1 research outputs found
Nanoparticle Assembly on Topographical Polymer Templates: Effects of Spin Rate, Nanoparticle Size, Ligand, and Concentration
The ability to assemble nanoparticles (NPs) into desired
patterns
in a controlled fashion is crucial for the study of collective properties
and for the fabrication of a variety of NP-based devices. Drying-mediated
assembly directed by a template provides a facile route for organizing
NPs in predefined patterns. We utilize the branched topographical
landscapes displayed by partially crystallized poly(ethylene glycol)
(PEG) films as a generic template for studying the drying-mediated
organization of dodecanethiol- and polystyrene thiol-protected gold
NPs (Au-DT and Au-PS), and explore the combined effects of NP size
and ligand, concentration, and spin rate on the distribution of NPs
inside the channels. We show how NP concentration and the spin rate
applied during NP deposition can be used to influence the tendency
of NPs either to fill the channel uniformly or to localize near the
channel edges, explain the important role of the enhanced aggregation
tendency of larger NPs on the resulting morphologies, and demonstrate
how this tendency can be tuned by the proper choice of ligands. The
different effects are explained in the context of possible scenarios
of drying-mediated assembly by analyzing the relevant interactions
and forces acting on the NPs during solvent evaporation