Anisotropic Thermal Transport in Tunable Self-Assembled Nanocrystal Supercrystals
Realizing tunable functional materials with built-in nanoscale heat flow directionality represents a significant challenge that could advance thermal management strategies. Here we use spatiotemporally resolved thermoreflectance to visualize lateral thermal transport anisotropy in self-assembled supercrystals of anisotropic Au nanocrystals. Correlative electron and thermoreflectance microscopy reveal that nano- to mesoscale heat predominantly flows along the long-axis of the anisotropic nanocrystals, and does so across grain boundaries and curved assemblies while voids disrupt heat flow. We finely control the anisotropy via the aspect ratio of constituent nanorods, and it exceeds the aspect ratio for nanobipyramid supercrystals and certain nanorod arrangements. Finite element simulations and effective medium modeling rationalize the emergent anisotropic behavior in terms of a simple series resistance model, further providing a framework for estimating thermal anisotropy as a function of material and structural parameters. Self-assembly of colloidal nanocrystals promises an interesting route to direct heat flow in a wide range of applications that utilize this important class of materials.
Authors
- Hervé Cruguel (ORCID: https://orcid.org/0000-0002-4437-1925)
- Emmanuelle Lacaze (ORCID: https://orcid.org/0000-0002-8380-8288)
- Charles Vernier (ORCID: https://orcid.org/0009-0005-2848-5892)
- Rahul Nag (ORCID: https://orcid.org/0000-0001-8562-8793)
- Emmanuel Lhuillier (ORCID: https://orcid.org/0000-0003-2582-1422)
- Danièle Fournier (ORCID: https://orcid.org/0000-0001-5485-3381)
- Hervé Portalès (ORCID: https://orcid.org/0000-0003-4446-8732)
- Sébastien Royer (ORCID: https://orcid.org/0000-0002-5635-0144)
- Florian Schulz (ORCID: https://orcid.org/0000-0003-4440-3680)
- Cyrille Hamon (ORCID: https://orcid.org/0000-0001-9529-9102)
- James K. Utterback (ORCID: https://orcid.org/0000-0002-2926-841X)
- Matias Feldman (ORCID: https://orcid.org/0009-0007-6201-9590)
- Juan J. Barrios‐Capuchino
Institutions
- Centre National de la Recherche Scientifique (FR)
- Universität Hamburg (DE)
- Université Paris-Saclay (FR)
- Laboratoire de physique des Solides (FR)
- Sorbonne Université (FR)
- Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies (FR)
- Institut des NanoSciences de Paris (FR)
Publication Details
- Journal
- ACS Nano
- Published
- 2024-12-06
- DOI
- https://doi.org/10.1021/acsnano.4c12991
- Citations
- 9
- Primary Topic
- nanoparticles nucleation surface interactions
- Type
- article
- Field-Weighted Citation Impact
- 3.39
Funders
- Centre National de la Recherche Scientifique
- Sorbonne Université