Chemistry Commons^™

Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles, Deepak Kunwar

Chemistry and Chemical Biology ETDs

Diesel oxidation catalysts deactivate due to Pt sintering, a major problem in automotive industries. To make sure they operate effectively throughout the lifetime of the vehicle, automotive industries are putting an excessive amount of Pt. There is a need to develop a catalyst that serves long term performance with minimal use of Pt. Jones et al^.1 demonstrated that ceria traps Pt atoms. His work generated some logical and valid questions such as what is the mechanism for the formation of anomalously large Pt particles? What is the upper limit of Pt metal loading in the form of single atoms …

An Experimental And Numerical Investigation Of Flow Accelerated Flibe Corrosion, David B. Weitzel

Nuclear Engineering ETDs

Renewed interest in molten salt reactor technology has brought to light the need for a better understanding of FLiBe corrosion. To this end a flowing FLiBe corrosion test loop was designed to test the flow effects of FLiBe corrosion. The loop consists of a pump, melt tank, and stainless-steel tubing assembly that heats the molten salt to high temperatures and circulates it over test specimens. The experiment has been constructed and has completed initial shakedown testing.

To support the flowing FLiBe experiment, a numerical corrosion model that couples FLiBe electrochemistry, solid metal diffusion, and mass transport was implemented. The model …

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble and …

Investigating Scalable Manufacturing Of High-Conductivity Wires And Coatings From Ultra-Long Carbon Nanotubes, Pouria Khanbolouki

Mechanical Engineering ETDs

Carbon nanotubes (CNTs) are a promising candidate for next generation of electrical wirings and electromagnetic interference (EMI) shielding materials due to their exceptional mechanical and electrical properties. Wires and coatings from ultralong nanotubes that are highly crystalline, well-aligned and densely packed can achieve this goal. High-performance CNT conductors will be relatively lightweight and resistant to harsh conditions and therefore can potentially replace current conductors in many industries including aerospace, automotive, gas and oil.

This thesis investigates a new manufacturing approach, based on conventional solution coating and wire drawing methods, to fabricate high conductivity wires and coatings from ultra-long carbon nanotubes. …

Molecular Tetrapods For Optoelectronic Applications, Jianzhong Yang

Chemistry and Chemical Biology ETDs

In this dissertation, several molecular tetrapods were synthesized for optoelectronic applications. In the first two sections, two tetrapodal breakwater-like small molecules: SO and SFBTD were synthesized and characterized. Absorption, X-ray scattering and differential scanning calorimetry experiments indicate crystalline nature of these compounds but slow crystallization kinetics. Solar cells employing SO or SFBTD and phenyl-C₆₁-butyric acid methyl ester (PCBM) were fabricated and evaluated. Relatively low performance was obtained mainly due to the lack of appropriate phase separation, which was caused by molecularly mixed blends with PCBM. The molecularly mixed blends is the result of slow crystallization …