Pressure and Temperature Dependence of Contact Angles for CO2/Water/Silica Systems Predicted by Molecular Dynamics Simulations
Pressure and Temperature Dependence of Contact Angles for CO2/Water/Silica Systems Predicted by Molecular Dynamics Simulations
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DOI：
10.1021/acs.energyfuels.6b00171
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发表时间：
2016-06-01
期刊：
影响因子：
5.3
通讯作者：
Song, Yongchen
中科院分区：
文献类型：
--
作者：
Chen, Cong;Dong, Bo;Song, Yongchen
润湿性控制注入二氧化碳的毛细管行为，包括毛细管入口压力、相对渗透率和残余流体饱和度，它是地质碳封存（GCS）中最活跃的主题之一。然而，文献中水接触角（CA）数据及其压力、温度和盐度依赖性的巨大不确定性限制了我们对润湿性的理解。分子动力学 (MD) 模拟已用于研究二氧化硅表面上水 CA 的压力 (P) 和温度 (T) 依赖性。选择Q(2)、结晶Q(3)和非晶Q(3)三种典型的二氧化硅分子表面模型，在宽压力(2.8-32.6 MPa)和温度(318-383 K)条件下进行模拟。结果表明二氧化硅表面上水 CA 的 P 和 T 依赖性受表面官能团控制。这些发现提供了新的信息，有助于更好地理解不同 GCS 条件下润湿性的变化。
Wettability controls the capillary behavior of injected CO2 including capillary entry pressure, relative permeability, and residual fluid saturation, and it is one of the most active topics in geologic carbon sequestration (GCS). However, the large uncertainty of water contact angle (CA) data and its pressure, temperature, and salinity dependence in the literature, limit our understanding on wettability. Molecular dynamics (MD) simulations have been performed to investigate the pressure (P) and temperature (T) dependence of water CAs on the silica surface. Three typical molecular surface models for silica, namely, Q(2), crystalline Q(3), and amorphous Q(3), were selected, and simulations were conducted at wide pressure (2.8-32.6 MPa) and temperature (318-383 K) conditions. The results show that P and T dependence of water CAs on silica surfaces is controlled by surface functional groups. These findings provide new information to help with the better understanding of wettability alteration under different GCS conditions.