Layer-by-Layer Assembled Nanowire Networks Enable Graph-Theoretical Design of Multifunctional Coatings

Complex multifunctional coatings combining order and disorder are central for information, biomedical, transportation and energy technologies. Their scalable fabrication is possible using nanostructured composites made by layer-by-layer assembly (LBL). I am going to present our recent work which shows that structural description encompassing their non-random disorder and related property-focused design are possible using graph theory (GT). Two-dimensional images of LBL films of silver and gold nanowires (NWs) were used to calculate GT representations. We found that random stick computational models often used to describe NW materials give inaccurate descriptions. Concurrently, image-informed GT models, accurately predict the structure and properties of the LBL films including the unexpected non-linearity of charge transport vs LBL cycles. The conductivity anisotropy in LBL composites, not readily detectable from microscopy, was accurately predicted using GT models. Spray-assisted LBL offers direct translation of the GT predictions to additive, scalable coatings for drones and potentially other technologies.