Dynamic consequences of the fractal network of nanotube-poly(ethylene oxide) nanocomposites

Dispersions of single walled carbon nanotubes (SWNTs), with an effective aspect ratio of ∼650, in poly(ethylene oxide) (PEO) form fractal superstructures above their geometrical percolation and display rheological properties that follow time-temperature-composition-strain superpositioning. The concentration dependences of the elastic modulus of the network and the onset-strain for shear thinning are consistent with the short-range nature of the interactions that dominate these dispersions. The strain dependence of the damping behavior for the nanocomposites shows concentration invariance when represented against the local strain experienced by the network element, with the onset occurring at a local strain value of 0.1, similar to other nanocomposite systems dominated by weak interactions.