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应用CNDO/2方法从理论上研究了石英上十二烷基胺的电子状态及键合状态。在PZC附近带有硅醇的石英表面转入碱性区域时其质子从表面上脱离并且表面上氧的负电荷增大。十二烷基胺离子上氮的电荷分布呈现出中性状态,而十二烷基胺分子上的却带有负电荷。与胺离子上氮键合的氢的正电荷要比胺分子上的大得多。十二烷基胺同石英问的相互作用主要归因于H(十二烷基胺离子)-O(石英)、N(十二烷基胺分子)-Si(石英)及N(十二烷基胺分子)-H(硅醇)等的库仑键,其强度几乎是水的二聚物氢键的一半。进而,同石英形成强键的胺离子上的原子与胺分子上的不同。基于吸附系的胺离子与石英间的成键强度和吸附稳定能判断,十二烷基胺离子在碱性区域要比在PZC附近更易于吸附在石英上。十二烷基胺离子和胺分子在与石英表面上或双电层中水分子或钠离子交换后都能有力地吸附在石英上。
CNDO / 2 method was applied to study the electronic state and bonding state of dodecylamine on quartz. When the quartz surface with silanol near PZC is transferred to the alkaline region, its protons are detached from the surface and the negative charge of oxygen on the surface increases. The charge distribution of nitrogen on the dodecylamine ion shows a neutral state, while the dodecylamine molecule has a negative charge. The hydrogen bonded to the nitrogen of the amine ion has a much larger positive charge than the amine molecule. The interaction of dodecylamine with quartz was mainly attributed to H (dodecylamine ion) -O (quartz), N (dodecylamine molecule) -Si (quartz) and N Amine molecule) -H (silanol) and the like, the intensity of which is almost half that of hydrogen dimer of water. Further, the atoms on amine ions that form strong bonds with quartz differ from those on amine molecules. Based on the bond strength and adsorption stability between the amine ion and the quartz of the adsorption system, it can be judged that the dodecylamine ion is more easily adsorbed on the quartz in the alkaline region than in the vicinity of the PZC. The dodecylamine and amine molecules are strongly adsorbed on the quartz after exchange with water molecules or sodium ions on the quartz surface or in the electric double layer.