Structure evolution of nanodiamond aggregates: a SANS and USANS study.

Area of Science:

• Materials Science
• Nanotechnology
• Neutron Scattering

Background:

• Nanodiamonds (NDs) are synthesized via detonation or laser ablation.
• Understanding ND structure is crucial for optimizing their applications.
• ND suspensions exhibit complex aggregation behavior.

Purpose of the Study:

• To investigate the multi-length scale structure of nanodiamonds (NDs) and their aggregates.
• To characterize the shape and outer shell of ND particles.
• To understand the role of solvents and hydrogen in ND aggregation.

Main Methods:

• Ultra-small-angle neutron scattering (USANS) and small-angle neutron scattering (SANS).
• Contrast variation technique using H2O and deuterated solvents.
• Analysis using a defined shape model.

Main Results:

• NDs form aggregates significantly larger than individual particles.
• ND particles exhibit an ellipsoidal shape.
• The non-diamond outer shell thickness was determined.

Conclusions:

• USANS/SANS provide insights into ND aggregation and structure.
• Characterization of NDs and their aggregates aids in sample preparation.
• Understanding particle interactions is key to controlling aggregation.