High-resolution inelastic neutron scattering from water in mesoporous silica.
High-resolution inelastic neutron scattering from water in mesoporous silica.
复制标题
介孔二氧化硅中水中的高分辨率非弹性中子散射。
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
--
通讯作者：
H. Peemoeller
中科院分区：
文献类型：
--
作者：
F. Mansour;R. Dimeo;H. Peemoeller
本文报道了用高分辨非弹性中子散射法测量水分子动力学的实验结果。水分子动力学是在一种多孔基质中进行的，这种基质是一种被称为MCM-41的分子筛，它具有一个平均孔径为27埃的平行孔的六边形阵列。以前的中子测量探测更高的能量转移，从而更短的时间尺度，已经分析了旋转平移扩散模型和拉伸指数中间散射函数。这里提出的较长时间尺度上的动力学模型，以及在一个封闭的几何形状的拉伸指数松弛。所观察到的水的分子动力学是三个数量级慢于以前报道的水限制在MCM-41。
High-resolution inelastic neutron scattering measurements of the molecular dynamics of water confined to a porous host, the molecular sieve known as MCM-41, which has a hexagonal array of parallel pores with average pore diameter of 27 A, are reported. Previous neutron measurements probing higher-energy transfers, and thus shorter time scales, have been analyzed with both a rotation-translation diffusion model and a stretched exponential intermediate scattering function. The dynamics on longer time scales presented here are modeled well with a stretched exponential relaxation in a confining geometry. The observed molecular dynamics of water are three orders of magnitude slower than has been previously reported for water confined in MCM-41.