The wettability of coal dust by surfactant-regulated solutions is influenced by the hydrophilic structures of the surfactants. This study combines macro- and microscopic experiments to determine the wettability performance of four surfactants with identical hydrophobic groups but different hydrophilic groups. Through molecular simulation, a molecular-level evaluation standard for the surfactant’s impact on coal dust wettability was established. Additionally, the correlation mechanism between the electrostatic potential distribution of the hydrophilic groups and their wettability was identified. Sulfonic groups—compared with sulfate, hydroxyl, and amino groups—can more effectively enhance the solution’s wettability, reducing the solution’s surface tension to as low as 22.1 mN/m and achieving a molecular wettability area of 78.84. Furthermore, the electrostatic potential extreme of the sulfonic group was − 53.61 kcal/mol, with an electrostatic potential wettability area of 28.99 Å2. This represents an improvement of approximately 34.43 % and 5170.91 %, respectively, compared with hydroxyl groups. Greater electrostatic potential extremes and electrostatic potential wettability areas led to stronger electrostatic adsorption, more adsorbed water molecules, and better wettability of coal dust. This study provides theoretical guidance for the rational design of functional surfactants for surface engineering and pollution control applications.

中文翻译：

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煤粉润湿性的分子机制：增强表面相互作用的亲水基团调制


表面活性剂调节溶液对煤粉的润湿性受表面活性剂的亲水结构的影响。本研究结合了宏观和微观实验，以确定具有相同疏水基团但亲水基团不同的四种表面活性剂的润湿性能。通过分子模拟，建立了表面活性剂对煤尘润湿性影响的分子水平评价标准。此外，还确定了亲水基团的静电电位分布与其润湿性之间的关联机制。与硫酸盐、羟基和氨基相比，磺酸基团可以更有效地增强溶液的润湿性，将溶液的表面张力降低到低至 22.1 mN/m，并实现 78.84 的分子润湿面积。此外，磺基的静电势极值为 − 53.61 kcal/mol，静电势润湿面积为 28.99 Å2。与羟基相比，这分别提高了约 34.43% 和 5170.91%。更大的静电电位极值和静电电位润湿性区域导致更强的静电吸附、更多的吸附水分子和更好的煤尘润湿性。本研究为表面工程和污染控制应用中功能性表面活性剂的合理设计提供了理论指导。