New method for characterizing paper coating structures using argon ion beam milling and field emission scanning...

Area of Science:

• Materials Science
• Surface Science
• Analytical Chemistry

Background:

• Characterizing paper coating microstructures is crucial for understanding material properties.
• Conventional methods for porosity analysis can lead to overestimations and inaccuracies.

Purpose of the Study:

• To develop and validate a novel, high-resolution method for paper coating microstructure characterization.
• To accurately quantify porosity and investigate coating non-uniformities.

Main Methods:

• Utilizing argon ion beam milling for sample preparation.
• Employing field emission scanning electron microscopy (FESEM) for high-quality imaging.
• Implementing marker-controlled watershed segmentation on secondary electron images for quantitative analysis.

Main Results:

• The new method provides high-quality images with minimal artifacts, enabling precise quantitative analysis.
• Secondary electron imaging avoids the overestimation of porosity common with backscattered electron imaging.
• The conventional method overestimated pore area by 20% and detected 5% more pores compared to the new technique.
• Binder migration and the correlation between coating porosity and base sheet mass density were directly observed.

Conclusions:

• The developed method offers a significant improvement for characterizing paper coating microstructures.
• Accurate porosity quantification and the visualization of microstructural features like binder migration are now possible.
• This technique provides direct evidence for previously suspected coating non-uniformities and their relationship with base sheet properties.