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Full-Text Articles in Engineering

Development Of Catalytic Chromia-Based Aerogels, Fiona Fitzgerald Jun 2020

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 …


Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon Jun 2018

Optimization Of Superhydrophobic Surface Production Using Ambient-Dried Silica-Based Aerogels, Elizabeth Donlon

Honors Theses

Superhydrophobic surfaces exhibit particular properties that make them functional in various anti-sticking, anti-contamination, self-cleaning and drag reduction applications. Though such surfaces are found in nature - most notably the lotus leaf - they are difficult to produce. There are numerous methods and techniques for fabricating superhydrophobic surfaces. One such method is the sol-gel method, in which aerogel, a highly porous and lightweight material that can be made hydrophobic or superhydrophobic, is coated onto a surface. The purpose of this project is to devise a simple and repeatable procedure for making hydrophobic silica aerogel coatings that can be used for drag …


Computational Model Of Pore Collapse And Densification In Aerogels Under Compression, Lutao Xie Jun 2014

Computational Model Of Pore Collapse And Densification In Aerogels Under Compression, Lutao Xie

Honors Theses

Aerogels are solid, porous and light materials that are 90-99% air by volume, with particularly small pore sizes and large specific surface areas. According to previous studies, silica aerogels have appeared to be typical fractal materials. Its microstructure can be described as a fractal network in the length scale 10-1000Å, which is considered to be the result of an aggregation mechanism. To model the behavior of this material, a non-linear finite element code was developed to determine the sequence in which elements fail under compressive load for different starting pore distributions. The 2D geometry of the brittle silica lattice was …


Effects Of Superhydrophobic Aerogel Surface Coatings On Drag Reduction, Robin A. Barabasz Jun 2011

Effects Of Superhydrophobic Aerogel Surface Coatings On Drag Reduction, Robin A. Barabasz

Honors Theses

The objective of this project was to determine if superhydrophobic aerogel-based surface coatings have an effect on hydrodynamic drag. Superhydrophobic aerogels were fabricated using Union College’s patented rapid supercritical extraction technique. These aerogels were crushed and combined with a perfluorinated ion-exchange membrane to create a superhydrophobic coating that can be painted on to surfaces. These coatings are 250% aerogel by weight to Nafion in solution, and exhibit an average contact angle with water of 160°. An investigation of the aerogel powders and films using a scanning electron microscope (SEM) revealed that the most successful films had an average aerogel material …