Interfacial properties are of critical importance to various separation applications. In heavy oil recovery, for example, a low oil–water interfacial tension (IFT) benefits the separation of heavy oil from their host rocks, which becomes problematic in the later stage of oil–water separation. CO₂‐responsive surfactants were investigated to enhance the overall heavy oil recovery by switching their interfacial activity to the desired state in each stage. The surfactants at interfacially active state greatly enhanced the separation of heavy oil from hosting solids, as demonstrated by measuring contact angle and oil liberation using a custom‐designed on‐line visualization system. Meanwhile, the resulting heavy oil‐in‐water emulsions could also be easily demulsified by the bubbling of CO₂ gas, which switched off the interfacial activity of the surfactants. Furthermore, CO₂‐responsive surfactants could be partially recycled in process water to improve sustainability, making CO₂‐responsive surfactants to be promising chemical aids in heavy oil production and many other vital industries.

中文翻译：

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通过对二氧化碳有响应的表面活性剂，在重油采收中加强油固和油水分离

界面性质对于各种分离应用至关重要。例如，在重油采收中，较低的油水界面张力（IFT）有利于将重油从其宿主岩中分离出来，这在油水分离的后期变得很成问题。通过在每个阶段将其界面活性转换为所需状态，研究了对CO ₂响应型表面活性剂可提高总重油采收率。界面活性状态下的表面活性剂极大地增强了重油从固体中的分离，这通过使用定制设计的在线可视化系统测量接触角和油的释放来证明。同时，产生的重水包油乳液也很容易通过鼓泡CO ₂破乳。气体，从而切断了表面活性剂的界面活性。此外，对CO ₂敏感的表面活性剂可以在生产用水中部分回收，以提高可持续性，使对CO ₂敏感的表面活性剂成为重油生产和许多其他重要行业中有希望的化学助剂。