Co-existing morphologies of lamellae and double arrays of cylinders by A1BA2C tetrablock terpolymer

Here, we observed, via small-angle X-ray scattering and transmission electron microscopy, co-existing morphologies of lamellae and cylinders by precisely tailoring the volume fraction of each block in polystyrene-b-polyisoprene-b-polystyrene-b-poly(2-vinylpyridine) tetrablock terpolymer (S1IS2V). The PI cylinders are located inside the PS microdomains. This is due to the presence of the mid-block PS2 which effectively isolates PI cylinders from the interface between PS and P2VP lamellae. The experimentally observed morphology is in good agreement with the predicted phase by self-consistent field theory. Furthermore, we successfully adjusted the position of the PI cylinders inside the PS lamellar microdomains by changing the length of the PS2 mid-block. Finally, we obtained vertically oriented lamellae and cylinders in S1IS2V films with the aid of solvent annealing.