Conrad Jacinta C, Dhillon Param P, Weeks Eric R, Reichman David R, Weitz David A
Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2006 Dec 31;97(26):265701. doi: 10.1103/PhysRevLett.97.265701. Epub 2006 Dec 27.
We use confocal microscopy to visualize individual particles near the colloidal glass transition. We identify the most slowly-relaxing particles and show that they form spatially correlated clusters that percolate across the sample. In supercooled fluids, the largest cluster spans the system on short time scales but breaks up on longer time scales. In contrast, in glasses, a percolating cluster exists on all accessible time scales. Using molecular dynamics simulation, we show that these clusters make the dominant contribution to the bulk elasticity of the sample.
我们使用共聚焦显微镜来观察接近胶体玻璃化转变的单个颗粒。我们识别出弛豫最慢的颗粒，并表明它们形成了在整个样品中渗流的空间相关簇。在过冷流体中，最大的簇在短时间尺度上跨越整个系统，但在较长时间尺度上会分解。相比之下，在玻璃中，一个渗流簇在所有可及的时间尺度上都存在。通过分子动力学模拟，我们表明这些簇对样品的体弹性起主要作用。
