Editing Liquid crystal (section)

===Laboratory analysis of mesophases===

Thermotropic [[mesophase]]s are detected and characterized by two major methods, the original method was use of thermal optical microscopy,<ref name="Tomczyk2017">
{{cite journal | vauthors = Tomczyk W, Marzec M, Juszyńska-Gałązka E, Węgłowska D | date = 2017 | title = Mesomorphic and physicochemical properties of liquid crystal mixture composed of chiral molecules with perfluorinated terminal chains | journal = Journal of Molecular Structure | volume = 1130 | pages = 503–510 | doi = 10.1016/j.molstruc.2016.10.039 | bibcode = 2017JMoSt1130..503T }}</ref><ref>{{cite journal | vauthors = Juszyńska-Gałązka E, Gałązka M, Massalska-Arodź M, Bąk A, Chłędowska K, Tomczyk W | title = Phase Behavior and Dynamics of the Liquid Crystal 4'-butyl-4-(2-methylbutoxy)azoxybenzene (4ABO5*) | journal = The Journal of Physical Chemistry B | volume = 118 | issue = 51 | pages = 14982–9 | date = December 2014 | pmid = 25429851 | doi = 10.1021/jp510584w }}</ref> in which a small sample of the material was placed between two crossed polarizers; the sample was then heated and cooled. As the isotropic phase would not significantly affect the polarization of the light, it would appear very dark, whereas the crystal and liquid crystal phases will both polarize the light in a uniform way, leading to brightness and color gradients. This method allows for the characterization of the particular phase, as the different phases are defined by their particular order, which must be observed. The second method, [[differential scanning calorimetry]] (DSC),<ref name="Tomczyk2017" /> allows for more precise determination of phase transitions and transition enthalpies. In DSC, a small sample is heated in a way that generates a very precise change in temperature with respect to time. During phase transitions, the heat flow required to maintain this heating or cooling rate will change. These changes can be observed and attributed to various phase transitions, such as key liquid crystal transitions.

Lyotropic mesophases are analyzed in a similar fashion, though these experiments are somewhat more complex, as the concentration of mesogen is a key factor. These experiments are run at various concentrations of [[mesogen]] in order to analyze that impact.