A series of polymer-matrix composites were synthesized by using a variety of carbon nanotubes (single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs) and multi-walled carbon nanotubes (MWCNTs)) and a polymer matrix (either polystyrene (PS) or poly(methyl methacrylate) (PMMA)). Different surfactants and polymerization methods were also used in order to generate a wide range of different composites. These different composites were all tested for thermal and electrical conductivity and characterized ...