To study the wetting mechanism of surfactants at the solid–liquid interface of anthracite, a combination of experiments and molecular simulation was used to explore the adsorption and wetting processes of four surfactants, namely, fatty alcohol polyoxyethylene ether N = 9 (AEO), Triton X-100, rapid penetrant T (PRT), and sodium alkyl ether sulfate (AES) on anthracite. The wetting mechanism of surfactants on anthracite was analyzed at both macroscopic and microscopic levels by surface tension, contact angle, settling time, and changes in surface morphology and functional groups on the anthracite surface. The presence of OH-π and C = O was determined to significantly enhance anthracite wettability. The anthracite/surfactant/water system was constructed from a microscopic perspective, and the interaction energies, relative concentration distributions along the Z-axis, diffusion coefficient () of water molecules, radial distribution functions (RDF) of hydrophilic groups and water molecules, and coordination numbers of the components were analyzed. The results show that the wetting effect depends on the adsorption state of the surfactant at the anthracite/water interface and the strength of the interaction between the surfactant and water molecules. The addition of surfactants enhances the adsorption thickness of water molecules along the Z-axis and generates more hydrogen bonds, which play a role in fixing water molecules and lead to a decrease in the D of water molecules. RPT forms the highest number of hydrogen bonds with water molecules and has the lowest D of 0.479 × 10 cm/s, indicating strong wetting ability. The RDF of O atoms in surfactants and water molecules shows a similar trend, with two peaks one strong and one weak. The coordination numbers are 1.356, 1.057, 1.003, and 0.903, respectively. The final wettability of the surfactant on the anthracite depends on the synergistic interaction between the oxygen functional groups (OGs) as compared to the coordination number of the individual OGs.

中文翻译：

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表面活性剂类型对无烟煤粉尘润湿性的影响：实验和分子模拟


为了研究表面活性剂在无烟煤固液界面的润湿机理，采用实验与分子模拟相结合的方法，探讨了脂肪醇聚氧乙烯醚N=9（AEO）、Triton等4种表面活性剂的吸附润湿过程。 X-100、快速渗透剂 T (PRT) 和烷基醚硫酸钠 (AES) 在无烟煤上。通过表面张力、接触角、沉降时间以及无烟煤表面形貌和官能团的变化，从宏观和微观两个层面分析了表面活性剂对无烟煤的润湿机理。 OH-π 和 C = O 的存在被确定可显着增强无烟煤的润湿性。从微观角度构建了无烟煤/表面活性剂/水体系，计算了相互作用能、沿Z轴的相对浓度分布、水分子的扩散系数（）、亲水基团和水分子的径向分布函数（RDF）以及分析了组分的配位数。结果表明，润湿效果取决于表面活性剂在无烟煤/水界面的吸附状态以及表面活性剂与水分子相互作用的强度。表面活性剂的添加增强了水分子沿Z轴的吸附厚度，并产生更多的氢键，起到固定水分子的作用，导致水分子的D减小。 RPT与水分子形成的氢键数量最多，D最低，为0.479 × 10 cm/s，润湿能力强。表面活性剂和水分子中O原子的RDF表现出相似的趋势，有一强一弱两个峰。配位数为 1.356、1.057、1。分别为 0.003 和 0.903。表面活性剂在无烟煤上的最终润湿性取决于氧官能团 (OG) 之间与各个 OG 的配位数相比的协同相互作用。