Response of a gas‐liquid interface to concentration pulses

Publisher Website
Google Scholar
Abstract
Frequency response techniques have been applied to the study of the absorption of sulfur dioxide in water contaminated with surface‐active material. The response of a 0.004‐in. thick liquid film to a sinusoidally varying sulfur dioxide pressure was determined for frequencies ranging from 1 to 10 cycles/sec.The total quantity of sulfur dioxide dissolved was observed continuously by measuring the amount of light absorbed by the film, which contained a colored hydrogen ion indicator, cresol red. The experimental data indicate the presence of a surface phase of absorbed material through which sulfur dioxide molecules had to pass as they were transferred between gas and liquid. In addition to creating a resistance to the passage of the solute molecules, the surface phase apparently was capable of storing the molecules temporarily.