Characterization\nof Surface Patterning on Polymer-Grafted\nNanocubes Using Atomic Force Microscopy and Force Volume Mapping

Atomic\nforce microscopy (AFM), in particular force spectroscopy,\nis a powerful tool for understanding the supramolecular structures\nassociated with polymers grafted to surfaces, especially in regimes\nof low polymer density where different morphological structures are\nexpected. In this study, we utilize force volume mapping to characterize\nthe nanoscale surfaces of Ag nanocubes (AgNCs) grafted with a monolayer\nof polyethylene glycol (PEG) chains. Spatially resolved force–distance\ncurves taken for a single AgNC were used to map surface properties,\nsuch as adhesion energy and deformation. We confirm the presence of\nsurface octopus micelles that are localized on the corners of the\nAgNC, using force curves to resolve structural differences between\nthe micelle “bodies” and “legs”. Furthermore,\nwe observe unique features of this system including a polymer corona\nstemming from AgNC–substrate interactions and polymer bridging\nstemming from particle–particle interactions.