Interfacial tension and contact angle in CO 2 ‐water/nanofluid‐quartz system

• Published in: Greenhouse gases: science and technology 2018-08, Vol.8 (4), p.734-746
• Main Authors: Zheng, Xianglei, Barrios, Ana C., Perreault, François, Yun, Tae Sup, Jang, Jaewon
• Format: Article
• Language: English
• ISSN: 2152-3878; 2152-3878
• DOI: 10.1002/ghg.1781

Nanoparticles can modify the interface properties that are critical for fluid flow in porous media. The interfacial tension (IFT) between CO 2 and water and the contact angle (CA) of a water droplet on a mineral surface under high CO 2 pressure are critical parameters for CO 2 ‐related applications such as CO 2 geological sequestration and CO 2 ‐enhanced resource recovery. This study investigated the IFT and CA in a water‐CO 2 ‐quartz system and a nanofluid (water including either Al 2 O 3 or TiO 2 nanoparticles)‐CO 2 ‐quartz system. The values of the IFT and CA were obtained by axisymmetric drop shape analysis (ADSA) for a droplet on a quartz surface in a chamber pressurized with CO 2 . The effect of nanoparticles on the IFT and CA was explored by comparing the values for the pure water‐CO 2 ‐quartz system. In addition, the effect of CO 2 adsorption onto the substrate on the wettability was investigated. The results show that the values of the IFT decrease with increasing CO 2 pressure, and the addition of nanoparticles to pure water lowers the IFT further (∼up to a 40% reduction in the liquid CO 2 pressure range). The de‐wetting phenomenon was observed for both gaseous and liquid CO 2 conditions. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.