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We investigate the static properties of monodisperse polymer/single wall carbon nanotube (SWCNT) nanocomposites in comparison to polymer melts by molecular dynamics simulations. The SWCNT has a large aspect ratio and radius smaller than the polymer radius of gyration. We find that although the local chain structure is significantly affected, the overall configuration, as characterized by the radius of gyration, is not perturbed either by the interaction strength between the polymer and the SWCNT or by variations in the SWCNT radius.

We investigate the effect of various spherical nanoparticles on chain dimensions in polymer melts for high nanoparticle loading which is larger than the percolation threshold, using molecular dynamics simulations. We show that polymer chains are unperturbed by the presence of repulsive nanoparticles. In contrast polymer chains can be perturbed by the presence of attractive nanoparticles when the polymer radius of gyration is larger than the nanoparticle radius. At high nanoparticle loading, chains can be stretched and flattened by the nanoparticles, even oligomers can expand under the presence of attractive nanoparticles of very small size.

We investigate the polymer packing around nanoparticles and polymer/nanoparticle topological constraints (entanglements) in nanocomposites containing spherical nanoparticles in comparison to pure polymer melts using molecular dynamics (MD) simulations. The polymer-nanoparticle attraction leads to good dispersion of nanoparticles. We observe an increase in the number of topological constraints (decrease of total entanglement length Ne with nanoparticle loading in the polymer matrix) in nanocomposites due to nanoparticles, as evidenced by larger contour lengths of the primitive paths. An increase of the nanoparticle radius reduces the polymer-particle entanglements. These studies demonstrate that the interaction between polymers and nanoparticles does not affect the total entanglement length because in nanocomposites with small nanoparticles, the polymer-nanoparticles topological constraints dominate.

Nanoparticle and polymer dynamics in nanocomposites containing spherical nanoparticles were investigated by means of molecular dynamics simulations. We show that the polymer diffusivity decreases with nanoparticle loading due to an increase of the interfacial area created by nanoparticles, in the polymer matrix. We show that small sized nanoparticles can diffuse much faster than that predicted from the Stokes-Einstein relation in the dilute regime. We show that the nanoparticle diffusivity decreases at higher nanoparticle loading due to nanoparticle -polymer interface. Increase of the nanoparticle radius slows the nanoparticle diffusion.