Presenter:Prof. Klaus Müllen
Max Planck Institute for Polymer Research, Germany
Topic: A Polymer Chemistry of Graphenes and Graphene Nanoribbons
Time: 10:00 AM, Oct. 26th (Wednesday)
Location: Conference Room B, BLDG 909-1F
Carbon materials are of immense practical importance, but are often known as structurally ill-defined “black stuff” such as soot. Graphenes and graphene nanoribbons (GNRs), their geometrically restricted cutouts, are new additions to the carbon family which are widely praised as multifunctional wonder materials and rich playgrounds for physicists. Indeed, graphenes hold enormous promise as materials for energy technologies. Further, GNRs are regarded as a new generation of semiconductors superior to i) silicon in view of the required miniaturization of printed circuits and superior to ii) classical conjugated polymers due to better band structure control. Above all, however, graphene as a two-dimensional polymer and GNRs are true challenges for materials synthesis.
Herein, we approach graphene fabrication in two steps. “Top-down” protocols such as electrochemical exfoliation are applied for batteries, fuel cells and photodetectors. In the “bottom-up” synthesis of GNRs, repetitive cycloaddition reactions in solution are shown to afford multiply branched polyphenylene polymers which then serve as precursors for perfectly “graphitized”, solution-processable GNRs as long as 600 nm. An alternative on-surface synthesis utilizes immobilization of suitable monomers and in-situ STM-control of the polymerization to secure structural perfection.
It is thus a synthetic breakthrough which leads to new materials science and physics such as single-molecule field effect transistors from GNRs and even spintronics. The present fundamental study is far away from robust technologies, but an attempt can be made at predicting some future trends.
Klaus Müllen was director at the Max Planck Institute for Polymer Research. Since the beginning of 2016, he holds an emeritus position for continuation of his research there and is fellow of the Gutenberg Research College of Mainz University. His broad research interests range from the development of new polymer-forming reactions, to the chemistry and physics of single molecules as well as graphenes, dendrimers and biosynthetic hybrids. He published about 1700 papers.His papers have more than 79,000 citations with an H-index of 125. He received many awards such as the Max Planck Forschungspreis, the Philip Morris Forschungspreis, the Nozoe-Award, the Science Award of the “Stifterverband”, the Innovation Award of the State of North Rhine Westphalia, the Nikolaus August Otto Award, Society of Polymer Science Japan International Award, ACS Award in Polymer Chemistry, Tsungming Tu Award, Taiwan, BASF-Award for Organic Electronics, Franco-German Award of the Sociéte Chimique de France, Adolf-von-Baeyer-Medal, GDCh, Utz-Hellmuth-Felcht Award, SGL Group, China Nano Award, the Carl Friedrich Gau?-Medal, van’t Hoff Award of the Royal Netherlands Academy of Sciences and the Hermann-Staudinger Award. From 2008-2009 he served as president of the German Chemical Society (GDCh). 2013-2014 he was president of the German Association for the Advancement of Science and Medicine. He is member of the American Academy of Arts & Sciences, the North-Rhine-Westphalian Academy for Sciences and Art, the National Academy Leopoldina, the European Academy of Sciences (EURASC), and the Braunschweigische Wissenschaftliche Gesellschaft. In 2010 he received an Advanced ERC Grant for his work on nanographenes. He is associate editor of the Journal of the American Chemical Society.
Contact: Prof. Lifeng Chi