Ayusman Sen Named Head of Department of Chemistry

Ayusman Sen, professor of chemistry, has been named head of the Department of Chemistry. His research encompasses the twin themes of catalysis and new materials, with the goal of developing new metal catalysts that will enable the synthesis of polymers and related materials with novel combinations of properties.

Efforts in Sen’s lab are focused on a number of research goals. Taking lessons from spider’s silk, Sen is exploring ways to form polymer nanofibers with controlled orientation and morphology, or structure. A new solvent-free process uses high pressure gas to force a polymer through small orifices to form microfibers and nanofibers in bundles, tapes, and sheets on the nanometer scale. Non-melt-processible polymers, such as polytetrafluoroethylene (PTFE), better known by the trade name Teflon®, are readily processed by this technique.

Sen also is developing antimicrobial polymers that can be used to coat surfaces to render them antiseptic—a process that could have applications in decontamination kits and personal protective gear—as well as cell-transfection polymers that can be used for the delivery of drugs and nanoparticles into cells for the treatment of diseases.

Sen also is interested in developing ways that miniature “engines” could convert stored chemical energy into motion, providing the power for micromotors and nanomotors through catalytic reactions. A local chemical-energy source would eliminate the problems of delivering energy to nanoscale objects from macroscopic sources.

Several years ago, Sen’s team discovered catalysts that enable the synthesis of copolymers that alternate carbon monoxide with alkenes, such as ethylene, under unusually mild conditions. These polymers, known as polyketones, are of great interest because carbon monoxide is very plentiful and inexpensive, and the copolymers created are photodegradable. Also, because they are easy to modify chemically, the polyketones serve as excellent starting materials for other classes of functionalized polymers.

A major goal of Sen’s ongoing research in this area is the design of metal-catalyzed systems for the homopolymerization and copolymerization of “functionalized alkenes.” “Although both electron-rich and electron-deficient functionalized alkenes are currently produced commercially using free-radical polymerization, this method provides very little control over the molecular weight and tacticity, or chemical arrangement, of the materials produced,” Sen explains. “The discovery of general metal-catalyzed pathways for the homopolymerization and copolymerization of functionalized alkenes, especially if it offered greater control over the end products, would constitute a major breakthrough in polymer synthesis.”

Sen is a member of the American Chemical Society. He holds 19 patents and has published more than 185 scientific papers related to his research. His research accomplishments were recognized in 2003 with a Faculty Scholar Medal from Penn State and in 1988 with a Paul J. Flory Sabbatical Award from IBM. He held an Alfred P. Sloan Research Fellowship from 1984 to 1988, and received a Young Investigator Award from the Chevron Research Company in 1982. He has held named professorships and lectureships at several universities including the Imperial Oil Distinguished Lectureship at the University of Toronto in Canada in 1993; the Iberdrola Visiting Professorship at the University of Valladolid in Spain from 1999 to 2000; and the Gerhard Closs Lectureship at the University of Chicago in 2002.

Sen was a Research Fellow at the California Institute of Technology from 1978 to 1979 prior to joining the faculty of the Penn State Department of Chemistry as an assistant professor in 1979. He was promoted to the ranks of associate professor in 1984 and professor in 1989. He received a bachelor’s degree with honors from the University of Calcutta in India in 1970, and a master’s degree from the Indian Institute of Technology in Kanpur in 1973. He received his doctoral degree from the University of Chicago in 1978.