Rigorous understanding of the self-assembly of colloidal nanocrystals is crucial to the development of tailored nanostructured materials. Despite extensive studies, a mechanistic understanding of self-assembly under non-equilibrium driven by an external field remains an ongoing challenge. We demonstrate self-assembly by optical tweezers imposing an external attractive field for cubic-phase sodium yttrium fluoride nanocrystals. We show that surface roughness of the nanocrystals is a decisive factor for contact leading to assembly between the nanocrystals, manifested by the roughness-dependent hydrodynamic resistivity. This provides direct evidence that dynamics are equally important to energetics in understanding self-assembly. These results have implications in a wide variety of different fields, such as in understanding the factors that mediate oriented attachment-based crystal growth or in interpreting the structure of binding sites on viruses.
@article{arxiv.2310.06774,
title = {Optical assembly of nanostructures mediated by surface roughness},
author = {Robert G. Felsted and Jaehun Chun and Gregory K. Schenter and Alexander B. Bard and Xiaojing Xia and Peter J. Pauzauskie},
journal= {arXiv preprint arXiv:2310.06774},
year = {2025}
}
Comments
21 pages, 3 main figures, 8 supplemental figures, 2 supplemental videos. Submitted to Physical Review Letters