Engineering Multimaterial Nanostructured Deposits by the Amphiphilicity Degree and Intermolecular Forces

Achieving desired performance from self-assembly of nanoparticles (NPs) is challenging due to the stochastic nature of interactions among the constituent building blocks. Self-assembly of nano-colloids through evaporation of particle-laden droplets can be exploited to fabricate tailored nanostructures that add functionality and engineer the properties of manufactured components. The particle-particle and particle-solvent interactions, and delicate force balance among them are the main factors that define the pattern of the final 3D nanostructure. Here, a nanoparticle-agnostic approach that allows the fabrication of nanostructures with precisely engineered patterns is introduced. Evaporative droplets of aqueous suspensions of pristine Carbon Nanotubes, Graphene Nanoplatelets, and Boron Nitride Nanotubes representing NPs of different elemental compositions, sizes, and shapes are investigated. Cellulose nanocrystals (CNCs) are used as a platform to make hybrid systems of CNC-NP and utilize the repulsive-attractive-directional interactions in these multimaterial systems to enforce the desired final pattern between ring and disk. It is shown that irrespective of the type of NPs, the amphiphilicity of the hybrid system dictates the formation of deposited patterns. Finally, the effect of self-assembled patterns on the functionality of multi-material systems is demonstrated. The proposed method creates new capabilities in the precisely controlled nanostructures and facilitates smart self-assembly systems.