Ultra-short helix pitch and spiral ordering in cholesteric liquid crystal revealed by resonant soft X-ray scattering

Abstract

An ultra-short helix pitch of 104 nm was revealed by anomalous soft X-ray scattering at the carbon K edge and AFM technique in a room temperature cholesteric liquid crystal with a lactate unit in a molecular chain.

Modulating the Chiroptical Response of Chiral Polymers with Extended Conjugation within the Structural Building Blocks

“…We estimated the helical pitch length from the height profile over the fiber structure (Table S1, Figure S14) as seen in AFM images, which came to approximately 350 nm for PF8TS, 250 nm for PF8TTS, and 180 nm for PF8TTTS, respectively. 54,55 This was consistent with the observation that the PF8TTTS polymer film with a tightly coiled structure (low pitch length) showed an enhanced CD response in pristine form. Further, annealed PF8TS polymer film showed horizontally directed helical morphology in (Figures 3G,J and S11) height and phase AFM images, whereas the PF8TTS polymer film in annealed form showed an interconnected platelet-like appearance, corresponding to a cholesteric mesophase (Figures 3H,K and S12).…”