Remarks on the Interpretation of Data from the Dynamic Drop Volume Method

Abstract

The maximum bubble pressure, drop volume, and ring methods were used to measure the dynamic surface tension for aqueous solutions of dodecyldimethylphosphine oxide in a wide concentration range. It was shown that for some concentrations the experimental data obtained from the drop volume method do not agree with the results from the maximum bubble pressure method. The drop volume data differ also from values predicted by theoretical models which account for surface expansion and convection transfer only. To achieve agreement between data from the drop volume method and theoretical results, the actual drop surface area and the state of this surface at the initial time moment have to be included into the boundary conditions of the theory. Conditions are defined at which a discrepancy can be expected between different experimental techniques.