Low voltage tunable cholesteric liquid crystal based on electrochemical process

ABSTRACT

A low voltage tunable cholesteric liquid crystal doped with electrochemical chiral molecules was successfully fabricated and studied in detail. Chiral molecules with different structures composed of binaphthol derivatives and ferrocene unit (CD-Fc) were successfully synthesised and characterised. The helical twisting power (HTP) values of the molecular CD-Fc and ionic CD-Fc+ were calculated. In the experiment, it was found that the developed low voltage tunable cholesteric liquid crystal exhibited two tunable processes, one with a reversible tuning process between blue and green reflection colour at an applied voltage of 1.5 V, and the other with an incomplete recovery of reflection colour at an applied voltage of more than 2.0 V. At present, there were few reports of cholesteric liquid crystal that combined both operating modes and can exhibit a wide tuning wavelength range at low voltages. The low voltage-driven characteristic of the developed device in this work showed potential applications in anti-counterfeiting and other fields.

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KEYWORDS:

• Cholesteric liquid crystal
• low voltage tuning
• electrochemical reaction
• reversible tuning process
• incomplete recovery of reflection color

Acknowledgements

This work was supported by the National Key R&D Program of China (2018YFB0703703); National Natural Science Foundation of China (No.61370048, No.51673023, No.51773017, No.51973017).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [No.61370048, No.51673023, No.51773017, No.51973017]; National Key Research and Development Program of China [2018YFB0703703]