Design of Selective Chemical/Biological Reactions in Liquid Crystals via Chemical Selectors

Abstract

Due to the unique combination of fluidity of liquids and long-range molecular ordering of crystals, liquid crystals (LCs) have been widely used for design of functional materials that sense a variety of stimuli and report them into macroscopic optical output. Notably, their amplification ability facilitates the extraordinary sensitivity even to nanoscopic and molecular phenomena (e.g., molecular assembly). However, the relatively low selectivity has prevented the realization of their full potential. In this presentation, we will show simple and versatile design rules to control not only selectivity but also sensitivity by decorating the interface of LC films with organic ionics (OIs). Specifically, the resulting OI-LC film was shown to selectively sense and optically report the exposure of specific toxic gas or bacteria even at very low concentration. In addition, we experimentally and theoretically demonstrated that their characteristics are precisely controllable by modulating the length of carbon chain and type of counter ion in OIs. We will also discuss the interactive holographic system via OI-LC film that can provide visual information about their environment, such as the arrival of chemical and biological cues. This work was supported by the NRF (2021R1A4A1030944 & 2021R1A2C2095010 & 2022M3C1A3081312) and Samsung Electronics Co., Ltd.