Theoretical Study of the Roles of Na+ and Water on the Adsorption of Formamide on Kaolinite Surfaces
Theoretical Study of the Roles of Na+ and Water on the Adsorption of Formamide on Kaolinite Surfaces
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DOI：
10.1021/jp3045324
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发表时间：
2012-11
影响因子：
3.7
通讯作者：
Andrea Michalkova Scott;M. M. Dawley-M.;T. Orlando;F. Hill;J. Leszczynski
中科院分区：
文献类型：
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作者：
Andrea Michalkova Scott;M. M. Dawley-M.;T. Orlando;F. Hill;J. Leszczynski
采用密度泛函理论研究了甲酰胺（FA）在高岭石表面的吸附行为以及Na+和水对吸附的影响。计算结果表明，吸附的FA能够与高岭石的四面体和八面体表面形成稳定的复合物。八面体表面具有更大的结合亲和力对FA比高岭石的四面体网站部分由于表面羟基的存在下，更活跃的分子间相互作用比硅氧烷或四面体网站的基础氧原子。计算的（基组叠加误差校正）FA在高岭石八面体和四面体表面的结合能分别为−14.8和−13.7 kcal/mol。FA也形成了稍微不太稳定的复合物与带负电荷的高岭石片段比与中性的。钠离子的加入在吸附中起关键作用，而水分子的加入影响吸附剂的结合强度。
The adsorption of formamide (FA) on kaolinite surfaces and the roles of Na+ and water on the adsorption were investigated theoretically using a density functional theory. The calculations reveal that adsorbed FA is able to form stable complexes with the tetrahedral and octahedral surfaces of kaolinite. The octahedral surface possesses a larger binding affinity toward FA than the tetrahedral site of kaolinite partially due to the presence of the surface hydroxyl groups that are more active in the intermolecular interactions than the basal oxygen atoms of the siloxane or tetrahedral sites. The calculated (basis set superposition error corrected) binding energies of FA on the kaolinite octahedral and tetrahedral surfaces are −14.8 and −13.7 kcal/mol, respectively. FA also forms slightly less stable complexes with the negatively charged kaolinite fragments than with neutral ones. The addition of a sodium cation plays a key role in this adsorption, while addition of one water molecule affects the binding stren...