Investigation of Proton Dynamics within the Hydrogen-Bond Network of the Layer Silicate Na−RUB-18
Investigation of Proton Dynamics within the Hydrogen-Bond Network of the Layer Silicate Na−RUB-18
复制标题
层状硅酸盐 Na-RUB-18 氢键网络内的质子动力学研究
DOI：
10.1021/cm0012522
复制
发表时间：
2002
影响因子：
8.6
通讯作者：
H. Gies
中科院分区：
文献类型：
--
作者：
Markus Borowski;Ingo Wolf;H. Gies
用固体1H和29SiMAS核磁共振谱研究了水合层硅酸盐Na−RUB-18晶体内形成的氢键网络随温度的变化。可以区分两种不同的质子环境。在230K以下，插层水形成的弱氢键和硅醇基团形成的强氢键不相互作用。当温度达到360K时，硅醇基上越来越多的氢键断裂。在此温度下，材料中形成了一维无限的氢键网络，导致质子导电。分子动力学(MD)模拟得出了这些氢键的振动增加作为断裂的解释。从修饰样品的~1H MAS核磁共振实验中，很明显只有一半的水分子参与了网络。进一步的研究表明，一维网络的最小相干性是稳定高温S的必要条件。
Solid-state 1H and 29Si MAS NMR spectroscopies were applied to the hydrous layer silicate Na−RUB-18 to investigate the hydrogen-bond networks formed within the crystals as a function of temperature. Two different proton environments can be differentiated. At temperatures below 230 K, the weak hydrogen bonds formed by the intercalate water and the strong hydrogen bonds formed by the silanol groups do not interact. At temperatures up to 360 K, an increasing number of hydrogen bonds localized at silanol groups breaks up. At this temperature, 1D infinite hydrogen-bond networks are formed in the material, resulting in proton conductivity. Molecular dynamics (MD) simulations yielded increasing vibrations of these hydrogen bonds as an explanation for the breaking. From 1H MAS NMR experiments with modified samples, it becomes obvious that only one-half of all water molecules participate in the network. Further, it is shown that a mimimum coherence of the 1D network is necessary to stabilize the high-temperature s...