Tailoring the self-assembly of multilayer polymer grafted nanocube thin films

Polymer grafted nanoparticles (PGNPs) can modulate a multitude of factors like composition, nanoparticle (NP) shape, size, polymer ligand chemistry, and ligand length to drive self-assembly for multifunctional thin films. In particular, varying NP shape is incredibly powerful since surface anisotropy results in orientation controlled packing in multilayer films. In this study we demonstrate that polymer grafted nanocubes assemble in a layer by layer fashion that lends to varying degrees of vertical and lateral uniformity. We find that the orientational uniformity of polymer grafted nanocubes, both within a monolayer and between layers, is highly dependent on the roundness of the NP facets. By simply modulating the nanocube roundness through polymer ligand length, we are able to sift through different packing structures from hexagonal to face-centered cubic to body-centered cubic to simple cubic. This library of assemblies can subsequently be used to develop a deeper analysis of the PGNP thin film structure-property relationship. Furthermore, we can use this study to extend our understanding of how to create controlled self-assembled structures from the nanoscale to the macroscale.