Surface modeling of wettability transition on α-quartz: Insights from experiments and molecular dynamics simulations

The wettability of quartz surfaces is a critical property in numerous energy-related industrial processes. However, accurately quantifying wettability is challenging due to the multitude of factors that can influence wetting behavior. Herein, we proposed a generalized surface modeling procedure addressing microscopic insights to calculate the contact angles of liquids on quartz under different scenarios. An optical goniometer experimentally measured the contact angles and validated the proposed surface modeling procedure. The effects of surface density of hydroxyl groups, temperature, surfactants, and crude oil composition on the wettability of quartz surfaces were studied. The results revealed that an increased hydroxyl group density significantly improved water wettability on a quartz surface. An increased temperature reduced the water contact angle on quartz, and such decreasing rates became steeper at high temperatures. The surfactants' adsorption morphology determined the wettability of a quartz surface. Moreover, the polar components in crude oil significantly increased the hydrophobicity of a quartz surface, making it easier to adsorb more oil molecules to alter the quartz wettability further. The valuable outcomes of this paper contribute to understanding the complex quartz wettability and pave the way for further studies involving quartz surface modeling.