Nanopatterned Thermoresponsive Functionalization of Substrates via Nanosphere Lithography

Abstract

1Self-assembled monolayers (SAMs) have been widely utilized as a way of tailoring surface chemistry through the adsorption of organic molecules to different materials. SAMs are easy to prepare and offer a wide variety of organic molecules that afford additional or improved properties to the coated material. Spatial control of SAM placement has been achieved over many length-scales, even at the nanoscale. However, nanopatterned SAMs are usually prepared through serial processes utilizing atomic scanning probes or soft-lithography utilizing elastomeric masters. These techniques are expensive or not repeatable. Here we present the use of nanospheres for the creation of nanopatterned Au:Cu films which spatially control the grafting of a thermoresponsive SAM made from poly(N-isopropyl acrylamide) (PNIPAM). Chemical characterization validates the presence of PNIPAM and environmental atomic force microscopy showed its response to temperature which was evidenced by a change in stiffness. Our approach represents an affordable large area methodology for repeatable spatial control of SAMs at the nanoscale.