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, however, 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.