Computer modeling of complex block copolymer micelles with metal-ligand self-assembly

Z. Wang, E.E. Dormidontova
University of Connecticut, US

Keywords: self-assembly, polymer micelles, supramolecular complexes, smart materials


For many applications of nanostructured materials it is essential to understand the principles controlling self-assembly, which is often a challenging task due to the heterogeneity of building blocks, (different chemical nature, size, shape, deformability, etc.) and the presence of multiple interactions. Computer modeling can considerably facilitate this task and guide experimental and industrial research. The aim of the present research to gain understanding of molecular mechanism of self-assembly of nanostructures formed by diblock copolymer micelles interconnected by means of metal-ligand complexation. These systems possess two levels of self-assembly: 1) self-assembly of diblock copolymers into micelles and 2) reversible inter-micelle bridging by coordination bonding between metal ions and ligands attached to the corona of nanoparticles, which controls the viscoelastic properties. The interest to these systems is based their potential future applications in mechano-sensors, actuators and self-healing materials. While large-scale properties of these materials can be successfully characterized experimentally, it is much harder to achieve molecular-level details of self-assembly which can be accomplished by computer modeling. Our results show that the number of crosslinks between micelles, which determines viscoelastic properties of these materials, strongly depends on the nature of the metal ion and the fraction of metal ions relative to ligands.