Systems and methods for the controlled release of a guest composition that is sequestered within a host composition made up of an anisotropic fluid are disclosed. The guest composition is immiscible in the host composition, thus forming an interface between the compositions upon which elastic repulsion forces act to prevent the release of the guest composition from the host composition. The disclosed systems and methods work by changing the elastic repulsion forces and/or introducing one or more counter forces such that the elastic repulsion forces are no longer sufficient to prevent release of the guest composition. Exemplary methods include mechanically changing the host material (e.g., changing its temperature) or inducing a chemical (e.g., electrostatic) attraction sufficient to overcome the elastic repulsion forces. The disclosed systems and methods can be used for a variety of applications requiring on-demand delivery of a chemical composition.

Liquid crystal-based devices for detecting chlorine in a sample and methods of using such devices to detect chlorine are disclosed. Such devices have a substrate surface that includes either metal cations or a metal that is in contact with a composition that includes a liquid crystal. When the device is contacted with a sample that contains chlorine, an observed change in the orientational ordering of the liquid crystal signals the presence of the chlorine. In the absence of chlorine, no change in orientational ordering occurs.

A liquid crystal composition includes a nematic liquid crystal, and a compound of Formula (I) where R is an alkyl, aryl, aralkyl or heteroaryl having 6 to 30 carbon atoms, wherein the compound accounts for 0.3 to 0.6% of the liquid crystal composition.

##STR00001##

Further, a sensing device includes a substrate, a frame, an alignment film, the liquid crystal composition as described above, and two polarizers. The frame is connected to the substrate and forms an accommodation space having an opening, and the alignment film and the liquid crystal composition are both located inside the accommodation space. One of the polarizers is arranged in correspondence with the opening such that a channel exists between the polarizer and the frame, the other polarizer is located at a lateral side of the substrate, and the polarization directions of the two polarizers intersect with each other.

Methods and compositions for detecting a targeted analyte, such as volatile organic compound (VOCs), are disclosed. Specifically, a cholesteric liquid crystal composition comprising a nematic liquid crystal and a chiral dopant transitions to a liquid crystal blue phase or undergoes other optical changes when in contact with a sample containing the analyte. The phase transition can be readily detected with the naked eye. The disclosed methods and compositions may be used in, for example, dosimeters for detecting analyte (e.g., VOC) exposure. Methods and compositions for producing arrays of liquid crystal thin films are also disclosed. The surface between the microwells in a microwell array is coated with a liquid-crystal-phobic material, such as a fluorinated polymer or a fluorinated silane, creating isolated microwell domains that are preferentially wetted by liquid crystal. Liquid crystal can be added to the microwell domains by simple techniques such as spin coating.

Methods and compositions for detecting a targeted analyte, such as volatile organic compound (VOCs), are disclosed. Specifically, a cholesteric liquid crystal composition comprising a nematic liquid crystal and a chiral dopant transitions to a liquid crystal blue phase or undergoes other optical changes when in contact with a sample containing the analyte. The phase transition can be readily detected with the naked eye. The disclosed methods and compositions may be used in, for example, dosimeters for detecting analyte (e.g., VOC) exposure. Methods and compositions for producing arrays of liquid crystal thin films are also disclosed. The surface between the microwells in a microwell array is coated with a liquid-crystal-phobic material, such as a fluorinated polymer or a fluorinated silane, creating isolated microwell domains that are preferentially wetted by liquid crystal. Liquid crystal can be added to the microwell domains by simple techniques such as spin coating.

Liquid-crystalline (LC) media or LC materials and energy saving liquid-crystal displays (LCDs) containing these media, especially gaming displays and AR/VR headsets addressed by an active matrix and in particular to LC displays of the TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, HB-FFS, XB-FFS, PS-FFS, SA-HB-FFS, SA-XB-FFS, polymer stabilised SA-HB-FFS, polymer stabilised SA-XB-FFS, positive VA or positive PS-VA type.

Heteroaromatic isothiocyanates of formula N ##STR00001##
wherein R.sup.N, A.sup.N1, A.sup.N2, Z.sup.N1, Z.sup.N2, W, X.sup.1, X.sup.2, and n are as defined herein can be used in liquid crystalline media. Liquid-crystalline media comprising one or more compounds of formula N are suitable for use in high-frequency components, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g., phased array antennas.

A liquid crystal element including: two substrates having a transparent conductive layer formed thereon, the substrates being arranged so that the transparent conductive layers face each other, and a liquid crystal-polymer composite film sandwiched between the two substrates having a transparent conductive layer, wherein the liquid crystal-polymer composite film includes a polymer matrix and a liquid crystal composition surrounded by the polymer matrix, the liquid crystal composition contains a liquid crystal component and a dichroic dye, the liquid crystal component has positive dielectric constant anisotropy, and has an NI point of 110 C. or higher and 150 C. or lower, the liquid crystal component has a refractive index anisotropy of 0.01 or more and 0.1 or less, and the liquid crystal-polymer composite film can be switched between a transparent state and a colored state by applying a voltage.