Global coarse-grained simulation of hierarchical self-assembly in ABn dendron-like giant molecules: Phase behavior, molecular packing, and the role of rigidity

We present a global dissipative particle dynamics simulation study of hierarchical self-assembly in ABn dendron-like giant molecules, drawing upon the experimental platform where hydrophilic and hydrophobic polyhedral oligomeric silsesquioxane cages serve as the amphiphilic building blocks. Without imposing any pre-assumed structural bias, our coarse-grained model spontaneously evolves from disordered melts into lamellar, double gyroid, hexagonal cylinder, and spherical micelle phases as the number of hydrophobic peripheral units increases—a sequence that faithfully mirrors experimental observations. A key innovation lies in comparing three topologically isomeric representations of the molecular building block: a rigid cage, a flexible chain, and a ring. This systematic comparison reveals that molecular rigidity alone can significantly alter phase boundaries and reduce micelle sizes, a finding that disentangles the role of shape persistence from that of composition or molecular weight. Our simulations further uncover hidden organizational features, including ordered linker arrays within lamellar interphases and the emergence of perforated lamellar structures upon linker elongation. While complete ordering into Frank–Kasper lattices remains computationally demanding, statistical characterizations of the spherical micelles consistently recover experimental trends, affirming the predictive capacity of our approach. This work establishes global coarse-grained simulation as an effective tool for exploring the rich phase behavior of giant molecules and lays the groundwork for the modular, in silico design of programmable supramolecular materials.