Modifying metal–polymernanostructures using UV exposure

Abstract

Metals have a variety of behaviors when deposited onto diblock copolymer films, in particular, poly(styrene-b-methylmethacrylate). Silver is known to form nanowires, whereas gold forms ellipsoidal nanoparticles of different sizes on each of the blocks, and chromium creates a uniform film on PS-b-PMMA. We show that with UV light we can alter the separation between silver nanowires, by making each wire narrower. We also demonstrate the effects of UV light on PS-b-PMMA coated with thin layers of gold and chromium, as observed with atomic force microscopy and transmission electron microscopy. We have found that UV exposure increased corrugation of such metal–polymer hybrids by removing PMMA domains, but did not remove metal residing on top of those domains. The ability to manipulate the morphology of these nanomaterials has potential application in areas such as electronics and sensor technology.