Degree Type

Dissertation

Date of Award

2012

Degree Name

Doctor of Philosophy

Department

Materials Science and Engineering

First Advisor

Nicola Bowler

Abstract

Electromagnetic composite materials have

attracted much interest in recent years, due to their desirable

microwave and optical applications. One class of these is negative

refractive index materials, or double negative materials, in which

both permittivity and permeability of materials are simultaneously

negative. Many exciting potential applications of double negative

materials have been proposed, such as the perfect lens and the

cloaking device. Here, a simple-cubic lattice of identical,

homogeneous or coated non-metallic spherical particles embedded in a

matrix is analyzed. One contribution of this work is the derivation

of an analytical formula for the threshold dielectric loss angle of

spherical inclusions, above which DNG behavior of the system is

extinguished. In addition, analytical formulas are derived from

which double negative bandwidth of a simple-cubic lattice of

identical, magnetodielectric homogeneous or coated spheres can be

determined.

Another case of interest is nanocomposites, which commonly consist

of nanoparticles embedded in a polymer matrix. These materials show

superior dielectric or mechanical performance by taking advantage of

the merits of their individual non-hybrid components. In one

manifestation, diblock copolymers can be utilized to spatially

separate nanoparticles by incorporating them in one block,

preferentially, to form a long-range ordered structure. By designing

this structure, the electromagnetic properties can be tailored for

potential applications in novel devices. Here, molecular dynamics of

polymer matrices and nanocomposites is analyzed by parametric

modeling of their dielectric spectra, supporting design of a

composite with desired electromagnetic properties.

DOI

https://doi.org/10.31274/etd-180810-2698

Copyright Owner

Jin Liu

Language

en

File Format

application/pdf

File Size

108 pages

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