Changes in the order-to-disorder transition in salt-doped, polar block copolymer

Multiblock polymers, absent other intermolecular forces, typically aggregate into ordered structures with well-known behavior. This separation is characterized by the Flory-Huggins χ parameter, which generally encapsulates all enthalpic effects into a single parameter. While this model preforms well for materials dominated by relatively simple van der Waals forces, it loses fidelity when more complex intermolecular forces come into play. Introducing ions into a multiblock polymer with high dielectric mismatch is predicted to produce a regime dominated by solvation effects. In this work, we use coarse-grained polymer models to study the order-to-disorder transition (ODT) in a series of block copolymers with a dielectric mismatch between the blocks in the presence of charges. Two distinct charge architecture are compared, one with the anion free and the other with the anion integrated in the backbone. We find that this simple change in the anion placement has a significant effect on the ODT, and the changes depend on the relative salt concentration and the dielectric mismatch between the two blocks. We will discuss the resulting trends in the ODT in the context of recent experiments and theoretical predictions.