Event
Special ChBE/MSE Seminar: Charles C. Han on Polymers for Medical Devices
Thursday, March 13, 2014
9:30 a.m.-10:30 a.m.
Marker Room (0112), Chemistry Building
Some Recent Studies on the Dynamically Asymmetrical Polymer System and an Application of Polymer Blend in a Category III Medical Device
1. Crystallization & Phase Separation in a Dynamically Asymmetric Blend
2. An Electrospun Fibrous Anti-adhesion Membrane with Multiple Drug Delivery Functions
Charles C. Han
Beijing National Laboratory for Molecular Sciences
Joint Laboratory of Polymer Science and Materials
Institute of Chemistry
Chinese Academy of Sciences, Beijing
Abstract:
Crystallization and phase separation are two intriguing phase transitions in nature and have been intensively studied in the past decades. Recently, the mechanism of simultaneous or interactive transitions of crystallization and phase separation has become a popular research topic due to its importance to both fundamental understandings as well as technological applications.
In the first part of this talk, the interactive phase transitions are extended to a dynamically asymmetrical system. Two kinds of phase diagrams and many different structures and dynamics can be obtained in a dynamically asymmetric blend such as poly(methyl methacrylate) (PMMA) and poly(ethylene oxide) (PEO). The structure features include concentric alternating ring structures with positive birefringence and crystal lamellae mostly aligned in the tangential direction in PEO-rich layers (so called target pattern). Also with enhanced phase separation and glassy component influences, stepwise growth mode of phase separation and frustrated crystallization can be observed. All these phenomena can be qualitatively explained by two-fluid model with the addition of compression modulus influence.
In the second part of this talk, a polymer blend PLGA/PLLA-b-PEG was used to fabricate an electro-spun anti-adhesion membrane. The anti-adhesion property and many in-vitro and in-vivo testing have been carried out in China. The final clinical trial has been finished and the FDAC license has been applied and the process has reached the final stage. Many follow up research on functional applications and targeted drug deliveries will be discussed.
About the Speaker:
Dr. Charles C. Han received his B.S. in Chemical Engineering from National Taiwan University in 1966, his master’s degree in Physical Chemistry from the University of Houston in 1969, and his Ph.D. in Physical Chemistry from the University of Wisconsin, Madison in 1973.
Over the course of his nearly 3 decade career at NIST, he served first as a research scientist and later as the leader of the polymer blends and multiphase materials groups. He was elected a NIST Fellow in 1995.
Dr. Han joined the Institute of Chemistry at the Chinese Academy of Sciences in 2002 as the chief scientist and the director for the joint laboratory of polymer science and materials. His research interests include dynamic light, neutron, and small angle X-ray scattering in polymer research; order-disorder transition and pattern formation of block copolymers; equilibrium phase behavior and kinetics of spinodal decomposition of polymer mixtures and crystallization behaviors; and shear dependence of the static and kinetic phase behavior of polymer mixtures and its application in polymer processing. More recently he has studied in-reactor alloying of polyolefins with compound catalysts.
His honors and awards include the American Physical Society's High Polymer Physics Prize and Dillon Medal, the Humboldt Senior Research Award from the Alexander von Humboldt Foundation, and the International Award of the Society of Polymers, Japan.
Dr. Han has published more than 360 papers, and is the author or co-author of 27 books. He holds more than 30 disclosed and approved patents in China and the U.S.
