Ripening and focusing of aggregate size distributions with overall volume growth
Ripening and focusing of aggregate size distributions with overall volume growth
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随着总体数量的增长，总尺寸分布的成熟和集中
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
M. Rohloff
中科院分区：
文献类型：
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作者：
J. Vollmer;A. Papke;M. Rohloff
我们探索了在聚集体通过质量的扩散吸积生长的系统中聚集体尺寸分布的演化。控制过饱和度的方式是使总骨料体积随时间线性增长。经典的奥斯特瓦尔德成熟是在整体增长消失的极限内恢复的，构成了动态的不稳定解。在存在整体生长的情况下，骨料的蒸发总是将动力驱动到一个新的、质的不同的生长区域，在那里成熟停止，并且生长以恒定的骨料数密度进行。我们全面地描述了在恒定密度区域内集料尺寸分布的演化：集料尺寸分布并不接近通用形状，即使总体增长率适中，集料半径的标准差也单调衰减。讨论了这一理论对聚集尺寸分布聚焦的影响，适用于一系列不同的设置，包括云中微小雨滴的生长(只要它们还没有感觉到重力)，以及纳米粒子和量子点的合成。
We explore the evolution of the aggregate size distribution in systems where aggregates grow by diffusive accretion of mass. Supersaturation is controlled in such a way that the overall aggregate volume grows linearly in time. Classical Ostwald ripening, which is recovered in the limit of vanishing overall growth, constitutes an unstable solution of the dynamics. In the presence of overall growth evaporation of aggregates always drives the dynamics into a new, qualitatively different growth regime where ripening ceases, and growth proceeds at a constant number density of aggregates. We provide a comprehensive description of the evolution of the aggregate size distribution in the constant density regime: the size distribution does not approach a universal shape, and even for moderate overall growth rates the standard deviation of the aggregate radius decays monotonically. The implications of this theory for the focusing of aggregate size distributions are discussed for a range of different settings including the growth of tiny rain droplets in clouds, as long as they do not yet feel gravity, and the synthesis of nano-particles and quantum dots.