Luna Innovations seminar -- Robert Klein
Abstract not provided.
Publications
Radiation tolerance in polymeric dielectrics by small-molecule doping I: Dopant uptake as a function of temperature time and chemistry
Polymer
Abstract not provided.
Radiation tolerance in polymeric dielectrics by small-molecule doping II: Thermodynamic and kinetic parameters
Polymer
Abstract not provided.
Effect of dopant structure on reduction of radiation-induced conductivity in poly(ethylene terephthalate)
Applied Physics Letters
Abstract not provided.
Near edge x-ray fine structure and dynamic contact angle measurements of polystyrene oxidized by ultraviolet-ozone
Langmuir
Abstract not provided.
Aging of self-assembled monolayers for anti-stiction coatings studied by near edge x-ray absorption fine structure
Abstract not provided.
Copy of Radiation Tolerant Polymeric Materials through the Incorporation of Small Molecule Dopants
Abstract not provided.
Counterion effects on ion mobility and mobile ion concentration of doped polyphosphazene and polyphosphazene ionomers
Macromolecules
A physical model of electrode polarization is applied to dielectric (impedance) data from two poly(methoxyethoxy-ethoxy phenoxyphosphazene) systems with nearly identical chemical structures, one composed of an ionomer with a single mobile cation and the other composed of a salt-doped polymer with mobile cation and mobile anion. Quantitative comparison of the ion mobility and mobile ion concentration, based on chemical structure, is achieved. Both conductivity and ion mobility are reduced to common curves by normalizing T with T g, indicating that Tg of the polymer matrix is a major factor controlling ion diffusion. Even with the use of normalized temperature, both the mobility of ions and the mobile ion concentration in the doped polymers are ∼ 10 times larger than those in the ionomers. These factors arise from faster diffusion of the anion and the local environment surrounding ion pairs. Also, Arrhenius and VFT parameters associated with mobile ion concentration and ion mobility, respectively, reveal differences in activation energies between ionomer and doped polymer that are due to interactions between the ion pairs and polymer segments. © 2007 American Chemical Society.
8 Results