SUBJECT: Ph.D. Dissertation Defense
   
BY: Eric Tervo
   
TIME: Friday, July 26, 2019, 11:00 a.m.
   
PLACE: Love Building, 210
   
TITLE: Thermal Radiative Energy Transfer in Polaritonic Nanostructure Arrays
   
COMMITTEE: Dr. Baratunde Cola, Co-Chair (ME)
Dr. Zhuomin Zhang, Co-Chair (ME)
Dr. Michael Filler (ChBE)
Dr. Mathieu Francoeur (ME, U. Utah)
Dr. Satish Kumar (ME)
 

SUMMARY

Thermal radiation in arrays of nanostructures can exhibit interesting and unusual collective effects. When the nanostructures support surface plasmon polaritons or surface phonon polaritons, coupling between nanostructures can be very strong and enable large radiative energy transfers. However, practical uses of this effect have been limited due to deficiencies in the understanding of the thermal and electromagnetic interactions, particularly for closely spaced nanostructures and nonhomogeneous environments. This dissertation aims to improve the theoretical description, advance the modeling approach, and perform an experimental investigation of radiative energy transport in polaritonic nanostructure arrays. The thermal properties of packed beds of coated silica nanoparticles were measured, and the results suggest that their thermal conductivities exhibit significant radiative contributions. A kinetic theory model was used to investigate the radiative thermal conductivity of nanoparticle chains in isotropic surroundings, and a new kinetic modeling method based on absorption spectroscopy data was proposed for more complex geometries and environments. Two different exact methods based on fluctuational electrodynamics were unified, and a computationally efficient system Green’s function approach to these methods was developed. To compare radiation to other modes of heat transfer, an algorithm to determine radiative thermal conductivity from fluctuational electrodynamics results was established and applied to ordered and disordered nanoparticle arrays. Results from these studies provide insight on the interactions between thermal and electromagnetic effects, and they demonstrate that radiation in polaritonic nanostructure arrays can be a significant contributor to thermal transport.