Thin Films of Block Copolymer-Based Supramolecules with Feature Size Over 50 nm

Block copolymer-based supramolecular self-assembly offers a simple method to
overcome issues with incommensurability, surface chemistry, and assembly kinetics to
access nanostructures in thin films. Much work has been focused on creating
nanostructures with periodicities between 10-50 nm. However, for some applications,
including the interaction with visible light, larger periodicity features are necessary.
Creating thin films with feature sizes larger than 100 nm is challenging. Large
MW nanocomposites have differing kinetic and thermodynamic considerations when
compared to the low MW analogs. Thermodynamically, incorporation of particles does
not have the same entropic penalty when the polymer chain length increases. Kinetically,
the diffusions of nanoparticle and supramolecule may play a more critical role in
determining the NP placement and NP packing within supramolecular microdomains.
Here, we demonstrate that nanocomposites with controllable morphology can be created
with a periodicity of up to ~100 nm. The size and loading of nanoparticles, as well as the
solvent annealing condition, determines the final morphology as well as the periodicity,
grain size, and packing of nanoparticles.