Nguyen Thao X D, Razavi Sepideh, Papavassiliou Dimitrios V
School of Sustainable Chemical, Biological and Materials Engineering, The University of Oklahoma, 100 East Boyd Street, Norman, Oklahoma 73019, United States.
J Phys Chem B. 2024 Mar 28;128(12):3016-3026. doi: 10.1021/acs.jpcb.3c08092. Epub 2024 Mar 19.
A coarse-grained modeling approach is employed to probe the effect of nanoparticles and their wettability on the stability of the interface between two immiscible fluids. In this study, pure oil (dodecane) and water are placed side by side in a nanochannel, forming a meniscus. Homogeneous hydrophilic nanoparticles, Janus particles, and homogeneous hydrophobic nanoparticles are placed at the oil-water interface, and their dynamics are studied as they rearrange at the oil-water interface. The results show that when the water is set in motion, two instabilities occur: the formation of fingers and the detachment of water from the channel wall. It is observed that the formation of fingers is affected by the wettability of the nanoparticles. The second instability may lead to the formation of a drop that propagates through the channel. However, it is found that the wetting properties of the nanoparticles do not affect the critical flow rate for the detachment of the water from the wall. Therefore, detachment occurs at the same three-phase contact angle regardless of the nanoparticle wetting properties. These findings can be important for industrial applications such as enhanced oil recovery, separation technologies, and microfluidic and nanofluidic technologies.
采用粗粒度建模方法来探究纳米颗粒及其润湿性对两种不混溶流体间界面稳定性的影响。在本研究中，纯油（十二烷）和水在纳米通道中并排放置，形成一个弯月面。将均匀亲水性纳米颗粒、Janus颗粒和均匀疏水性纳米颗粒置于油水界面处，并研究它们在油水界面重新排列时的动力学。结果表明，当水流动时，会出现两种不稳定性：指状结构的形成以及水从通道壁分离。观察到指状结构的形成受纳米颗粒润湿性的影响。第二种不稳定性可能导致形成一个液滴并在通道中传播。然而，发现纳米颗粒的润湿特性并不影响水从壁面分离的临界流速。因此，无论纳米颗粒的润湿特性如何，分离都在相同的三相接触角下发生。这些发现对于诸如提高采收率、分离技术以及微流控和纳流控技术等工业应用可能具有重要意义。
