Fig. 1. Self-assembly of PS₆₃₆-b-PtBA₂₅₀ into a hierarchical structure.

(A) Optical image of a PS₆₃₆-b-PtBA₂₅₀ film cast from 20 wt % solution in 1:3 (wt %) THF/DMF on a glass plate. (B) Corresponding SEM cross-sectional image after 5 min of evaporation with details of a macrocavity and its fine mesoporous structure. (C) Plot of the average cavity diameter, measured by SEM, as a function of evaporation time (10, 20, and 30 s); effect of the addition of 6 wt % β-CD (calculated with respect to block copolymer amount) to the casting solution.