煤矿安全2025，Vol.56Issue(10)：86-93,8.DOI:10.13347/j.cnki.mkaq.20240424
表面活性剂保水机理的分子动力学研究
Molecular dynamics research on water retention mechanism of surfactants
摘要
Abstract
Surfactants are widely employed in coal mine dust suppression operations because they can significantly enhance the effi-ciency of spray dust suppression.To systematically investigate the water retention performance and mechanism of surfactants,an ex-perimental study combined with molecular dynamics simulation was conducted.The influence of surfactants on the water retention performance of coal dust was analyzed through experimental methods.The weight of coal dust samples with four different types of surfactants(dodecyltrimethylammonium bromide(DTAB),sodium dodecyl sulfate(SDS),dodecyl trimethyl betaine(BS-12),and aliphatic alcohol polyoxyethylene ether(AEO-7))was regularly measured,and the water retention rates of different coal types were calculated.The water retention capabilities of various surfactants were analyzed.To reveal the microscopic mechanism,a 4-compon-ent surfactant aqueous solution model containing 30 surfactant molecules and 1 800 water molecules was constructed for molecular dynamics simulation.The characteristics of the hydration layer formed around the hydrophilic head groups of surfactant molecules and the differences in the dissociation energy barriers were analyzed.The microscopic mechanism of the differences in water reten-tion abilities of different surfactants was studied.The results demonstrated that,after a 100-hour test period,all surfactant-treated coal samples exhibited significantly enhanced water retention,among them,the anionic surfactant SDS showed the most effective performance;the surfactant head groups attract water molecules through electrostatic interactions or hydrogen bonding,forming hy-dration layers around them,this is the fundamental mechanism enabling their water-retention capacity;specifically,the average dis-tances between the hydrophilic head groups and the first-layer water molecules for DTAB,SDS,BS-12,and AEO-7 were found to be 0.41 nm,0.15 nm,0.15 nm,and 0.18 nm,respectively,SDS(anionic)and BS-12(zwitterionic)exhibited shorter distances to the first hydration layer,a greater number of hydrogen bonds,and higher peak intensities,indicating stronger hydration and more stable water retention.Based on the comparison of dissociation energy barriers between water molecules and surfactant head groups,the water-retention capacities of the four surfactants decrease in the following order:SDS>BS-12>AEO-7>DTAB.关键词
表面活性剂/保水机理/分子动力学/水合层/离解能垒Key words
surfactants/water retention mechanism/molecular dynamics/hydration layer/dissociation energy barriers分类
矿业与冶金引用本文复制引用
雷咸锐,徐晓波,刘硕..表面活性剂保水机理的分子动力学研究[J].煤矿安全,2025,56(10):86-93,8.基金项目
山西省基础研究计划资助项目(202203021212218,202203021222132) （202203021212218,202203021222132）
