Dewetting Suppression of Polystyrene Thin Film Using Titanium Dioxide Nanoparticles

Abstract

Effects of titanium dioxide nanoparticles on thermal stability of polymeric thin film are investigated in this study. Polystyrene with molecular weight of 52,000 g/mol is used as a base polymer. The concentrations of titanium dioxide nanoparticles in polystyrene are varied from 0-0.20 wt.%. Films are fabricated by spin casting on Si wafer substrate and annealed at 180 °C and 190 °C for various times in order to study dynamics of dewetting. Film morphologies are analysed by optical microscopy and atomic force microscopy. Dewetting areas of each film as a function of annealing time are determined. It is found that addition of titanium dioxide nanoparticles suppresses dewetting in polystyrene film with thicknesses of ~30 nm and ~100 nm. The same titanium dioxide amounts, on the other hand, accelerate dewetting process in the film with thickness of ~265 nm. Mechanisms of dewetting suppression in polymeric film by titanium dioxide nanoparticles are discussed.