Soft Condensed Matter, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
Phys Rev Lett. 2010 Aug 20;105(8):088302. doi: 10.1103/PhysRevLett.105.088302. Epub 2010 Aug 16.
Using simulations we identify three dynamic regimes in supersaturated isotropic fluid states of short hard rods: (i) for moderate supersaturations, we observe nucleation of multilayered crystalline clusters; (ii) at higher supersaturation, we find nucleation of small crystallites which arrange into long-lived locally favored structures that get kinetically arrested; and (iii) at even higher supersaturation, the dynamic arrest is due to the conventional cage-trapping glass transition. For longer rods we find that the formation of the (stable) smectic phase out of a supersaturated isotropic state is strongly suppressed by an isotropic-nematic spinodal instability that causes huge spinodal-like orientation fluctuations with nematic clusters diverging in size. Our results show that glassy dynamics and spinodal instabilities set kinetic limits to nucleation in highly supersaturated hard-rod fluids.
利用模拟，我们确定了短硬棒各向同性过饱和流体状态中的三种动力学状态：（i）在适度过饱和度下，我们观察到多层结晶簇的成核；（ii）在更高的过饱和度下，我们发现小晶体的成核，这些小晶体排列成长寿命的局部有利结构，这些结构会被动力学捕获；（iii）在更高的过饱和度下，动态捕获是由于常规的笼捕获玻璃转变。对于更长的棒，我们发现，过饱和各向同性状态中（稳定）层状相的形成受到各向同性-向列型 spinodal 不稳定性的强烈抑制，该不稳定性导致具有向列型簇的巨大类似 spinodal 的取向波动，这些向列型簇的尺寸不断发散。我们的结果表明，玻璃态动力学和 spinodal 不稳定性对高度过饱和硬棒流体中的成核设定了动力学限制。
