Unconventional spinodal surface fluctuations on polymer films.

Stability of polymer films as a 2D system

According to classical theory of phase transition, fluctuations in systems with low dimensions are so violent that the phase boundary between unstable and metastable states would be smeared. In this experiment, we measure the growth of surface fluctuations on an unstable polymer film with a thickness, h0 = 5.1 nm, which is much less than the spinodal thickness, hsp(= 243 nm) thereby the film is...

Restructuring-induced dewetting and re-entrant wetting of thin glassy films

– Thin films of glass-forming liquid crystalline molecules on float glass substrates showed restructuring-induced dewetting in the film thickness range of 40–100 Å upon increasing temperature after spin coating. This dewetting proceeded by the appearance of fluctuations at the free surface caused by restructuring taking place at the interface with the supporting substrate. Films thicker than 10...

Concentration fluctuation in binary polymer blends: x parameter, spinodal and Ginzburg criterion

A theory for concentration fluctuations in binary polymer blends is developed using field-theoretic techniques. The theory provides a simple, unified framework for addressing a number of important issues. First, consideration of the fluctuation and correlation effects on different length scales leads to a clarification of three different x parameters and their interrelationship. By incorporatin...

Patterning Polymer Thin Films: Lithographically Induced Self Assembly and Spinodal Dewetting

Thermal noise influences fluid flow in thin films during spinodal dewetting.

Experiments on dewetting thin polymer films confirm the theoretical prediction that thermal noise can strongly influence characteristic time scales of fluid flow and cause coarsening of typical length scales. Comparing the experiments with deterministic simulations, we show that the Navier-Stokes equation has to be extended by a conserved bulk noise term to accomplish the observed spectrum of c...