Theory of polygonal phases self-assembled from T-shaped liquid crystalline molecules

TL;DR

This paper presents a theoretical analysis of the phase behavior of T-shaped liquid crystalline molecules, revealing how molecular parameters influence the formation of polygonal phases and matching experimental observations.

Contribution

It provides a comprehensive theoretical framework for understanding the stability and formation mechanisms of polygonal phases in TLCMs, filling a gap in current knowledge.

Findings

Number of polygonal edges increases with side chain length and interaction strength.

Theoretical phase diagrams match experimental phase sequences.

Systematic analysis of stability mechanisms of polygonal phases.

Abstract

Extensive experimental studies have shown that numerous ordered phases can be formed via the self-assembly of T-shaped liquid crystalline molecules (TLCMs) composed of a rigid backbone, two flexible end chains and a flexible side chain. However, a comprehensive understanding of the stability and formation mechanisms of these intricately nanostructured phases remains incomplete. Here we fill this gap by carrying out a theoretical study of the phase behaviour of TLCMs. Specifically, we construct phase diagrams of TLCMs by computing the free energy of different ordered phases of the system. Our results reveal that the number of polygonal edges increases as the length of side chain or interaction strength increases, consistent with experimental observations. The theoretical study not only reproduces the experimentally observed phases and phase transition sequences, but also systematically analyzes the stability mechanism of the polygonal phases.