Abstract The influence of the anionic surfactant sodium fatty alcohol polyoxyethylene ether carboxylate (AEC) on the wettability of coal surfaces was studied by combining molecular dynamics simulations and experimental research. First, a molecular dynamics simulation of the AEC adsorption process on a low-rank coal surface was carried out. The simulation results show that AEC promotes the adsorption of water molecules on the coal surface, moves more water molecules to the coal surface, and improves the mobility of water molecules; AEC molecules were detected at the coal-water interface. After adsorption, the AEC molecules were connected to each other through alkyl chains to form a spherical-like structure, which covered the coal surface laterally. The calculated interaction energy between coal and water is negative, which shows that the adsorption process is spontaneous, and AEC enhances the interaction between coal and water. Second, the abovementioned simulation results are verified by experiments. The adsorption experiments show that AEC adsorbs on the lignite surface by monolayer adsorption, which can be described by the Langmuir isothermal adsorption equation; the contact angle first increases and then decreases, reaching a maximum near the critical micelle concentration (CMC). The XPS analysis shows that the change in the content of the oxygen-containing functional groups is the main reason for the wettability of the lignite surface. Among these oxygen-containing functional groups, the C-O group has the most significant effect on the wettability.

中文翻译：

---

阴离子表面活性剂的分子动力学模拟与实验表征：对低阶煤润湿性的影响

摘要 结合分子动力学模拟和实验研究，研究了阴离子表面活性剂脂肪醇聚氧乙烯醚羧酸钠（AEC）对煤表面润湿性的影响。首先，对低阶煤表面的 AEC 吸附过程进行了分子动力学模拟。模拟结果表明，AEC促进了水分子在煤表面的吸附，使更多的水分子移动到煤表面，提高了水分子的流动性；在煤-水界面检测到 AEC 分子。吸附后的AEC分子通过烷基链相互连接形成球形结构，横向覆盖煤表面。计算出的煤和水之间的相互作用能为负，这表明吸附过程是自发的，AEC 增强了煤和水之间的相互作用。其次，通过实验验证了上述模拟结果。吸附实验表明，AEC以单层吸附方式吸附在褐煤表面，可用Langmuir等温吸附方程描述；接触角先增大后减小，在临界胶束浓度 (CMC) 附近达到最大值。XPS分析表明，含氧官能团含量的变化是褐煤表面润湿性的主要原因。在这些含氧官能团中，CO基团对润湿性的影响最为显着。上述模拟结果均经过实验验证。吸附实验表明，AEC以单层吸附方式吸附在褐煤表面，可用Langmuir等温吸附方程描述；接触角先增大后减小，在临界胶束浓度 (CMC) 附近达到最大值。XPS分析表明，含氧官能团含量的变化是褐煤表面润湿性的主要原因。在这些含氧官能团中，CO基团对润湿性的影响最为显着。上述模拟结果均经过实验验证。吸附实验表明，AEC以单层吸附方式吸附在褐煤表面，可用Langmuir等温吸附方程描述；接触角先增大后减小，在临界胶束浓度 (CMC) 附近达到最大值。XPS分析表明，含氧官能团含量的变化是褐煤表面润湿性的主要原因。在这些含氧官能团中，CO基团对润湿性的影响最为显着。接触角先增大后减小，在临界胶束浓度 (CMC) 附近达到最大值。XPS分析表明，含氧官能团含量的变化是褐煤表面润湿性的主要原因。在这些含氧官能团中，CO基团对润湿性的影响最为显着。接触角先增大后减小，在临界胶束浓度 (CMC) 附近达到最大值。XPS分析表明，含氧官能团含量的变化是褐煤表面润湿性的主要原因。在这些含氧官能团中，CO基团对润湿性的影响最为显着。