Photonic crystals are periodic optical nanostructures that can selectively disallow the propagation of specific ranges of electromagnetic radiation. Among photonic crystals, three-dimensionally ordered macroporous (3DOM) materials are of interest for a new class of colored pigments, UV reflectors, and modified thermal emission devices synthesized from a wide range of materials.For color pigment applications of 3DOM materials, this dissertation explores the important role of light-absorbing species within the 3DOM structure through the variation of processing parameters in the synthesis of 3DOM zirconia. It was found that intense coloration strongly depended on the concentration of in-situ carbon generated within the structure, which was controlled by processing temperature and atmosphere. The tunability of color in 3DOM silica through variations in maximum processing temperature is also discussed as well as the discovery of a unique additive color-mixing mechanism found in 3DOM pigments.3DOM materials with stop bands outside of the visible spectrum were also investigated. 3DOM TiO2/SiO2 was synthesized with UV stop bands that, coupled with strong TiO2 absorbance, decreased overall UV transmittance. Thermally-stable metallic photonic crystals with stop bands in the IR range were also synthesized for thermophotovoltaic applications where tailored emission could be potentially coupled with specific diode materials.
University of Minnesota Ph.D. dissertation. January 2014. Major: Chemistry. Advisor: Andreas Stein. 1 computer file (PDF); xix, 213 pages.
Josephson, David Peter.
Three-dimensionally ordered macroporous materials for use as color pigments, ultraviolet reflectors, and modified thermal emission devices.
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