Immersion Depth Independent Computer Analysis of Wilhelmy Balance Hysteresis Curves

Computerized methods and algorithms have been developed for operator-independent, batch processing of data from regular Wilhelmy balance hysteresis curves. Regular hysteresis curves were generated by measuring wetting forces along the perimeter of an object as it was immersed into or withdrawn from a liquid phase of interest by initially contacting liquid, repeating an arbitrary number of advancing and receding cycles, and terminating in a final removal step. Data were analyzed in sequential point-number space rather than in conventional immersion-depth coordinates to eliminate need for and reliance on a separately calibrated displacement transducer. Two methods of locating turning points were compared and statistics of wetting measurements discussed. Good agreement between computerized and manual methods was obtained for advancing and receding wetting tensions of water on siliconized glass slides and rods.