Abstract Janus nanoparticles with amphiphilic surfaces could be of particular significance for enhanced oil recovery (EOR) of reservoirs. However, currently available methods for preparing Janus nanoparticles are often complicated. Here we present a highly efficient and easily scalable one-step chemical etching method with NaOH as the etching agent for fabricating amphiphilic Janus-SiO2 nanoparticles. The structure, interfacial behavior and improved oil recovery (IOR) potential of the as-prepared Janus-SiO2 nanoparticles were systematically studied. Results show that Janus-SiO2 nanoparticles with size less than 10 nm exhibit good dispersibility in water and amphiphilicity as well. When combined with various surfactants, they can significantly improve the oil recovery upon simulated water flooding, due to their good abilities to increase the sweep efficiency of surfactants and reduce the interfacial tension of oil-water emulsion. Oil recoveries are improved by 7.4∼9.8% with addition of Janus-SiO2 in surfactants compared to pure surfactant solutions, showing promising potential for EOR.

中文翻译：

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利用无超低界面张力的 Janus-二氧化硅/表面活性剂纳米流体提高石油采收率

摘要 具有两亲性表面的 Janus 纳米粒子对于提高油藏采收率 (EOR) 具有特别重要的意义。然而，目前可用的制备 Janus 纳米粒子的方法通常很复杂。在这里，我们提出了一种高效且易于扩展的一步化学蚀刻方法，以 NaOH 作为蚀刻剂，用于制造两亲性 Janus-SiO2 纳米粒子。系统地研究了所制备的 Janus-SiO2 纳米粒子的结构、界面行为和提高石油采收率 (IOR) 的潜力。结果表明，粒径小于10 nm的Janus-SiO2纳米粒子在水中表现出良好的分散性和两亲性。当与各种表面活性剂结合使用时，它们可以显着提高模拟水驱时的采收率，由于它们具有提高表面活性剂的波及效率和降低油水乳液界面张力的良好能力。与纯表面活性剂溶液相比，在表面活性剂中加入 Janus-SiO2 后，原油采收率提高了 7.4~9.8%，显示了提高采收率的潜力。