有机硅表面活性剂对煤表面润湿性影响的分子模拟

Molecular simulation of the impact of organic silicon surfactants on coal surface wettability

为寻找对煤尘抑制具有良好效果的表面活性剂,以Wiser煤化学结构模型为附着基底,利用Materials Studio分子模拟软件建立水-表面活性剂-煤吸附体系,以研究有机硅表面活性剂在煤表面的润湿机制。分别以阴离子型碳氢表面活性剂十二烷基苯磺酸钠(Sodium Dodecyl Benzene Sulfonate, SDBS)、非离子型碳氢表面活性剂烷基糖苷(Alkyl Polyglucoside, APG-0810)、MD′M型聚醚改性三硅氧烷表面活性剂、Si—C侧链型聚醚改性聚硅氧烷表面活性剂等4种润湿剂构建润湿体系,模拟烟煤-表面活性剂-水体系对水分子的吸附过程,深入分析吸附构型、空间分布,以及相互作用能、静电势、水分子均方位移等,进而研究煤表面润湿作用机理和界面行为。模拟结果显示:有机硅表面活性剂对煤表面的润湿性能明显优于碳氢表面活性剂;在范德华力作用下,硅氧烷链段可与烟煤稳定结合;聚醚链段具有亲水性以及良好的静电驱动作用,在煤表面形成对水分子的紧密吸附层;在润湿过程中,有机硅表面活性剂的聚醚长链吸附聚集更多水分子在煤表面,促进煤的润湿进程。研究结果为有机硅表面活性剂在煤尘控制的应用提供了理论依据。

To identify a surfactant with superior effectiveness in suppressing coal dust,we established a water-surfactants-coal adsorption system,utilizing the Wiser coal chemical structure model as the adhesion base.Employing Materials Studio molecular simulation software,we investigated the wetting mechanism of organosilicon surfactants on the coal surface.The wetting system comprised anionic hydrocarbon surfactant Sodium Dodecyl Benzene Sulfonate(SDBS),non-ionic hydrocarbon surfactant alkyl glycoside(APG 0810),MD′M polyether modified trisiloxane surfactant,and Si—C side chain polyether modified polysiloxane surfactant.The adsorption process of water molecules in the bituminous coal-surfactants-water system was simulated,and the adsorption configuration and spatial distribution characteristics were thoroughly analyzed.The study delved into the interaction energy between coal and surfactant molecules,the electrostatic potential distribution between surfactants and water molecules,alongside examining the Mean Square Displacement of water molecules and the Diffusion coefficient.The wetting mechanism and interface behavior of the coal surface were examined through a comparative analysis of the wettability characterization data between organosilicon surfactants and traditional hydrocarbon surfactants.The simulation results demonstrate that organosilicon surfactants exhibit significantly better wettability to the coal surface compared to hydrocarbon surfactants.Under the influence of van der Waals force,the siloxane segments can securely bond with bituminous coal.Additionally,the polyether chain segment possesses hydrophilicity and exerts a strong electrostatic driving effect,facilitating the formation of a dense adsorption layer for water molecules on the coal surface.During the wetting process,the elongated polyether chain of the silicone surfactant adsorbs a greater number of water molecules on the coal surface,thereby facilitating the wetting process of the coal.The research results analyzed the factors influencing the wetting of coal dust by various types of surfactants,elucidating the wetting mechanism inherent in different bituminous coal-surfactant-water systems.These findings provide a theoretical foundation for the utilization of organosilicon surfactants in coal dust control applications.