Quantification of microstructures in stable and gelated suspensions from Cryo-SEM

Area of Science:

• Materials Science
• Colloid Science
• Microscopy

Background:

• Understanding concentrated suspensions is crucial for various applications.
• Characterizing microstructure quantitatively remains challenging.

Purpose of the Study:

• To develop and validate a quantitative method for analyzing concentrated suspension microstructures.
• To investigate particle arrangements in electrostatically stabilized and flocculated states.

Main Methods:

• High-pressure freezing of silica particle suspensions.
• Cryo-scanning electron microscopy (cryo-SEM) with stereo imaging.
• 3D particle position determination and pair correlation function extraction.

Main Results:

• Successfully visualized and quantified microstructures of concentrated silica suspensions.
• Demonstrated the ability to differentiate between stabilized and flocculated states.
• Obtained 3D pair correlation functions from cryo-SEM data.

Conclusions:

• Cryo-SEM of high-pressure frozen samples provides a robust method for quantitative microstructure analysis.
• Experimental results show good agreement with Brownian Dynamics simulations.
• The developed technique is applicable to various suspension states.