报告题目：Stimuli Responsive Materials Based on a Polymer Bilayer Structure
报告人： Dr. Luyi Sun
主持人： 徐涛 副研究员
Dr. Luyi Sun is a Castleman Professor in Engineering Innovation in the Department of Chemical & Biomolecular Engineering and Polymer Program, Institute of Materials Science at the University of Connecticut. His current research focuses on the design and synthesis of nano-structured multifunctional materials for various applications. Dr. Sun has published more than one hundred (100) peer-reviewed journal articles and is the inventor/co-inventor of thirty nine (39) International and US patents/patent applications. The scientific results by Dr. Sun have been reported by major media including Chemical & Engineering News of the American Chemical Society, Plastics Engineering magazine of the Society of Plastics Engineers (SPE), Materials360 Online of the Materials Research Society (MRS), Yahoo, MSN, etc. Dr. Sun was selected to be a Fellow of the Society of Plastics Engineers (SPE) in 2016.
A number of marine organisms use muscle-controlled surface structures to achieve rapid changes in color and transparency with outstanding reversibility. Inspired by these display tactics, we develop analogous deformation-controlled surface-engineering approaches via strain-dependent cracks and folds. A bilayer structure composed of polyvinyl alcohol composite thin film atop elastomer substrate was designed and prepared to achieve dynamic strain-responsive optical properties. The transition between a transparent state to an opaque state can be easily achieved by uni-axially stretching and releasing the device. Also, a series of derivative mechanochromisms with capabilities of switch “on/off” fluorescence, change fluorescent color, reveal/hide information upon mechanical stimuli are prepared. These devices feature virtually no changes in optical/mechanical properties after being repeatedly stretched and released thousands of times, promising for widespread applications. Corresponding mechanics simulation was also explored, which helped to guide a more precise design of the bilayer structure.