Tetragonally and Rectangularly Packed Hierarchical Cylinders from A 1 BA 2 C Tetrablock Terpolymer.

Hierarchical cylindrical nanostructures with different diameters (or shapes) have received much attention because of potential applications to next-generation lithography or advanced optical devices. Here, we observed, via small-angle X-ray scattering and transmission electron microscopy, tetragonally and rectanguarly packed hierachical cylindrical nanostructures by tailoring the volume fraction of polystyrene mid-block in polystyrene-b-polyisoprene-b-polystyrene-b-poly(2-vinylpyridine) tetrablock terpolymer (S 1 IS 2 V). P2VP becomes the main cylinder, while PI forms satellite cylinders surrounding the main P2VP cylinder. When the length of S 2 block is relatively short, tetragonal arrangement of cylinders is observed. But, a rectanguar arrangement of cylinders is formed for larger S 2 block. The experimentally observed hierarchical cylindrical nanostructures are in good agreement with the prediction by the self-consistent field theory. This article is protected by copyright. All rights reserved.