The stability of thin polymer films as controlled by changes in uniformly sputtered gold

Amarandei, George; O'Dwyer, Colm; Arshak, Arousian; Corcoran, David

The stability of thin polymer films as controlled by changes in uniformly sputtered gold

Files

Amarandei_Soft_Matter_2012_revised_form.pdf(805.74 KB)

Accepted version

Date

2013-01-22

Authors

Amarandei, George

O'Dwyer, Colm

Arshak, Arousian

Corcoran, David

Publisher

Royal Society of Chemistry (RSC)

Published Version

10.1039/c3sm27130g

Abstract

The stability of polystyrene thin films of low molecular weight on a solid substrate is shown to be controlled by the presence of uniformly distributed gold sputtered at the air–polymer interface. Continuous gold coverage causes the formation of wrinkles. High coverage and Au nanoparticle (NP) density leads to the development of a spinodal instability while low coverage and NP density retards the nucleation dewetting mechanism that beads up the thin polymer film into drops when no coverage is present. Heating at temperature larger than the polymer glass transition temperature for extended periods allows the gold NPs to coalesce and rearrange. The area of polymer surface covered by NPs decreases as a result and this drives the films from unstable to metastable states. When the gold NPs are interconnected by polymer chains a theoretically predicted spinodal instability that patterns the film surface is experimentally observed. Suppression of the instability and a return to a flat film occurs when the polymer interconnections between particles are broken. While the polymer films maintain their physical continuity changes in their chemical surface composition and thickness are observed. The observed film metastability is nevertheless in agreement with theoretical prediction that includes these surface changes.

Keywords

Polymer films , Gold , Phase interfaces , Polymers , Polystyrenes , Stability , Air-polymer interface , Chemical surface composition , Low molecular weight , Polymer glass transition , Polymer interconnections , Polystyrene thin films , Spinodal instability , Thin polymer films

Citation

Amarandei, G., O'Dwyer, C., Arshak, A. and Corcoran, D. (2013) 'The stability of thin polymer films as controlled by changes in uniformly sputtered gold', Soft Matter, 9(9), pp. 2695-2702. doi: 10.1039/c3sm27130g