Influence Mechanisms of the Benzene Ring Structure of Surfactant on the Wettability of Coal Dust
Surfactants can effectively assist in the suppression of coal dust.In order to reveal the microscopic influence mechanism of surfactant microstructure on the wettability of coal dust,two surfactants,fatty alcohol polyoxyethylene ether(AEO9)and nonylphenol polyoxyethylene ether(OP9),were selected.The influence of the benzene ring structure on the wettability of coal dust was analyzed from various angles and by various means.The surface tension experiment was used to predict that OP9 containing benzene ring structure had lower surface tension and faster reduction rate.The contact angle determination and natural sedimentation tests indicated that OP9 containing benzene ring structure could adsorb more at the surface of lignite through hydrophobic interaction and π-π stacking,and had a stronger ability to enhance the wettability.The HOMO and LUMO distributions of the two surfactants were calculated by density functional theory(DFT),and it was found that OP9 had more adsorption sites with lignite.Finally,the adsorption energy,relative concentration distribution,mean square displacement of water molecules and the number of hydrogen bonds in different adsorption systems were calculated.The results indicate that the coal modified by OP9 could produce more hydrogen bonds,thus limiting the movement of water molecules in the Z axis and enhancing the hydrophilicity of lignite.The research results can provide a strong theoretical basis for the suppression of coal dust.
Coal dustWettabilityBenzene ring structureNonionic surfactantMolecular dynamics simulation
万方数据
维普
