Controlling the coassembly of highly amphiphilic block copolymers with a hydrolytic sol by solvent exchange

Abstract

The coassembly of an inorganic sol by organic structure-directing agents is a widely established technique for solution processed mesoporous metal oxides. Block copolymers with highly amphiphilic blocks are promising candidates for fast and robust material assembly into a range of periodic nano-morphologies. The high polarity difference is however an inherent challenge for the simultaneous processing of hydrophilic and hydrophobic components. Here, we show that a solvent exchange through the evaporation of the initial volatiles and redissolution in an azeotrope mixture of polar and apolar solvents with a common high boiling point allows the evolution of a micellar solution towards block copolymer-dictated structures near thermodynamic equilibrium, with controlled access to inorganic cylinders, lamellae and organic cylinders within a continuous inorganic matrix.