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hierarchical structure, nano-helices, metamaterials, focal asymmetry, block copolymers, self-assembly
NSRRC Scientist Wei-Tsung Chuang and User Yeo-Wan Chiang’s Collaborative Research Highlighted as a Cover Image of J. Mater. Chem. C
The research of Dr. Wei-Tsung Chuang and Prof. Yeo-Wan Chiang on bioinspired optical crystal materials using Taiwan Light Source was selected as a cover image of Journal of Materials Chemistry C.
A collaborative research team, led by NSRRC scientist Dr. Wei-Tsung Chuang and user Prof. Yeo-Wan Chiang in Materials and Optoelectronic Science at National Sun Yat-Sen University, used TLS 23A1 and TLS 01C2 of the NSRRC to conduct research on bioinspired artificial optical crystal materials. Their latest findings were published in Journal of Materials Chemistry C and were highlighted with an illustration on the inside front cover of the issue.
Helical nanostructures are fascinating subjects in physical, chemical and biological fields, but the fabrication of three-dimensional helical structural templates of metamaterials at submicron scale is still a tricky issue. Their structures are too large to be made by molecular synthesis, and also too time-consuming to process by top-down approaches. On the other hand, the bottom-up strategy offered by self-assembly block copolymers requires synthesis of ultrahigh molecular weight with monodispersion in chiral blocks, and the control of twisting power of helices is a big challenge. The team solved the bottleneck by developing novel hierarchical superhelices from self-assembly of achiral dendron-jacketed block copolymers. The presence of focal asymmetry (shown as the pink petals in the schematic illustration of the cover image) in both the stereochemistry of the dendrons (donors) and interactive binding sites of the copolymer chains (acceptors) plays a pivotal role in generating a spontaneous symmetry and thus the formation of helical assemblies (shown as green and red branches). Rheo-SAXS and WAXD measurements of the research were respectively performed at beamlines TLS 23A1 and TLS 01C2 at the NSRRC. Their findings might provide a new pathway for the industrial use of metamaterials.