Adhesion Failure and Rupturing of Ultra-Thin Polymer Film Near Melt: Role of Interfacial Effects

Abstract

The results for the case of rupturing of an ultra-thin polymer film confined in a narrow planar geometry, are presented in this paper. NVT Monte Carlo simulation technique with Glauber kinetics has been used. Periodic boundary conditions are applied along [Formula: see text] and [Formula: see text] directions. Two planar surfaces at separations of [Formula: see text] and 6.75[Formula: see text] are used to confine the film. The lower substrate at [Formula: see text] has square well attractive affinity to the polymer beads, whereas the upper substrate at [Formula: see text] interacts with beads via hard sphere interaction. The properties as-pair correlation function, mean square displacement, density distribution, etc., are sampled for different parameters as pore widths [Formula: see text] and 6.75[Formula: see text], average number densities [Formula: see text] beads/[Formula: see text], 1.78 beads/[Formula: see text] and 1.56 beads/[Formula: see text], surface-film interaction of square well strengths [Formula: see text] and [Formula: see text] with range [Formula: see text] at different temperatures [Formula: see text], 2.0, 2.2 and 2.4. Aggregation of monomers at free ends of the chains appears to initiate tearing of the film, causing formation of strip-like structures. Repulsive force arising because of overlap in excluded volume regions, re-organize the beads. Stronger surface force leads to the crystallization of the film whereas lower surface affinity leads to adhesion failure. For moderate values of surface affinities, there exists a delicate balance between molecular forces amongst beads and the surface affinity. The complex nanopatterns thus formed are a result of interplay of these forces. The phenomena discussed in the paper mimics spinodal dewetting.