Core-Shell Double Gyroids Directed by Selective Solvation for ABC Triblock Terpolymers.

The formation of ABC triblock terpolymers through solution casting is still challenging. In this study, we fabricated core-shell double gyroid network structures via solution casting using poly(2,2,2-trifluoroethyl methacrylate)-b-poly(4-vinylpyridine)-b-polystyrene (FPS) triblock terpolymers in N,N-dimethylformamide (DMF). Upon heat treatment, the polymer tended to form a sphere-in-lamellar structure at the F/S interface. Given the solubility properties of each component in DMF, it was anticipated that the effective volume fraction of F relative to P would increase in concentrated solutions and the effective volume fraction of S would decrease. The microphase-separated structure derived from the DMF solution consistently resulted in the formation of a network structure composed of a core-shell double gyroid, with F as the matrix, P as the shell, and S as the core, and their periodic lengths gradually increased to 110.8, 131.8, and 162.7 nm as increase molecular weight of PS blocks to 13.8, 20.7, and 28.8 kg mol -1 . Based on the solubility properties of the polymer components highlighted in this study, the solvent selection strategy is broadly applicable to ABC triblock terpolymers featuring various polymer components, offering a more efficient avenue for fabricating core-shell double gyroid structures. This article is protected by copyright. All rights reserved.