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Basic Study on Molecular Motion in Suplamolecules and Its Application by Field Gradient NMR and ESR.

超分子中分子运动的基础研究及其场梯度NMR和ESR的应用。

基本信息

批准号：
09640717
负责人：
WATANABE Tokuko
金额：
$ 1.92万
依托单位：
Tokyo University of Fisheries
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640717/
关键词：
Water Polysaccharide Sol-gel Transition Field gradient NMR Spin Probe ESR Saturation Transfer EPR Diffusion Coefficient NMR Relaxation 糖鎖磁場勾配NMR 飽和移動EPR 拡散計測

项目摘要

I Coil-Helix Transition and Sol-Gel Transition in Gellan / Cation / Water SystemCation dependence of both transitions has been studied by NMR relaxation time and molar ellipticity by CD.The transition temperature and a reversibility in the coil-helix transition showed cation dependence, in which KandCs ions differently affected from other alkali cations, For the sol-gel transition, divalent cation enhanced the gelation by forming crosslinks, while monovalent cation firstly contributed a shielding of anionic charge of gellan chain and then helped the gelation by hydrogen-bonding. Gelation mechanism was explained on the basis of the hydrogen bonding behavior of water which clearly appears in T_2 relaxation time.II Gelation Mechanism in Dextran / Cation / Water SystemOnly K ion contributed to gelation of the neutral dextran polymer by potassium bonding, which was proved by K-NMR and water diffusibility. The selectivity for K ion is due to the ionic radius and hydration behavior of K ion : … More Na ion enhanced K/dextran gel structure and resulted thermal stability of the gel.III Gel Formation Mechanism for Low-set and High-set Curdlan GelsGel formation process of the curdlan showed very complicated structural change of the chain. Water mobility and proton exchange reflected the change in details. Existence of three types of water in the gel matrix was proved by spin-probe ESR method in cooling and heating process.IV Hydration Behavior in Pullulan SolutionHigh concentration of pullulan solution showed a stable hydration sphere around the polymer chain, where motional exchange of hydrated water molecules into bulk water was very slow. The specific hydration behavior in pullulan solution was investigated.V Freezing and Thowing Process in Starch and Curdlan GelsThe process was monitored by spin-probe ESR method An amorphously freezing water molecules were detected and the amount of the water was estimated. Rotational correlation time was evaluated in super-cooled, unfrozen and frozen water molecules. Less

I.结冷胶/阳离子/水体系中的卷曲-受阻转变和溶胶-凝胶转变用核磁共振弛豫时间和圆二色谱的摩尔椭圆率研究了这两种转变的阳离子依赖性。卷曲-螺旋转变的转变温度和可逆性表现出阳离子依赖性，其中KandCs离子与其他碱金属阳离子的影响不同。对于溶胶-凝胶转变，二价阳离子通过形成交联而促进凝胶化，而一价阳离子首先屏蔽了结冷胶链上的阴离子电荷，然后通过氢键作用促进了凝胶化。II葡聚糖/阳离子/水体系中的甘氨酰化机理通过K-NMR和水扩散系数证明，只有K离子参与了葡聚糖/阳离子/水体系中的钾离子键合，使中性葡聚糖聚合物凝胶化。对K离子的选择性是由于K离子的离子半径和水合行为： ...更多信息 Na离子增强了K/葡聚糖凝胶的结构，并导致凝胶的热稳定性。III低凝固性和高凝固性凝胶的凝胶形成机理凝胶的形成过程表现出非常复杂的链结构变化。水的迁移率和质子交换率反映了细节上的变化。用自旋探针ESR方法证明了凝胶基质中存在三种类型的水。IV普鲁兰多糖溶液的水合行为高浓度普鲁兰多糖溶液在聚合物链周围形成一个稳定的水合球，水合水分子向本体水的运动交换非常缓慢。研究了普鲁兰多糖在水溶液中的特殊水合行为。V淀粉和可得兰凝胶的冻结和解冻过程用自旋探针ESR方法监测了这一过程，检测到无定形冻结水分子，并估算了水的量。在过冷，未冻结和冻结的水分子的旋转相关时间进行了评估。少