| 초록 |
Nanoscopic dispersions of inorganic nanoparticles in a polymer have been shown to enhance many aspects of the materials performance. Critical to advancing nanocomposite technology are understanding and controlling the factors which determine the nano- and mesoscale morphology of the constituents. Coarse grain molecular dynamics simulations have been used to examine the behavior of three types of systems. A bead-spring model was used to represent low molar mass fluids, polymer chains, and the inorganic phases (either rod-like or layered). Simulations were first used to examine layered silicates in binary (low molar mass) fluid mixtures, a model relevant to the morphology development and phase behavior for in situ polymerized nanocomposites. Partitioning of the fluid components is governed both by the relative strengths and individual magnitudes of the interactions between the fluids and the silicate sheets. The mixing sequence used for two-part reactive materials could substantially influence the structure and properties of the resulting nanocomposite. Simulations were then used to examine the initial stages of polymer melt intercalation into layered or rod-like reinforcing materials, relevant to polymer-silicate and polymer-nanotube nanocomposites. The influence on intercalation behavior of the stiffness, dimensions, temperature, and the relative energies of polymer interactions with the reinforcing phases were studied. Finally, the deformation behavior of the nanocomposites has been simulated in order to provide data for higher order (finite element) models of these materials. |
