2D analysis of polydisperse core-shell nanoparticles using analytical ultracentrifugation

Area of Science:

• Nanotechnology
• Materials Science
• Physical Chemistry

Background:

• Accurate characterization of nanoparticle (NP) size, density, and composition is crucial for their applications.
• Small NPs in liquid media behave as core-shell systems due to solvation and stabilizer layers, influencing their hydrodynamic properties.
• Existing analytical ultracentrifugation (AUC) data evaluation methods struggle with the resolution and accuracy required for polydisperse core-shell NPs.

Purpose of the Study:

• To address the challenges in hydrodynamic characterization of polydisperse core-shell NPs using AUC.
• To evaluate the performance of current data evaluation models for polydisperse core-shell NP characterization.
• To develop and validate a novel methodology for resolving the size and effective density of polydisperse core-shell NPs.

Main Methods:

• Utilized analytical ultracentrifugation (AUC) to measure sedimentation and diffusion transport of NPs.
• Employed simulated data to investigate the performance of various data evaluation models.
• Developed a new methodology based on parametrically constrained spectrum analysis for core-shell NP characterization.

Main Results:

• Demonstrated that polydisperse NPs present significant challenges for current state-of-the-art data evaluation methods.
• Showcased the limitations of existing methods in terms of resolution and accurate reproduction of core-shell properties.
• Successfully resolved the size and effective density of polydisperse ZnO and CuInS2 NPs with high resolution using a 2D AUC approach.

Conclusions:

• The proposed parametrically constrained spectrum analysis method provides complete access to the size and effective density of polydisperse NPs.
• This novel 2D AUC analysis approach enables high-resolution characterization of core-shell structures, overcoming limitations of previous methods.
• The findings are validated with experimental data from ZnO and CuInS2 NPs, paving the way for more accurate NP characterization.