Detailed statistical contact angle analyses; "slow moving" drops on inclining silicon-oxide surfaces.

Area of Science:

• Materials Science
• Surface Chemistry
• Physics

Background:

• Contact angle determination is crucial for characterizing surface properties in science and industry.
• Existing methods for advancing/receding contact angles often lack reproducibility and are subjective.
• Standardized, valid methods are needed for accurate contact angle measurements.

Purpose of the Study:

• To introduce novel, reproducible techniques for analyzing dynamic contact angle measurements (sessile drop).
• To provide objective methods for determining advancing and receding contact angles, independent of operator skill.
• To analyze droplet motion on inclined surfaces and understand surface reactivity.

Main Methods:

• Utilized sessile drop technique for dynamic contact angle measurements.
• Developed novel analytical approaches for both axisymmetric and non-axisymmetric drops.
• Applied sigmoid function fitting and independent/dependent analysis of parameters (inclination, velocity).
• Investigated droplet motion on inclined silicon-oxide surfaces after treatments.

Main Results:

• Achieved contact angle data independent of operator subjectivity.
• Demonstrated sensitivity to "slow moving" dynamic contact angle determination.
• Presented statistical analysis of triple points, inclination, advancing, and receding angles.
• Observed reactive de-wetting and acceleration behavior on freshly cleaned silicon wafer surfaces.

Conclusions:

• The novel analytical techniques provide standardized and reproducible methods for dynamic contact angle determination.
• These methods enhance the objective characterization of surface properties and droplet dynamics.
• The study offers new insights into droplet motion on inclined surfaces and surface reactivity.