聂文, 牛文进, 鲍秋, 于丰宁, 田起凡. 基于Dmol3模块的不同表面活性剂对煤尘润湿性的影响[J]. 煤炭学报, 2023, 48(3): 1255-1266.
引用本文: 聂文, 牛文进, 鲍秋, 于丰宁, 田起凡. 基于Dmol3模块的不同表面活性剂对煤尘润湿性的影响[J]. 煤炭学报, 2023, 48(3): 1255-1266.
NIE Wen, NIU Wenjin, BAO Qiu, YU Fengning, TIAN Qifan. Effect of different surfactants on the wettability of coal dust based on Dmol3 module[J]. Journal of China Coal Society, 2023, 48(3): 1255-1266.
Citation: NIE Wen, NIU Wenjin, BAO Qiu, YU Fengning, TIAN Qifan. Effect of different surfactants on the wettability of coal dust based on Dmol3 module[J]. Journal of China Coal Society, 2023, 48(3): 1255-1266.

基于Dmol3模块的不同表面活性剂对煤尘润湿性的影响

Effect of different surfactants on the wettability of coal dust based on Dmol3 module

  • 摘要: 煤尘防治一直是煤矿井下亟需解决的现实难题,以喷雾技术为基础,通过添加抑尘剂实现对煤尘的有效沉降具有较好的应用前景。但制备抑尘剂的过程中,原材料表面活性剂的遴选往往以实验方式进行,存在效率较低、成本较高以及实验条件苛刻等技术难题。随着分子模拟技术已相当成熟并广泛应用于物理、化学、生物等多个领域,成为物质结构分析、过渡态搜索等重要手段,因此利用分子模拟技术,借助量子化学分析中前线轨道能量差作为表面活性剂润湿性的主要判据,以表面活性剂分子的静电势极值大小和氢键数量为辅助手段,对快速渗透剂T、十二烷基苯磺酸钠(SDBS)、椰油酰胺丙基甜菜碱(CAB)的煤尘润湿性进行讨论。通过表面张力、表面活性剂毛细反渗透实验和接触角实验对上述表面活性剂的润湿性进行宏观论证;并在分子层面通过建立煤/水/表面活性剂动力学模型进行分子动力学分析,观察不同表面活性剂体系下各分子间的相互运动趋势,并对模拟结果进行相对浓度、均方位移和径向函数分布分析,在分子层面对不同的表面活性剂的润湿性能进行验证。结果表明:快速渗透剂T的前线轨道能量差与水分子形成的氢键数目为5.077 eV、1 098个,SDBS为4.387 eV、1 046个,CAB为2.077 eV、1 029个;而3者的水溶液对煤尘的最小表面张力、接触角和煤尘渗透高度分别是23.80 mN/m、27.12°、4.1 cm; 26.83 mN/m、32.69°,3.2 cm; 29.94 mN/m、39.61°、1.4 cm。随着轨道能量差的减小,表面活性剂溶液对煤尘的润湿效果也逐步下降,表面活性剂前线轨道能量差与其润湿性有直接联系,表面活性剂轨道能量差越大,与水分子形成的氢键数量越多,则表面活性剂溶液的润湿性越好,这与相对浓度、径向函数等分析也相一致,实验结果与与分子模拟结果展现出相同的变化规律,验证了模拟的合理性。

     

    Abstract: Coal dust control has always been a real problem in underground coal mines and the addition of dust suppressants to achieve effective deposition of coal dust based on spray technology has good application prospects. However, in the preparation of dust suppressants, the selection of raw material surfactants is often carried out experimentally, which has some technical difficulties such as low efficiency, high cost and harsh experimental conditions. As the molecular simulation technology has become quite mature and been widely used in many fields such as physics, chemistry and biology as an important tool for material structure analysis and transition state search, using molecular simulation technology, with the help of the front-line orbital energy difference in quantum chemical analysis as the main criterion for surfactant wettability, and the electrostatic potential polar size and hydrogen bonding number of surfactant molecules as an auxiliary means, the coal dust wettability of fast penetrant T,sodium dodecyl benzene sulfonate(SDBS),and cocamidopropyl betaine(CAB) was discussed. The wettability of the above surfactants was macroscopically demonstrated by surface tension, surfactant capillary reverse osmosis experiments and contact angle experiments. The molecular dynamics analysis was carried out at the molecular level by establishing a three-phase kinetic model of coal/water/surfactant to observe the trend of mutual motion between the molecules under different surfactant systems, and the simulation results were analyzed in terms of relative concentration, mean square displacement and radial function distribution. The simulation results were validated at the molecular level to verify the wetting performance of different surfactants. The results show that the number of hydrogen bonds formed with water molecules by the frontline orbital energy difference of the fast penetrant T molecule is 5.077 eV,1 098,the SDBS is 4.387 eV,1 046 and the CAB is 2.077 eV,1 029.While the minimum surface tension, contact angle and coal dust penetration height of the aqueous solutions of the three to coal dust are 23.80 mN/m, 27.12°,4.1 cm; 26.83 mN/m, 32.69°,3.2 cm; 29.94 mN/m, 39.61°,1.4 cm. As the orbital energy difference decreases, the wetting effect of surfactant on coal dust also gradually decreases, the surfactant frontline orbital energy difference is directly related to its wettability, the larger the surfactant orbital energy difference, the more the number of hydrogen bonds formed with water molecules, the better the wettability of surfactant solution, which is consistent with relative concentration, and radial function. The experimental results are also consistent with the molecular simulation results table, showing the same variation pattern, which verifies the reasonableness of the simulation.

     

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