In this work, an unsteady‐state strategy for rapid measurement of gas diffusivity in liquid is proposed, which has a quick perturbation of the liquid flow rate in inner tube for obtaining the change of gas flow rate across the membrane with time. The strategy has taken full advantages of the tube‐in‐tube reactor that possesses a high permeability Teflon AF‐2400 membrane to accelerate the diffusion rate of gas to liquid without direct contact between the two phases. With a developed mathematical model fitting the recorded variation of gas flow rate with time, the gas diffusivity in liquid can be determined within 0.5–3 min compared with the conventional methods of 4–14 hr. In addition, the strategy is demonstrated with several gas–liquid systems (O₂‐DMSO, CO₂‐[Emim] [NTf₂] and CO₂‐[Bmim] [BF₄]) with varied viscosities and temperatures, showing a good agreement with literature values with less than 10% deviation.

中文翻译：

---

使用具有非稳态策略的管内反应器快速测量液体中的气体扩散率

在这项工作中，提出了一种用于快速测量液体中气体扩散率的非稳态策略，该策略可以快速扰动内管中的液体流速，从而获得穿过膜的气体流速随时间的变化。该策略已充分利用了具有高渗透性的Teflon AF-2400膜的管中反应器的优势，可加快气体向液体的扩散速度，而无需两相之间直接接触。利用开发的数学模型拟合记录的气体流速随时间的变化，与传统方法4-14小时相比，可以在0.5-3分钟内确定液体中的气体扩散率。此外，该策略还通过多种气液系统（O ₂ -DMSO，CO _2- [Emim] [NTf ₂]和CO _2- [Bmim] [BF ₄ ]）随粘度和温度变化而变化，与偏差小于10％的文献资料显示出很好的一致性。