十二胺在Fe^(2+)掺杂高岭石层面吸附的密度泛函研究

DFT calculations on the adsorption of dodecylamine on surface of Fe^(2+)-doped kaolinite

为探究Fe^(2+)掺杂对十二胺分子(DDA)及其阳离子(DDA+)在高岭石层面吸附的微观影响机制,对DDA和DDA+在Fe^(2+)掺杂高岭石(001)及(■)面的吸附进行了密度泛函理论(DFT)计算.结果表明:DDA和DDA+在Fe^(2+)掺杂高岭石层面的吸附机理为氢键和范德华静电引力共同作用.DDA在Fe^(2+)掺杂高岭石层面吸附以氢键作用为主,范德华静电引力作用为辅;DDA+在Fe^(2+)掺杂高岭石层面吸附以范德华静电引力作用为主,氢键作用为辅.Fe^(2+)的杂质缺陷增强了高岭石(001)面的表面活性,对(■)面的表面活性影响较小.研究结果可为进一步研究煤泥水中黏土颗粒表面的真实吸附状态及煤泥水高效处理药剂的设计提供理论依据.

To investigate the microscopic mechanism of Fe^(2+)doping on the adsorption of dodecylamine molecules(DDA)and its cations(DDA+)on the kaolinite surfaces,density functional theory(DFT)was applied for the adsorption of DDA and DDA+on the Fe^(2+)-doped kaolinite(001)and(001)surfaces.The results show that the interaction of hydrogen bonding and van der Waals electrostatic attraction are the mainly adsorption mechanism of DDA and DDA+adsorption on the Fe^(2+)-doped kaolinite surfaces.The adsorption mechanism of DDA on Fe^(2+)-doped kaolinite surfaces gives priority to the hydrogen bonding,and van der Waals electrostatic attraction plays an auxiliary role,while the adsorption mechanism of DDA+adsorption on Fe^(2+)-doped kaolinite surfaces is opposite.The activity of kaolinite(001)surface is enhanced due to Fe^(2+)impurity defects,but the activity of kaolinite(001)surface is less affected.Results of this research have enormous potential to provide a theoretical basis for further research on the real adsorption state of clay particles in coal slurry water and the design of efficient treatment reagents for coal slurry water.