title: Transfer of chirality from molecule to phase in self-assembled chiral block copolymers.
abstract: Here, we report the mechanisms of chiral transfer at various length scales in the self-assembly of enantiomeric chiral block copolymers (BCPs*). We show the evolution of homochirality from molecular chirality into phase chirality in the self-assembly of the BCPs*. The chirality of the molecule in the BCP* is identified from circular dichroism (CD) spectra, while the handedness of the helical conformation in the BCP* is determined from a split-type Cotton effect in vibrational circular dichroism spectra. Microphase separation of the BCP* is exploited to form a helical (H*) phase, and the handedness of helical nanostructure in the BCP* is directly visualized from transmission electron microscopy tomography. As examined by CD and fluorescence experiments, significant induced CD signals and a bathochromic shift of fluorescence emission for the achiral perylene moiety as a chemical junction of the BCPs* can be found while the concentration of the BCPs* in toluene solution is higher than the critical micelle concentration, suggesting a twisting and shifting mechanism initiating from the microphase-separated interface of the BCPs* leading to  formation of the H* phase from self-assembly.
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan. rmho@mx.nthu.edu.tw
authors.forename: Rong-Ming
authors.initials: RM
authors.lastname: Ho
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Li
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Lin
authors.forename: Hsiao-Fang
authors.initials: HF
authors.lastname: Wang
authors.forename: Yu-Der
authors.initials: YD
authors.lastname: Lee
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Edwin L
authors.initials: EL
authors.lastname: Thomas