Forging Nanoparticle Superlattices with Colloidal Metallurgy
Journal
ACS Nano
Journal Volume
19
Journal Issue
22
Start Page
20753
End Page
20764
ISSN
1936-0851
1936-086X
Date Issued
2025-05-31
Author(s)
Thrasher, Carl J.
Murphy-Genao, Nolan J.
Sbalbi, Nicholas A.
Hueckel, Theodore
Ye, Matthew
Hart, A. John
Macfarlane, Robert J.
Abstract
Nanoparticle superlattices present transformative opportunities for material design by enabling precise control over both nanoscale organization and composition; however, translating these assemblies into macroscopic constructs while preserving nanoscale order remains a critical challenge due to the incompatibility of traditional processing techniques with colloidal systems. This study introduces “colloidal metallurgy,” a framework for understanding and controlling defect evolution and densification in nanoparticle superlattices during colloidal sintering. We investigate the effects of pressure and temperature to elucidate mechanisms of particle transport, defect annealing, and densification as single-crystal colloidal assemblies coalesce into polycrystalline superlattices. Pressure-driven crystallite fracture is identified as the primary mode of densification, while temperature enhances particle mobility, enabling defect reduction and grain growth. A multistage sintering strategy employing high temperature annealing to grow grains and restore fracture-based capacity for densification was developed to produce dense (∼1% porosity) polycrystals with low defect counts, demonstrating a pathway for processing nanoparticle superlattices. By exploring the parallels and distinctions between atomic and colloidal sintering, this work establishes critical insights into the mechanisms governing colloidal material processing. These findings lay the groundwork for defect engineering in colloidal systems, offering a scalable approach to design macroscopic materials with tailored properties.
Subjects
colloidal crystals
microstructure
nanoparticle superlattices
porosity
self-assembly
sintering
supramolecular structures and assemblies
Publisher
American Chemical Society (ACS)
Type
journal article