| This dissertation focuses on: (1) the development of synthetic routes to fabricate robust photonic crystal composites that allows for a wide range of monomeric systems to be utilized in the encapsulation procedure to a priori design the final optical and thermomechanical characteristics of the composite and (2) the characterization of the optical and thermomechanical properties of the composites and their exploitation in potential applications.; In the first section, two strategies were developed, one using poly(ethylene glycol) (PEG) and its acrylate derivatives as matrixes to encapsulate the CCA of polystyrene spheres and to form a photonic crystal hydrogel (PCH) composite. The second strategy employs the technique of first dehydrating the PCH composite, then swelling it in a monomeric solution, and finally photopolymerizing it in situ, to form a water-free photonic crystal, or photonic band gap (PBG) composite.; In the second section, the mechanochromic and solvatochromic responses of the PBG composite composed of poly(EGMEA) were characterized. This composite exhibited a reversible color variation at deformation frequencies up to 200 Hz and a 172 nm total stop band tuning range between +/-120V applied voltages when it was coupled with a piezoelectric actuator. Based on this effect, approaches for generating complex permanent multicolor patterns in both PBG and PCH films were developed.; Finally, two types of potential sensing systems were explored in this dissertation. One is a chemical vapor sensing system composed of the poly(EGMEA)-based PBG composite film. The second is a label-free optical bio-recognition system composed of an antigen-selective photonic crystal hydrogel (PCH). The avidin molecules were first covalently immobilized in the PCH film. The biotinylated capture antibody was then introduced into the film through the non-covalent avidin-biotin binding. (Abstract shortened by UMI.)... |
