Surface Engineering of Patterned Polymer-Tethered Nanoparticles

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles . The generation of micrometer- and submicrometer-sized patchy colloids is now reached the state of the art, however surface patterning of nanoparticles with dimensions of the order of tens of nanometres remains a challenge.<br/><br/>We develoepd a strategy for surface patterning nanoparticles by utilizing thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and copolymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.