Self-assembly dynamics and accumulation mechanisms of ultra-fine nanoparticles.

The self-assembly of nanomaterials into three-dimensional hierarchical structures is a fundamental step impacting a large number of synthetic and natural processes. These range from the scalable fabrication of nano-devices such as batteries, sensors and third generation solar cells to the uptake and accumulation of particulate pollution in the lung alveoli. Here, we show that the Dynamic behavior of ultra-fine particles (UFP < 100 nm) diverges significantly from that of sub- and micro equivalents. For freely diffusing bodies, this leads to the formation of stochastically reproducible films that approach the morphology and density of ballistically deposited ones. A novel deposition mechanism and regime are proposed that successfully capture the full spectrum of size-dependent self-assembly dynamics. These findings are a significant step toward the engineering of scalable parallel nano-fabrication approaches, and the understanding of the interaction of unbound nanostructures with their surrounding.