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Updated: Mar 4, 2026
08:55
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
9.0K
Nearest-neighbour nanocrystal bonding dictates framework stability or collapse in colloidal nanocrystal frameworks
Teresa E Williams1, Daniela Ushizima, Chenhui Zhu
1Graduate Group in Applied Science and Technology, University of California-Berkeley, Berkeley, CA 94720, USA.
Chemical Communications (Cambridge, England)
|April 20, 2017
Summary
Block copolymers guide nanocrystal assembly into ordered frameworks or disordered films. The transition depends on nanocrystal volume fraction and neighbor interactions, revealing minimums for structural integrity.
Area of Science:
- Materials Science
- Nanotechnology
- Polymer Science
Background:
- Block copolymers are key for directing nanocrystal self-assembly.
- Mesoporous solids and films are formed using these directed assemblies.
- Understanding assembly transitions is crucial for material design.
Purpose of the Study:
- To investigate the fundamental order-disorder transition in block copolymer-directed nanocrystal assemblies.
- To identify critical parameters influencing the assembly outcome (ordered vs. disordered).
- To determine the minimum nanocrystal loading required for structural stability.
Main Methods:
- Extensive image analysis of nanocrystal films after thermal processing.
- Quantification of nearest-nanocrystal neighbor interactions.
- Correlation of assembly structure with nanocrystal volume fraction (fNC).
Main Results:
- Identified a critical order-disorder transition in nanocrystal assemblies.
- Demonstrated that the number of nearest neighbors dictates assembly outcome.
- Established the relationship between nanocrystal volume fraction (fNC) and assembly structure.
- Found the minimum fNC necessary to prevent structural collapse.
Conclusions:
- The order-disorder transition in block copolymer-directed nanocrystal assemblies is governed by inter-nanocrystal interactions.
- Nanocrystal volume fraction is a primary determinant of assembly morphology and stability.
- This work provides fundamental insights into designing robust mesoporous nanocrystal materials.
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