When gas dissolves into a liquid, interface resistance can limit the mass flux. Increasing or decreasing interface resistance by means of surface-active agents is of interest in applications ranging from biomedicine to petroleum recovery. This paper describes a pressure-decay methodthat allows systematic investigation of both interface resistance and internal (diffusive) resistance during gas-to-liquid mass transfer; introduces a mathematical modeling approach that determines both resistances simultaneously; and provides experiments in which only the interface resistance varies. In the pressure decay method, the system pressure is recorded as gas transfers across the gas/liquid interface and diffuses within the liquid. It allows initiating the experiment at a prescribed pressure with high reproducibility, facilitating the interpretation of a series of experiments. The exact solution of the 1D resistance-in-series model is derived. An accurate approximation is further reported to analyze experiments conveniently. The interface resistance is systematically varied in a static nitrogen/water system by adding small concentrations of oleic acid. As the concentration of oleic acid increases, the mass transfer coefficient decreases or the interface resistance increases. The effect is significant: at a concentration of 2 ppm, at which concentration the interface resistance is almost four times greater than that for pure water. The oleic acid has little effect on the diffusion coefficient of nitrogen in water due to its low concentration. The model comparison indicates the range of Biot number when the interface resistance or internal resistance must be accounted for. The characteristic chart can effectively contribute to a qualitative analysis of the gas-liquid mass transfer process when the effect of surface-active agents is considered.

当气体溶解到液体中时，界面电阻会限制质量通量。借助于表面活性剂来增加或降低界面电阻在从生物医学到石油回收的应用中是令人感兴趣的。本文描述了一种压力衰减方法，可以系统地研究气液传质过程中的界面电阻和内（扩散）电阻。引入了一种数学建模方法，可以同时确定两个电阻；并提供仅界面电阻会发生变化的实验。在压力衰减方法中，系统压力记录为气体通过气/液界面传输并在液体中扩散。它可以在规定的压力下以高重现性启动实验，促进一系列实验的解释。推导出一维串联电阻模型的精确解。进一步报道了精确的近似值以方便地分析实验。通过添加少量油酸，在静态氮/水系统中界面电阻会系统地变化。随着油酸浓度的增加，传质系数降低或界面电阻增加。效果显着：浓度为2 ppm时，界面电阻几乎是纯水的四倍。油酸浓度低，因此对氮在水中的扩散系数影响很小。模型比较表明必须考虑界面电阻或内部电阻时的比奥数范围。当考虑表面活性剂的作用时，该特性图可以有效地有助于对气液传质过程进行定性分析。