CH-π interactions as the driving force for silicone-based nanocomposites with exceptional properties

The change in the physical and rheological behavior of the PDMS resin was demonstrated when a very low amount of self-pure carbon nanotubes (MWCNT) is added into the silicone matrix. Only a α,ω vinyl-terminated PDMS with a degree of polymerization equal to 434 and a partially cross-linked PDMS functionalized with terminal carbon double bonds was used. The self pure multiwall carbon nanotubes were kindly supplied by Nanocyl S.A; PDMS and fillers were mechanically blended with a helical blade at 1200 rpm for 2 h 30 mm before characterization. Approximately 30 g of heptane were added to the blend, so that the PDMS concentration is the same in every experiment. The mixture is placed under stirring at a controlled temperature during 4 h. The tube was centrifuged, and the products were dried under vacuum at 70°C until mass stabilization. The importance of the surface state of the filler is provided by the lower viscosity observed when the carbon nanotubes are treated.