Useful strategy for assuming complex ordered phases possibly formed by ABC-type block copolymers

Abstract

Block copolymers (BCPs) provide a versatile platform for the formation of various nanostructures. Among them, ABC-type BCPs have great potential to form complex structures, which may have promising applications in nanotechnology. However, the self-assembly behavior of ABC-type BCPs is still not well understood because of its complexity, especially about the formation of complex structures that are difficult to be assumed from AB-type BCPs. In this paper, we propose a useful rule to systematically assume ordered structures possibly formed by ABC-type BCPs. We hypothetically change an AB-type BCP to an ABC-type architecture by replacing the ending portion of each free B block with a C block, to see how the C blocks separate from the ordered structure preformed by the AB-type BCP. We propose that the C domains firstly aggregate at the vertices of the Voronoi cell of the precursory AB-type structures to form spheres, then along the edges to form struts, and finally on the faces to form layers. Accordingly, we have obtained a large number of ABC-type structures, some of which are very complex and have not been reported before. The validity of the assumption rule is testified by using self-consistent field theory to determine the stability of some assumed structures. This rule can serve as a useful guide for the exploration of interesting novel structures in ABC-type BCPs. Published by the American Physical Society 2024