Synthesis and Electrical Properties of Conjugated Polymers Based on Nitrogen and Sulfur

With the support of the Macromolecular, Supramolecular, and Nanochemistry Program in the Division of Chemistry, Dr. Bowden and Dr. Leddy of the University of Iowa will synthesize polymers that have potential applications as flexible solar cells, supercapacitors, and wires for the next generation of electrical devices. The polymers to be synthesized are based on sulfur and nitrogen, inexpensive materials commonly found throughout nature. This project will result in the design and synthesis of numerous examples of these polymers, followed by an extensive investigation of their electrical and electrochemical properties, including how well the polymers conduct electricity. The electrical properties will identify their best technological and, potentially, practical applications. A key broader impact of this work is that it will result in the fabrication of polymers that are vastly underexplored and can yield new insights into how to make electronic devices from plastics. A further broader impact will be integration of graduate and undergraduate students throughout the research project to teach them advanced methods for the synthesis of polymers and measurement of their properties. Students will also investigate how these polymers can be used to remediate highly polluted Superfund sites by the removal of toxic heavy metal and lead contaminants from water. The proposed work will result in the synthesis and characterization of polymers with backbones that contain only sulfur and nitrogen. These polymers are rare in macromolecular science despite the potentially high electrical conductivity of the polymer backbones that may find applications in advanced technologies. Professor Bowden’s group will synthesize these polymers using carbamates, amides, and urethanes and some of these polymers will be further reacted to yield well-defined polymers that are greater than 98% by weight nitrogen and sulfur. The electrical and electrochemical properties of these polymers will be thoroughly investigated by Professor Leddy’s group to determine how polymer structures relate to electrical conductivities. The synergy of this collaboration will advance our fundamental understanding of sulfur and nitrogen rich polymers and the development of these novel materials as electroactive polymers. In addition, as these polymers possess both soft and hard atoms along their backbones, the polymers will be investigated for their efficiency to complex and remove heavy metals from Superfund sites. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.