Nanotube Networks in Polymer Nanocomposites:  Rheology and Electrical Conductivity

ABSTRACT: Single-walled carbon nanotube (SWNT)/poly(methyl methacrylate) (PMMA) nanocomposites were prepared via our coagulation method providing uniform dispersion of the nanotubes in the polymer matrix. Optical microscopy, Raman imaging, and SEM were employed to determine the dispersion of nanotube at different length scales. The linear viscoelastic behavior and electrical conductivity of these nanocomposites were investigated. At low frequencies, G ′ becomes almost independent of the frequency as nanotube loading increases, suggesting an onset of solidlike behavior in these nanocomposites. By plotting G ′ vs nanotube loading and fitting with a power law function, the rheological threshold of these…