Nanoscience and Nanotechnology Commons^™

Deconvolving The Steps To Control Morphology, Composition, And Structure, In The Synthesis Of High-Aspect-Ratio Metal Oxide Nanomaterials, Lei Yu

Theses and Dissertations--Chemistry

Metal oxides are of interest not only because of their huge abundance but also for their many applications such as for electrocatalysts, gas sensors, diodes, solar cells and lithium ion batteries (LIBs). Nano-sized metal oxides are especially desirable since they have larger surface-to-volume ratios advantageous for catalytic properties, and can display size and shape confinement properties such as magnetism. Thus, it is very important to explore the synthetic methods for these materials. It is essential, therefore, to understand the reaction mechanisms to create these materials, both on the nanoscale, and in real-time, to have design control of materials with desired …

Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra

Theses and Dissertations--Chemical and Materials Engineering

Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.

Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these …

Utilization Of Bio-Renewable Lignin In Building High Capacity, Durable, And Low-Cost Silicon-Based Negative Electrodes For Lithium-Ion Batteries, Tao Chen

Theses and Dissertations--Chemical and Materials Engineering

Silicon-based electrodes are the most promising negative electrodes for the next generation high capacity lithium ion batteries (LIB) as silicon provides a theoretical capacity of 3579 mAh g^-1, more than 10 times higher than that of the state-of-the-art graphite negative electrodes. However, silicon-based electrodes suffer from poor cycle life due to large volume expansion and contraction during lithiation/delithiation. In order to improve the electrochemical performance a number of strategies have been employed, such as dispersion of silicon in active/inactive matrixes, devising of novel nanostructures, and various coatings for protection. Amongst these strategies, silicon-carbon coating based composites are one …