Editing State of matter (section)

===Microphase separation===
{{Main|Copolymer}}

[[File:Sbs block copolymer.jpg|thumb|right|SBS block copolymer seen with [[transmission electron microscopy]] (TEM)]] [[Copolymers]] can undergo microphase separation to form a diverse array of periodic nanostructures, as shown in the example of the [[Kraton (polymer)|styrene-butadiene-styrene block copolymer]] shown at right. Microphase separation can be understood by analogy to the phase separation between [[oil]] and water. Due to chemical incompatibility between the blocks, block copolymers undergo a similar phase separation. However, because the blocks are [[covalent bond|covalently bonded]] to each other, they cannot demix macroscopically as water and oil can, and so instead the blocks form [[nanometer|nanometre-sized]] structures. Depending on the relative lengths of each block and the overall block topology of the polymer, many morphologies can be obtained, each its own phase of matter.

[[Ionic liquid]]s also display microphase separation. The anion and cation are not necessarily compatible and would demix otherwise, but electric charge attraction prevents them from separating. Their anions and cations appear to diffuse within compartmentalized layers or micelles instead of freely as in a uniform liquid.<ref>Álvarez, V.H.; Dosil, N.; Gonzalez-Cabaleiro, R.; Mattedi, S.; Martin-Pastor, M.; Iglesias, M. & Navaza, J.M.: Brønsted Ionic Liquids for Sustainable Processes: Synthesis and Physical Properties. Journal of Chemical & Engineering Data 55 (2010), Nr. 2, S. 625–632. {{doi|10.1021/je900550v 10.1021/je900550v}}</ref>