Characterization of polymer/clay nanocomposites

In this dissertation a new method of physical characterization of nanolayers and nanocomposites in polymers at engineered interfaces has been developed. The method allows to determine fraction of the volume occupied by nanoparticles in polymer nanocomposites and homogeneity of their distribution and to investigate the filler crystal orientation in the volume of polymer matrix.; It is shown that filler crystals can be oriented in a polymer by means of hydrostatic extrusion. The angular dependence of the Fe3+ EPR spectrum in the polymer/kaolinite nanocomposite has been for the first time investigated. A preferred direction of the kaolinite-plate orientation is observed, made visible by the direction of maxima in the angular dependence of the resonance field of EPR spectral lines.; Research was conducted on determining the main experimental parameters affecting the thickness of nanocomposite films in order to develop a technique of creating nanocomposite films with preset parameters.; The dependence of spin-cast polystyrene film thickness on silicon substrates is examined as a function of concentration (in toluene) and molecular weight with the help of SIMS analysis. For very dilute concentrations, atomic force microscopy reveals that the films break up into a uniform distribution of voids or islands with submicron dimensions.; The effects of solute concentration (in toluene), spin rate and the time of spinning on polystyrene/clay nanocomposite film thickness were examined. For uniform films ranging in thickness from 0.μm to 10μm, thickness follows a power-law dependence on spin rate and on spinning time. The relative influence of viscosity and evaporation rate on the final nanocomposite film thickness was examined. A simple numerical model for nanocomposite film thickness prediction was developed.