Self-Organization of Phase Clusters in Homogeneously Disordered Polymer Composite Materials

Abstract

The surface morphologies of homogeneously disordered polymer composite films and coatings prepared using mixtures of components with limited or negligible mutual solubility are studied by electron microscopy. We elaborate on the characteristic self-organization of phase clusters in our samples, in which one phase gives rise to the structural scaffold of the composite, an internal percolation cluster of particles. The cluster cavities filled with discrete particle aggregates of the other phase are characterized by a relatively narrow Gaussian-like size distribution. This topological structure arises if composites are prepared by observing specific concentration conditions or using structure modifiers that affect particle aggregation. Self-organization of phase clusters minimizes the entropy production when the components are mixed and gives rise to local ordering in spatial alternation of particle aggregates. The local order transforms into cellular disorder as the length scale increases.