Self-assembly of nanorods in ternary mixtures: promoting the percolation of the rods and creating interfacially jammed gels

Abstract

Using a hybrid computational model, we simulate the self-assembly of nanorods in phase-separating A:B:C ternary melts, where C constitutes the minority phase. We assume that the rods are coated with C ligands and thus have a preferential affinity for the C phase. Due to the preferential wetting interaction, the steric repulsion between the coated rods and the phase separation within the mixture, the rods are driven to form percolating networks at very low volume fractions. Furthermore, since the minority C phase localizes at the interface between the A and B components, the C-like rods also lie at the boundaries between the A and B. We find that by decreasing the volume fraction of C or increasing the number of nanorods, the domain growth of the A and B phases can be dramatically curtailed. In other words, the coarsening of these domains is arrested by nanorods that are spatially constrained to lie at the A/B interfaces; this gives rise to an interfacially jammed gel. Because the structural evolution of the composite depends on the volume fraction of rods and the amount of C, our findings point to effective means of controlling the dynamic behavior and morphology of this system. The latter ability opens the path to tailoring the optoelectronic and mechanical properties of the nanocomposite.