Optics of multilayered cholesteric liquid crystals with disorder: towards LC-nose.

Optical properties of multilayered disordered cholesteric liquid crystals (CLC) with different types of disorders were performed by employing 4x4 matrix method in order to simulate a diffusion of volatile organic compound (VOC) molecules inside the cholesteric material. A simulated CLC consisted of three layers, the central layer being unaffected by VOCs and two outer layers being subjected to diffusion of VOC molecules. The diffusion of VOCs inside the CLC was simulated by changing either the order parameter or helical pitch of the two outer layers of the CLC. The results were compared with experiments of VOC diffusion in a number of CLC systems. It was determined that the change of order parameter plays an important role in liquid CLCs and change of helical pitch mostly affects CLC polymers. The applicability of these calculations for designing artificial LC-nose [1] is discussed.

[1] Liquid crystal nose, chiral case: towards increased selectivity and low detection limits

PV Shibaev, D Carrozzi, L Vigilia, H DeWeese
Liquid Crystals, 1-9