The ABC of Pattern Evolution in Self-destruction of Thin Polymer Films

Abstract

We present the rst real time observation of the pattern evolution in selfdestruction of thin polymer lms based on experiments with polydimethylsiloxane lms sandwiched between silicon wafers and aqueous surfactant solutions. Four distinct stages of pattern evolution have been identied: (A) amplication of surface fluctuations, (B) breakup of the lm and formation of holes, (C) growth and coalescence of holes and, (D) droplet formation and ripening. Only one of these stages, A, is unique to self-destruction of thin lms as stages B, C and D are also present in nucleation induced dewetting of the lm. As similar looking undulating patterns characterize stages A and C, it becomes imperative to have a full temporal evolution of the pattern to identify dierent stages and the likely mechanism of lm breakup.