Identifier

etd-07112011-153829

Degree

Doctor of Philosophy (PhD)

Department

Chemistry

Document Type

Dissertation

Abstract

Organic semiconducting polymers are the unique materials that considered a basis for the next generation of electronic and optoelectronic applications. However, high device performance of semiconducting polymers strongly depends on their molecular structure and nanoscale organization. Therefore, it is an essential task to develop robust and versatile synthetic approaches to build such well-defined semiconducting polymer materials. This Ph.D. study aimed at design of state-of-the-art synthetic approaches towards organic semiconducting polymers via chain-growth living polymerization as well as development of polymer architectures which can self-organize into supramolecular nanoassemblies or allow external control of the polymer’s properties. First, we prepared a series of temperature-responsive water-soluble poly(N-isopropylacrylamide)-functionalized polythiophenes, and showed that their supramolecular organization and temperature control of their conformation and conjugation length was strongly dependent on the extent of regioregularity of the polythiophene backbone. In order to improve the regioregularity, we developed a general approach to highly efficient external catalytic initiators for the synthesis of various semiconducting polymers. Extensive studies allowed better understanding of the unusual catalytic systems, and their behavior in chain-growth living polymerization reactions. Using this approach, we synthesized a variety of amphiphilic polythiophene block copolymers incorporating a low energy gap perylenedicarboximide (PDCI) unit to demonstrate the possibility to control supramolecular organization and photophysical properties of such systems by using external stimuli (such as solvent and temperature). As part of our general studies towards design of near-infrared (NIR) fluorescent conjugated polymers, we developed a synthetic approach to a novel class of such materials which are based on cyanine dyes as monomeric repeating units. The obtained polymers showed a variety of properties (thermal stability, solubility, absorption and fluorescence in the NIR range) that may make them a useful class of NIR fluorescent conjugated polymers.

Date

2011

Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Nesterov, Evgueni. E.

Included in

Chemistry Commons

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