Morphology and optical properties of chiral polymer films containing hetero-atoms prepared by electrochemical polymerisation in a cholesteric liquid crystal

Abstract

Synthesis of chiral films in chiral liquid crystal is reported. The monomers (3, 3^′-hexylsilane-2, 2^′-bithiophene and 3,6-bis(3, 4-ethylenedioxythienyl)pyridazine) in cholesteric liquid crystal (CLC) electrolyte solution were elecropolymerised by the application of voltage to yield a thin film. Circular dichroism measurements display the Cotton effect for the films. The polymers show a fingerprint texture very similar to that of the CLC. The structure developed during polymerisation was preserved even after washing. Note that no chiral molecule reacted chemically with the monomer during polymerisation. The electrolyte functioned as a chiral matrix. This simple method can be defined as asymmetric polymerisation in chiral environment.

Keywords:

• chiral
• circular dichroism
• liquid crystals
• optical absorption