Viscosity and real-space molecular motion of water: Observation with inelastic x-ray scattering
Viscosity and real-space molecular motion of water: Observation with inelastic x-ray scattering
复制标题
水的粘度和真实空间分子运动：非弹性 X 射线散射观察
DOI：
10.1103/physreve.98.022604
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发表时间：
2018
影响因子：
2.4
通讯作者：
Egami Takeshi
中科院分区：
文献类型：
--
作者：
Shinohara Yuya;Dmowski Wojciech;Iwashita Takuya;Wu Bin;Ishikawa Daisuke;Baron Alfred Q. R.;Egami Takeshi
尽管粘度是液体的基本性质之一，但其微观起源尚未完全了解。通过高分辨率非弹性X射线散射测量，我们确定了室温附近水分子运动的时空相关性及其在皮秒时间尺度和亚纳米空间尺度上的温度变化。结果表明，在室温附近，分子相关性衰减的时间尺度与麦克斯韦弛豫时间直接相关，而麦克斯韦弛豫时间与粘度成正比。用含时的对相关函数（称为货车霍韦函数）表示的结果表明，分子相关性衰减的时间尺度与室温附近的麦克斯韦弛豫时间直接相关。这一结论证实了我们先前的发现，即原子或分子连接性的拓扑变化是液体粘度的起源。
Even though viscosity is one of the fundamental properties of liquids, its microscopic origin is not fully understood. We determined the spatial and temporal correlation of molecular motions of water near room temperature and its temperature variation on a picosecond timescale and a subnanometer spatial scale, through high-resolution inelastic x-ray scattering measurement. The results, expressed in terms of the time-dependent pair correlation function called the Van Hove function, show that the timescale of the decay of the molecular correlation is directly related to the Maxwell relaxation time near room temperature, which is proportional to viscosity. This conclusion validates our earlier finding that the topological changes in atomic or molecular connectivity are the origin of viscosity in liquids.