Self-assembly of three-component bolaform giant surfactants with branched architectures

Branched architecture profoundly influences the physical properties of polymers, making it an important topic in the field of polymer science. Herein, we report a facile synthetic strategy to introduce one site-specific side chain at the junction point to fabricate a series of bolaform giant surfactants with branched architecture. By tuning the volume fraction and the ratio between the linking chain and side chain, various phases have been identified, including three-phase-four-layer lamellae, graphene-like honeycombs, tetragonally packed cylinders, and two-phase lamellae. Notably, the lattice dimension of obtained columnar structures is ∼12 nm, corresponding to sub-10 nm cylinder diameters. As revealed by temperature-dependent small-angle X-ray scattering profiles, a branched architecture significantly decreases the order-disorder transition temperature by ∼90 °C. We also use semi-quantitative calculations to analyze the thermodynamic properties of the observed phases and build rational connections between phase behaviors and the corresponding branching ratios. This study shed light on fine-tuning the macromolecular assembly via molecular topology engineering.