Nanomorphology dependent optical and mechanical properties of aerogels

<p>"Aerogels are very low density, light weight open pore materials. A hypothesis that is under intense current investigation by the scientific community states that the mechanical properties of nanostructured polymers depend on their nanomorphology. Aerogels are nanostructured ultra-lightweight nanoporous materials with skeletal frameworks that can display a wide range of nanomorphologies. Thereby aerogels comprise a suitable platform for testing not only that hypothesis but also a wide range of other properties such as light scattering for applications, for example, in thermally insulating windows.</p><p>To study the mechanical properties of nanostructured matter as a function of nanomorphology, various shape-memory polyurethane aerogels were prepared with identical density, porosity, and chemical composition, but with vastly different nanostructures. Based on 5 different catalysts at 5 different concentrations each, the elastic modulus of all materials followed a well-defined trend whereas, all other factors being equal, bicontinuous structures were by several times stiffer than spheroidal nanostructures.</p><p>In order to develop silica aerogels as thermal insulators for windows, one must achieve a balance of clarity, strength, and thermal insulation value. Light scattering (haze) was studied with an integrating sphere, thermal conductivity with the hot plate method and mechanical strength with uniaxial compression. Delamination of wet-gels from glass substrates during drying into aerogels was traced to the nature mass fractal of the secondary particles that allows them to merge with one another"--Abstract, page v.</p>

Name thesis:degree_name

Ph. D. in Chemistry

Grantor

Missouri University of Science and Technology

Author dc:creator

• Mandal, Chandana

• Aerogels
• Chracterization
• Crosslinking
• Nanomorphology
• Polyurethane
• Silica
• Chemistry
• Materials Science and Engineering
• Polymer Chemistry

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2810

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3815