Abstract Wettability alteration analysis form gas-repellent to gas-wet with the aid of chemical agents has been subjected of numerous studies. However, fundamental understanding of the effect of surface tension of liquid on repellency strength, the change in the intermolecular forces due to the adsorption of nanoparticles onto the rock surfaces, and exposure of treated rock in brine are not well discussed in the available literature. In this study, X-ray diffraction, Atomic Force Microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were applied to characterize the treated and fresh samples. Dynamic and static contact angle measurements were then combined with six methods of surface free energy analysis; Neumann, Zisman plot, geometric, harmonic, acid-base, and Chibowski, to model liquid intermolecular forces effect on contact angle and to calculate the surface forces. Surface characterization results showed that adsorbed fluorine and silicon elements onto the calcite surface due to treatment in the nanofluid resulted in an increment of surface roughness. The weight percent of 0.93 and 1.22 and surface fraction of 0.265 and 0.014 for adsorbed Fluorine and Silicon were observed, respectively. A reduction for surface free energy in the range of 20–35 mN/m was observed for different applied approaches. The results of geometric, harmonic, and acid-base models indicated that calcite intrinsically has a mildly polar surface with a negative surface charge. It was revealed that the magnitude of the dispersive component was nearly 1.6 times greater than the polar component. For the treated surfaces, the geometric, harmonic, and acid-base methods showed a high reduction in the polar force of surface (

中文翻译：

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使用氟化纳米流体改变方解石岩石从气体排斥到气体湿润的润湿性：表面分析研究

摘要 借助化学试剂从气体拒气到气湿的润湿性变化分析已经进行了大量研究。然而，关于液体表面张力对排斥强度的影响、由于纳米颗粒吸附到岩石表面引起的分子间力的变化以及处理过的岩石暴露在盐水中的基本认识，在现有文献中没有得到很好的讨论。在这项研究中，应用 X 射线衍射、原子力显微镜、扫描电子显微镜和能量色散 X 射线光谱来表征处理过的和新鲜的样品。然后将动态和静态接触角测量与六种表面自由能分析方法相结合；Neumann、Zisman 图、几何、谐波、酸碱和 Chibowski，模拟液体分子间力对接触角的影响并计算表面力。表面表征结果表明，由于纳米流体的处理，吸附在方解石表面的氟和硅元素导致表面粗糙度增加。观察到吸附的氟和硅的重量百分比分别为 0.93 和 1.22，表面分数分别为 0.265 和 0.014。对于不同的应用方法，观察到表面自由能降低了 20-35 mN/m。几何、调和和酸碱模型的结果表明方解石本质上具有带负表面电荷的温和极性表面。结果表明，色散分量的大小几乎是极性分量的 1.6 倍。对于处理过的表面，几何、谐波、