A robust algorithm for the simultaneous parameter estimation of interfacial tension and contact angle from sessile...

Area of Science:

• Materials Science
• Physical Chemistry
• Computational Fluid Dynamics

Background:

• Accurate measurement of interfacial tension (gamma) and contact angle (theta(c)) is crucial for understanding surface properties.
• Traditional methods can be limited by assumptions or experimental complexities.

Purpose of the Study:

• To present and validate the pendant and sessile drop profile analysis using the finite element method (PSDA-FEM) algorithm.
• To focus on the application of the fixed contact angle boundary condition within the PSDA-FEM framework for sessile drops.

Main Methods:

• The PSDA-FEM algorithm solves the Young-Laplace equation in spherical coordinates.
• It utilizes boundary conditions at the drop apex and the contact line with the substrate.
• The study specifically employs a fixed contact angle boundary condition for sessile drops.

Main Results:

• The PSDA-FEM algorithm was tested with simulated drop profiles, including those with added random error.
• The impact of random error, simulating camera resolution, on the accuracy of gamma and theta(c) estimates was evaluated.
• Experimental results for water and corn oil on acrylic substrates showed error ranges consistent with simulations.

Conclusions:

• The PSDA-FEM algorithm provides a robust method for simultaneous determination of interfacial tension and contact angle.
• The algorithm demonstrates accuracy and reliability, even when subjected to simulated experimental errors.
• The findings support the use of PSDA-FEM for precise surface property analysis in materials science.