Synthesis and properties of cholesteric liquid crystal elastomers with selective reflection centred on D(+)-camphoric acid

ABSTRACT

In this study, a series of cholesteric liquid crystal elastomers (ZSD series) was synthesised by hydrosilylation reaction among monomer ML₁ containing cholesteryl group, monomer ML₂ as the crosslinking agent, monomer ML₃ containing D(+)-camphoric acid group. The chemical structures and mesogenic properties of monomers and elastomers were studied by conventional testing methods. By characterising the liquid crystal elastomers, it was found that they all showed colourful Grandjean texture, good elasticity and high thermal stability. For the ZSD series, the values of T_g first decreased and then increased and the values of T_i always decreased with the change of the content of chiral liquid crystal monomers, and all elastomers had the wide mesophase temperature ranges (ΔT). ZSD₁-ZSD₃ had selective reflection in the visible light region, while the observation for ZSD₄-ZSD₇ could only be observed under the appropriate external pressure. The effect of the novel chiral monomer (ML₃) on the properties of elastomers had been investigated.

Graphical abstract

KEYWORDS:

• Cholesteric liquid crystal elastomers
• D(+)-camphoric acid
• mesogenic properties
• selective reflection

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Joint fund of National Natural Science Fund [U1708258]; Fundamental Research funds for the Central Universities [N180705004].