Liquid Crystal

Liquid Crystal

Liquid crystals (LCs) are a state of matter that have properties between those of a conventional liquid and those of a solid crystal. For instance, an LC may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of LC phases, which can be distinguished by their different optical properties (such as birefringence). When viewed under a microscope using a polarized light source, different liquid crystal phases will appear to have distinct textures. The contrasting areas in the textures correspond to domains where the LC molecules are oriented in different directions. Within a domain, however, the molecules are well ordered. LC materials may not always be in an LC phase (just as water may turn into ice or steam).

Liquid crystals can be divided into thermotropic, lyotropic and metallotropic phases. Thermotropic and lyotropic LCs consist of organic molecules. Thermotropic LCs exhibit a phase transition into the LC phase as temperature is changed. Lyotropic LCs exhibit phase transitions as a function of both temperature and concentration of the LC molecules in a solvent (typically water). Metallotropic LCs are composed of both organic and inorganic molecules; their LC transition depends not only on temperature and concentration, but also on the inorganic-organic composition ratio.

Examples of liquid crystals can be found both in the natural world and in technological applications. Most electronic displays are currently based on liquid crystals. Lyotropic liquid-crystalline phases are abundant in living systems. For example, many proteins and cell membranes are LCs. Other well-known LC examples are solutions of soap and various related detergents, as well as the tobacco mosaic virus.

Read more about Liquid Crystal:  History, Design of Liquid Crystalline Materials, Liquid Crystal Phases, Biological Liquid Crystals, Pattern Formation in Liquid Crystals, Theoretical Treatment of Liquid Crystals, External Influences On Liquid Crystals, Effect of Chirality, Applications of Liquid Crystals

Other articles related to "liquid crystal, liquid crystals, liquid":

Lenny Lipton - Patents
... twisted nematic liquid crystal device and eyewear incorporating the device" US patent 5239372, "Stereoscopic video projection system" US patent 5193000, "Multiplexing technique for stereoscopic video ...
Cholesteryl Benzoate
... It is a liquid crystal material forming cholesteric liquid crystals with helical structure ... oleyl carbonate in some thermochromic liquid crystals ... It can be also used as a component of the liquid crystals used for liquid crystal displays ...
Blue Phase Mode LCD - First Blue Phase LC-display
... Samsung's Blue Phase mode does not require liquid crystal alignment layers, unlike today's most widely used TFT LCD modes such as Twisted Nematic (TN), In-Plane Switching (IPS) or Vertical ... it has been claimed that Blue Phase panels would reduce the sensitivity of the liquid crystal layer to mechanical pressure which could impair the lateral ... external electric field induces a birefringence in the liquid crystal via the Kerr effect ...
Blue Phase Mode LCD - History
... due to at least two new and very different liquid crystalline phases ... Since this distance is on the order of the pitch of the chiral nematic liquid crystal (typically 100 nm) and since the geometries of usual liquid crystal samples are much ... more stable than the same volume filled with a single twist chiral nematic liquid crystal ...
Applications of Liquid Crystals
... See also Liquid crystal display Liquid crystals find wide use in liquid crystal displays, which rely on the optical properties of certain liquid crystalline substances in the ... In a typical device, a liquid crystal layer (typically 10 μm thick) sits between two polarizers that are crossed (oriented at 90° to one another) ... The liquid crystal alignment is chosen so that its relaxed phase is a twisted one (see Twisted nematic field effect) ...

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