KES2-0036
Homochiral Evolution from Self-Assembly of Chiral Block Copolymers
Topic
S2. High-End Characterization/Polymer Physics/Properties
When and Where
Oct 1, 2026
10:20 - 10:45
Room 103
Session Chairs
Soo-Hyung CHOI
Presenter(s)
Rong Ming Ho (National Tsing Hua University)
Co-Author(s)
Abstract
Block copolymer is able to self-assemble into a variety of nanostructured phases. Block copolymer composed of chiral block with one-handed helical polymer chain is referred to as chiral block copolymer, giving a unique helical phase with hexagonally packed helices (H*) by symmetry breaking from self-assembly. Herein, polylactide-containing chiral block copolymer is used as a representative system for the investigation of homochiral evolution from self-assembly. Optical activity of the build unit for polymer (molecular chirality) can be examined by electron circular dichroism (ECD) whereas conformational chirality can be determined by the signals of C=O vibrational circular dichroism (VCD) spectrum, resulting from intrachain chiral interaction along the polymer chain. The chirality of hierarchical superstructure from the self-assembly of helical polymer chains can be resolved by C-O-C VCD spectrum, resulting from interchain chiral interaction between helical polymer chains. By taking advantage of homochiral evolution, chirality transfer from self-assembly can be well addressed from molecular to conformational and finally to phase chirality, giving rising to the formation of H* with controlled chirality as evidenced by electron microscopy tomography (3D TEM). Most interestingly, gyroid, G, (a chiral network) with controlled chirality can be obtained by self-assembling chiral triblock terpolymer at which the chirality of the G is determined by the chiral end block and the achiral end block gives the G with opposite chirality, giving a double network structure referred to alternating gyroid with controlled chirality (GA*). Furthermore, by taking advantage of induced circular dichroism (ICD), it is feasible to create chiral block copolymer by association of chiral dopant with an achiral block. As a result, it is possible to create H* and GA* with controlled chirality from the self-assembly of achiral block copolymer and triblock terpolymer with ICD, respectively.
