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Full-Text Articles in Engineering
Development Of Catalytic Chromia-Based Aerogels, Fiona Fitzgerald
Development Of Catalytic Chromia-Based Aerogels, Fiona Fitzgerald
Honors Theses
Over one billion automobiles are in use around the world, the majority of which employ internal combustion engines. Catalytic converters are used to convert the toxic compounds found in car exhaust -- carbon monoxide, nitrogen oxides (NOx) and hydrocarbons -- to less harmful gases. The typical catalytic converter employs as catalysts expensive raw materials (platinum, palladium and/or rhodium) wash-coated onto an alumina-based ceramic substrate. Aerogel materials have high surface area and thermal stability, properties that make them attractive for catalysis applications. Aerogels made with transition metal oxides are candidates to replace platinum in the catalytic converter. Chromium oxide (chromia) materials …
Porous Silica Nanotube Thin Films As Thermally Insulating Barrier Coatings, Derric B. Syme, Jason M. Lund, Brian D. Jensen, Robert C. Davis, Richard R. Vanfleet, Brian D. Iverson
Porous Silica Nanotube Thin Films As Thermally Insulating Barrier Coatings, Derric B. Syme, Jason M. Lund, Brian D. Jensen, Robert C. Davis, Richard R. Vanfleet, Brian D. Iverson
Faculty Publications
The fabrication and examination of a porous silica thin film, potentially for use as an insulating thin film, were investigated. A vertically aligned carbon nanotube (CNT) forest, created by chemical vapor deposition (CVD), was used as scaffolding to construct the porous film. Silicon was deposited on the CNT forest using low-pressure CVD (LPCVD) and then oxidized to remove the CNTs and convert the silicon to silica for electrical or thermal passivation (e.g., thermal barrier). Thermal conductivity was determined using a 1D heat-transfer analysis that equated radiative heat loss in a vacuum with conduction through the substrate and thin film stack. …