] E J Garcia, B L Wardle, and A J Hart, "Joining prepreg composite interfaces with aligned carbon nanotubes,"Composites: Part A, vol. 39, pp. 1065 1070, 2008.[5] R J Mora, J J Vilatela, and A H Windle, "Properties of composites of carbon nanotube fibres," Comp. Sci.Tech. , vol. 69, pp. 1558 1563, 2009.