*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
GEORGIA INSTITUTE OF TECHNOLOGY
Under the provisions of the regulations for the degree
DOCTOR OF PHILOSOPHY
on Tuesday, November 24, 2020
2:00 PM
via
BlueJeans Video Conferencing
https://bluejeans.com/120252940/3244?src=calendarLink
will be held the
DISSERTATION PROPOSAL DEFENSE
for
Daron Spence
“Understanding Heat Management Enabled by Silica Based Insulating Microstructures and Dielectric Mirrors ”
Committee Members:
Prof. Shannon Yee, Advisor, ME
Prof. Kyriaki Kalaitzidou, ME/MSE
Prof. Natalie Stingelin, ChBE/MSE
Prof. Baratunde Cola, ME/MSE
Jaswinder Sharma, Ph.D., Oak Ridge National Laboratory
Abstract:
Due to increasing global temperatures, the energy used for space cooling in buildings will increase by 300% by 2050 and account for 13% of all electricity usage worldwide. Consequently, to meet global cooling demand, fossil fuels and refrigerants, which release carbon dioxide and volatile chemicals with large global warming potentials, will be used at higher rates. This increase in greenhouse gas emissions thus results in a growing demand for space cooling. Several energy consumption models indicate the importance of reducing energy usage to slow the rate of global warming [1]. Improving the performance of conventional thermal materials can directly reduce the amount of energy required for space cooling by reducing the thermal load on buildings [2]. Therefore, the theoretical framework, synthesis and characterization of super insulating and low emissivity thermal materials will be critical in efforts to reduce these thermal loads.
The theoretical framework that predicts the effective thermal conductivity (ETC) of super-insulating hollow silica particles (HSPs) in a binary matrix is first presented. Discussion of the framework is followed by the synthesis process needed to achieve the designated particle parameters. Additionally, electromagnetic properties of thin-films are presented to inform the design parameters for dielectric mirrors. I propose four areas to contribute to scientific knowledge of these materials. First, I propose a parametric study to investigate the physical parameters that govern the effective thermal conductivity of HSPs. Second, I propose the thermal assessment of a ternary composite material with interstitial fillers in between particle clusters. Third, I propose the means for characterizing the mechanism and degree of switchability achieved by polymer dielectric mirrors used to variably reflect solar radiation over a tunable range. Lastly, I propose a novel in-situ technique to characterize the dielectric mirror’s thermal conductivity and chemical state as a function of switching degrees. The proposed work will provide a deeper understanding of the relationship between HSP design and performance and provide necessary information to further develop the foundation of switchable dielectric mirrors used for dynamic thermal radiation management.
