Aggregation-induced emission from the crowded coronal chains of block copolymer micelles

Abstract

Aggregation-induced emission (AIE) has been an emergent research topic recently, and has been utilized to monitor the self-assembly process of block copolymers. But most of the efforts were focused on the AIE process in the micellar cores. In the current study, we incorporated tetraphenyl ethylene (TPE) into the corona-forming block of block copolymers. Despite their low content and that the TPE groups remained soluble with the coronal chains stretching into solution, significant fluorescence emission was observed upon micellization, due to the restriction of movement from the highly crowded and stretched coronal chains. In sharp contrast, in our control experiment, in which weak spatial confinement on the TPE groups was applied, negligible photoluminescence was observed. This process was also utilized to monitor the micellization process and determine solvent conditions for micellization. Finally, we showed that this method was extendable to various other micellar morphologies as well, demonstrating its robustness and versatility.