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Published on: September 27, 2011
Evaporation-Induced Phase Transitions in Free-Standing Plasmonic Nanoparticle Assemblies
Claire Hotton1, Jaime Gabriel Trazo1, Evgeny Modin2
1Laboratoire de Physique des Solides, Université Paris-Saclay, CNRS, Orsay 91405, France.
Nano Letters
|June 12, 2026
Summary
Surfactant concentration controls silver nanorod self-assembly into plasmonic superlattices. Micelles drive ordering, then gelation halts assembly, revealing key mechanisms for nanoparticle design.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Evaporation-induced self-assembly is crucial for creating ordered plasmonic superlattices from nanoparticle suspensions.
- Microscopic mechanisms governing anisotropic nanoparticle assembly in aqueous solutions are not fully understood.
Purpose of the Study:
- To investigate the drying kinetics and self-assembly mechanisms of silver nanorods (AgNRs) in cetyltrimethylammonium chloride (CTAC) aqueous dispersions.
- To identify key parameters influencing the formation of ordered plasmonic superlattices.
Main Methods:
- Utilized time-resolved levitated small-angle X-ray scattering (SAXS) to monitor drying kinetics.
- Employed microbeam SAXS and focused ion beam-scanning electron microscopy (FIB-SEM) for analyzing dried samples.
Main Results:
- Initial surfactant (CTAC) concentration emerged as the critical factor for superlattice formation, more so than nanoparticle concentration or shape.
- Nanoparticle ordering was synchronized with surfactant organization, with CTAC micelles inducing depletion attractions for nucleation and growth.
- Assembly process experienced structural arrest upon CTAC gelation.
Conclusions:
- CTAC concentration is paramount for controlling AgNR self-assembly into plasmonic superlattices.
- The dual role of CTAC micelles—promoting ordering and then causing arrest via gelation—provides a generalizable mechanism for nanoparticle assembly systems.
- Findings offer insights for designing advanced plasmonic metamaterials and nanoparticle assemblies.
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