谷氨酸插层镁铝水滑石微观结构与性能:实验与理论研究

采用共沉淀法合成了谷氨酸插层镁铝水滑石(LDHs-Glu),并使用XRD表征技术以及分子动力学模拟方法对其微观结构与性能进行了研究。结果表明随着LDHs-Glu中水分子数量增加,层间距d003逐渐增大。XRD表征得到其层间距为1.328 nm,与理论模拟得到的当水分子数Nw=7时的水滑石层间距d003=1.323 nm相近。随着层间水分子数量增加,水合能逐渐增大,最终趋于流体水的特征值(-41.8 kJ/mol)。水合过程中,水滑石层板与阴离子间的氢键逐渐减少,而层板与水分子间的氢键逐渐增多,说明水分子与层板间的亲和力更强。实验表征与理论模拟相结合的研究方法,有望成为插层复合材料微观结构研究的重要手段。

Structure and Properties of Mg/Al Layered Double Hydroxides Intercalated with Glutamic Acid:Experimental and Theoretical Studies

Mg/Al layered double hydroxides intercalated with glutamic acid (LDHs-Glu) were synthesized by coprecipitation method.And the structure and properties of LDHs-Glu were in-depth studied by XRD characterization and molecular dynamics simulations(MD).The results show that the interlayer spacing of LDHs-Glu increases with increasing water contents.The d003 value of MD modeling is 1.323 nm when Nw=7,which is close to the experimental result(d003=1.328 nm) of LDHs-Glu.With increasing water content,the energetics of hydration gradually increases,and approaches the characteristic value of bulk liquid water(-41.8 kJ/mol).In the process of hydration,the hydrogen bonds between the layers and anions are gradually reduced,and between the layer and water molecules are gradually increased.It means water molecules have more affinity than the glutamic acid molecules with layer.The combined method with experimental characterization and theoretical modeling would become to an important method to investigate the microstructure of intercalated materials.