Molecular dynamics simulation of anionic clays containing glutamic acid

作者：Xu, Qian; Ni, Zheming^*; Yao, Ping; Li, Yuan

来源：Journal of Molecular Structure, 2010, 977(1-3): 165-169.

DOI：10.1016/j.molstruc.2010.05.027

• Nanostructures
• Molecular dynamics simulation
• Microscopic structure
• Surface properties

Supra-molecular structure of glutamic acid intercalated ZnAl layered double hydroxides (Glu-ZnAl-LDH) was modeled by molecular dynamics (MD) methods. Hydrogen bonding, hydration and swelling properties of Glu-LDH have been investigated. For N-w < 8, interlayer spacing d(c) increased slowly. For N-w >= 8, the variation of d(c) followed the linear equation d(c) = 0.432 N-w + 8.837 (R-2 = 0.9983). The hydration energy gradually increased as water content increased until N-w = 36. Glu-LDH exhibited a tendency to adsorb water continuously at high water content. Hydration of Glu-LDH occurred as follows: Water molecules initially formed hydrogen bond with layers and anions. When A-W type H-bonds gradually reached a saturation state, water molecules continued to form hydrogen bonds with the hydroxyls of the layers. The L-W type H-bonds gradually substituted the L-A type H-bonds and Glu anions moved to the center of an interlayer and then separated with the layers. Last, a well-ordered structural water layer was formed on the surface hydroxyls of Glu-LDH. The lower releasing content of Glu-LDH maybe was influenced by the lower balance hydration energy and existence of L-A type H-bonds in high water content.

• 出版日期2010-8-10
• 单位浙江工业大学