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Title: The mechanisms for nanoparticle surface diffusion and chain self-assembly determined from real-time nanoscale kinetics in liquid

The mechanisms for nanoparticle self-assembly are often inferred from the morphology of the final nanostructures in terms of attractive and repulsive interparticle interactions. Understanding how nanoparticle building blocks are pieced together during self-assembly is a key missing component needed to unlock new strategies and mechanistic understanding of this process. Here we use real-time nanoscale kinetics derived from liquid cell transmission electron microscopy investigation of nanoparticle self-assembly to show that nanoparticle mobility dictates the pathway for self-assembly and final nanostructure morphology. We describe a new method for modulating nanoparticle diffusion in a liquid cell, which we employ to systematically investigate the effect of mobility on self-assembly of nanoparticles. We interpret the observed diffusion in terms of electrostatically induced surface diffusion resulting from nanoparticle hopping on the liquid cell window surface. Slow-moving nanoparticles self-assemble predominantly into linear 1D chains by sequential attachment of nanoparticles to existing chains, while highly mobile nanoparticles self-assemble into chains and branched structures by chain–chain attachments. Self-assembly kinetics are consistent with a diffusion-driven mechanism; we attribute the change in self-assembly pathway to the increased self-assembly rate of highly mobile nanoparticles. Furthermore, these results indicate that nanoparticle mobility can dictate the self-assembly mechanism and final nanostructure morphology in amore » manner similar to interparticle interactions.« less
 [1] ;  [1]
  1. Ames Lab. (AMES), Ames, IA (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1932-7447
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 119; Journal Issue: 36; Journal ID: ISSN 1932-7447
American Chemical Society
Research Org:
Ames Lab. (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY self-assembly; in situ TEM; liquid cell TEM; nanoparticle aggregation; kinetics; nanoparticle diffusion