Light Scattering Studies of Supercooled Water (Chemistry)

计划对过冷水进行光散射实验 和水溶液来阐明结构机制 导致过冷水中的热力学异常。 从这项工作中获得的拉曼数据将具有直接的结构 过冷水的信息。 OH拉伸模式将 产生包括氢键的最近邻信息 概率和平均O-O分离和分布。 低 频率分子间模式将产生关于 第二相邻壳体，其中最显著的结构 与过冷异常有关的变化被认为是 发生. 光子相关光谱测量将 用于提取有效的密度相关长度， 许多水分子之间的合作行为。 水在地球表面的重要性 言过其实 这种重要性源于两个来源： 丰富，其独特的物理和化学性质。 在 在过去的十年里，人们发现液态水甚至 在零度以下的过冷状态下更不寻常 摄氏度。 在这里它显示了其热力学的异常 和传输特性可能接近 奇点 水的关键在于它的氢键 结构 拉曼光谱可以给出微观信息 关于结构和动力学。 它可以确定 氢键，决定冰状或 笼形结构，并提供有关第一个 邻壳层和分子簇。

Light scattering experiments are planned for supercooled water and aqueous solutions to elucidate the structural mechanisms responsible for thermodynamic anomalies in supercooled water. Raman data obtained from this work will have direct structural information for supercooled water. The OH stretch modes will yield nearest neighbor information including hydrogen bond probability, and mean O-O separation and distribution. The low frequency intermolecular modes will yield information regarding the second neighbor shell wherein the most dramatic structural changes relevant to the supercooled anomalies are thought to occur. The photon correlation spectroscopy measurements will be used to extract effective density correlation lengths due to cooperative behavior between many water molecules. Water's importance on the face of the earth cannot be overstated. This importance stems from two sources: its abundance, and its unique physical and chemical properties. In the past decade it has been found that liquid water is even more unusual in the supercooled regime below zero degrees Centigrade. Here it displays anomalies in its thermodynamic and transport properties which may be approaching a singularity. The key to water is in its hydrogen bonded structure. Raman spectroscopy can give microscopic information regarding structure and dynamics. It can determine the extent of hydrogen bonding, make decisions regarding ice-like or clathrate structures, and give information on both the first neighbor shell and molecular clustering.