Hydrogen‐Bonded Cholesteric Liquid Crystals—A Modular Approach Toward Responsive Photonic Materials

Abstract

A supramolecular approach for photonic materials based on hydrogen‐bonded cholesteric liquid crystals is presented. The modular toolbox of low‐molecular‐weight hydrogen‐bond donors and acceptors provides a simple route toward liquid crystalline materials with tailor‐made thermal and photonic properties. Initial studies reveal broad application potential of the liquid crystalline thin films for chemo‐ and thermosensing. The chemosensing performance is based on the interruption of the intermolecular forces between the donor and acceptor moieties by interference with halogen‐bond donors. Future studies will expand the scope of analytes and sensing in aqueous media. In addition, the implementation of the reported materials in additive manufacturing and printed photonic devices is planned.

Direct Digital Photonic Patterning of Hydrogen-Bonded Cholesteric Liquid-Crystalline Films

“…In an initial approach, St* or St8 was partially substituted by mAp* and mAp8 (1−8 mol %) in the DFP(St*/St8) complexes, and the materials were investigated by polarized optical microscopy (POM). 26 The micrographs prove the formation of a variety of chiral mesophases, including blue phases (BP), cholesteric (N*), and chiral smectic phases (Sm*, Figure S10). As a representative example, the phase behavior of the DFP(St* 45 mAp* 5 /St8 50 ) system will be described in detail (Figure 2).…”

“…Here, our modular methodology allows us to systematically investigate the structure-property relationship by partial substitution of the components. In an initial approach, St* or St8 was partially substituted by mAp* and mAp8 (1–8 mol %) in the DFP ( St* / St8 ) complexes, and the materials were investigated by polarized optical microscopy (POM) . The micrographs prove the formation of a variety of chiral mesophases, including blue phases (BP), cholesteric (N*), and chiral smectic phases (Sm*, Figure S10).…”

“…23−25 Recently, we reported a modular approach toward structurally colored hydrogen-bonded (HB) liquid crystals at room temperature, which exhibited stimulus responsiveness to temperature changes and the presence of gaseous analytes. 26 We could demonstrate that structurally colored octyloxy-and citronellyloxystilbazole-based (St8/St*) 3,5-difluorophenol (DFP) assemblies respond to iodine vapors with a red shift of 70 nm of the selective reflection band (SRB). The shift of the reflection band could be assigned to an interference of the iodine with the hydrogen bond between stilbazole and DFPforming halogen-bonded assemblies.…”

A room temperature 9CB‐based chemical sensor

“…As a consequence, liquid crystals are deemed a fascinating class of functional and responsive materials, which can be used as probes to detect and translate events at the molecular level into measurable outputs and hence find use within a wide variety of technological applications, [ 1–9 ] namely in liquid crystal‐assisted chemical and biological sensing technologies. [ 6,10–23 ] The most commonly used liquid crystal sensor geometries include liquid crystal confinement in thin films with a free surface, [ 24–28 ] droplets, [ 29–36 ] and fibers. [ 37–41 ]…”

Thermal Paper and Time Temperature Integrators Made From a Structural Colored Polymer Crosslinked With Hydrogen Bonded Cyclohexanoic Acid Derivatives

“…Development of structural color-based polymer systems that function as temperature-responsive optical indicators offers a range of advantages including robustness, low-cost production, and easy readout. [8][9][10] Furthermore, such photonic polymer systems allow for a significant freedom of molecular programmability in color transition, response range, and sensitivity. [11,12] Cholesteric liquid crystal (CLC) polymers are a specific class of structural colored materials having a helical molecular organization.…”