表面活性剂对硅尘润湿性影响的分子模拟

Molecular simulation of the influence of surfactants on the wettability of silica dust

研究表面活性剂对SiO_(2)粉尘润湿性影响,对SiO_(2)粉尘治理具有重要意义。以SiO_(2)-表面活性剂-水模型为基础,采用蒙特卡罗和分子动力学的方法,结合沉降试验,探究不同表面活性剂对SiO_(2)润湿性的影响。模拟结果表明:表面活性剂能够提高SiO_(2)的吸水量,且在十六烷基三甲基溴化铵(Cetyl Trimethyl Ammonium Bromide, CTAB)条件下吸水量提升得最多;分子动力学模拟后,SiO_(2)-CTAB-水模拟体系中分子间相互作用能最大,表明CTAB对SiO_(2)润湿性的影响最大;当CTAB和月桂基葡萄糖苷(Alkyl Polyglucoside, APG1214)以物质的量比3∶1复配时SiO_(2)的吸水量最高。沉降试验表明,SiO_(2)粉尘在单体CTAB和物质的量比3∶1复配的CTAB/APG1214溶液中沉降时间较短,说明这2种溶液对SiO_(2)的润湿效果较好,与模拟结果一致。

The research on the influence of surfactants on the wettability of Si,dust is of great significance to the treatment of SiO_(2) dust.Based on the construction of the SiO_(2)-surfactant-water model,this paper uses Monte Carlo and molecular dynamics methods to carry out the simulation of SiO_(2) adsorption and molecular dynamics under different surfactant conditions and investigate the influence of different surfactants on SiO_(2) wettability incombination withsedimentation tests.The simulation results show that no matter what kind of surfactant,it can improve the water absorption of SiO_(2) to a certain extent,and the water absorption of SiO_(2) is the largest under the condition of Cetyl Trimethyl Ammonium Bromide(CTAB)surfactant,followed by Dodecyl Trimethyl Ammonium Bromide(DTAB),Sodium Dodecyl Benzene Sulfonate(SDBS),fast-penetrating T,APG1214,BS-12,OA-12,and OP-10.After different SiO_(2)-surfactant-water simulation systemssaresimulated by molecular dynamics,the water and surfactant molecules in the system are mixed and approach the surface of the SiO_(2) molecules,and the distance between the three is reduced.The intermolecular interaction energy is the largest in the SiO_(2)-CTAB-water simulation system,which indicates that the surfactant CTAB has the largest effect on the wettability of SiO_(2).Besides,in the adsorption simulation of the compound surfactants,the water absorption of SiO_(2)is the largest when the surfactant CTAB is compounded with APG1214 in a molar ratio of 3:1.The sedimentation tests of SiO_(2) dust under different surfactants show that the sedimentation time of SiO_(2) dust in pure water is the longest,which is 80.57 s.However,the sedimentation time of SiO_(2) dust in the monomer CTAB and CTAB/APG1214 solution with molar ratio of 3:1 is the shortest,which is 21.50 s and 16.71 s,respectively.This result shows that the two solutions have a better wetting effect on SiO_(2)dust,which is consistent with the simulation results.The research results provide a reference for the application of surfactants in the treatment of SiO_(2)dust.