Stability of Frank–Kasper Phases in AB_<i>n</i> Miktoarm Star Polymers with Dispersity in <i>n</i>: Simulations and Experiments

Miktoarm star polymers with two or more blocks connected at a common junction are known to stabilize Frank–Kasper phases such as σ and A15 over wide regions of phase space due to arm-number asymmetry. To date, studies on ABn miktoarm stars in this context have focused on well-defined materials with a precise number of A and B arms. Here, using a combination of self-consistent field theory simulations and experiments, we demonstrate that mixtures of ABn miktoarm stars with dispersity in the number of B arms per molecule (n) similarly stabilize σ and A15. This insight highlights the utility of a synthetic technique known as μSTAR (miktoarm synthesis by termination after ring-opening metathesis polymerization) that simplifies the synthesis of miktoarm star polymers but inherently produces a mixture of ABn molecules having a distribution in n.