Dynamic contact angle measurement on materials with an unknown wet perimeter

Area of Science:

• Physical Chemistry
• Materials Science
• Pharmaceutical Science

Background:

• Contact angle measurements are vital for characterizing surface properties.
• The Wilhelmy balance technique provides accurate results for planar surfaces.
• Characterizing particulate materials using this technique requires precise wet perimeter determination.

Purpose of the Study:

• To evaluate the accuracy of a specific wet perimeter determination method for particulate materials.
• To highlight potential limitations in existing methodologies.
• To propose alternative, more reliable approaches for wet perimeter assessment.

Main Methods:

• Review and analysis of the Pepin et al. approach for wet perimeter determination.
• Theoretical consideration of liquid-solid interactions with particulate surfaces.
• Exploration of alternative methods for calculating the wet perimeter.

Main Results:

• The Pepin et al. method using non-polar liquids may yield inaccurate wet perimeter values for powders.
• Dependence on accurate wet perimeter is critical for reliable contact angle data.
• Existing methods may not adequately account for the complex geometry of particulate surfaces.

Conclusions:

• The commonly used Pepin et al. method for wet perimeter determination in particulate systems may be flawed.
• Accurate wet perimeter calculation is essential for meaningful contact angle measurements of powders.
• Further research into robust methods for wet perimeter determination in heterogeneous systems is warranted.