Solidification kinetics of hard-sphere colloidal suspensions
Solidification kinetics of hard-sphere colloidal suspensions
复制标题
硬球胶体悬浮液的凝固动力学
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
T. Palberg
中科院分区：
文献类型：
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作者：
C. Sinn;A. Heymann;A. Stipp;T. Palberg
我们同时应用小角光散射和布拉格光散射研究了硬球胶体悬浮液的凝固动力学。这些实验允许一个一致的图片上的大规模的密度波动和密度波动的水平上的单个微晶的成核和晶体生长。我们观察到一个时间上几乎恒定的成核率后的诱导时间，减少过饱和。成核速率密度作为过饱和度函数的经典期望值与我们的数据一致。我们调查的有效性的威尔逊-弗伦克尔增长定律的硬球系统，这也符合我们的数据令人满意。动力学前因子被发现是只有2个数量级较小（成核）和1个数量级较大（晶体生长）比预期从经典的考虑。我们讨论了粒径多分散性对我们的数据的影响。
We investigate the solidification dynamics of hard-sphere colloidal suspensions applying simultaneously small-angle and Bragg light scattering. These experiments allow a consistent picture of nucleation and crystal growth on the level of large-scale density fluctuations and of density fluctuations on the level of individual crystallites. We observe a temporally almost constant nucleation rate after an induction time that decreases with supersaturation. The classical expectation for the nucleation rate density as a function of supersaturation is in accordance with our data. We investigate the validity of the Wilson—Frenkel growth law for hard-sphere systems, which also fits our data satisfactorily. The kinetic prefactors are found to be only 2 orders of magnitude smaller (for nucleation) and 1 order of magnitude larger (for crystal growth) than expected from classical considerations. We discuss the influences of particle size poly-dispersity on our data.