ORGS3-0842
Molecular Dynamics Study of Terminal Chain Length Effects on Phase Structure of Bent-Core Liquid Crystals in the B4 Phase
Topic
GS3. Graduate Student Oral Session III: Polymer Synthesis, Structure, Properties, and Processing
When and Where
Sep 28, 2026
16:48 - 17:00
Room 103
Session Chairs
Jiwon KIM
Junmin LEE
Youngwoon KO
Presenter(s)
HyeonJun Kim (Korea University)
Co-Author(s)
Abstract
To rationalize the experimentally observed polymorphism in azobenzene-containing dimeric liquid crystals, we performed all-atom molecular dynamics (MD) simulations to investigate the impact of terminal alkyl chain length on supramolecular assembly. The simulations reveal that increasing the terminal chain length progressively decreases the stacking order parameter, indicating that extended chains hinder π–π overlap and disrupt the dense core-core stacking essential for helical nanofilament (HNF) formation. Analysis of chain packing behavior shows that longer chains induce significant fluctuations and local steric crowding at short intermolecular distances, which interferes with interlayer tilt propagation. Conversely, at intermediate distances, longer chains enhance parallel alignment, maximizing van der Waals interactions. Furthermore, flexibility analysis confirms that longer terminal chains exhibit reduced relative end-to-end distances and increased root mean square (RMS) distances, signifying enhanced bending and conformational freedom. Collectively, these results demonstrate that longer terminal chains drive the structural transition toward heliconical-layered microcylinders (HLµC) by destabilizing π–π stacking and increasing entropic fluctuations, thereby modulating curvature selection in the B4 phase.
