不同质量分数SDBS对煤体润湿性影响的分子模拟  

Effect of SDBS of different mass fractions on coal’s wettability by molecular simulation

作　　者：李树刚 郭豆豆[1,2] 白杨 严敏 林海飞 石钰[1,2] LI Shugang;GUO Doudou;BAI Yang;YAN Min;LIN Haifei;SHI Yu(College of Safety Science and Engineering,Xi'an University of science and Technology,Xi'an Shaanxi 710054,China;Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an Shaanxi 710054,China)

机构地区：[1]西安科技大学安全科学与工程学院,陕西西安710054 [2]教育部西部矿井开采及灾害防治重点实验室,陕西西安710054

出　　处：《中国安全科学学报》2020年第3期21-27,共7页China Safety Science Journal

基　　金：国家自然科学基金资助(51734007,51674192,11802231);陕西省自然科学基金资助(2019JLP-02)。

摘　　要：为研究表面活性剂对煤体润湿性能的影响,选择十二烷基苯磺酸钠(SDBS)表面活性剂作为研究对象,采用Wiser煤化学结构模型,利用Materials Studio分子模拟软件,构建6种不同质量分数SDBS与水、煤共存的系统,分析系统吸附构型及能量变化,以及相对浓度分布、水分子均方位移(MSD)等。研究结果表明:SDBS分子的疏水烷基链吸附在煤表面,带苯环的亲水基团翘向水相,降低了水及煤的液-固界面张力;随着SDBS质量分数增加,系统总能量更低,SDBS与煤之间的相互作用能增大,分子间吸附作用更稳定,更有利于润湿煤;SDBS分子疏水烷基链的空间分布差异是影响煤润湿性能的主要原因之一;水分子扩散系数随着SDBS质量分数增加而增大,对煤体润湿性产生显著影响。In order to study effects of surfactant on coal’s wettability,with SDBS taken as research object,Wiser coal chemical structure model and Material Studio molecular simulation software were used to establish a system where SDBS of six different mass fractions coexisted with water and coal.Then,the system’s adsorption configuration,energy changes,relative concentration distribution as well as mean square displacement(MSD)of water molecules were analyzed.The results show that hydrophobic alkyl chains of SDBS molecules are adsorbed on coal surface,and hydrophilic group with benzene ring warps to water phase,which reduces liquid-solid interfacial tension of water and coal.As mass fraction of SDBS increases,the system’s total energy decreases,but interaction energy between SDBS and coal increases,indicating that adsorption between molecules is more stable and wettability is enhanced.Spatial distribution difference of hydrophobic alkyl chains of SDBS molecules is one of the main factors affecting wettability.Diffusion coefficient of water molecules increases along with the growth of SDBS mass fraction,which has a significant effect on wettability of coal.

关 键 词：十二烷基苯磺酸钠(SDBS) 煤润湿性 分子动力学 吸附构型 相对浓度分布 

分 类 号：X936[环境科学与工程—安全科学]