Mamontov E, Cole D R
Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6475, USA.
Phys Chem Chem Phys. 2006 Nov 14;8(42):4908-14. doi: 10.1039/b610674a. Epub 2006 Sep 29.
Quasielastic neutron scattering was used to probe the diffusion of water molecules in 2.3 molal CaCl(2) solution confined in 100% hydrated Vycor glass in the temperature range of 220 to 260 K. We observed a gradual transition from the restricted diffusion regime at lower temperatures to unrestricted diffusion regime at higher temperatures. The diffusion parameters were compared with the data on pure water confined in Vycor available in the literature. We found that the effect of dissolved ions onto the diffusion dynamics of the water molecules in the solution was amplified by confinement by at least an order of magnitude compared to bulk form, even though the dissolved ions were found to have little effect on the spatial characteristics of the restricted diffusion process of water molecules. At 260 K, the local diffusion coefficient of water molecules in the H(2)O-CaCl(2) confined in Vycor was only 6% of the value reported for pure water confined in Vycor.
准弹性中子散射被用于探测在220至260 K温度范围内， confined在100%水合Vycor玻璃中的2.3摩尔浓度氯化钙溶液中水分子的扩散情况。我们观察到从低温下的受限扩散状态到高温下的非受限扩散状态的逐渐转变。将扩散参数与文献中关于confined在Vycor中的纯水的数据进行了比较。我们发现，与本体形式相比，受限作用至少将溶液中溶解离子对水分子扩散动力学的影响放大了一个数量级，尽管发现溶解离子对水分子受限扩散过程的空间特征影响很小。在260 K时，confined在Vycor中的H₂O-CaCl₂中水分子的局部扩散系数仅为文献报道的confined在Vycor中的纯水值的6%。
