Tuning Diblock Copolymer Morphologies by Stimuli-Responsive Supramolecular Interactions

Ability to tune the microstructures formed by block copolymers via easy-to-use physical approaches offers additional handles to the materials for practical applications. One common approach is through adding homopolymers, which induces morphological changes due to preferential partitioning of homopolymers into specific micro-domains. Recently, supramolecular forces that are chemistry-specific and stimuli-responsive have been exploited to enable stimuli-switchable morphologies. To offer microscopic insights into this process, here we present a simulation study of diblock copolymers blended with homopolymers that are associative to one of the blocks through supramolecular forces. By manipulating the manner of associations, we investigate structural changes induced by supramolecular complexations, and to elucidate the differences from the counterpart van der Waals (VDW) force-driven systems. It is found that the homopolymer-receiving microdomain exhibits non-monotonic size changes accompanied by cluster formation as preferential partitioning occurs. Dynamics analysis suggests that both morphologies and supramolecular binding kinetics exert significant influence on the diffusion of homopolymers across the microdomains, implicative of the extent of “responsiveness” of such materials.