Characterizing the internal structure of laboratory ice samples with nuclear magnetic resonance
Characterizing the internal structure of laboratory ice samples with nuclear magnetic resonance
复制标题
利用核磁共振表征实验室冰样品的内部结构
DOI：
10.3189/2015jog14j133
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发表时间：
2015
影响因子：
3.4
通讯作者：
Jennifer R. Brown
中科院分区：
文献类型：
--
作者：
Timothy I. Brox;M. Skidmore;Jennifer R. Brown
由于多晶冰中的溶质杂质和冰点下降，在固体冰基质中冰晶颗粒之间的边界处形成了复杂的动态液态水网络。杂质浓度、温度和压力影响这种网络结构，并影响冰的物理、运输和流变特性。然而，这种内部网络结构的性质尚未完全了解。在这里，我们利用扩散和磁弛豫的核磁共振（NMR）测量来研究由7 g L−1 NaCl溶液形成的实验室冰中充满液体的网络的几何形状和互连性，以及由于重结晶过程而导致的演变。此外，我们应用这些NMR测量观察冰的微观结构的影响，冰结合蛋白（IBP）分泌的V3519-10生物体（黄杆菌科）分离的东方冰芯在南极洲。观察到再结晶抑制作为IBP浓度的函数。这项工作展示了先进的核磁共振技术的应用程序，冰的微观结构的效用，并了解冰冻圈系统的地球物理特性具有更广泛的影响。
Abstract Due to solute impurities and freezing-point depression in polycrystalline ice, a complicated and dynamic network of liquid water forms within the solid ice matrix at the boundaries between ice crystal grains. Impurity concentrations, temperature and pressure influence this network structure and impact physical, transport and rheological properties of ice. However, the nature of this internal network structure is not fully understood. Here we utilize nuclear magnetic resonance (NMR) measurements of diffusion and magnetic relaxation to study the geometry and interconnectivity of the liquid-filled network in laboratory ice, formed from a 7 g L−1 NaCl solution, and its evolution due to recrystallization processes. Additionally, we apply these NMR measurements to observe the impact on ice microstructure of an ice-binding protein (IBP) excreted by the V3519-10 organism (Flavobacteriaceae family) isolated from the Vostok ice core in Antarctica. Recrystallization inhibition was observed as a function of IBP concentration. This work demonstrates the utility of advanced NMR techniques for applications to ice microstructure and has broader implications for understanding geophysical properties of cryospheric systems.