State Key Laboratory of Mining Disaster Prevention and Control Co⁃founded by Shandong Province and the Ministry of Science and Technology,Shandong U⁃niversity of Science and Technology
College of Safety and Environmental Engineering,Shandong University of Science and Tech⁃nology

Coal dust control has always been a real problem in underground coal mines and the addition of dust sup⁃pressants to achieve effective deposition of coal dust based on spray technology has good application prospects. Howev⁃er,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 mo⁃lecular simulation technology has become quite mature and been widely used in many fields such as physics,chemistryand biology as an important tool for material structure analysis and transition state search,using molecular simula⁃tion technology,with the help of the front⁃line orbital energy difference in quantum chemical analysis as the main crite⁃rion for surfactant wettability,and the electrostatic potential polar size and hydrogen bonding number of surfactant mol⁃ecules 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 dem⁃onstrated by surface tension,surfactant capillary reverse osmosis experiments and contact angle experiments. The mo⁃lecular 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 func⁃tion distribution. The simulation results were validated at the molecular level to verify the wetting performance of differ⁃ent surfactants. The results show that the number of hydrogen bonds formed with water molecules by the frontline orbit⁃al 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 is2.077 eV,1 029.While the minimum surface tension,contact angle and coal dust penetration height of the aqueous so⁃lutions 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 de⁃creases,the surfactant frontline orbital energy difference is directly related to its wettability,the larger the surfactant or⁃bital energy difference,the more the number of hydrogen bonds formed with water molecules,the better the wettabilityof surfactant solution,which is consistent with relative concentration,and radial function. The experimental results arealso consistent with the molecular simulation results table,showing the same variation pattern,which verifies the rea⁃sonableness of the simulation.