Hoshino Taiki, Fujinami So, Nakatani Tomotaka, Kohmura Yoshiki
RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.
Phys Rev Lett. 2020 Mar 20;124(11):118004. doi: 10.1103/PhysRevLett.124.118004.
We experimentally studied the shear effect on dynamical heterogeneity near glass transition temperature. X-ray photon correlation spectroscopy was utilized to study the dynamics of polyvinyl acetate with tracer particles near its glass transition temperature, to determine the local shear rate from the anisotropic behavior of the time autocorrelation function and to calculate the dynamical heterogeneity using higher-order correlation function. The obtained results show a decrease in the dynamical heterogeneity and faster dynamics with increasing shear rate. This is the first experimental result that proved the predictions of previous molecular dynamics simulations.
我们通过实验研究了玻璃化转变温度附近剪切对动力学非均匀性的影响。利用X射线光子相关光谱研究了在玻璃化转变温度附近含有示踪粒子的聚醋酸乙烯酯的动力学，根据时间自相关函数的各向异性行为确定局部剪切速率，并使用高阶相关函数计算动力学非均匀性。所得结果表明，随着剪切速率的增加，动力学非均匀性降低，动力学加快。这是首个证实此前分子动力学模拟预测结果的实验结果。
