Morphology of polymer networks formed in the chiral and non-chiral phases of an antiferroelectric liquid crystal

Abstract

We introduced photo-polymer networks into the various liquid crystalline phases of the antiferroelectric liquid crystal AS612 and studied the effects of these networks by measuring the temperature dependence of the Bragg wavelengths selectively reflected. After polymerization, the decrease in Bragg wavelengths with respect to the original values is consistent with a shorter helical pitch due to polymer network shrinkage. Also, by removing the liquid crystalline material, we are able to image the residual polymer network using scanning electron microscopy and polarized light microscopy. The polymer strands are a few microns thick and the networks show both chiral and nonchiral features.

A Review of Developments in Polymer Stabilized Liquid Crystals

“…PSFLCs are materials that can be applied in optical shutters, privacy protection windows, and photonics [11]. Due to the fast switching times (~ms) of ferroelectric LCs (FLCs) and antiferroelectric LCs (AFLCs), polymer stabilization is utilized for enhancing their mechanical integrity, improving their alignments, and further reducing their response times in displays [12].…”

“…When the polymer concentration is only 3 wt.%, the SmC* phase stability is not affected. Compared to the original Bragg wavelengths, the Bragg wavelengths of PSFLCs will decrease because of polymer network shrinkage [12,63]. The effect of polymer networks on the dielectric properties of FLCs has been studied extensively.…”