Metrological Protocols for Reaching Reliable and SI-Traceable Size Results for Multi-Modal and Complexly Shaped...

Area of Science:

• Nanotechnology
• Materials Science
• Metrology

Background:

• Reliable nanoparticle size measurements are crucial for various applications.
• Existing methods face challenges with complex nanoparticle shapes and ensuring traceability.
• The European nPSize project aimed to address these limitations.

Purpose of the Study:

• To propose new reference certified nanomaterials for the market.
• To improve the reliability and traceability of nanoparticle size measurements.
• To compare different characterization techniques for nanoparticle sizing.

Main Methods:

• Synthesis of bimodal populations and complexly shaped nanoparticles (bipyramids, cubes, rods).
• An inter-laboratory comparison using electron microscopy (TEM, SEM, TSEM), atomic force microscopy (AFM), and small-angle X-ray scattering (SAXS).
• Detailed description of calibration processes and error source analysis for each method.

Main Results:

• Good consistency in size measurements across different techniques when proper sample preparation and calibration were employed.
• Observed data dispersion in microscopy for complex shapes due to nanoparticle orientation.
• Hybrid approaches combining complementary techniques improved the reliability of size results for complex materials.

Conclusions:

• Careful methodology, including sample preparation and calibration, is essential for accurate nanoparticle size determination.
• Standardized reference materials are needed to ensure reliable and traceable nanoparticle measurements.
• Hybrid techniques offer enhanced reliability for characterizing complex nanomaterials.