Physics Commons^™

Composition Dependence Of The Flory-Huggins Interaction Parameter In Polymer Blends: Structural And Thermodynamic Calculations, Travis H. Russell

Doctoral Dissertations

Flory-Huggins Theory has been the basis for understanding polymer solvent and blended polymer thermodynamics for much of the last 60 years. Within this theory, a parameter (χ) [chi] was included to quantify the enthalpic energy of dispersion between distinct components. Thin film self-assembly of polymer melts and block copolymers depends critically on this parameter, and in application, χ has generally been assumed to be independent of the concentrations of the individual components of the system. However, Small-Angle Neutron Scattering data on isotopic polymer blends, such as polyethylene and deuterated polyethylene, have shown a roughly parabolic concentration dependency for …

Structural Dynamics And Charge Transport In Room Temperature Ionic Liquids, Philip James Griffin

Doctoral Dissertations

Room temperature ionic liquids are an important class of materials due to their chemical tunability and numerous advantageous physicochemical properties. As a result, ionic liquids are currently being investigated for use in a wide array of chemical and electrochemical applications. Despite their great potential, however, the relationship between the chemical structure and physicochemical properties of ionic liquids is not well understood.

To this end, this dissertation presents experimental studies of the reorientational structural dynamics and charge transport properties of a variety of room temperature ionic liquids using quasielastic light scattering spectroscopy and broadband dielectric spectroscopy.

Studies of a series of …

Understanding The Plasmonic Properties Of Metallic Nanostructures With Correlated Photon- And Electron-Driven Excitations, Vighter Ozezinimize Iberi

Doctoral Dissertations

The collective oscillation of the conduction band electrons in metal nanostructures, known as plasmons, can be used to manipulate light on length scales that are smaller than the diffraction limit of visible light. In this dissertation, a correlated approach is used to probe localized surface plasmon resonances (LSPRs) in metallic nanostructures, and their application to surface-enhanced spectroscopy. This correlated approach involves the measurement of LSPRs with dark-field optical microscopy (resonance-Rayleigh scattering), and electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM). Structural parameters of the exact same nanostructures obtained from the STEM are subsequently used in performing fully …