Blending-induced helical morphologies of confined linear triblock copolymers

Highly diversified microphase-separated morphologies are readily formed for linear ABC triblock copolymers confined in a cylindrical pore. However, helical morphologies which have potential for the fabrications of metamaterials emerge only at specific block compositions. In this study, we have shown by dissipative particle dynamics simulations the phase behaviors of confined linear triblock copolymers. It is found that helical nanostructures can be induced by blending non-helix-forming triblocks with homopolymers or diblock copolymers. The formation of A/C single helix + B double helixes or A/C double helixes + B quadruple helixes can be precisely controlled by tuning the binary blend ratio to acquire the effective compositions corresponding to those associated with helix-forming pure triblocks.