Electronic Theses and Dissertations

Identifier

6197

Author

Makunda Aryal

Date

2018

Date of Award

7-27-2018

Document Type

Thesis

Degree Name

Master of Science

Major

Physics

Concentration

Materials Science

Committee Chair

Firouzeh Sabri

Committee Member

Muhammad Shah Jahan

Committee Member

Xiao Shen

Abstract

Phosphor thermometry is an accurate, versatile, and rapid mechanism for inferring temperature information, remotely. The working principle of this technique is based on the different emission characteristics of thermographic phosphors which varies from compound to compound and depends on the specific electronic structure(s) of the phosphor under investigation. Either temporal or spectral composition of the emission characteristics can be used to determine the temperature of the surface that the phosphors are in contact with. In this work thermographic phosphors have been encapsulated in inert transparent or translucent polymers and the behavior of the phosphor-polymer composites was studied as a function of temperature. Silica aerogels and Sylgard184 were chosen for this study and an array of phosphor patches was created on both sides of each material in an off-axis manner. Both aerogels and elastomers are widely used as insulating material but mostly in passive form. Here, the feasibility of imparting sensing capabilities to these materials and potentially measuring heat flux is explored and characterized. Results showed that because of the scattering that occurs in the aerogel material the maximum material thickness that can be accessed by phosphor thermometry is limited to ~ 6 mm, with the setup used in this study. In the case of Sylgard184 an upper limit was not reached. Both up-converting and down converting phosphors were studied. Finally, the performance of thin flexible ceramic films as a thermal buffer was investigated and fully characterized.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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