Programmable surface-architectures derived from hybrid polyoxometalate-based clusters

Abstract

The exploration of the self-organization of a range of the polyoxometalate-based molecular structures reveals a diverse range of surface patterns and morphologies on solid substrates of technological interest, including methylated and hydroxylated silicon surfaces (namely, SiCH3 and SiOH). By exploiting the interplay between the intrinsic molecular properties and the surface chemistry as well as dynamic spatiotemporal phenomena (e.g., dewetting), we show that these systems can yield 0D, 2D, and 3D architectures via solution deposition at the solid surface, including nanodots, discs, lamellas, porous networks, and layer-by-layer assemblies. In general, we observed that layer-by-layer growth is a common feature on low surface energy SiCH3. In addition, the polyoxometalate derived architectures are able to effectively modulate the drop spreading dynamics on high surface energy SiOH, so that dewetting induces the formation of nanodots from dilute solutions of the precursor POM hybrid, whereas using high concentration results in the formation of complex architectures whose shape depends on the molecular structure of the POM-based building block utilized. Finally, we show that hybrid POM derivatives with one or more functional moieties can be organized in an ordered fashion, thus yielding interesting model systems for the assembly of POM-based multifunctional nanostructures on surfaces.