Regular Article - Soft Matter
Twist elastic constant in the SmC* phase of an antiferroelectric liquid crystal with and without photo-polymer networks
Physics Department, University of the West Indies, Cave Hill Campus, BB11000, Bridgetown, Barbados
Accepted: 7 April 2021
Published online: 11 May 2021
Chiral liquid crystalline phases with pitches that are comparable to visible wavelengths, all Bragg-reflect visible light. We measured Bragg reflections from the chiral SmC* phase of the antiferroelectric liquid crystal (AFLC), AS612, and explored how applied electric fields and polymer networks modify these reflections. From the critical field that unwinds the helix and destroys Bragg reflections, the twist elastic constant of the SmC* phase is determined. We estimate from this result, the elastic constant of polymer network, which when introduced into the liquid crystal matrix, fixes the helical pitch (and hence, Bragg peaks). These parameters are crucial for designing both FLC and AFLC displays since networks enhance the mechanical properties of the liquid crystal host while not affecting their optical properties.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021