Discovering the micellization of linear A-b-(B-alt-C)2-b-A multiblock terpolymers in selective solvents

Abstract

The self-assembly of ABC amphiphilic multiblock terpolymers into multicompartment micelles in dilute solutions has gained significant attention. In this study, we employed the three-dimensional (3D) self-consistent field theory (SCFT) method to explore the micellization behavior of amphiphilic linear A-b-(B-alt-C)₂-b-A multiblock terpolymers in a solvent selective for the terminal A block. A variety of intriguing micellar structures were identified, including B- and C-disk segmented vesicles, B- and C-toroidal packing within a tubular structure, BC-segmented toroidal micelles, infinite BC-segmented cylindrical micelles, and BC-mixed toroidal micelles. Owing to the connection of blocks B and C with block A, the segmented arrangement of layers B and C follows the axial direction of the structures. As the volume fraction of the A block (fA) decreases, a structural transition from vesicles to micelles occurs in the linear A-b-(B-alt-C)₂-b-A system, in contrast with the behavior of A(BC)n multiblock terpolymers, which transition from micelles to vesicles. The SCFT method has proven to be an effective tool for identifying molecular architectures with the potential to self-assemble into complex, technologically valuable hierarchical structures. This study systematically explored the micellization of A-b-(B-alt-C)₂-b-A multiblock terpolymers using SCFT, revealing how block composition, interaction strength, and solvent selectivity govern diverse morphologies—including segmented vesicles, toroids, and cylinders. Symmetric and asymmetric solvent conditions yielded distinct BC-segmented structures, while poor solvent conditions led to hierarchical transitions. These insights offer design principles for functional materials like drug carriers by enabling precise control over self-assembled nanostructures.