Influence of molecular weight on helical twisting power of oligomer chiral dopants

Chiral mesogenic monomers have been widely used in applications based on chiral liquid crystals, where polymerization is normally required to fulfill the device function. The change of molecular weight has a notable impact on the properties of the formed polymers. Herein, we systematically investigate the influence of molecular weight on the helical twisting power (HTP) of chiral oligomers when used as chiral dopants. Two series of side-chain and main-chain liquid crystal oligomers are synthesized and examined in terms of phase behavior, HTP value and dependence on temperature. The relationship between the HTP value and molecular weight of the oligomer is established, which is markedly dependent on the molecular structure. The insights obtained from the current study could help develop methods to in-situ analyze functional devices based on chiral liquid crystal polymers. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study systematically investigates the influence of molecular weight on the helical twisting power (HTP) of chiral oligomers used as chiral dopants, establishing a relationship between HTP value and molecular weight that depends on molecular structure. These insights could aid in developing analytical methods for functional devices based on chiral liquid crystal polymers.