Papadakis Integrated Sciences Building (PISB), Room 120, located on the northeast corner of 33rd and Chestnut Streets.
Designed Polymer Crystallization for Biomedical Engineering
Christopher Li, PhD
Department of Materials Science and Engineering (MSE)
College of Engineering
Crystallization is ubiquitous in nature and semi crystalline polymers are of crucial importance in our daily life. Compared with small molecules, polymers crystallize via a more complex pathway because of their long chain nature and various metastable states associated with polymer crystals. In this talk, I will show that this complex conformational change of polymer chains upon crystallization can be employed to design and fabricate functional nanomaterials for biomedical engineering applications. A few examples will be discussed.
First, crystallization can be used to control the morphology of collagen-mimicking polymer scaffolds for bone tissue engineering. Second, ordered hybrid nanomaterials can be formed by controlling the interaction between nanoparticles and polymer single crystals (PSC). These ordered hybrids can find applications in artificial nanomotors and drug delivery. Third, a miniemulsion crystallization method was developed to grow nanosized, PSC capsules. We coined the name “crystalsome” to describe this unique structure because their structure mimics liposomes and polymersomes. Ultra-long blood circulation has been realized using this unique crystalsome.
Furthermore, super dense and loop polymer brushes with precise chain anchoring points can be synthesized. Novel responsive molecular Velcro was also prepared. Such brush structure may have profound impact on designing biomedical devices. We envisage that designed polymer crystallization offers a powerful tool to synthesize novel functional nanomaterials for biomedical applications.
Christopher Li, PhD, received his B. S. from the University of Science and Technology of China in 1995 and his Ph. D. from the Department of Polymer Science, The University of Akron in December, 1999. After working as a post-doc at the Maurice Morton Institute of Polymer Science, UA for 2 years, he joined Drexel University, the Department of Materials Science and Engineering in January, 2002 as an assistant professor, and was promoted to associate and full professor in 2007, and 2011, respectively.
Dr. Li's research interests center on the structure and morphology of ordered polymeric systems and hybrid materials. He is a Fellow of American Physical Society and North American Thermal Analysis Society, and is on the Editorial Advisory Board of Macromolecules/ACS macro letters (14-17), Polymer, Materials Research Express, and Chinese Chemical Letter.
Dr. Li has received a number of awards including the NSF Creativity Award, NSF-CAREER Award, the Inaugural Provost Award for Outstanding Mid-Career Scholarly Productivity, Alexander von Humboldt Research Fellowship, ASM Bradley Stoughton Award, DuPont Young Faculty Award, among others. He served as the President of the North American Thermal Analysis Society (NATAS) in 2016.