Manipulation of co-ordering behaviour in crystalline-amorphous PEO-based block copolymers for one-step fabrication of hierarchical organized breath figure arrays

Hierarchically organized porous materials are indispensable for advancing high-performance device applications. In this study, a morphological evolution of the primary-to-hierarchical microporous architecture was demonstrated by a facile one-step manipulation of the crystalline and breath figure (BF) co-ordering behaviour in poly(ethylene oxide)- block -polystyrene (PEO- b -PS) and PEO/PEO- b -PS blend films. The characteristic parameters of hierarchically ordered micro- and submicroporous films could be controlled by changing the volume content of the crystalline PEO block ( f PEO ). With the increasing of f PEO (0 ∼ 0.278), the shape of the pores changed from an open spheroid to a semiopen polygon and hierarchical ellipsoid within the polygon. Notably, 14% PEO/PEO- b -PS multilevel porous films exhibited an optimal morphology, with a relatively large micropore diameter (3.73 ± 0.94 μm) and submicropore diameter of (0.75 ± 0.70 μm). In addition, some hierarchical TiO 2 @C porous films with high porosity were successfully fabricated by the sol–gel, ageing and calcination methods. This simultaneous active control over both the crystallization process and the polymer solidification process offers an affordable one-step route for fabricating diverse predictable hierarchically organized porous materials.