Effect of different concentrations of surfactant on the wettability of coal by molecular dynamics simulation

• Published in: 矿业科学技术学报（英文版） 2019, Vol.29 (4), p.577-584
• Main Authors: Junqing Meng, Feifei Yin, Shichao Li, Ruquan Zhong, Zeyuan Sheng, Baisheng Nie
• Format: Article
• Language: English
• ISSN: 2095-2686
• DOI: 10.3969/j.issn.2095-2686.2019.04.009

Anionic surfactant sodium dodecyl benzene sulfonate (SDBS) at varying concentrations was selected to investigate the influence on the wettability of Zhaozhuang Coal by molecular dynamics simulation. Six groups of water/surfactant/coal systems with different concentrations were constructed. The influence of surfactant with different concentrations on the wettability of coal was concluded by analyzing various properties from the energetic behaviors to the dynamic characteristics. The results show that the interfacial tension decreases sharply and then rises slowly with the increase of SDBS surfactant concentration, obtaining that surfactants can obviously reduce the interfacial tension. The surfactant molecules could be detected at the water/coal interface through analyzing the system's relative concentration distribution. In addition, the difference in the wettability of surfactants on coal surfaces is caused by the spatial distribution differences of alkyl chains and the benzene ring of the surfactant molecules. And the negative interaction energy between SDBS and the coal surface indicates that adsorption process is spontaneous. Furthermore, it is of great practical significance for improving the dust reduction effect and reducing the disaster of coal dust by exploring the effects of surfactant molecules on the wettability of coal.