Corona Liquid Crystalline Order Helps to Form Single Crystals When Self-Assembly Takes Place in the Crystalline/Liquid Crystalline Block Copolymers

Crystalline/ionic liquid crystalline block copolymers (BCPs) with various compositions have been successfully prepared by sequential reactions. The effect of corona liquid crystalline order on self-assembly of BCPs in selective solvent is investigated in detail. It is found that two-dimensional single crystals with well-developed shapes are formed when the liquid crystalline order is present. By contrast, ill-developed platelets with small size or one-dimensional worm-like micelles are assembled if the liquid crystalline order of the corona segments is lost. It is speculated that the preferred parallel arrangement of liquid crystalline block enables it to expose more growth front of crystals. Accordingly, epitaxial crystallization will proceed readily, leading to fabrication of the well-defined single crystals

Surfactant-Mediated Crystallization-Driven Self-Assembly of Crystalline/Ionic Complexed Block Copolymers in Aqueous Solution

A series of crystalline/ionic complexed block copolymers (BCPs) with various compositions have been prepared by sequential reactions. The BCPs with different hydrophilic fractions can self-assemble into various morphologies, such as spindlelike, rodlike, and spherical micelles with different crystallinity of the core. Bis­(2-ethylhexyl) sulfosuccinate sodium salt (AOT) is added as a surfactant to induce the morphological transition of BCPs in aqueous media. The introduced AOT can be tightly bound to the cationic units, and a water-insoluble unit in the corona forms, leading to a reduced tethering density. Consequently, morphological variety changing from rods to platelets to fibril to dendrite-like micelles can be observed