Cholesteric liquid crystal 5322156 224139117 2008-07-07T14:19:42Z Sijarvis 1518088 [[WP:UNDO|Undid]] revision 223150942 by [[Special:Contributions/Sendilab|Sendilab]] ([[User talk:Sendilab|talk]]) [[Image:Cholesterinisch.png|right|The image shows a rotation of the director about 180° in a cholesteric phase. The corresponding distance is the half-pitch, p/2.]] A '''cholesteric liquid crystal''' is a type of [[liquid crystal]] with a [[helical]] structure and which is therefore [[Chirality (chemistry)|chiral]]. Cholesteric liquid crystals are also known as ''[[Liquid_crystal#Chiral_phases| chiral nematic liquid crystals]]''. They organise in layers with no positional ordering within layers, but a director axis which varies with layers. The variation of the director axis tends to be periodic in nature. The period of this variation (the distance over which a full rotation of 360° is completed) is known as the pitch, p. The pitch is varying with temperature and it can also be affected by the boundary conditions when the chiral nematic liquid crystal is sandwiched between two substrate planes. Examples of compounds known to form cholesteric phases are [[hydroxypropyl cellulose]] and [[cholesteryl benzoate]]. {{physical-chemistry-stub}} [[Category:Liquid crystals]] [[Category:Matter]] [[Category:Soft matter]] [[bg:Шаблон:Химия-мъниче]] [[fr:Modèle:Ébauche chimie]] [[ru:Холестерические жидкие кристаллы]] [[zh:Template:Chem-stub]]