Electrical & Computer Engineering, Department of


In situ microscopy of the self-assembly of branched nanocrystals in solution

Eli A. Sutter, University of Nebraska–Lincoln
Peter Sutter, University of Nebraska-Lincoln
Alexei V. Tkachenko, Brookhaven National Laboratory
Roman Krahne, Istituto Italiano di Tecnologia
Joost de Graaf, University of Stuttgart
Milena Arciniegas, Istituto Italiano di Tecnologia
Liberato Manna, Istituto Italiano di Tecnologia

Document Type Article



Solution-phase self-assembly of nanocrystals into mesoscale structures is a promising strategy for constructing functional materials from nanoscale components. Liquid environments are key to self-assembly since they allow suspended nanocrystals to diffuse and interact freely, but they also complicate experiments. Real-time observations with single-particle resolution could have transformative impact on our understanding of nanocrystal self-assembly. Here we use real-time in situ imaging by liquid-cell electron microscopy to elucidate the nucleation and growth mechanism and properties of linear chains of octapod-shaped nanocrystals in their native solution environment. Statistical mechanics modelling based on these observations and using the measured chain-length distribution clarifies the relative importance of dipolar and entropic forces in the assembly process and gives direct access to the interparticle interaction. Our results suggest that monomerresolved in situ imaging combined with modelling can provide unprecedented quantitative insight into the microscopic processes and interactions that govern nanocrystal self-assembly in solution.