Narayanunni, Vinay (2010-05). Transport Properties of Nanocomposites. Master's Thesis. Thesis uri icon

abstract

  • Transport Properties of Nanocomposites were studied in this work. A Monte Carlo technique was used to model the percolation behavior of fibers in a nanocomposite. Once the percolation threshold was found, the effect of fiber dimensions on the percolation threshold in the presence and absence of polymer particles was found. The number of fibers at the percolation threshold in the presence of identically shaped polymer particles was found to be considerably lower than the case without particles. Next, the polymer particles were made to be of different shapes. The shapes and sizes of the fibers, as well as the polymers, were made the same as those used to obtain experimental data in literature. The simulation results were compared to experimental results, and vital information regarding the electrical properties of the fibers and fiberfiber junctions was obtained for the case of two stabilizers used during composite preparation ? Gum Arabic (GA) and Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS). In particular, the fiber-fiber connection resistances, in the case of these 2 stabilizers, were obtained. A ratio between the fiber path resistance and the total connection resistance, giving the relative magnitude of these resistances in a composite, was defined. This ratio was found through simulations for different fiber dimensions, fiber types and stabilizers. Trends of the ratio with respect to composite parameters were observed and analyzed, and parameters to be varied to get desired composite properties were discussed. This study can serve as a useful guide to choose design parameters for composite preparation in the future. It can also be used to predict the properties of composites having known fiber dimensions, fiber quality and stabilizing agents.
  • Transport Properties of Nanocomposites were studied in this work. A Monte
    Carlo technique was used to model the percolation behavior of fibers in a
    nanocomposite. Once the percolation threshold was found, the effect of fiber dimensions
    on the percolation threshold in the presence and absence of polymer particles was found.
    The number of fibers at the percolation threshold in the presence of identically shaped
    polymer particles was found to be considerably lower than the case without particles.
    Next, the polymer particles were made to be of different shapes. The shapes and sizes of
    the fibers, as well as the polymers, were made the same as those used to obtain
    experimental data in literature. The simulation results were compared to experimental
    results, and vital information regarding the electrical properties of the fibers and fiberfiber
    junctions was obtained for the case of two stabilizers used during composite
    preparation ? Gum Arabic (GA) and Poly(3,4-ethylenedioxythiophene)
    poly(styrenesulfonate) (PEDOT:PSS). In particular, the fiber-fiber connection
    resistances, in the case of these 2 stabilizers, were obtained. A ratio between the fiber
    path resistance and the total connection resistance, giving the relative magnitude of these
    resistances in a composite, was defined. This ratio was found through simulations for different fiber dimensions, fiber types and stabilizers. Trends of the ratio with respect to
    composite parameters were observed and analyzed, and parameters to be varied to get
    desired composite properties were discussed. This study can serve as a useful guide to
    choose design parameters for composite preparation in the future. It can also be used to
    predict the properties of composites having known fiber dimensions, fiber quality and
    stabilizing agents.

publication date

  • May 2010