Design of New Multifunctional Materials

Citation

Zeidan, Ryan K. (2007) Design of New Multifunctional Materials. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/CK8E-7H82. https://resolver.caltech.edu/CaltechETD:etd-02212007-101608

Abstract

Research in areas of science and technology critical to society, such as energy, medicine, electronics, protective equipment, and consumer goods relies on the ability to create new materials with desirable properties. The diversity in the properties of these materials is enormous. An important factor in the quest for developing exciting new materials is the ability to use synthetic chemistry to prepare new materials starting from a molecular point of view. It is this approach that I use in this work.

I have used principles of synthetic organic chemistry to guide the molecular design of materials that contain a variety of functionalities. This thesis describes three types of designed functional materials. First, new heterogeneous catalysts have been prepared that incorporate two organic functional groups in a manner that allows for cooperativity between them in catalyzing organic reactions, giving increases in reaction rates and selectivities. In particular, thiol/sulfonic acid bi-functional mesoporous materials have been prepared that give significant enhancements in reactivity and selectivity towards bisphenol A synthesis. These enhancements arise from interactions between thiol and sulfonic acid sites due to their proximity on the surface of the catalyst. Acid-base bi-functional materials have also been synthesized that exhibit excellent reactivity in the aldol condensation between acetone and 4-nitrobenzaldehyde. These catalysts are particularly important as the acid and base groups are mutually incompatible in solution and provide reactivity not achievable without immobilization on the surface of solids. Second, a method for incorporating traceable and quantifiable labels onto cyclodextrins and cyclodextrin containing polymers has been designed that utilizes the reactivity between the primary alcohols on cyclodextrins and ethylene oxide gas, and allows the cyclodextrins to be labeled for use in animal biodistribution studies. Third, polymers bearing aromatic disulfide groups have been prepared that can be degraded through a dual-trigger mechanism requiring simultaneous photochemical and hydrogen peroxide activation.

Thesis Files