Nanoparticle organisation into branched morphologies using thin films of crystalline polymers as dynamic templates

Abstract

We present a facile route for the fabrication of hierarchical, hyper-branched nanoparticle superstructures guided by a two-dimensional polymer template. Our approach utilises semi-crystalline poly(ethylene glycol) (PEG) films featuring branched arrays of channels as templates for the patterning of gold nanoparticles of different sizes and surface chemistry. The deposited nanoparticles preferentially adhere to the channel edges, forming nanoparticle chains decorating the contours of the surface topography. This preference is shown to be independent of nanoparticle size and surface chemistry; however, smaller nanoparticles appear to be more sensitive to subtle topographical attributes of the film. Additionally, the ability to induce the dissolution of the crystalline polymer domains during the nanoparticle patterning process leads to a controlled exchange of these domains with fractal nanoparticle arrays. This dynamic templating methodology adds another dimension to the toolbox of existing patterning methodologies.