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Low-temperature structure formation and glass transition behaviors oflow-dimensional water

低维水的低温结构形成和玻璃化转变行为

基本信息

批准号：
18350003
负责人：
OGUNI Masaharu
金额：
$ 10.2万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18350003/
关键词：
Low-temperature properties Surface・Interface Thermal properties Mesoscopic systems 表面・界面物性

项目摘要

Static and dynamic properties of the water confined within nano-pores were studied by adiabatic calorimetry and DSC. The internal water within the pores of silica MCM-41 showed its glass transition at 160 K and then 210 K as the pole size increases, while the interfacial water at around 115 K. The 210 K is the glass transition temperature firstly observed and claimed.Inorganic and organic hybrid crystals [Ni(cyclam)(H2O)2]3・24H2O, [Co(H2bim)3](TMA)・0H2O, and [Cr(H2bim)3](TMA)・nH2O have pore diameters 1.0, 1.5, and 1.6 nm, respectively, with the pore wall structure of crystalline framework. No phase transition was observed in the first substance. The water within the nanopores in the latter two shoved its structural ordering and glass transitions, the cooperativeness in the ordering was higher in the Cr compound than in the Co one. While the interfacial water in MCM41 is disordered in any size, the one in these crystals famed the ordered structures conforming to the crystalline framewor … More k of the pore wall.InNa-RUB-18 crystal possessing nano-sheet water between day layers, the water without participating in the hydrogen-bond network showed a phase transition at 194 K and a glass transition at 106K. No anomaly was observed in the hydrogen-bond chain inclding silanol groups.It was found in methanol aqueous solutions within 1.1 nm pores of silica gel that the glass transition behavior in the high concentration region corresponds to that of the systems in which a hydrogen-bond network inherent to pure water is not formed, and that the inherent network is formed in the dilute region and accordingly the glass transition temperature increases rapidly to approach 160K in the pure water. The similar behavior was observed in the ethylene glycol aqueous solutions within MCM41 pores. On the other hand, it was suggested in hydroxylamine solutions that the hydrogen-bond network structure formed by water molecules is not destroyed by introduction of the second component, and a possibility was indicated that a kind of liquid-liquid phase transition occurs.It was concluded that water molecules forms their own characteristic hydrogen-bond network at low temperatures, and that the relaxation time and therefore the glass transition temperature jumps according to the stages of the development in the network. Less

利用绝热量热法和DSC研究了纳米孔中水的静态和动态性质。随着孔径的增大，孔内水在160 K和210 K发生玻璃化转变，而界面水在115 K左右发生玻璃化转变。无机和有机杂化晶体[Ni（cyclam）（H2O）2]3·24 H2O、[Co（H2 bim）3]（TMA）·0 H2O和[Cr（H2 bim）3]（TMA）·nH 2 O的孔径分别为1.0、1.5和1.6 nm，具有晶体骨架的孔壁结构。在第一种物质中没有观察到相变。后两者中纳米孔内的水推动了其结构有序化和玻璃化转变，Cr化合物中有序化的协同性高于Co化合物。虽然MCM 41中的界面水在任何尺寸下都是无序的，但这些晶体中的界面水以符合晶体框架的有序结构而闻名。 ...更多信息在Na-RUB-18晶体中，层间存在纳米片状水，未参与氢键网络的水在194 K发生相变，在106 K发生玻璃化转变。含硅醇基团的氢键链未观察到异常，在硅胶1.1nm孔内的甲醇水溶液中，高浓度区的玻璃化转变行为与未形成纯水固有氢键网络的体系相对应，在稀相区形成固有网络，玻璃化转变温度迅速升高，在纯水中接近160 K。在MCM 41孔内的乙二醇水溶液中观察到类似的行为。另一方面，在羟胺溶液中，第二组分的引入并没有破坏水分子形成的氢键网络结构，并指出了一种液-液相变的可能性，得出结论：水分子在低温下形成了自己的特征氢键网络，并且弛豫时间以及因此玻璃化转变温度根据网络中的发展阶段而跳跃。少