Public defence in Chemistry, M.Sc. (Tech.) Aida Khayyami
Title of the thesis: Atomic/Molecular Layer Deposition of Photoresponsive Azobenzene-Containing Thin Films
Doctoral student: M.Sc. (Tech.) Aida Khayyami
Opponent: Professor Catherine Marichy, Université Claude Bernard Lyon 1, France
Custos: Professor Maarit Karppinen, Aalto University School of Chemical Engineering, Department of Chemistry and Materials Science
Photoresponsive azobenzene-containing thin films by atomic/molecular layer deposition
Photoresponsive materials can be prepared by incorporating photochromic molecules in the material structure. Photochromic molecules can undergo configurational or conformational modifications by light absorption, which lead to changes in the molecule's chemical and physical properties. Azobenzene, one of the most employed photochromic molecules, is an aromatic molecule that undergoes efficient and reversible trans–cis photoisomerization. The large change in azobenzene molecular structure and properties enables effective control over the chemical, mechanical, and optical properties of the whole material system into which the chromophore is incorporated. Applications of azobenzene as novel functional materials are highly attractive in diverse fields, such as optical switches, sensors, actuators, optical data storage, nano valves, and local drug dispensers.
In this thesis, the emerging atomic/molecular layer deposition (ALD/MLD) thin-film technique was used to fabricate novel photoresponsive inorganic-organic azobenzene-based materials. ALD/MLD processes were developed for three types of photoresponsive materials: zinc-azobenzene containing hybrids, zinc oxide-azobenzene superlattice thin films, and metal-organic frameworks with azobenzene as the linker. The photoresponsive behavior and the effect of structure on the kinetic of photoisomerization were also studied, demonstrating that the azobenzene moieties in the grown films can experience the trans-cis photoisomerization reaction. Furthermore, the reversible absorption/desorption of small molecules (water) for the crystalline films was demonstrated, opening up new horizons for applications such as remote drug delivery and gas storage.
Thesis available for public display 10 days prior to the defence
M.Sc. (Tech.) Aida Khayyami
Doctoral theses in the School of Chemical Engineering