Charge-containing polymers have received considerable attention for many decades, as these polymers combine the flexibility of polymer chains with electrochemical properties of the ions to provide a highly tunable, chemically and mechanically versatile class of materials. These materials have found use in energy conversion devices, high-density energy storage devices such...
Significant deviations in the glass transition temperature (Tg) of nanoconfined polymer films from the bulk have been studied for over twenty years with the focus on high molecular weight (MW), linear polymers. This thesis explores low MW polymers, which represent an important class of materials widely used as coatings, detergents,...
Patterning hierarchical structures in three-dimension (3D) has created nature-inspired functional surfaces. Gecko feet structures have been mimicked for reversible adhesive properties, shark skin for reduced drag, and lotus leaves for self-cleaning surfaces. Rational design of out-of-plane patterns across multiple length scales is crucial because each micro- and nano-feature has different...
Self-assembly is an important process in biological system to build various bioactive structures from small amphiphilic molecules. The structural versatility of amphiphile self- assembly also provides a unique platform for the design of functional soft materials with controllable structural features. However, little is known about the correlation between external stimuli,...
This dissertation presents research on solid oxide fuel cell (SOFC) cathodes. It specifically covers two main topics: the electrochemical performance of porous two-phase composite cathodes, and the degradation mechanisms of porous single-phase mixed conducting cathodes. Current-voltage measurement and electrochemical impedance spectroscopy were used extensively to evaluate the cell performance. The...
The assembly of nanoscale building blocks into larger ensembles with well-defined architecture has the potential to create entirely new classes of designer photonic and plasmonic metamaterials with unique properties not found in nature. Electromagnetic metasurfaces, or 2D metamaterials, operating at optical wavelengths are of particular interest due to ease of...
Perovskite oxide materials for the wide array of properties that make them candidate materials for application ranging from catalysis, to electronics, to beyond-Moore computation. As many of these oxides share similar structures they can be combined in a seemingly-endless number of ways to produce the desired properties for a given...
The use of polymeric membranes have become ubiquitous in our daily lives. From simple chip bags to million-dollar cockpits, these membranes find diverse applications in packaging, protective coating, electronic device, gas and liquid separation, and medicine. The 2-dimentional geometry of the membranes offered unique mechanical and interfacial properties that often...
Electrochemical energy storage devices have become increasingly relevant to the operation and sustainability of the modern world, as proliferation of mobile electronics, renewable electrical energy generators, electrical vehicles, and various high-tech bio-medical sensing device continues. The widespread need of easier to produce, better performing, and multifunctional energy storage materials in...
Intermolecular charge transfer between electron-rich donor and electron-poor acceptor molecules offer great promise in the development of novel, low-cost electronic materials. It is hypothesized that control over the intermolecular interactions and supramolecular self-assembly of these systems could tune electronic properties and discover new functions. To that end, a series of...