Contact angle and contact angle hysteresis measurements using the capillary bridge technique

Area of Science:

• Surface Science and Engineering
• Experimental Physics and Chemistry
• Materials Characterization

Background:

• Accurate measurement of contact angles is crucial for understanding liquid-solid interactions.
• Existing methods for measuring advancing and receding contact angles can be complex and prone to errors.
• Characterizing surfaces with low contact angle hysteresis presents a significant challenge.

Purpose of the Study:

• To propose and validate a new, accurate experimental technique for measuring advancing and receding contact angles.
• To demonstrate the technique's feasibility on a low-energy perfluorinated surface using water and hexadecane.
• To provide a detailed methodology for experimental procedures and computational modeling.

Main Methods:

• Analysis of capillary bridge evolution between a liquid bath and a spherical solid surface.
• Slowly varying the distance between the solid surface and the liquid bath.
• Utilizing computational modeling alongside experimental procedures to determine contact angle values.

Main Results:

• The proposed technique achieves unprecedented accuracy in measuring both advancing and receding contact angles.
• Feasibility demonstrated on a perfluorinated surface with water and hexadecane.
• High accuracy attributed to automatic averaging of contact angles over the entire contact periphery.

Conclusions:

• The new experimental technique offers an easy and accurate method for contact angle measurement.
• The technique is particularly well-suited for characterizing surfaces exhibiting very low contact angle hysteresis.
• This method advances the field of surface science by providing a reliable tool for surface property evaluation.