Engineering of Ultra-Hydrophobic Functional Coatings Using Controlled Aggregation of Bicomponent Core/Shell Janus Particles

The morphology and wetting properties of coatings prepared using fully-covered, mono- and bicomponent polymeric Janus particles are investigated and compared. The particles are adsorbed on silica wafers, which were preliminarily coated by thin layers of chemically grafted polymer. The fully-covered particles form hexagonally packed layers with very hydrophobic wetting properties. In contrast, the Janus particles tend to form aggregates. This is possible due to their ability to self-assemble and form hierarchical structured aggregates in dispersions. The deposition of these agglomerates on the substrate leads to the formation of hierarchical rough layers which possess a certain level of fractality. The obtained layers are either very hydrophobic or ultra-hydrophobic, depending on the chemical structure of the polymers grafted to the Janus particles, on the nature of supported substrate, and on the level of aggregation of Janus particles into hierarchical structures. The obtained findings could be very important for design of novel materials with advanced properties.