We propose and evaluate an improvement of the inverted bubble method, originally proposed by McLachlan and Cox [Rev. Sci. Instrum. 46, 80 (1975)], a technique for measuring small contact angles at crystal–solution–vapor interfaces on a gas bubble under a solid immersed in a test solution. A simple experimental setup is used to evaluate the proposed method. We conclude that the method is suitable for measuring small contact angles with a minimum detectable angle of about 3°. Improvements in instrument design are proposed to lower the detection limit to 0.5° or below.
© 2007 Optical Society of America
Instrumentation, Measurement, and Metrology
Original Manuscript: March 16, 2007
Revised Manuscript: June 27, 2007
Manuscript Accepted: June 28, 2007
Published: August 9, 2007
Thierry Corti and Ulrich K. Krieger, "Improved inverted bubble method for measuring small contact angles at crystal-solution-vapor interfaces," Appl. Opt. 46, 5835-5839 (2007)