Du Limin, Nian Jun, Fu Jinqi, Zhu Jingchi, Yu Hongfei, He Xiaoxia, Yang Chaowei, Zhang Lei
College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
Postdoctoral Workstation, Shanxi Coking Coal Group Co., LTD., Taiyuan, Shanxi 030021, China.
ACS Omega. 2025 Feb 10;10(6):6105-6118. doi: 10.1021/acsomega.4c10578. eCollection 2025 Feb 18.
This study investigates the effects of composite surfactants on the wettability of different coal types using a combination of macroscopic experiments, mesoscopic experiments, and microscopic molecular dynamics simulations, with coal samples of varying degrees of metamorphism as research subjects. First, contact angle and surface tension experiments were performed at the macroscopic level to determine the optimal concentration and ratio of the composite surfactants. The results showed that the composite solution formed by mixing SLES and AEO-9 in a 3:2 ratio significantly reduced both the surface tension of the solution and the contact angle of the coal samples at a mass concentration of 0.5 wt %. Second, the effects of the composite surfactants on the wetting properties of coal samples were analyzed at the mesoscopic level using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and ζ-potential measurements. The results revealed that the total content of hydrophobic groups (-CH, -CH&-CH, C=C) in the coal molecules was significantly reduced after treatment with the composite solution, weakening the hydrophobicity of the coal samples. Additionally, the absolute value of the surface potential of the coal samples was significantly decreased, enhancing the aggregation tendency between coal particles. This facilitated the formation of larger agglomerated coal particles, which contributed to the settling of coal dust. Simultaneously, the cracks between coal particles promoted the penetration of aqueous solutions, aiding in the wetting of the coal seam. Finally, molecular dynamics simulations were conducted to analyze the synergistic wetting mechanism of the composite surfactants at the microscopic level. The results showed that the composite surfactant molecules were effectively adsorbed onto the surface of coal molecules, facilitating the movement of water molecules to the coal surface, increasing the diffusion coefficient of water molecules, and enhancing the interaction energy within the coal/composite surfactant/water system. These findings provide valuable insights for the development of new composite surfactants with wetting effects, offering significant potential for applications in mine dust control.
本研究以不同变质程度的煤样为研究对象，采用宏观实验、细观实验和微观分子动力学模拟相结合的方法，研究了复合表面活性剂对不同煤种润湿性的影响。首先，在宏观层面进行了接触角和表面张力实验，以确定复合表面活性剂的最佳浓度和比例。结果表明，质量浓度为0.5 wt%时，以3:2比例混合的十二烷基醚硫酸钠（SLES）和脂肪醇聚氧乙烯醚（AEO-9）形成的复合溶液显著降低了溶液的表面张力和煤样的接触角。其次，在细观层面利用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和ζ电位测量分析了复合表面活性剂对煤样润湿性的影响。结果显示，用复合溶液处理后，煤分子中疏水基团（-CH、-CH&-CH、C=C）的总含量显著降低，削弱了煤样的疏水性。此外，煤样表面电位的绝对值显著降低，增强了煤颗粒之间的聚集趋势。这促进了更大的团聚煤颗粒的形成，有助于煤尘的沉降。同时，煤颗粒之间的裂缝促进了水溶液的渗透，有助于煤层的湿润。最后，进行了分子动力学模拟，在微观层面分析了复合表面活性剂的协同润湿机理。结果表明，复合表面活性剂分子有效地吸附在煤分子表面，促进了水分子向煤表面的移动，增加了水分子的扩散系数，并增强了煤/复合表面活性剂/水体系内的相互作用能。这些发现为开发具有润湿效果的新型复合表面活性剂提供了有价值的见解，在矿井粉尘控制应用中具有巨大潜力。
