Seminar Date : September 16 (Mon.) 2019, 16:00 ~ Venue : Engineering Building 2 (25314) Speaker : Prof. Myung-Han Yoon [School of Materials Science and Engineering Gwangju Institute of Science and Engineering (GIST)] - Host : Prof. Gi Ra Yi(School of Chemical Engineering, SKKU) Title: Solid-state Driven Hydrogel Nano-/Microstructures with Predefined Geometry and Controlled Swelling Via Hydrogelification Abstract In this research, we report solid-state crosslinking-based transparent hydrogels with controlled swelling and predefined micro/nanoscale geometry. Unlike the conventional solution-phase crosslinking utilized for highly-swollen bulk hydrogel materials, we employed i) the solid-state crosslinking between water soluble polymer and crosslinker polymer, and ii) the subsequent process for breaking physical crosslinking (e.g., hydrogen bonding) among waters-soluble polymer chains. This novel approach called hydrogelification enables both the facile definition of overall shape/dimension and the effective control over swelling ratio of the resultant hydrogel. The possible mechanisms on solid-state crosslinking and dramatic water swelling were proposed based on various characterization results. As demonstrated by micro/nanofibrillar hydrogel scaffolds prepared from electrospun nanofibers, the present method can provide a novel approach to fabricate nanofiber-structured transparent hydrogel scaffolds with good biocompatibility, diverse polymer composition, controlled swelling/mechanical properties, and large porosity. Finally, we demonstrate that the hydrogel nanofiber structures can be beneficial for a variety of biomedical applications such as 3-dimensional cell culture.