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Updated: Nov 18, 2025

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Inversion of Circular Dichroism Signals in Chiral Polythiophene Films Induced by End-On-Oriented Surface-Segregated
Fanji Wang1,2, Kyohei Nakano1, Hiroshi Segawa3,4
1RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Abstract:
A chiral polythiophene surfactant based on poly(3-(S)-2-methylbutylthiophene) ((S)-P3MBT) with a semifluoroalkyl group at one end of the main chain was synthesized and used to form surface-segregated monolayers (SSMs). Films of pure (S)-P3MBT mainly adopted the edge-on orientation, whereas (S)-P3MBT films with a SSM of the polymer surfactant (S)-P3MBT-F17 contained a large proportion of end-on-oriented polythiophene, both at the surface and inside the films. The thin films with the SSM showed circular dichroism signals, with the sign opposite to those observed in (S)-P3MBT films. These findings suggest that the orientation-controlled SSM layers induced changes in the packing of the polymer aggregates in the films, resulting in a dramatic change in the excitonic interactions of the chiral semiconducting polymers.
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