Functional Liquid Crystalline Block Copolymers: Order Meets Self-Assembled Nanostructures
8.1 What are Functional Liquid Crystalline Block Copolymers?
Liquid crystalline block copolymers (LC-BCPs) are block copolymers of which one or more constituting polymers have mesogens either as side groups or in the main chain. The great interest of LC-BCPs has long been recognized. The most important feature is the interplay between two levels of order and self-assembly: the LC order formed by mesogens and the ordered nanostructures arising from the microphase separation of the blocks. There have been many studies on the mutual influence of the two levels of order in LC-BCPs [1–10]. A representative example was reported by Finkelmann and co-workers in 2000 . It was found that when the microphase-separation occurred in the isotropic phase of a LC-BCP, the gyroid morphology was formed, while when the microphase separation was allowed to develop in a smectic phase, observed was a lamellar morphology. It is easy to picture that a layered smectic order of mesogens accommodates well a lamellar structure and thus can promote its formation.
In a broad sense, all LC-BCPs are functional and entitled with a combination of the characteristic properties of liquid crystalline polymers (LCPs) and BCPs: they can form LC phases and give rise to a variety of self-assembled nanostructures. However, what we ...