Chiral Gyroidal Thin Films from Block Copolymer Self-Assembly as Structural Directing Templates for Fabrication of Mesostructured Crytalline Inorganic Materials*

It has always been a challenge to fabricate crystalline materials with well-defined mesopores, which could find applications in microelectronics and catalysis. Block copolymer self-assembly offers a scalable, facile pathway to intricate mesostructures. We present on the use of amphiphilic triblock terpolymer co-assembly with additives to prepare high-temperature stable, mesoporous thin-film templates with chiral alternating gyroid structures (G^A). This mesoscale chirality emerges from the calcination and preservation of only one of the interpenetrating G^A domains and is inaccessible via conventional top-down approach. The resulting mesoporous molds can be backfilled with a wide range of inorganic materials to direct their mesostructures. Upon melting via transient laser heating on the nanosecond time scale, crystallized materials conformally fill the 3D continuous mesopores and inherit the chirality, without destroying the underlying template. Template removal yields mesoporous, crystalline inorganic materials, with optional epitaxy on the substrate.