Study on Mechanism of Surfactant Hydrolyzed Ions Synergizing with Special Group on Wetting Coal Dust
In order to improve the prevention and control efficiency of coal dust,the wettability of three surfactant solutions of ammonium dodecyl polyoxyethylene ether sulfate(ALES),sodium dodecyl polyoxyethylene ether sulfate(SLES)and sodium dodecyl sulfate(SDS)on coal rock and their adsorption capacities on coal dust surface were tested by means of surface tension,Walker sedimentation,scanning electron microscopy and infrared spectroscopy.The ALES,SLES,SDS molecular models and LRC models were constructed.The molecular dynamics simulation software was used to optimize the geometric and annealing optimization of the molecular structure.The electrostatic potential(EP),hydrogen bond and density distribution of different surfactant solutions on the coal surface were calculated.The effects of hydrolyzed ions and special groups on wetting coal dust were investigated.The results show that the ALES solution has a stronger ability to wet and adsorb coal dust than the SDS and SLES solutions,which is mainly due to the fact that the hydrolyzed anions and cations of ALES solution can penetrate into the surface of low rank coal at 27 Å and 35 Å,and the penetration ability is stronger.The hydrolyzed anion and cation of SDS solution have large EP values,which are-0.177 59 a.u.and 0.326 26 a.u.,respectively,which makes the surrounding water molecules constrained and difficult to diffuse on the surface of coal dust.NH4+and EO groups are conductive to increasing the number of hydrogen bond associations,enhancing the adsorption capacity of ALES,and improving its wetting effect on coal dust.The research results can provide a basis for the prevention and control of coal and rock disasters.
SurfactantWettingAdsorptionMolecular dynamics simulationLow rank coalPrevention of coal dust